You ______ be polite to the old man.

My grandfather          us stories when I was young.

---Who is the tallest boy?        ---It ______  be John. John is of medium height.

Susan’s parents bought a large house with a swimming pool. It ______be very expensive.

Today is Wednesday. He _______ be at home. He _____ be at school.

You’re too tired. You _______ have a good rest.

— Must I stay here with you?
—No, you_____. You may go home, but you ______go to the net bar.

—Mr. Wang __________ be in the office. The light is still on.
—No, he __________ be. Because he phoned me from the farm just now.

—Can you tell me what to wear at the party?
—If I            you, I            the blue jeans.

He____know the answer, but I’m not sure.
A:maybe  B:may be  C:may  D:must