The teacher highly recommended that I___________ more to improve my English.

The question that puzzled them is ____ they can getrid of the air pollution in the area

―Is Tom coming to the concert this evening―No, he _________ be at the concert. He _______ abroad.

Parents ______ good conditions(条件) _______ us. We should be grateful（感激的）to them.

Who is the man over there Is it Mr. Wu — It ________ him, but I am not quite sure.