16. We ( ) supper when a policeman came to the door.
A. just have B. were having C. just had D. had had just
17. Can you say something about Pop music in China? —— ( )。
A. What is pop music?
B. I know that. C. I've never been to China. D. Yes, I'd like to.
18. I can never remember ( ) drawer he keeps his shirts in.
A. what. B. as C. which D. where
19. Jefferson thought that it was conflict and not unquestioning agreement () keeps freedom alive.
A. A which B. B that C. C what D. D as a
20. Although George has many personal problems, he ( ) present every day since the first day of class.
A. has been B. had been C. is D. was