Question

The reason _____ he explained is ___ she was ill.

A．that , that

B．which , that

C．why,because

D．why, that

Answer 1

A

考查定语从句和表语从句。第一空是定语从句，先行词为The reason，从句he explained后缺少宾语，所以用关系代词which/that，第二空是表语从句，that 无词义，起引导作用。所以选A。