问题描述： I dont know the reason why he was late 为什么不用that 1个回答 分类：英语 2014-11-10 问题解答： 我来补答 I don't know the reason why he was late.我不清楚他为迟到的原因.解析：why he was late 为定语从句 ,修饰限制前面的中心语 reasonwhy 是定语从句里的原因状语 展开全文阅读
