The reason ——he didn′t come was ——he was ill第一个空是why为什么不是that 第二个空为什么用that 呢
问题描述：
The reason ——he didn′t come was ——he was ill
第一个空是why为什么不是that 第二个空为什么用that 呢
答
固定用法 the reason why
后面那个是 从句 用that
答
The reason why是固定搭配 第二个空用that 做定语从句的表语
答
the reason——he didn't come 是定语从句,WHY做先行词.
the reason ...was ____ he was ill 是表语从句,用that引导.