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

You had better ________some food and drinks before the field trip ________.

It is usually warm in my hometown in March, but it _____ be rather cold sometimes.

— There is somebody at the door. ________ it be Tom?— No, it _______ be him. It’s just six o’clock. It’s too early.

--Must we move to the next room?--No, you____________ . You may still live here if you like.