According to common practice, the president _________ hold office for five years.

Facts prove that the world’s economic development is not a win-lose game but one in which all ______ be   winners. 

To forbid the cheating strictly in this important exam, the authorities have released a rule that students _________ bring any reference books and stationery into their classrooms.

You       buy a gift, but you can if you want to.

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

A girl calling herself Mary is waiting outside; _____ she come in now?

―Thank you very much for giving me a hand when I was in trouble.―Don’t mention it. I only did what anyone else _______ in my place.

Liza ______ well want to go on the trip ― she likes traveling.

--- I once got lost during my first visit to Beijing.-- Oh, did you? You _______ me as your guide.

It's nearly time for the meeting to start. The manager ________ be here soon.

--Is Professer Smith giving the speech today?--It ________ be him. He is abroad right now.

A left-luggage office is a place where bags ________ be left for a short time, especially at a railway station.

One ought ________ for what one hasn't done.

I can’t leave. She told me that I _______ stay here until she comes back.

The World Wide Web is sometimes jokingly called the World Wide Wait because it ______ be very slow.

Mary _______ be in the hospital. I saw her play basketball a minute ago.

It was so dark outside that the little child ________ go out by himself. 

According to the school rules, no child _______ be allowed out of the school during the day, unless accompanied by an adult

--Why didn’t you come to Simon’s party last night?---I wanted to, but my mom simply _________ not let me out so late at night.

 —Mum, would you please buy me an MP5 player?—If you can help do the dishes the whole vacation, you ________ have one as a reward.