Thinkingyou know in fact you don’t know is a terrible mistake.A. that thatB. what whatC.

问题补充：

Thinkingyou know in fact you don’t know is a terrible mistake.

A. that, that

B. what, what

C. that, what

D. what, that

答案：

A. that, that

B. what, what

(答案→)C. that, what

D. what, that

解析：考查名词性从句。句中that引导宾语从句，在从句中作主语；what引导宾语从句，在从句中作宾语，故选C。