If you are free to walk through out city, please ________ us.A drop in B drop in at C. drop in on
—Excuse me. Can you please tell me _________?—Sure. There’s a bookstore on River Road.
Mrs. Smith often goes to visit those AIDS patients in hospitals to_________.
We all know how wonderful you are. You needn’t _________.
There _________a girl singing next door. Can’t you hear her beautiful voice?
—Oh, the room is too dirty, Tony! —Sorry, Mom. It _____ yesterday. I’ll do it right away.