There is a new problem________in the popularity of private cars that road conditions need improving.

Those children don’t have to ____________ learn , for they always work hard voluntarily.

What he wants is _______ his mother as quickly as he can; and what he must do is ____ to the hospital at once．

In the reading-room, we found Winifred ____at a desk, with her attention _____on a novel．

___ to give up smoking, he threw away his _____ cigarettes．

The managers discussed the plan that they would like to see ______ the next year.

__________ his project, the boy had to stay up late.

She ________ to catch the early train，but she didn’t get up in time.

Fortunately，he escaped ________in the accident.

When he looked up，he suddenly found himself ______by a group of teenagers，____looked at him anxiously.