Do you have any idea what has ______ him mad?
He was busy writing a story, only ____ once in a while to smoke a cigarette. A. to stop B stopping C to have stopped D having stopped
The computer system suddenly ____ while he was searching for information on the Internet.
— Did you go to see the football match in the stadium?— _________ , but my cousin called on me.
The financial crisis has led to a sharp ______ in profits in many factories.
---It’s burning hot today, isn’t it? ---Yes. ______ yesterday.