Thecleverboymadeaholeinthewall,_? ,简单的描述是The clever boy made a hole in the wall, _______ he could see _____ was going on inside house.A. which; what B. through which; what . through that; what D. what; that 【答案】 【解析】,答案是选B
 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