In such a fierce petition, a person has to make every effort if he .
A. has succeeded
B. would succeed
C. will succeed
D. is to succeed
网友回答
A. has succeeded
B. would succeed
C. will succeed
(答案→)D. is to succeed
解析：考查be to do用法.be to do sth表示一定要做某事；必须坐某事；if引导条件状语从句，句子里使用一般现在时代替将来时。句意：在如此激烈的竞争中，如果一个人要成功，他不得不非常努力。故D正确。