The fans never expected their favourite team, which owns so many excellent players, ________have been defeated in the first round!

Sir, you ________ take this seat. It’s just for the old.

—Listen ! Helen is singing in the next room.—It __________ be Helen. She is in Tianjin now.   

You’d better put on a heavy coat.Sometimes it________be very cold here at night.

—Why are those people gathering in the middle of the street?—I don’t know. There ________ be an accident.