Question

Knowing _____, as a matter of fact, one shouldn’t know is a terrible thing．

A．whether

B．that

C．what

D．when

Answer 1

C

考查宾语从句，what为连接词作one shouldn’t know 的宾语，as a matter of fact,为插入语。句意：事实上一个人知道了不该知道的事情是非常可怕的。