问题补充：
In such a fierce competition, a person has to make every effort if he .
A. has succeeded
B. is to succeed
C. would succeed
D. will succeed
答案：
A. has succeeded
(答案→)B. is to succeed
C. would succeed
D. will succeed
解析：考查时态。if he is to succeed的意思是“如果他一定要成功”，这是一种常用结构，全句“在这样激烈的竞争中，一个人如果一定要成功，就得全力以赴”。
