24. We must do the experiment carefully ＿＿＿Miss Liu told us.

　 A. what　　　 B. since　　　 C. as　　　 D. while　

23. The science of medicine,＿＿＿progress has been very rapid lately, is perhaps the most important of all the sciences.

　 A. to which　　 B. in which　　 C. which 　D. with which

22. ＿＿＿everybody is here,let’s set out right away.

　 A. Now that　　 B. Because　　 C. For　　 D. After　

21. ＿＿＿the days went on,the situation there got worse.

　 A. With　　　　 B. Since　　　　 C. While　　　　 D. As

20. -- I don’t like chicken ＿＿＿ fish.

　 -- I don’t like chicken,＿＿＿I like fish very much.

　 A. and； and　　 B. and； but　　 C. or； but　　　 D. or； and

19. ＿＿＿several times about it,but he could not give the correct answer.

　 A. Being asked　　　　　 B. Having been asked

　 C. He would ask　 　　　　 D. He had been asked

18. There is plenty of rain in the south ＿＿ there is little in the north.

　 A. while　　　　 B. as　　　　 C. when　　　　 D. so　

17. ＿＿＿air is to man,so is water to fish.

　 A. Since　　　　 B. Just　　　　 C. Like　　　　 D. As

16. The students of the music school study ＿＿＿＿.

　 A. music but also some other subjects

　 B. some other subjects as well as music

　 C. music as well as some other subjects

　 D. some other subjects and music

15. What the doctors really doubt is＿＿＿＿my mother will recover from the serious disease soon.

　 A. when　　　 B. how　　　 C. whether　　　 D. what