4. A. air　　　　 B. steam　　 C. wind　　　　 D. ice

3. A. hands　　　 B. arms　　　 C. feet　　　　 D. teet

2. A. cold　　　　 B. wet　　　 C. warm　　　　 D. dry

1. A. sunlight　　 B. wind　　　 C. water　　　 D. heal

1.(典型例题检测)

　When you are swimming , you may shiver as you come out of the water. That is specially true if there is a light gentle　 1　 . You wrap up in a piece of cloth to keep　 2　 .But still you shiver,and your　 3 　knock together because of the cold. Water is changing into　 4　 　from your body, and the 　5　 takes away heat.

You shiver because the　 6　 of your body are trying to produce heat to put back the heat you are　 7　 . Most body heat is made 　8 　the muscles. In the cells oxygen is combined with carbo-hydrates(碳水化合物) and fats, producing 　9 　Animal bodies inluding human's" 　10　 "food just as wood is burned in a fire, 　11　 the process is slower in the body the heat is set off gradually. 　12　 always produce Sometimes more,sometimes 　13 　When you exercise,　 14　 more active and so more heat. When you are losing heat 　15　 , the best do is to 　16　 . If you don't,you will shiver. That is the other 　　17　 the muscles produce heat. Another way of sayir the muscles move rapidly and continuously　 　18　 wards. Next time you shiver, try　 　19 　a bit. You'll after two or three 　20　 the shivering will disappear can keep normal body temperature.

20. A. might　　 B. can　　　　　 C. will　　　　 D. should

答案: C　 指导：根据时间状语inthefuture可确定要用一般将来时。

19. A. touching B. knocking　　 C. pressing　　 D. turning

答案: C　 指导：press a button按键。操作员通过按键的方法获得数据。

18. A. picked　 B. produced　　 C. used　　　　 D. gathered

答案: D　 指导：the gathered data积累的数据。人们为了利用山上的积雪，需要不断地收集有关数据。

17. A. taken care of　　　　　　 B. made use of

C. piled up　　　　　　　　 D. saved up

答案: B　 指导:makeuse of使用。科学家正在研究使用山上积雪的方法。

16. A. rocks　　 B. tips　　　　 C. tops　　　　 D. trees

答案: C　 指导：on mountain tops在山顶上。根据常识可知，在冬天，雪会堆积在山顶上。