The research mainly deals with the difficulty the students have ______ their attention pm their study all the time.

Though great efforts have been on their study , Annie still can’t make any improvements , which makes her parents greatly ______

What’s Tom’s favorite city —______ favorite city is New York.

You will easily know ________ videorecorders are the same.

How is your leg, Mike Oh, don’t worry! The X-ray shows it is _______.