-The reason why he has been such a success is he had lost his money.A\B. becauseC.

问题补充：

---- The reason why he has been such a success is he had lost his money.

A\

B. because

C. that

D. what

答案：

A. \

B. because

(答案→)C. that

D. what

解析：考查表语从句：句意：他这么成功的原因是他失去了钱。当主语是reason的时候，表语从句用that连接。选C。