The reason he 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
网友回答
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。