the only letter which I have received is still on the shelf .

问题描述:

the only letter which I have received is still on the shelf .
the only letter which I have received is still on the shelf .
选择错误部分:A:which B:have received C:is D:on the shelf
并修改!

A
the only letter that I have received is still on the shelf .why?当修饰词是only这样的限定词的时候,定语从句的引导词要用that