20. It was only when I got home late in the evening, that ______ what had happened to my brother.

A. I knew　　　　　　　　　 B. I had known　　　　　 C. did I know　　　　　　　 D. had I known

19. It’s really stupid of you_____ him the news yesterday so it has been disturbing him all the time.

A. having told　　　　　　 B. telling　　　　　　　　　　 C. to tell　　　　　　　　　　　　　　 D. to have told

18. Tom, you’d better make a turn up to the old bridge as the new one ________.

A. has been built　　　 B. was built　　　　　　　　 C. is being built　　　　　 D. is built