One of the reasons he explained to us was he had dreamt of doing so.
A. why; that
B. that; that
C. why; because
D. that; because
网友回答
A. why; that
(答案→)B. that; that
C. why; because
D. that; because
解析：本题修饰短语one of the reasons是一个定语从句，现行词是物，可用关系词that，本题的后半句是一个宾语从句可用that来连接，故本题选B。