The reason he was late was he hardly knew the way to the meeting place.A. what; becauseB.

问题补充：

The reason he was late was he hardly knew the way to the meeting place.

A. what; because

B. for which; that

C. that; because of

D. why; because of

答案：

A. what; because

(答案→)B. for which; that

C. that; because of

D. why; because of

解析：考查定语从句及名词性从句。第一空考查定语从句，先行词为the reason，在从句中作原因状语，故用关系词why或for which；第二空考查表语从句，在从句中不作成分，选B。