The reason he was late was he missed the train.
A. that; why
B. that; that
C. why; that
D. why; why
网友回答
A. that; why
B. that; that
(答案→)C. why; that
D. why; why
解析：考查定语和表语从句，第一空填why，引导定语从句，修饰the reason，定语从句中缺少原因状语，第二空是that，因为主语是the reason时，表语从句用that引导，句意是：他迟到的原因是他错过了火车。选C。