Modern Concept Science 3

c) Snowfall occurs in the ..................... region.

i. plain ii. valley iii. Himalayan

d) Common cold is common in ..................... .

i. warm season ii. spring season iii. winter season

e) Warm woolen clothes are necessary for ..................... season.

i. winter ii. summer iii. spring

4. Answer the following questions.
a) In which season do we feel cold?
b) Why do animals hide themselves in winter season?
c) Why is there greater chance of accident in foggy morning?
d) What is the common disease in winter season?
e) What happens if we drive a vehicle on snow-covered road?
f) How can we keep our body warm in winter?
g) What happens if we suffer from frost bite?

5. Observe the following figures and write three sentences about
each of them.

Activity

Collect the various pictures showing snowfall, naked trees, foggy
day, etc. and paste them in your project work copy.

COLD DAY 93

Uni t

12 WATER

Estimated teaching periods : 2

Objectives

After completing the study of this unit, students will be able to:
 name different states of water.
 explain water cycle.
 describe the formation of clouds and rainfall.

After air, water is the most abundant and important substance on the
earth. It is very necessary for all living beings. It is estimated that nearly
three-fourths of the earth surface is covered by water. Water is present
inside as well as outside the surface of the earth. Besides, it is also a
major component of the living body.

Memory Tips

After air, water is very important matter for living beings. It is a liquid matter
which covers two-third of the earth’s surface. It is present on, in and above
the earth’s surface.

Underground water

Water which is present inside the surface of the earth is called
underground water. We obtain underground water through well,
handpump, tube-wells, deep boring, stone spouts (dhunge dhara), etc.
Sometimes, underground water may also come out by itself through
springs.

Memory Tips

The water which is present inside the earth’s surface is called underground
water. This water is obtained through well, handpump, tube-well, deep
boring, stone spouts, etc.

94 Modern Concept Science, Health and Physical Education - 3

Fig: 12.1

Surface water

Water that is found on the surface of the earth is called surface water.
River, pond, lake, etc. are some examples of surface water. Ocean is the
largest reservoir of surface water. In the ocean, all types of surface water
get collected finally.

We can use surface water easily as it does not need any technology to
obtain. Rivers are formed either from the rainwater or from the melting
of ice caps of the Himalayas. Similarly, ponds or lakes are formed
either by the collection of rainwater or by the collection of water from
the streams or rivers. Rivers always flow from higher level to the lower
level while the water in ponds and lakes does not flow. Ponds and lakes
are similar in structure but they differ in their sizes.

Memory Tips

The water which is found on the surface of the earth is called surface water.
Examples: river, pond, lake, sea, ocean, etc. Rivers are formed either from
the rainwater or from the melting of ice caps of the Himalayas.

Fig: 12.2

WATER 95

In cold areas like high mountains and the polar regions, there is very cold.
So, water gets solidified and converts into ice. Ice caps of the Himalayas
and polar regions store water in solid form. Most of the rivers of Nepal
that flow round the year originate from the mountains and Himalayas.

Memory Tips

The process in which water converts into ice due to low temperature is called
freezing. Similarly, the process in which ice converts into water due to heat
is called melting.

Fig: 12.3
In the atmosphere, water is present in the form of water vapour. The
heat energy obtained from the sunlight heats the water on the surface of
the earth. As a result, water converts into water vapour. Then, this water
vapour rises up and remains suspended in air.

Memory Tips

The natural process in which water converts into steam is called
evaporation. Similarly, if we heat water at a certain temperature, it converts
into gas. This process is called vaporization.

Fig: 12.4

96 Modern Concept Science, Health and Physical Education - 3

States of water

Normally, water is present in liquid state. But when we supply heat, it
converts into water vapour which is the gaseous state of water. Similarly,
if we cool water, it converts into ice which is the solid state of water.

Fig: 12.5

Water cycle

Water is present in all three states on the

earth’s surace, i.e. solid, liquid and gas.

Thus, it changes its state from one to

another in different conditions of heat. Fig: 12.6 Water cycle
As a result, it moves from the surface of
the earth to the atmosphere and again
back to the earth surface in a close cycle
called water cycle.

Memory Tips

The cyclic movement of water from the surface of the earth to the atmosphere
and back to the earth again is called water cycle. In water cycle, one state of
water changes into another.

In water cycle, one state of water is changed into another. Water in the
seas, oceans, rivers, ponds, etc. gets heated due to the heat of the sun.
Similarly, some portion of soil water also gets heated and rises up in
the atmosphere. Water vapour is lighter than air, so it goes up in the
atmosphere easily. Now, water vapour in the atmosphere slowly cools
down and forms water droplets. This process is also known as
condensation. These droplets of water join together to form clouds.
Strong wind blowing in the sky moves the clouds here and there. So,
we can see the clouds moving in the sky. When clouds become heavy
they fall down in the form of rain. Black clouds carry more water in

WATER 97

comparision to other types of clouds. So, heavy rainfall occurs when we
see dark clouds in the sky. White clouds are very light and carry less
amount of water. So, they may not always cause rain.

Memory Tips

Water vapour in the atmosphere slowly cools down and forms water
droplets. This process is also known as condensation.

Fig: 12.7

In this way, water from the earth goes up to the sky and again falls
down as rain. This process of water changing into vapour and water
vapour into water again is called water cycle. Water cycle is a continuous
process in nature.

In high mountains, snow fall

occurs instead of rainfall. The

cold temperature in the high

mountains causes the water

droplets to convert into

snow. makes the Fig: 12.8
Snowfall

environment extremely cold and does not allow the plants to grow.

Sometimes small balls of ice come down instead of rainfall. These balls

of ice are called hailstones. The continuous up and down movement of

ice causes the ice balls to grow in size. Hailstones are not considered

to be good for agriculture as they hit the flowers, fruits and leaves of

various plants and cause them to fall down.

Memory Tips

Hailstones are formed when raindrops move up and down continuously at
a low temperature. They are bad for crops, flowers and fruits.

98 Modern Concept Science, Health and Physical Education - 3

Importance of water

Water is one of the most important substances on the earth. It is necessary
in each and every aspect of life. Some common uses of water are given
below:

i. Water is used for drinking purpose.

ii. We need water for cooking food and cleaning utensils.

iii. We need water for bathing and washing clothes.

iv. Water is used for boating, fishing and swimming.

v. Plants need water to prepare their food.

vi. Water is used to generate electricity.
Memory Tips

Water is used for drinking, cooking, washing, cleaning, bathing, boating,
fishing, swimming, generating electricity, etc. It is used by plants for
photosynthesis.

Fig: 12.9 Some uses of water

WATER 99

EXERCISE

1. Fill in the blanks with suitable words.

vaporization hailstones mountains vapour ice clouds heavy rainfall

a) Water changes into .................... on heating.
b) Dark and black clouds cause ....................... .
c) Water droplets join together to form.................. .
d) Water freezes at low temperature and forms.................... .
e) Mostly snowfall occurs in high.......................... .
f) Stones made of frozen water are called .................... .
g) The process in which water changes into water vapour is

called.............. .

2. Write ‘T’ for True and ‘F’ for Fasle statements.

a) Water vapour is lighter than air.

b) Hailstones are colourful.

c) Water converts into ice on freezing.

d) Black clouds carry more water than the light ones.

e) White clouds always cause heavy rainfall.

f) Mostly snowfall occurs in the high mountains.

g) Hailstones destroy plants.

h) Water vapour is cooled into water.

3. Match the following:

Evaporation falling of rain
Condensation lighter than air
Rainfall can cause heavy rainfall
Water vapour cooling steam to water droplets
Snow fall destroy plants
Hailstones change of water into water vapour
Black clouds mostly mountain areas

100 Modern Concept Science, Health and Physical Education - 3

4. Choose the best answer from the given alternatives.

a) Water present inside the earth’s surface is called ................... .

i. underground water ii. surface water iii. rain water

b) Water that flows on the surface is known as ................... .

i. ground water ii. surface water iii. rain water

c) The process in which water converts into ice is called ................... .

i. freezing ii. melting iii. boiling

d) Steam is the ................... state of water.

i. solid ii. liquid iii. gaseous

e) In normal temperature, pure water is present in ................... state.

i. solid ii. liquid iii. gaseous

5. Answer the following questions.

a) What is meant by underground water?
b) What do you mean by surface water? Name its sources.
c) Describe water cycle in short.
d) Draw a neat diagram of water cycle and colour it.
e) How does cloud form? Describe in brief.
f) What do black clouds indicate?
g) Define evaporation.
h) What do you mean by condensation?
i) How does snowfall occur?
j) How are hailstones formed?
k) Write any four uses of water.

Activity

Take some pieces of ice from the refrigerator. Keep them on a plate
and wait for 10 minutes. Again heat some water in a kettle and see
what happens. Cool down the water vapour blocking it by a plate or
saucer. Tell your friends what you understood from this experiment.

Project Work

Draw a figure of water cycle and colour it. Paste this picture in your
project work copy.

WATER 101

Unit

13 OUR EARTH

Estimated teaching periods : 15

Objectives

After completing the study of this unit, students will be able to:
 identify different layers of the earth.
 state the features of plain, plateau, hills, mountains and valley.
 differentiate between various land forms of the earth.

All living beings live on the earth. It is a common Fig: 13.1 The earth
home for all. It is made up of rocks, soil, air,
water, minerals, etc. The shape of the earth
is like that of an orange. Externally, the earth
appears as a solid mass but liquid matter is also
present inside the earth’s surface. The average
temperature on the surface of the earth is
about 15°C. The earth’s surface is covered by a
thick layer of gases called atmosphere.

Inner Core Similarly, water is abundantly

Outer Core present on the surface of the

Mantle earth. It is estimated that three-

Crust fourths (over 70 percent) of the
earth’s surface is covered by water.

It is called hydrosphere.

Fig: 13.2 Internal structure of the earth

Memory Tips

The earth’s surface is covered by a thick layer of gases called atmosphere.
Similarly, the layer of water present on the surface of the earth is called
hydrosphere.

102 Modern Concept Science, Health and Physical Education - 3

The surface of the earth is uneven. Some places are low while others are
high. The beds of seas and oceans are the examples of low lying land
while hills and mountains are the examples of higher landmass.

The land surface of the earth can be divided into following types.

i. Plain ii. Plateau iii. Hills
iv. Valley v. Mountains

Plain

Plain is the flat surface of the earth with

lower height. Generally the plain is warmer

than the hills. Fertile soil is also present in

the plain area. So, plains are suitable for

agriculture. Due to the lower height, the

rivers flowing down the hills finally reach

the plain region. Thus, there is plenty of

water in the plain areas. The deposition of Fig: 13.3
soil from the hills by the rivers makes the

soil more fertile.

Memory Tips

The flat surface of the earth with lower height is called plain. Generally, it is

warmer. The soil in plane area is fertile and good for agriculture.

Plateau

Fig: 13.4 Plateau Plateaus are the flat structures formed on
top of the hills. They are formed when
the water washes the soil present on the
hills. Human settlement can be seen on
the plateau. Plateaus are often used for
agriculture purpose. Tibetan plateau is the
highest plateau in the world. It supports
the human settlements, forests and wild
animals too.

Memory Tips

The flat structures formed on the top of the hills are called plateaus. Tibetan
plateau is the highest plateau in the world.

OUR EARTH 103

Hills

Hills are elevated landmass. Nepal is a hilly

country. Most of the land surface of our

country is covered by hills and mountains.

The elevation of land surface causes

the variation in climatic conditions. The

variation in climate causes the difference in

the vegetation present in these regions. In Fig: 13.5
general, hills are less suitable for the growth

and production of crops than the terai.

Memory Tips

The elevated landmass of the earth are called Hills. In general, hills are less
suitable for the growth and production of crops than the plains.

Valley

Valley is the low-lying area surrounded by hills. Rivers flowing from
the hills pass the valley and make the soil fertile. So, it is suitable for
crop production. Kathmandu, Pokhara, Banepa, Dang, etc. are some
examples of valleys in Nepal. We can find denser human settlement in
the valleys compared to the hills. Due to favourable geological condition
and easier access to water, the development activities are easy to carry
out in the valleys.

Memory Tips

The low-lying area surrounded by hills is called Valley. Examples:
Kathmandu, Pokhara, Banepa, Dang, etc. Valley is fertile and good for
agriculture.

Fig: 13.6

104 Modern Concept Science, Health and Physical Education - 3

Mountain

The areas higher than hills are called mountains. Due to high elevation,
the climate of mountains is generally cold. Thus, there is limitation in the
growth of plants in the mountain areas. The Himalayas are the world’s
longest mountain ranges. They include the world’s highest mountains
like Mt. Everest, Alps, Andes, etc.

Memory Tips

Mountains are the areas which are higher than hills. They are generally cold.
Rainwater washes the top layer of the soil from mountains. So, they are less
fertile.

Fig: 13.7 Mountain

EXERCISE

1. Fill in the blanks choosing the correct words.

Kathmandu valley three-fourths orange hills

a) The shape of the earth is like an ..................... .
b) About ..................... of the earth’s surface is covered by water.

c) A ..................... is the low lying area surrounded by hills.

d) ..................... is an example of valley.

e) Mountains are higher than ..................... .

OUR EARTH 105

2. Write ‘T’ for True and ‘F’ for Fasle statements.
a) Most of the earth’s surface is covered by land.

b) Plains have greater height than hills.

c) Tibetan plateau is the world’s highest plateau.

d) There are sufficient sources of water in the valleys.

e) Alps and Andes are the examples of plateau.

3. Match the following:

Eart valley

Himalayas highest plateau

Tibetan plateau longest mountain range

Terai common home for living beings

Pokhara plain

4. Choose the best answers from the given alternatives.

a) The average surface temperature of the earth is .................... .

i. 25ºC ii. 15ºC iii. 35ºC

b) Plain is the .................... elevated area.

i. least ii. greatly iii. most

c) Dang is an example of .................... .

i. plateau ii. hill iii. valley

d) The Himalayas are the world’s .................... mountain ranges.

i. shortest ii. longest iii. narrow

e) The areas higher than hills are called .................... .

i. mountains ii. valleys iii. plateaus

106 Modern Concept Science, Health and Physical Education - 3

5. Answer the following questions.
a) Define atmosphere and hydrosphere.
b) Name the major land forms seen on the earth.
c) What do you mean by plain and plateau?
d) What are hills?
e) Why is there greater settlement in a valley?
f) Which is the world’s longest mountain range?
g) What are mountains?
h) Which is the world’s highest plateau?

6. Observe the following figures and name them.

Activity
In which land form is your home located? Name it and write its major
features.

Project Work
Collect the pictures of plain, plateau, valley, hills and mountains and
paste them in your project work copy.

OUR EARTH 107

Unit INFORMATION AND
COMMUNICATION
14
Estimated teaching periods : 4

Objectives

After completing the study of this unit, students will be able to:
 define information and communication.
 name different means of communication.
 explain the importance of communication.

We watch various programmes on television. We read newspapers and
listen to the radio. They give s news or information about different
things. Then, we share these things with our friends in school.

Memory Tips

The process of getting news or information from one source and sharing
news or information with others is called communication.

Similarly, if your friends study in another school, they may call you and
ask about your study and daily life either by telephone or by sending a
letter or an e-mail. So, television, newspapers, telephone, radio, letter,
computer, etc. are the means of information and communication.

Fig: 14.1 Some means of information and communication
We get information from different sources like talking to others, reading
letters and newspapers, listening to the radio, watching television etc.
We can get current and hot news from radio and television. On the
radio, we can hear the news.

108 Modern Concept Science, Health and Physical Education - 3

Memory Tips

New information about something that has happened recently is called
news. News are obtained from letters, newspapers, radio, television, etc.
News comes each hour or at a certain interval of time. Unlike this, we can
hear and see the news on television. Newspapers are published daily or
weekly. They include news related to politics, economy, entertainment,
sports, etc. However, newspapers cannot give the latest news because
all the news published in the newspapers are yesterday’s news.

Fig: 14.2
Mobile phone, telephone and fax are other important means of
communication. We use telephone and mobile to talk with our friends
and family members. But people cannot communicate directly through
letters, newspapers, radio and television. Telephone and mobile work
with the help of signals sent through telecommunication stations. These
signals are distributed throughout the world with the help of satellites
in the space. Satellites are sent to the space by human beings.

Memory Tips

The medium through we get information are called means of communication.
Mobile phone, telephone, fax, internate, newspaper, television, letters, etc.
are important means of communication.

Fig: 14.3

INFORMATION AND COMMUNICATION 109

Fax is generally used to transfer documents which

are urgently required. It is mostly used in offices.

Nowadays, the use of internet has dominated

the use of fax. However, in the government

offices of Nepal, fax is still used to send important

documents from one place to another. Fig: 14.4 Fax machine

Memory Tips

Fax is a machine which is used to send important documents from one place
to another by means of telephone. It sends printed copy of the document.

Nowadays, computer has been a very efficient means of communication.
Computers are used for various purposes. We can use computers for
playing games, watching movies, sending e-mails, chatting with friends
and family members, writing and storing documents and many more.
Computers can be connected to a network called the internet. Using the
internet, we can call our relatives and friends. We can send e-mail to our
friends and family members using the internet. E-mail is the short form
of electronic mail (letter). It moves so fast that it reaches its destination
faster than you blink your eyes. Do you use e-mail and internet? Do you
have an e-mail ID or e-mail address?

Memory Tips

Computer is a recent mean of communication. We can use computers for
playing games, watching movies, sending e-mails, chatting, writing and
storing documents and many more.

Fig: 14.5

110 Modern Concept Science, Health and Physical Education - 3

Besides these, we can talk live with friends and family members by using
computers. This process is called chatting. We can chat either by writing
or exchanging text message in the chat room or by speaking through
headphones. The laptops are already fitted with microphones and don’t
even require headphones for talking. The spoken communication on
the computers or laptops is called voice chat. The use of web-camera in
the computer even shows the action of the persons involved in chatting.

Memory Tips

We can use various websites like Gmail, Yahoo, Hotmail, etc. in the internate
to do e-mail, chatting, vice call, etc.

Fig: 14.6 Some sites of internet

EXERCISE

1. Fill in the blanks choosing the correct words. Krishna Pandey
communication internet information talk e-mail

a) Radio, television, phone, etc. are the sources of ...................
b) ....................is the process of getting and sharing news.
c) We use telephone and mobile to ................... to friends and family

members.
d) Computers are connected to a network called ...................
e) ................... is an electronic mail.
2. Write ‘T’ for True and ‘F’ for Fasle statements.
a) News is information about event that happened recently.

INFORMATION AND COMMUNICATION 111

b) Mobile phones help two or more people to have direct
communication.

c) Talking is also a means of communication.

d) We can listen to and watch news on the radio.

e) People communicate through face-to-face talking only when
they are near.

f) We can have direct communication by means of letters.

g) Fax machine sends important documents through the internet.

h) E-mail is like a book in computer.

3. Choose the best answer from the given alternatives.

a) Which one of the following is a means of communication?

i. bus ii. bag iii. radio

b) ................ is the information that we like to know.

i. news ii. story iii. essay

c) Mobile phone is used to ..............with friends.

i. see movie ii. talk iii. read

d) Fax is widely used in ................

i. offices ii. homes iii. both

e) Newspaper is published .....................

i. daily ii. weekly iii. both daily and weekly

4. Answer the following questions.
a) a. What is meant by communication?
b) Name any four means of information and communication.
c) What is news?
d) What is the use of letter?
e) Why do we listen to the radio?
f) How are radio and television the sources of information?
g) How is television different from the radio?

112 Modern Concept Science, Health and Physical Education - 3

h) Why do we use telephone?
i) What does a fax machine do?
j) Can we transmit our bags and books through fax?
k) Why do we use computer?
l) What is e-mail?
m) Which means of communication do you like the most?
5. Observe the given figures of the means of communication and
state why they are used.

Activity
Take a long rope and two small cylinders of coarse paper as shown in
the figure. Join the two cylinders with
each end of a rope. Tell your friend to
take one cylinder and go. Put the
cylinder in your ear and ask your friend
to speak. Can you hear his sound?
Can you communicate with each other?

Project Work
1. Draw the pictures of any five means of communication in your

project work copy. Colour them and write their main uses.
2. Collect different types of daily, weekly and monthly newspapers

and magazines. Show these collections to your friends and teacher.

INFORMATION AND COMMUNICATION 113

Unit SOME LOCAL
TECHNOLOGIES
15
Estimated teaching periods : 3

Objectives

After completing the study of this unit, students will be able to:
 define local technology.
 state the role of local technologies in our daily life.
 apply local technologies in their daily life.

From ancient time, human beings have developed different technologies.
They have made their works easy and fast by using available tools and
technologies. Such technologies are called local technologies. Many
local technologies are made from the resources that have gone to waste.
The wastes may be natural or artificial, i.e. man-made.

Memory Tips

Those technologies which were developed by the ancient people to make their
work easier and faster are called local technologies. Example: water mill.

Water mill is an example of local technology made by utilizing flowing
water. Similarly, biogas, compost manure, etc. are the outcome of other local
technologies. They save energy and money. Local technologies are made by
people without proper knowledge of their scientific way of working.

Fig: 15.1

114 Modern Concept Science, Health and Physical Education - 3

Some of the local technologies used in our locality are given below:

i. Compost manure

Compost manure is a locally prepared organic fertilizer. It is an example of
proper management of organic solid waste. It is very useful to grow crops.

Memory Tips

Compost manure is a locally prepared organic fertilizer. The crops grown
by using compost manure are free from harmful chemicals.

Fig: 15.2

Method to prepare compost manure
We can simply make compost manure in our garden. To prepare compost
manure, we do not need any advance scientific tools and technology. A
pit should be dug to prepare compost manure. All the wastes from the
kitchen and garden like vegetable residues, waste food items and grasses
should be thrown in that pit. As the pit gets filled, it should be covered
by soil. The waste should be stirred at a regular interval of time. After
the waste gets decayed, it changes into compost manure. This compost
manure is used in the field to grow various types of vegetables, fruits
and foods.

Memory Tips

Compost manure is prepared by dumping degradable wastes like the wastes
from the kitchen and garden (e.g. vegetable residues, waste food, grasses,
etc.) in a pit.

Organic crops
We can find foods, fruits, vegetables, etc. grown by using compost
manure. While growing none of the chemical fertilizers are used on the
organic foods. That is why they are good for our health. So, we should
give priority to organic foods.

SOME LOCAL TECHNOLOGIES 115

Memory Tips

The vegetables, fruits and foods that are grown using compost manure are
called organic foods. They are free from the harmful chemicals.

Fig: 15.3

ii. Biogas (gobar gas)

Nepal is an agricultural country. Most of the families in the rural areas
of our country have cattle in their homes. They rear cows and buffaloes
for the purpose of milk. Along with milk, they also give stool called
gobar. Nowadays, the stool of animals is used to produce energy. For
this purpose, firstly animal dung is gathered and put into a tank with
some water. The decomposition of animal dung give off gas. This gas is
called biogas or gobar gas. It is one of the alternative sources of energy
in our country. This energy is used for cooking, heating and lighting
purposes.

Memory Tips

The gas which is obtained due to decomposition of the animal stool in a
tank is called biogas or gobar gas. It is used for cooking, heating and lighting
purposes.

Fig: 15.4

116 Modern Concept Science, Health and Physical Education - 3

To obtain biogas in a large scale, a biogas plant should be installed. For
this purpose, a well is constructed first. Then, the wastes produced by
animals are collected in it. Then the wastes are decomposed in absence of
oxygen. In this process, biogas is produced in a large scale. The residue
obtained after producing biogas can be used as manure in the farm.

Memory Tips

Gobar gas or biogas is one of the best alternative sources of energy in Nepal
because Nepal is an agricultural country. Most of the families in the rural
areas of our country have cattle in their homes which provide stool for biogas.

iii. Sharpening tools

We use different tools in our daily life. They are used both inside as well
as outside our home. After continuous use of these tools, they become
blunt. Blunt tools cannot cut things easily. So, they should be sharpened
regularly.

Fig: 15.5 Fig: 15.6 Sharpening khukuri
In our country, tools are sharpened by using local
knowledge. For this purpose, the cutting edges of the
tools are rubbed against stones or hard rough surfaces.
After rubbing, the cutting edge becomes thinner
and sharper. After sharpening, those tools cut things
easily. The sharp tools help to cut objects easily.

Memory Tips

The process in which cutting edges of the tools are rubbed against stones or
hard rough surfaces to make cutting edge thinner and sharpener is called
sharpening.

SOME LOCAL TECHNOLOGIES 117

This also saves money as we do not have to buy new tools. Sharpening
is a local technology, so it does not need any money. In this way, blunt
or rusted tools can be made useful once again.

iv. Local cold stores

Most of the crops do not grow throughout the year. However, we need
food to eat every day. To solve this problem, we need to store these food
items properly. If they are not stored well, they get damaged and we
face the scarcity of food. Thus, food items can be stored in cold stores
using local technology. As a result, we can get the food we want without
their quality and taste being destroyed.

Memory Tips

Different kinds of foods and fruits can be stored in the local cold stores
using local technology. As a result, we can get these food items in off-season
without losing their quality.

Fig: 15.7 Some local cold stores
Rice, wheat, maize, pea, gram, etc. are the foods that grow in only one
season. However, we need to eat these food items throughout the year.
Thus, in order to preserve them, they should be stored properly. Most
of the food items need to be stored in a cold place. In some cases, people
use ice box to store fruits and vegetables. In the urban areas, people
also use electricity to keep the store house cool.

Memory Tips

Rice, wheat, maize, pea, gram, etc. are grown in one season. However, we
need to eat these food items throughout the year. So, they are stored properly
in the local cold storage.

118 Modern Concept Science, Health and Physical Education - 3

EXERCISE

1. Fill in the blanks using the correct words.

cold storage rubbing time cooking pit

heating lighting money local technologies

a) Human beings have developed different types of ................ .
b) Local technologies save our ................ and ................ .
c) A ................ is made to prepare compost manure.
d) Biogas can be used for ................ , ................ and ............. purposes.
e) Tools are sharpened by ................ against hard stones.
f) Storage system where foods can be kept is called ................ .

2. Write ‘T’ for True and ‘F’ for Fasle statements.

a) Local technologies are made locally.

b) Compost manure is prepared in the industry.

c) Most of the families in the rural areas of Nepal keep cows and
buffaloes.

d) Biogas can save our money and energy.

e) Blunt tools cannot be sharpened again.

f) Electricity can also be used in cold store.

3. Match the following:

Compost manure produced from animal dung
uses local tools
Khukuri store foods
hygienic food
Biogas prepared from the kitchen wastes
local weapon
Local technology

Cold store

Organic food

SOME LOCAL TECHNOLOGIES 119

4. Choose the best answer from the given alternatives.

a) Local technologies use ................

i. machines ii. local resources iii. skilled person

b) Compost manure can be prepared in ................

i. garden ii. industry iii. forest

c) Organic food is free from ................

i. taste ii. quality iii. chemicals

d) Biogas is generated from ................

i. animals ii. animal dung iii. compost manure

e) Which object should be sharpened?

i. gun ii. khukuri iii. stick

f) Cold store is used to store ................

i. foods ii. clothes iii. fertilizers

5. Answer the following questions.
a) What is local technology?
b) Write the names of any three local technologies.
c) What is compost manure?
d) Why is compost manure better than chemical fertilizers?
e) What are organic foods?
f) Define biogas and write its uses.
g) Why should we sharpen domestic tools?
h) Name any three tools that we sharpen at home.
i) How do you sharpen a knife at your home?
j) What is cold store? Write its uses.

120 Modern Concept Science, Health and Physical Education - 3

6. Observe the following figures and write the names of concerned
local technologies.

Activity
Take two pairs of scissors and cut a piece of paper one by one. Which
one cuts easily? Sharpen the blunt one and cut the paper again. What
do you feel now?

Project Work
You may have seen some local technologies used in your home or your
community. How do they work? Write in your project work copy.

SOME LOCAL TECHNOLOGIES 121

Uni t

16 PERSONAL HYGIENE

Estimated teaching periods : 5

Objectives

After completing the study of this unit, students will be able to:
 state the importance of personal hygiene.
 explain the ways of cleaning the body and its parts.

Clean Body

A healthy person looks happy and smart. In our everyday life, we walk,
play, and perform various activities. While doing these activities, dirt
sticks to our body. This dirt may contain germs. If germs enter our body,
they cause various diseases. Apart from that, a foul smell comes out of a
dirty body. In this condition, no friends like to play with us.

Memory Tips

A clean body is necessary to be a healthy person. A healthy person looks
happy and smart. So, we should clean our body regularly.

Fig: 16.1
Some children may have the habit of wearing dirty clothes, playing
with dirty things and eating without washing hands. They also do not
take a bath regularly. These are some examples of bad habit. During the
rainy season, many children play with muddy water. This makes their

122 Modern Concept Science, Health and Physical Education - 3

body and clothes dirty. Dirty clothes also make their body dirty. If we
do not take a bath for a long time, sweat coming out of our body makes
our body dirty giving off a foul smell. Similarly, many orphans collect
plastic, bottles and other things from the waste materials. Wastes are the
homes of many diseases. This makes their body dirty and a dirty body
has a greater chance of being ill. So, we should not play with wastes.

Memory Tips

Playing with dirty things, wearing dirty clothes, lack of bathing and washing,
playing with the street children, etc. make us dirty.

Care of Skin

Skin is the outermost covering of our body. When we play and work,
dirt sticks to the skin. Bathing keeps our body clean. We should take a
bath regularly. We should use clean water and bathing soap to clean our
body. After bathing we should rub our body with a clean towel to make
it dry. Then, we should wear clean and comfortable clothes according
to the season.

Memory Tips

We should take a bath regularly to make our body clean. After bathing, we
should rub our body with a clan towel. Then, we should wear clean and
comfortable clothes.

Fig: 16.2

Care of Eyes

Eyes are our vital organs. We see things with our eyes. When we play,
walk and read, sometimes dirt enters into our eyes. Then, we should
wash our eyes with clean and cold water. We should never rub our eyes

PERSONAL HYGIENE 123

with dirty hands and clothes. We should never look at the sun directly.
We should not read in the dim light. We should have enough sleep to
keep our eyes healthy. A regular eye check up is also a must.

Memory Tips

To keep eyes healthy, we should wash our eyes with clean and cold water,
we should not rub our eyes and we should have enough sleep.

Fig: 16.3

Care of Teeth

We have teeth in our mouth. They help to chew the food and add beauty
to our face. When we eat food, our teeth become dirty. Dirty teeth
produce a foul smell and cause toothache. We should brush our teeth
with a soft tooth brush using tooth paste. It is necessary to brush our
teeth twice a day just after meals. We should get our teeth examined by
a dentist regularly.

Memory Tips

Dirty teeth produce a foul smell and cause toothache. So, we should brush
our teeth with a soft tooth brush using tooth paste. It is necessary to brush
our teeth twice a day just after meals.

Fig: 16.4

124 Modern Concept Science, Health and Physical Education - 3

Care of Tongue

We have a tongue in our mouth. It is very soft. It is surrounded by teeth.
The tongue helps us to speak. We taste food with our tongue. We should
clean our tongue with a tongue cleaner. We should wash our tongue
with clean water.

Memory Tips

Tongue is a soft and delicate sense organ for taste. So, we should clean our
tongue with a tongue cleaner gently.

Fig: 16.5

Care of Nose

We have a nose on our face. The nose is a sense organ to smell. We should
keep our nose clean. We should use a clean handkerchief to clean our
nose. We should not put a sharp object inside the nose. We should cover
our nose with handkerchief while sneezing.

Memory Tips

Nose is a soft and delicate sense organ for smell. So, we should clean our
nose with a soft and clean handkerchief gently and regularly.

Fig: 16.6

PERSONAL HYGIENE 125

Care of Ears

There are two ears in our head. Ears are the sense organs for hearing.
We should keep our ears clean. We should wash our ears with clean
water. A soft and clean towel should be used to dry our ears after we
take a bath. We should use cotton ear-buds to remove dirt from the ears.
We should not put sharp objects inside the ears.

Memory Tips

Ears are sense organ for haring. So, we should clean our ears with a soft and
clean ear-buds gently and regularly.

Fig: 16.7

Care of Nails

Nails are part of our fingers. Dirty things may get into the nails. Long
and dirty nails cause different types of diseases. We should keep our
nails short and clean. We should use a nail cutter to cut our nails. We
should not bite the nails with our teeth.

Memory Tips

Long nails are home for dirt and germs. So, we should trim our nails regularly
with nail cutter. We should not bite the nails.

Fig: 16.8

126 Modern Concept Science, Health and Physical Education - 3

Care of Hair

Hair adds beauty to our body. When we work and Fig: 16.9
play, it becomes dirty. Therefore, we should take
proper care of our hair. We should wash our hair with
soap and shampoo at least twice a week. We should
comb our hair daily with our own comb. We should
keep our hair short and simple

Memory Tips

Hair adds beauty to our body. So, we should take proper care of our hair. It
is necessary to wash our hair with soap and shampoo at least twice a week.

EXERCISE

1. Fill in the blanks choosing the correct words. sharp
twice dirt healthy blade

a) A clean body is a necessity to be ..................
b) .............. causes diseases.
c) We should brush our teeth ................. a day.
d) We should not cut our nails with a..........
e) We should not put .............objects inside the ears.
2. Write ‘T’ for true and ‘F’ for false statements.
a) We should not wear dirty clothes.

b) We should take a bath regularly.

c) We should not cover our nose while sneezing.

d) We should brush our teeth twice a week.

e) We should not play with dirt.

PERSONAL HYGIENE 127

3. Match the following:

Nail cutter ears
Handkerchief nails
Ear-buds nose
Tooth brush skin
Soap teeth

4. Choose the best answer from the given alternatives.

a) A clean person is ...................

i. smart ii. healthy iii. both

b) Dirty clothes make our body ................

i. dirty ii. clean iii. both

c) We should brush our teeth ............... a day.

i. once ii. twice iii. thrice

d) Long and dirty nails cause

i. diseases ii. smartness iii. both

e) While sneezing, we should cover our nose with ................

i. paper ii. a handkerchief iii. any cloth

5. Observe the following figures and identify the activity.

6. Answer the following questions.
a) Why should we clean our body?
b) What happens if our body is dirty?
c) How can we make our body clean?
d) How do germs enter our body?
e) What do you use to cut your nails?
f) How many times do you brush your teeth in a day?
g) How do you clean your tongue?

Activity

Write five sentences each about care of eyes, nose, tongue, teeth and
hair. Discuss various ways of cleaning eyes, nose, tongue, teeth and
hair in your class.

128 Modern Concept Science, Health and Physical Education - 3

EXERCISE, REST AND Unit
CLOTHING
17

Estimated teaching periods : 3

Objectives

After completing the study of this unit, students will be able to:
 state the importance of exercise.
 explain the need of a rest.
 name the clothes that we wear in various seasons.

A healthy person should be fit in all respects. He should be physically
strong and mentally active. To be strong and active, one should take
hygienic food and do regular exercise. One should take adequate rest
and put on clean and seasonal clothes.

Memory Tips

Hygienic food, regular exercise, enough rest, clean and seasonal clothes are
necessary for physically strong and mentally active body.

Physical exercise is very essential to keep ourselves healthy. Running,
walking, playing, working, etc. are the basic exercises that we perform
in our daily life. While taking exercises, our body parts get stretched
and become flexible. Exercise also helps to improve our respiratory and
circulatory systems. While doing exercises,oxygen and nutrients reach
all over the body. Exercises even sharpen our brain. For example, while
playing football, we develop new tricks to dribble the ball and keep our
mind active to score a goal. We get refreshed after playing games and
sports.

Memory Tips
Running, walking, playing, working, etc. are the basic physical
exercises. Exercise makes our body parts strong and flexible.

EXERCISE, REST AND CLOTHING 129

Fig: 17.1
After working for long hours, both our body and mind get tired. In
such a condition, we need to take a rest. In general, our body gets a rest
while we sleep. However, we also take a rest during the day if we feel
very tired. Normally a person needs 6-8 hours’ sleep, but the duration
of sleep depends upon the age of the person. For example, a small child
and an old man requires about 8-10 hours’ sleep. We feel hungry after
we wake up from the sleep even if our body does not perform any
activity. It is because during the sleep internal organs of our body keep
working. For example, respiration, circulation, digestion, etc. take place
continuously even when we are asleep.

Memory Tips

After exercise, our body and mind get tired. In such a condition, we need to
take a rest. About 6-8 hours’ sleep is a good rest.

Fig: 17.2: Different types of resting positions

Clothing

Like exercise and rest, clothing also has a vital role to maintain a healthy
life. Clean and proper clothes keep us safe from various diseases. A
person looks smart and healthy if s/he wears clean clothes. The use of
clothes depends on the season and the place we are in. For example,
the clothes we wear in winter are different from the clothes we use in
summer. Similarly, the clothes used in the Terai region are different
from the clothes used in the hills and mountains.

130 Modern Concept Science, Health and Physical Education - 3

Memory Tips

Clean, comfortable and seasonal clothes keep us safe from various diseases.
A person looks smart and healthy if s/he wears such clothes.

Fig: 17.3: Different types of clothes

Clothes used in summer season

In summer, the climate is warm and hot. So, we should wear thin and
white cotton clothes. This keeps our body cool. The white clothes reflect
the sunlight and do not allow our body to become warm. The different
types of clothes that we wear in summer are given below.

Memory Tips

White, thin, light and comfortable clothes are suitable in summer season.

Fig: 17.5: Clothes used in winter season

Clothes used in winter season

The climate is very cold during winter. In such condition, thin clothes
are not appropriate. We must wear thick and woolen clothes in winter.
They protect our body from cold. Common cold can be prevented by
wearing thick woolen clothes. Besides, we must cover our body with a
thick blanket or a quilt while sleeping.

Memory Tips

In the winter season, we should wear thick and woolen clothes. While
sleeping, we must cover our body with tick blanket and quilt.

EXERCISE, REST AND CLOTHING 131

Fig: 17.5: Clothes used in winter season
In this way, we need to wear appropriate clothes in different seasons to
live a healthy life. The clothes we wear should be neat and clean. They
should be washed when they get dirty. Besides, neat and clean seasonal
clothes also help to enhance our personality.

Memory Tips

According to the time, condition, season and occasion we should wear clean,
comfortable and proper clothes.

EXERCISE

1. Fill in the blanks choosing the correct words.
tired fit winter stretched rest

a) A healthy person should be ..................... in all respects.
b) While taking exercise, all the body parts get ..................
c) We need a ..................... after playing games and sports.
d) We become ................................. after continuous work.
e) Warm clothes should be used in the ..................... season.

2. Write ‘T’ for true and ‘F’ for false statements.
a) A healthy person is mentally alert.

b) Physical exercises improve our health.

c) We do not get a rest while sleeping.

d) We look smart if we put on clean clothes.

e) Cotton clothes are appropriate in summer season.

132 Modern Concept Science, Health and Physical Education - 3

3. Choose the best answer from the given alternatives.

a) Physical exercise is ................. to keep ourselves healthy.

i. not necessary ii. essential iii. both

b) We get a rest while................. ……………………

i. sleeping ii. walking iii. playing

c) We should wear .................. clothes in winter.

i. thin ii. cotton iii. woolen

d) We should wear...................clothes in summer.

i. thick ii. cotton iii. woolen

e) We look .................. in clean clothes.

i. sleepy ii. sick iii. smart

4. Answer the following questions.

a) Why do we need physical exercise?
b) What happens when we work continuously?
c) What should we do to get relief from tiredness?
d) Why do we feel hungry after we wake up from sleep?
e) Why are clean clothes important?
f) What kinds of clothes should we wear in winter?
g) Name any five clothes that are used in winter.
h) What kinds of clothes should we wear in summer?
i) Name any five clothes that are used in summer.

5. In which season do we wear the following clothes?

(a) (b) (c) (d)

Activity
What kind of clothes do you wear in summer and winter? Explain to your

Project Work
Collect the pictures of clothes used in different seasons and paste them
in your project work copy.

EXERCISE, REST AND CLOTHING 133

Uni t

18 CLEAN HOUSE

Estimated teaching periods : 25

Objectives

After completing the study of this unit, students will be able to:
 state the importance of a clean house.
 outline the ways of keeping the house clean.
 describe the condition of dirty and clean rooms.
 explain the importance of clean and proper rooms.
We live and spend most of our time in a house. It is the best shelter
for us. A good house has sufficient space for various purposes. There
should be a kitchen, bedrooms, a study room, a store, a bathroom and
a toilet in a good house. It should be clean and beautiful. Around the
house, there should be sufficient space and a garden. The house should
be free from water, air and sound pollution.

Memory Tips

The house is a place where we live and spend most of our time. It protects
us from heat, cold, rain, enemies and wild animals. It should be clean and
beautiful.

Fig: 18.1: A clean house

134 Modern Concept Science, Health and Physical Education - 3

Clean Rooms

The rooms of the house should be well ventilated. Sunlight and air
should pass easily inside the rooms. We should clean the rooms every
day. If the rooms are not clean, different types of insects like mosquitoes,
flies, etc. come inside the room.

Memory Tips

The rooms of the house should be clean and well ventilated. Air and sunlight
should pass easily.

Fig: 18.2

Clean Kitchen

Kitchen is the place where we cook and store food. So, to have a healthy
meal, the kitchen should be clean. We must clean the kitchen regularly.
If the wastes produced in the kitchen are not managed properly, flies
gather over there. If the flies sit on our food, the germs present in their
bodies may transfer onto the food. When we eat such contaminated
food, we become unhealthy and sick.

Memory Tips

We cook and store food in the kitchen. So, it should be clean and free of flies.

Fig: 18.3

CLEAN HOUSE 135

Clean Bedroom

The bedroom is the place where we sleep and take a rest. It should be
clean as well as quiet. The bed on which we sleep should not be high.
The bedcover, blanket and other clothes should be cleaned regularly.
We can use dim light while sleeping.

Memory Tips

We sleep and take a rest in the bedroom. It should be clean and well managed.
It should have sufficient ventilation for air and sunlight.

Fig: 18.4

Clean Study Room

Study room is a place where we study. It should be clean and well-
managed. The books and exercise books should not be thrown here and
there. If the study room is not managed properly, it irritates the mind.
When we feel irritated, we cannot concentrate on our study. Similarly,
noise also affects our study. Thus, a clean, well-managed and quiet
study room is essential for fruitful learning.

Memory Tips

We read, write and think in the study room. So, it should be clean, well-
managed and quite. It should have ventilation for light and air.

Fig: 18.5

136 Modern Concept Science, Health and Physical Education - 3

Clean Toilet

We go for defecation and urination in the toilet. Stool and urine are the
waste products from our body. They give off a foul smell and contain
germs as well. Therefore, the toilet should be cleaned properly after
its use. It should be flushed with sufficient water. If the toilet is not
cleaned properly, bad smell spreads from it. It also becomes the source
of various diseases.

Memory Tips

We go for defecation and urination in the toilet. Urine and stool produce foul
smell and are home for germs. So, it should be clean properly after its use.

Fig: 18.6

EXERCISE

1. Fill in the blanks choosing the correct words.
toilet kitchen ventilated space live

a) The house is the place where we................... ………
b) A good house has sufficient...................
c) The rooms of the house should be well...................
d) The...................should be cleaned every day.
e) The...................should be flushed properly after use.
2. Write ‘T’ for true and ‘F’ for false statements.

a) A good house should not have any windows.

b) The rooms of the house should be cleaned properly.

CLEAN HOUSE 137

c) Bedrooms and study room should be noisy.

d) A good and clean house is necessary for a healthy living.

e) A good house should have sufficient space.

3. Match the following:

Study room should be flushed properly
should be clean
Ventilation should be silent
provides fresh air
Toilet healthy living

Clean house

Kitchen

4. Choose the best answer from the given alternatives
a) A clean house is necessary for ................
i. a healthy living ii. an unhealthy living iii. sleeping
b) Wastes from the kitchen should be ................
i. thrown everywhere ii. managed properly iii. stored

c) Ventilation provides us ................

i. hot air ii. fresh air iii. nothing

d) A good house should have sufficient ................

i. books ii. clothes iii. space

e) The toilet should be ................

i. flushed properly ii. dirty ii. away from the house

5. Identify the following rooms and write their names.

138 Modern Concept Science, Health and Physical Education - 3

6. Answer the following questions.
a) Why is a clean house necessary for us?
b) How can we manage kitchen wastes?
c) What are the major wastes produced from the kitchen?
d) How can we keep the toilet clean?
e) How should we maintain our bedroom and study room?
f) What happens if our home is dirty?
g) What happens if our bedroom is not cleaned properly?

7. Look at the following figures and explain what differences you
observe between them

Activity
Ask your mother how she manages kitchen wastes and explain it to
your class.

Project Work
Collect the pictures of a clean and dirty house and write the ways in
which you can make the dirty house clean.

CLEAN HOUSE 139

Uni t

19 CLEAN ENVIRONMENT

Estimated teaching periods : 52

Objectives

After completing the study of this unit, students will be able to:
 differentiate between a clean and a dirty environment.
 explain the effects of a dirty environment.
 describe the importance of a clean environment.

Clean Environment

We live in the earth. There are various things around us. So, the
surroundings in which we live is called an environment. Like our
body, our home and community, environment also should be clean and
peaceful. Everyone likes to live in a clean and peaceful environment.
There are fewer chances of the outbreak and spread of diseases in a
clean environment. A clean environment looks attractive and everyone
prefers to live in it.

Memory Tips

The surroundings in which we live is called an environment. It should be
clean, well-managed, peaceful and attractive.
The pollution in our surroundings is called environmental pollution. It
is caused by various factors. A dirty environment causes several diseases

Fig: 19.1: Children cleaning the school compound

140 Modern Concept Science, Health and Physical Education - 3

Cause of Environmental Pollution

People living in a community are

responsible to keep their community

clean. If the wastes produced at

home are thrown haphazardly in

the surroundings, they make the

environment dirty. It pollutes air, water

and soil. The wastes thrown become the

home for flies and mosquitoes. They Fig: 19.2
spread various communicable diseases.

Memory Tips

Throwing wastes haphazardly, open defecation and urination, stagnant

water in the surroundings, etc. are the main causes of environment pollution.

Management of Wastes

Fig: 19.3 The wastes produced from the house should
be managed properly. Plastic bags, bottles
and metal cans should be reused. Similarly,
paper, plastic and other metals should be
recycled. Wastes produced from the kitchen
should be converted into compost manure.
Compost manure can be used in the garden
and on farms for growing plants.

Memory Tips

Different kinds of degradable and non-degradable wastes are the main cause
of environment pollution. So, they are separated and managed properly.

Clean Water Sources

The sources of water in a community like water taps, stone spouts, wells,
etc. should be kept clean. Water tanks should be properly covered. We
should not defecate or urinate around the sources of water. Most of the
diseases spread from the polluted water. So, everybody should be aware
of water pollution and its effects.

CLEAN ENVIRONMENT 141

Memory Tips

After air, water is very important thing for living beings. So, sources of water
like taps, stone spouts, wells, etc. should be kept clean.

Fig: 19.4

Clean Roads

Roads, streets and surroundings should be neat and clean. No one
should throw garbage on the roadside. People should not defecate or
urinate around the roads. The wastes around the roadside pollute the
environment.

Memory Tips

Roads and streets are the places through where we move on. So, they should
be wide, clean and greenery. We should not defecate or urinate around the
roads.

Fig 19.5: Clean road

142 Modern Concept Science, Health and Physical Education - 3