（ ） when she started complaining.

____________ , we will review all the lessons before the final exam.

—Shall we invite Tim? —No, it’s too late to invite any more people. _____, he hates parties, you know.

I won’t call you, （ ） something unexpected happens.

—Do you like the material? —Yes, it （ ） very soft.

When he awoke, he found himself _____ after by an old woman.

I stayed up all night _____ to find a new solution to the problem.

_____, the professor is still trying to learn a new language.

Scientists say it may be five or six years （ ） this medicine is tested on human beings.

It was in the factory （ ） you worked five years ago （ ） you learned the technique.

Ted, （ ） yourself and don’t get your coat dirty again, or you will get into trouble!

Such problems （ ） air pollution and traffic jams are becoming more and more serious in some big cities.