一Kurt stayed up for three days preparing for the exam and finally fell ill．
一So     ．I dare say if you overworked for several days in a row.

So clearly            English that he can always make himself understood.

I could have helped the old man ______ yesterday morning.

Two years ago I broke my arm ____ football.

The computer was used in teaching. As a result，not only _____，but students became more interested in the lessons.

Not until he had left his friend _______ how important friendship was for him.

When _________a career, you should consider all the aspects of a job.

Only when _____ in the afternoon _____ able to leave.

Every evening after dinner, if not      from work, I will spend some time walking my dog.

China Business Daily reported the 60% discounts on some Beijing-shanghai flights have now slipped back to 20% _______ one day in advance.