The reason why he failed is ____ he was too careless.

来源：百度知道 编辑：UC知道 时间：2024/05/20 23:30:04
A.because B.that C.for D.because of

答案是A,有异议啊

选B，主句是The reason is that
why he failed是对the reason 的修饰

对选A，其它说法：
He failed because of his carelessness
It was because of his carelessness that he failed.
The reason he failed is that he was careless.
He failed for his lack of carefulness.

应该选B
why....that 是典型的原因状语从句
怎么能选because呢

一定是选A
because 后接句子
because of 后接短语

个人感觉选A。我觉得why he failed是插入语，可有可无，that引导表语从句，很通

如果没有why, 就可以加that了吧