30.根據(jù)短文內(nèi)容選擇正確答案. AirAir is all around us.It is around us when we walk and play.It is around us when we sit down.It is also around us when we go to bed.We live in air.We can live without food or water for a few(一些) days,but we cannot live even for a few minutes without air.We take in(吸入) air.When we are working or running we need more air.When we are asleep,we need less(少量的) air. We live in air,but we cannot see it.We can only feel(感覺) it.We can feel it when it moves(移動(dòng)).Moving air is wind.How can we make air move?Here is one way.Hold an open book in front of your face and close it quickly(快速地).What can you feel?It's air. (1)We need air
. A.when we walk and play B.when we sit down C.a(chǎn)ll the time(一直) (2)What do we call moving air?