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