21、Dick, you can’t go out to play____________ your work is being done.

A. before          B. until             C. as                 D. with

20、Would you please give me the basic facts _____________ you have reduced what the speaker said？

A. by which        B. to which         C. of which            D. with which

19、The telephone ______________three times in the last hour，and each time it ________       for my father.

A. has rung; was                       B. had rang; would be

C. rang; has been                      D. was ringing; is

18、___________ to me to decide whether we should stay in school for additional classes or have a holiday，I should not hesitate a moment to prefer the latter.

A. Were it left                          B. It was left      

C. It left                                  D. Did it leave

17、 All our time __________ to doing our assignments，we have no time for movies.

A. devoting                             B. is devoted       

C. has devoted                        D. devoted

16、It’s dark and little Anne can’t find her way home. She really doesn’t know________ .

 A. when to leave                    B. what to do      

 C. whether to go                    D. which to choose

15、 It’s not ____________ that we want to talk about at the moment; let’s change the subject.

A. anything         B. something        C. nothing        D. everything

14、Don’t you know，my dear friend，_________it is your attitude not your talent that matters?

A. who            B. which            C. that               D. what

13、The students said hello to the teacher and_____________ with a smile.

A. were rewarded                       B. was rewarded

C. have rewarded                       D. has rewarded

12、 ―Mike is often absent from class.

―Tell him he ____________answer for it if he goes on behaving like that.

A. shall            B. will              C. should           D. could