Food safety is important. Rules____ to stop people from food pollution.

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

Though _______ money, his parents managed to send him abroad.

—There's someone knocking on the door．Who        it be?—It must be Mary．She promised to be here at 8：00．

— Where is my dictionary?— You ______ it in the wrong place.