1.
Option A
2.
Option A
3.
Air is needed for breathing and burning.
4.
Option B
5.
Industries and vehicles release harmful gaseous pollutants that make air dirty.
6.
The process of change of liquid water into water vapour is called as evaporation.
7.
Chlorination is a process to kill micro-organisms present in water.
8.
The movement of hot air and cool air causes Convection Currents.
9.
Option B
10.
Option B
11.
Option B
12.
Option A
13.
The sun is a big ball of fire.
14.
Option A
15.
Option C
16.
Humidity is the amount of water vapour present in the air.
17.
Convection currents are responsible for weather change in a particular place.
18.
Option B
19.
Option D
20.
The wind vane is a device to find the direction of the wind.
