20. We go to bed before ten, _________ in the summer.

　 A. except for　　　　　 B. except that　　　　　　　　　 C. except when　　　 D. except

19. Every day, the old lady would go to the park and sit in her ________ chair to have a little rest.

　 A. common　　　　　　　　　 B. ordinary　　　　　　　　 C. usual　　　　　　　　　　 D. general

18. An order came from the command _________ all the PLA men should rush to the disaster-hit area to help the people there.

　 A. how　　　　　　　　　　　　　 B. that　　　　　　　　　　　　 C. which　　　　　　　　　　 D. where

17. --- Did you notice the mayor just now?

　 --- No, I ________ of something else.

　 A. thought　　　　　　　　　　 B. was thinking　　　　　 C. have thought　　　 D. had thought

16. --- Jack has a high opinion of Mary.

　 --- It cannot be better than ________ of him.

　 A. she　　　　　　　　　　　 B. that　　　　　　　　　　　　 C. her　　　　　　　　　 D. hers

15. My family were watching TV that night ________ the door bell ________.

　 A. when; rang　　　　 B. as; was ringing　　　　　　 C. while; rang　　　　　 D. but; rang