－Why are you looking so worried? Is there anything I can do for you?
－The computer        break down when I nearly finished my composition.

It is recommended that the project ________ not be started until all the preparations have been made.

     we go to the McDonald’s? I’m sick of the food there!

--- The research on the new bird flu virus vaccine is challenging and demanding. Who do you think can do the job?
---____ my students have a try?

His failure suggested that he   the teacher’s suggestions．

If you _____ leave early on weekdays, do it quietly. The other classmates are also dying to have an early leave.

Whale beachings（搁浅）_______ be caused by factors such as illness, or disorientation（迷失方向）caused by extra noise in the oceans, ______ shipping or oil and gas drilling.

—How is the debate of your essay?
—It ____ well, but I ____one of the key points.

–When can I get the result of the test, sir?
–You ____ have it next Friday.

---- May I smoke here?
--- If you      , choose a seat in the smoking section.