.Mr.Wu spent as much time as he could____ (explain) the difficulties to us.

问题描述:

.Mr.Wu spent as much time as he could____ (explain) the difficulties to us.
答案为什么是explaining

不管采不采纳,我的回答就在这里

这里有个定语从句,你要去掉不看,就是 as much time as he could是修饰time 的,你要去掉不看,就变成:

Mr. Wu spent time (doing).的结构