—Tom graduated from college at a very young age.—Oh,he__________have been a very smart boy then.

You’d better take another flight to New York , for the AA 505 Flight ______ have been cancelled. But you should call the airport to make sure. 

Li Lei isn’t ____ Liu Ming. 

---I think Miss Lin must be in the library. She said she would go there.---No, she __________be there. I have just been there.

In our town, wood can ___________ a fire.