20. Father made a promise _______ I passed the exam he would buy me a ten-speed bicycle.

　 A. that　　　　　　　 B. if　　　　　　　　 C. that if　　　　　 　D. whether

19. The pictures were so lovely that they ________ in no time.

　 A. had been sold　　　 B. sold　　　　　　　 C. have been sold　　 D. were sold

18. ___ Where is Harry?

　 ___ He _________ be in the library, but I’m not sure.

　 A. may　　　　　　　 B. must　　　　　　　 C. should　　　　　　 D. can