Question

【题目】What was Jim doing when his sister______in?

A. cameB. was comingC. comeD. to come

Answer 1

【答案】B

【解析】

句意：吉姆在他姐姐进来时，正在做什么？came是一般过去时的形式，was coming是过去进行时的形式，come是一般现在时的形式，to come是动词不定式的形式。根据句型Sb was doing sth when sb did sth“当某人做某事时，某人正在做某事”，故when引导的时间状语从句用一般过去时，故选B。