―Look at the lady there. ______ it be Mrs. Green?―No, it _______ be her. She left for London this morning.

Mr. Wu is good ____ math. He teaches _____ math well.

－Mike, I can't stop playing computer games.－For your eyes, I am afraid you ______.

--- _________ pens are there on the desk?--- Eleven.

—Have you       that Amy’s a little quiet these days?—Yes, I wonder what has happened to her．