Is this Tommy’s suitcase?— No, it is not . It is .

He has read many books on history, so it’s _________ for him to answer these questions.

The number of foreign students attending Chinese universities ________ rising steadily since1990.

Do you have _____ trouble finishing the work?—The work is not so difficult as you think． We have finished it already．

Everyone __________ here now. Let’s __________.