Mencius believed that the reason why man is different from animals isMan is good. A. thatB

问题补充：

Mencius believed that the reason why man is different from animals isMan is good.

A. that

B. what

C. why

D. whether

答案：

(答案→)A. that

B. what

C. why

D. whether

解析：考察从句连词的选择。根据句子结构可知，该句为表语从句，从句中不缺少成分，所以选择that，B在从句中充当主语或者宾语，why充当状语，whether意为是否