Which one of the following do the plants use from air to prepare food?

What is the process of changing of water or any other liquid to vapour called?

What is added to purify the water?

During which process, the heavier impurities will settle down at the bottom of the beaker?

The thick blanket of air that surrounds our planet is called:

Which is the fourth layer of the atmosphere?

What is the first layer above the earth's surface?

What is needed for cooking, bathing, working and construction work?

What is as important as air for our survival?

The most important gas for the survival of living beings is: