Air，I can't see it．I can't touch it．But I 1.can live without it．This is air．Air 2.arevery important．It is all around US when we walk and play．It is all around US when we sit down3. orsleep．We need 4.airs．

All living things5.needsair．We can live without food or water for a few days，but we cannot live without air for even a few minutes．When we 6.arework or run．we need more air．When we are asleep，we need less air．