You ______ to the meeting this afternoon if you have something important to do.

"Those responsible for the accident      be punished while those contributing to solving the problems be rewarded," promised the official then and there.

You _________ to eat snacks in the classroom.

—I’m afraid you missed a fantastic lecture yesterday. How come you were absent from it?—If you _______ know, I asked for a day off and visited a relative of mine in hospital.

You     keep  quiet  in the library because everyone is reading here.