The reasonhe made such kind of mistakes is that he has had no experience of this kind of

问题补充：

The reasonhe made such kind of mistakes is that he has had no experience of this kind of job.

A. whether; previous

B. which; before

C. why; previous

D. that; before

答案：

A. whether; previous

B. which; before

(答案→)C. why; previous

D. that; before

解析：考查定语从句及形容词。句中先行词为the reason，在定语从句中作原因状语，故用关系副词why；previous为“以前的”，根据句意选C。