Question

The day ____I have been looking forward to will certainly come

A,in which B,when C,which D,where
怎么选、为什么

Answer 1

C
这是个定语从句的问题
look forward to doing/sth.
所以这个从句里不缺介词
直接用which代the day就可以了

追问

为什么不用when呢？

追答

我给你举个例子吧
where和when都是关系副词，which是关系代词，in which可以理解为where/when
用where举例：
This is the house where I live.
This is the house which I live in.=This is the house in which I live.
这里面就是有没有in这个介词的差别
有了where就不加in,which就要加，也可以说in which=where

when和where的用法是一样的
原句中，look forward to sth.不缺介词to，所以用which

Answer 2

选择C
looking forward to 要接宾语 所以只能选which
这是一个定语从句。which I have been looking forward to 修饰限定the day

Answer 3

C
这里的which做的是look forward to 的宾语，如果用when，就没有宾语了，句子就不完整了

Answer 4

The day __C,which __I have been looking forward to will certainly come.主语是一个定语从句。在从句中，由于从句里缺少宾语，所以只能用which和that来充当。从句主语I ，从句谓语have been looking forward to
大句子机构是，主语The day __C,which __I have been looking forward to ，谓语will certainly come。