Question

Thinking      you know        in fact you don’t know is a terrible mistake

1. A.
   that, that
2. B.
   what, what
3. C.
   that, what
4. D.
   what, that

Answer 1

C
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。