21、You never told us why you were late for the party，( ) ?

　　A. weren't you B. didn't you C. had you D. did you

　　22、He's ( ) to know the answer.

　　A. likely B. probable C. maybe D. probably

　　22、He's ( ) to know the answer.

　　A. likely B. probable C. maybe D. probably

　　24、The heavy snow could not keep us ( ) going out to work.

　　A. from B. on C. upon D. up

　　25、They found the lecture hard ( ) .

　　A. to be understood B. to understand C. for understanding D. to have been understood

　　26、I learned how to ( ) a bicycle when I was six years old.

　　A. drive B. ride C. pull D. draw

　　29、All the afternoon he worked in his study with the door ( )。

　　A. to lo ck B. locking C. locked D. lock

　　30、He is so shy that he ( ) speaks in the public.

　　A. often B. frequently C. seldom D. sometimes

　　31、It isn't quite ( ) that he will be present at the meeting.

　　A. certain B. sure C. right D. exact

　　32、He told her nothing， ( ) upset her.

　　A. that B. for which C. about which D. which

　　33、It's too expensive for me. I can't ( ) it.

　　A. spend B. cost C. pay D. afford

　　34、Would you like me ( ) the radio a bit?

　　A. turning down B. to turn down C. turn down D. turned down

　　35、"I saw Mary in the library yesterday." "You ( ) her， she is still in hospital."

　　A. mustn't have seen B. could not see

　　C. can't have seen D. must not see