一 When did the puter crash?
一 This morning, while I the reading materials downloaded from some websites.
A. have sorted
B. was sorting
C. am sorting
D. had sorted
网友回答
A. have sorted
B. was sorting
C. am sorting
D. had sorted
解析:首先根据时间状语this morning知道是发生过的事情,去除A、C两项,然后过去完成时的使用前提是有动作的先后顺序,然而本句指的是“今天早晨我正把从网上下载的阅读材料分类时电脑坏的。”指的是过去正在进行的动作用过去进行时,B项正确。