His ability is never in doubt----the question is he is prepared to work hard.AwhetherB.

问题补充：

His ability is never in doubt----the question is he is prepared to work hard.

Awhether

B. if

C. that

D. where

答案：

(答案→)A. whether

B. if

C. that

D. where

解析：考查名词性从句。句意：他的能力是不容置疑的——问题是他是否准备努力工作。if不可引导表语从句。