I never doubt he was dedicated to our firm.A. that B. whetherC. if D. what

问题补充：

I never doubt he was dedicated to our firm.

A. that

B. whether

C. if

D. what

答案：

(答案→)A. that

B. whether

C. if

D. what

解析：考查doubt用于否定句中，常用that，用于肯定句时，常用whether，句意：我从来不怀疑他专心致力于我们的公司。故选A。