The result of the survey showssuccessful people have in common isthey all have confidence.

问题补充：

The result of the survey showssuccessful people have in common isthey all have confidence.

A. whether; that

B. what; that

C. what; why

D. which; that

答案：

A. whether; that

(答案→)B. what; that

C. what; why

D. which; that

解析：考查名词性从句，第一空填what，引导宾语从句，在宾语从句中what做have的宾语。Have sth in common是“和…有共同之处”，第二空填that，引导表语从句，that指起到连接作用，不做成分，句意是：调查的结果显示，成功的人共有的东西是他们都很自信。选B。