We should  keep  our doors  and  windows

We need  air to

When air moves fast it is called

Air has

We need _______ to breathe.

________ keep our body strong and fit.

While  sleeping  we should  keep our face

________makes  the air  fresh and pure.

The  percentage  of  oxygen  in the air  is about

A  ___________  can uproot  trees and, at sea  it can  sink  ships.