the reason he died so quickly is that he didn't
2个回答

对不起我刚才忽略了一个问题

都可以的

因为本句子是一个同位语从句

他死得这么快的原因是不停医生劝告

reason后面的he died so quickly 是修饰reason的同位语 用why that都可以

但有时候需要注意定语从句和同位语从句的区别

可以给你举个例子

他迟到的原因是他妈妈病了

The reason why he is late is that his mother is ill.同位语从句

他给我们的理由是不可信的

The reason that he gave us is unbelievable.定语从句