As is known to all Yang Liwei has become a space hero is we have expected.A. what;thatB.

问题补充：

As is known to all, Yang Liwei has become a space hero is we have expected.

A. what;that

B. what;which

C. that;what

D. that;which 

答案：

A. what;that

B. what;which

(答案→)C. that;what

D. that;which 

解析：前空,that引导一个一般陈述性的主语从句,what引导一个从句。