While sleeping we should keep our face

What are the things from factories and vehicles makes the air impure?

Impure air harms

What is very strong wind called?

Which habit keeps our body fit and strong ?

We need  _______  to breathe.

Wind pushes the water in the rivers  and the sea, and causes

When air moves gently it is called

The percentage of oxygen in the air is about

Water vapor is water in the form of