7.　　　　 I heard someone _______________ (go) upstairs at 12:00 last night.

6.　　　　 It took us two hours ______________ ( finish ) the work.

5.　　　　 He needn’t 　___________ (come)here so early.

4.　　　　 Listen! Someone _____________ (sing).

3.　　　　 The old man is ill. He ___________ (must send) to the hospital.

2.　　　　 That play __________(put) on again sometime next month.

1.　　　　 The students _________ often __________(tell) to take care of their desks and chairs.

16. She ______________ ( learn ) about 30,000 words in the past three years

15. Recently Mary __________ ( do ) her work regularly.

14. How many songs ________ they___________ by now? ( learn)