You’d better put a cloth over the salad to ______ the flies for the sake of health.

Pip agreed to give some piano lessons to the girl_______ for a generous gift from her mother.

As there was no spare bedroom, Susan had to ______ her friend for a night in the sitting-room.

. China’s quick reaction and the public efforts have ________ the rapid restoration（恢复）and reconstruction of Wenchuan.

The book, which sells well, is         on a true story.