No air means death. There is air around us 36 we can’t see it. Air is everywhere and it gives 37 to every living thing. We can’t live 38 it. Bad air makes people ill. We must have fresh air to keep us 39 . In the city there are a lot of people and there are too many 40 running on the road. The gas which the car sends out is made up of(组成) bad gases. Every day we 41 it in and out. This makes us feel sick. There are many 42 , too. From the chimneys(烟囱) of these factories, we 43 get the smoke in black color. This kind of smoke is 44 to our health. So in order to keep us healthy, we have to go out to the 45 to breathe more fresh air. Or we can go up hills to get more fresh air. 小题1:A. because            B. though              C. so 小题2:A. life               B. name     　        C. pleasure 小题3:A. with               B. without         C. below 小题4:A. quiet              B. tall      　   C. healthy 小题5:A. dogs           B. trains     　  C. cars 小题6:A. breathe            B. draw      　   C. bring 小题7:A. animals            B. people          C. factories 小题8:A. usually  　　      B. never    　        C. seldom 小题9:A. helpful    　　    B. dangerous       C. necessary 小题10:A. office   　      B. city            C. Countryside