The air surrounding us is important to everyone. Without air, we could not （1） Everyone understands that. But air is necessary（2）many other ways that are not always so obvious or widely known. For example, if we did not have air, （3） would be no sound. Sound travels through air. Where there is no air, there is no sound. （4）air, there would be no fire. There would be no automobiles, （5） motors need air in order to operate. Without air there would be no wind or clouds. There would be no （6）, as we know it. The night time would be very（7）, the days very hot. We would be forced to seek shelter from the sun, （8）there would be no atmosphere to protect us from the sun’s deadly rays. The atmosphere is all the air surrounding the （9） . Atmosphere pressure is the weight of all that air against the （10）of the earth. If we did not have atmospheric pressure, we could not have automobile tires. The tires would swell or burst if they did not have the pressure of the atmosphere against their surface.

1、 A. living B. lively C. exist D. alive

2、 A. under B. of C. on D. in

3、 A. there B. they C. it D. we

4、 A. Despite B. With C. As D. Without

5、 A. however B. but C. since D. and

6、 A. air B. weather C. breeze D. climate

7、 A. warm B. cool C. cold D. hot

8、 A. as B. so C. that D. so that

9、 A. floor B. ground C. land D. earth

10、 A. top B. surface C. face D. coverage