I know the reason___he was unhappy at the party that day.A in which B on which C for which D thatI know the reason___he was unhappy at the party that day.A in which B on which C for which D that

问题描述:

I know the reason___he was unhappy at the party that day.A in which B on which C for which D that
I know the reason___he was unhappy at the party that day.
A in which B on which C for which D that

c
for which引导原因定语从句

先行词是表示原因的名词,即reason,用why,在定语从句中充当原因状语,这时一般可以用for +which来代替:
I don’t know the reason why/ for which he did it.
.
The reason why/ for which he was afired was not clear.

选C

表原因,用FOR。

选C。相当于why.

C for which =====why为何,之所以

选C
我第一反应就是填Why
既然没why,用C答案是一样的,不过好像D理解为同位语其实没多少不对。。