Bob, you do well in English. Can you help me with it— Sure, but it’s ___________ for you to find your own learning ways.

(2013·宿州模拟)QQ, 　　　you can chat with your friends, makes communication easy.

Why hasn’t she come to the party? —– I’m afraid she can’t. She is _______ in preparing her graduation paper.

It was in the lab ___was taken chargeof by our teacher____ they did the experiment

Bob used to ______difficulties in studies, but now he does well in all subjects.