Question

【题目】It's not polite to keep others ________ for a long time.

A. wait B. to wait C. waiting D. waited

Answer 1

【答案】C

【解析】句意：让别人等很长时间是不礼貌的。考查动词短语。Keep sb. doing sth.：keep sb. doing sth. 意为“让某人做某事”，keep在这里有“使……处于某状态”之意，doing的动作不是主语来完成，而是由宾语sb.来完成的。结合句意和语境可知选C。