I knocked on the door several times but_______________ answered, so I left.

Don’t look down upon Bob. He has his own advantages. —-Oh, yes. ______ others are weak, he is strong.

The price of this kind of computer varies from 3,000 yuan, to 10,000 yuan, the brand(品牌).[ ]

Mr. Wang, I have trouble ____ the text.—Remember ____ it three times at least.

______ be MrJohnson who is in the office— No, it _______ be himI saw him off at the airporthalf an hour ago