The reason he didn’t come is he was ill.A. why；thatB. that；whyC. why；becauseD. why；what

问题补充：

The reason he didn’t come is he was ill.

A. why；that

B. that；why

C. why；because

D. why；what

答案：

A. why；that

B. that；why

C. why；because

D. why；what

解析：A

解析第一空填入的词引导的是定语从句，修饰the reason，故用why；第二空是表语从句，从句中不缺少主要成分，故填that。