—I thought you wouldn't mind.
— Well, as a matter of fact, I don't, but you ______ me first.

单项选择题All of them try to use the power of the workstation ______ information in a more effective way.

单项选择题We（）on this project for four hours. Let's have a rest.

A. are working
B. have been working
C. worked
D. had worked