21. All the doctors in the hospital insisted that he ________ at once.　

　 A. be operated　 B. must be operated on　 C. operate on　 D. be operated on

20._________ get to the company in time, we set out early in the morning.　

　A. So as to　 B. In order to　　 C. So that　　 D. In order that

19.Those _________ not only from books but also through practice will succeed.

　A. learn　 B. who has learned　 　C. that learns　 D. who learn

18.It is the second time that he ______ our country.　

　 A. visits　 B. visited　 C. has visited　 D. had visited

17.---Put on your coat, my dear son. I ______ you down to the doctor.　 　

---Yes, I will.　　 　

A. am taking　 　B. take　 　C. took　 　　D. have taken

16.The difference in the _____ towards money makes one different from another.

A. attitude　 　B. concern 　　C. opinion 　　　D. quality

从A、B、C、D 四个选项中，选出可以填入空白处的最佳答案。

15.______ cheerful friend is like a sunny day spreading _____brightness all around.

A. A; the　 　B. A; \　 　C. The; the　 　D. The; \