Question

英语达人进。The clever boy made a hole in the wall，__he could see what was going inside the house

A on which B at which Cin which Dthrough which 怎么做完全不理解

Answer 1

D
可把这句从句改为两个分句：The clever boy made a hole in the wall.
He could see what was going inside the house through the hole.
现在这句从句合并两句话，which就相当于第二句的 the hole，那么就是through which
如果有不懂欢迎继续提~~

Answer 2

d 透过这个 一个聪明的男孩在墙上挖了个洞，透过这个，他就能够看到房子里发生了什么

Answer 3

throught which, which 引导一个非限定性定语从句,which 代替 a hole；
what was going on... what 引导一个宾语从句，在屋外发生了什么