.______ his homework, he went on to preview the next lesson.
-I'm sorry for what I said.-Forget it. I can't remember _____.
It is reported that the scientists in Europe are _____ all possible ways to control it.
-How do you deal with the disagreement between the company and the customers?-The key _____ the problem is to meet the demand _____ by the customers.
-Tom and Mary got married last month.-Are you kidding? They have _____ in common.
It is said that Columbus Day is Christopher Columbus who discovered the New World in the USA.A. in honour of B. for the honour ofC. in favour of D. in place of