【问】 You must re frain to spit in the street.

你必须避免在街上吐痰。

这个句子据说有误，请分析。

【答】 refrain本身是个不及物动词，必须与介词from连用。因此，上面的句子应改为：

You must refrain from spitting in the street.

类例：

Please refrain from smoking during the performance. (LDCE)

演出时请不要吸烟。

请做下面的英语试题：

Would you please____from smoking while the lecture is in progress?

A. avoid B. refrain

C. stop D. keep yourself(Nelson. 500A)