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CBSE Worksheet-02

CLASS - IV EVS Air

Answer the following.

1. How are storms harmful?

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2. How do we make use of the force of wind?

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3. What adds smoke to the air?

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4. How does dust rise in the air?

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5. From where do germs come into the air?

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6. What makes air foul?

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7. Why are germs harmful?

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8. Why does air get clean after rain?

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9. How is wire-mesh on doors and windows useful?

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10. Why should we not cover our face while sleeping?

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Material downloaded from http://myCBSEguide.com and http://onlineteachers.co.in Portal for CBSE Notes, Test Papers, Sample Papers, Tips and Tricks

Answers

1. How are storms harmful?

a) They uproot trees and pole.

b) They blow away roofs from huts and sheds.

c) They damage trees, crops, houses and animals.

d) They sink ships and boats sailing in the sea.

2. How do we make use of the force of wind?

The force of wind can be used:

a) In moving the sail boats.

b) To work a wind mill.

3. What adds smoke to the air?

a) Smoke from a fire.

b) Smoke given out from chimneys in factories and stoves in kitchens.

c) Smoke from running cars and buses.

4. How does dust rise in the air?

a) Dust raised by wind

b) Sweeping of floors and roads.

c) Running buses and cars.

5. From where do germs come into the air?

a) Germs come from dirty drains, rubbish and animal dung.

b) Dust carries germs.

6. What makes air foul?

Smoke and dust make the air foul.

7. Why are germs harmful?

Germs cause diseases. The germs get into our throat and lungs when we breathe

through our mouth.

8. Why does air get clean after rain?

Rain brings down the dust and the smoke in the air and makes the air clean. So we

get clean air after rain.

9. How is wire-mesh on doors and windows useful?

Wire-mesh allows fresh air into our homes and keeps the flies and mosquitoes

out.

10. Why you should not cover our face while sleeping?

We should breathe in fresh air and so we should not cover our face while sleeping.