No air means death．Though we see it，there is air around us. air is everywhere and it gives life to every living thing．Without it we can’t live．Bad air makes people ．We must have fresh(新鲜) to keep us in good health．

In the city there are a lot of people and there are too many running on the road．The gas(气体) which the car sends out(排放) is made up of(组成) bad gases．Every day we breathe it in and ．This makes us sick． So people should door as much as they can．There are many factories，too．From the chimneys of these factories，we get the smoke usually in black color．This kind of smoke does harm our health．So in order to(为了) keep us ，we have to go out to the countryside to breathe more fresh air．Or we can go up hills to get more fresh air．

1.A．can B．can’t C．may D．must

2.A．Or B．But C．Because D．So

3.A．happy B．fat 　 C．ill D．well

4.A．air B．fruit C．food D．water

5.A．planes B．trains 　 C．cars D．bikes

6.A．away B．outside C．off D．out

7.A．feel B．seem C．to feel D．to seem

8.A．go out 　　 B．go out of C．get out D．get up

9.A．in B．with C．to D．about

10.A．health B．healthy C．good D．better

No air means death．Though we       see it，there is air around us.       air is everywhere and it gives life to every living thing．Without it we can’t live．Bad air makes people       ．We must have fresh(新鲜)       to keep us in good health．
In the city there are a lot of people and there are too many         running on the road．The gas(气体) which the car sends out(排放) is made up of(组成) bad gases．Every day we breathe it in and     ．This makes us        sick． So people should        door as much as they can．There are many factories，too．From the chimneys of these factories，we get the smoke usually in black color．This kind of smoke does harm         our health．So in order to(为了) keep us      ，we have to go out to the countryside to breathe more fresh air．Or we can go up hills to get more fresh air．

根据短文内容及首字母提示，填写所缺单词，使短文意思完整。每空限一词。

Air is very important to everything that lives. But the air we breathe is g  1.   dirty. People all over the world are looking for w  2.   to make it clean again.

Have you ever watched the smoke from chimneys(烟囱) r  3.   high in the air? Have you s   4.___ the smoke from cars and trucks on roads or the smoke from planes? The smoke is h  5.   to everyone, especially old people and children. If we want to keep well and strong, we need to breathe f  6.   air.

With more and m   7.   factories everywhere and more and more cars, trucks and planes, it is getting harder and harder to do with the air p  8.   .

Scientists have a 9.   found ways to stop or slow down some of the things that make the air dirty. They will not stop working u  10.  we have clean air again.

Air is all around us.It is around us as we talk and play, From the moment we were born , we are surrounded(围绕) by air. When we sit down ,air is also around us ,we live in air .
All living things need air:living things cann’t live without air.
We can go without food or water for a few days ,but we can not live for more than a few minutes without air. When we are working or running ,we need some air. So we breathe faster than usual. When we are asleep, we need less air.
【小题1】From the text ,we know that on the earth _____