Question

that is the day ( ) I'll never forget. A.which B.on which c. in which D.when

Answer 1

that is the day ( ) I'll never forget. A.which B.on which c. in which D.when
选A
这是一句定语从句，先行词【day】在从句中作宾语
I'll never forget 【the day】所以用which
有不会的可以再问我

Answer 2

定语从句，本句用that which均可，但是前面有一个that，所以后面用which

Answer 3

A. which
forget可以直接跟“the day”，所以这里用which就行了。