Question

【题目】It may be necessary to stop______in the learning process and go back to the difficult points in the lessons.

A. at intervals B. at random

C. at ease D. at length

Answer 1

【答案】A

【解析】A 考查介词短语辨析。A．at intervals 不时；B．at random随意的；C．at ease自在的；D．at length详尽地；句意：可能有必要学一定的内容再停下来回顾一下本课的难点。根据语境可知选A项。