题目内容：

The reason ___ he is late 什么从句
The reason ___ he is late is that there is a break-down on the railway
A.why
B.because
C.that
选A,为什么,这是一什么从句
why引导的是什么从句

优质解答

A.why
这是定语从句
The reason 是先行词 表原因 用why