539. All but one ___here just now.

　　 A. is　 B. was　 C. has been　 D. were　　　　　　 　　　　　　　

538. I still don’t know what ___while I was away from home.

　　 A. had happened　 B. was happened　 C. has happened　　 D. happened

537. I’m not sure if he ____tomorrow.

　　 A. will come　 B. has come　 C. come　 D. would come　　

536. “Do you know when ______again?” “ When he ____, I’ll get you know.”

A.　 he comes; comes　　　 B. will he come; will comes　

C. he comes; will come　　 D. will come; comes　　　　　　

535.----- Will you go to the museum tomorrow?

　　　 ----I will if I ____no visitors.

　　 A. have　 B. will have　 C. shall have　 D. am having　　　　

534. Lao Wang will certainly be given a new house if more houses______.

　　 A. will be given　 B. are built　 C. will build　 D. be built　　

533. I have to finish my homework before my mother _____back.

　　 A. comes　 B. will come　 C. shall come　 D. had come　　

532. It is the first I ______to this city.

　　 A. came　 B. come　　 C. have come　 D. had come

531. They ____their lessons for an hour, but they have finished only half .

　　 A. will be doing　 B. did　 C. have been doing　 D. will have done

530. He promised that he ____me a piano.

A.　 bought　 B. will buy　 C. would buy　 D. had bought