the children were playing ball games ()i walked down the street.

题目

the children were playing ball games ()i walked down the street.
应该填什么呢?

答案

最好是when
如果题目是在when和while之间选择,那么一定是when了.因为while表示动作同时发生,有对比的涵义,像这样
the children were playing ball games while I was walking down the street.这样就比较好