21.The notice ______ “No smoking”. 　A is told　　 B reads　　　　　 C tells　　　 D is read

(三)情态动词

20.The doorbell had been ringing for several minutes before it ______.

　 A answered　 B had answered　　 C was answering　 D was answered

19.The box _____.Better call in a mechanic(修理工).

　 A isn’t open　 B hasn’t been open　 C isn’t be open　 D won’t open

18.The workers _____busily when the boss came to look for something she ______in the office.

　 A had worked, had left　 　B were working ; had left C working ; had left　 D had worked; left

(二)语态

17. I’m afraid it will be two months______.

　A when I come back　 B when I’ll come back　 C before I come back　 D before I’ll come back

16.The lake will be further polluted unless some measures ______.

　 A will be taken　　 B are taken　　　 C were taken　　　　 D had been taken

15. ---- How is the old man now?

　 ---- Sorry, he ______ though they did all they could to save him.

　 A. was dead　　　　 B. had died　　　 C. has been dead　　　 D. died

14. ---- Do you live in this city?

　 ---- No, we ______ it for holidays.

A. just visit　　　　 B. just visited　　　 C. are just visiting　　　 D. have visited

13. Nothing _______ clear about the meeting.

　 A. has made　　 B. has been made　 C. has done　　　 D. has been done

12. I’d rather you did some housework when you are free, but you __________.

　 A. weren’t　　　 B. didn’t　　　　 C. wouldn’t　　　 D. don’t