21. Let her do that, if she________.

　 A. does　　　　　 B. is　　　　　　 C. will　　　　 D. will do

20. If you _______ it, I will lend the novel to you.

　 A. read　　　　　 B. will read　　　 C. have read　　 D. want read

19. You’ll fail in the driving test______ you have more practice.

　 A. if　　　　　　 B. unless　　　　 C. when　　　　 D. after

18. Do you mind_______?

　 A. if I sit here for a moment　　　　 B. if my sitting here for a moment

　 C. if I will sit here for a moment　　 D. I sitting for a moment

17. -Did you catch the first bus this morning?

　 -No. It had left the stop______ I got there.

　 A. as soon as　　　 B. at the time　　 C. by the time　　 D. during the time

16. It seemed only seconds______ the boy finished washing his face.

　 A. when　　　　　 B. till　　　　 C. after　　　　 D. before

15. It’s a long time since I enjoyed myself. This sentence means______.

　 A. I enjoyed myself for a long time

　 B. I haven’t enjoyed myself for a long time

　 C. I want to enjoyed myself

　 D. what a long time after I enjoyed myself

14. There have been ten thousand visitors to the exhibition since______.

　 A. its opening　　　 B. it’s opening　　 C. it opens　　　 D. one month

13. It is at least three years______ these trees were planted.

　 A. that　　　　　　 B. when　　　　　 C. since　　　　 D. as

12. He was so interested in the book that he had read for three hours______ he realized it.

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