The reason he hasn’t come is .A. that; because he is illB. that; because of his illnessC.

问题补充：

The reason he hasn’t come is .

A. that; because he is ill

B. that; because of his illness

C. why; for he is ill

D. why; that he is ill

答案：

A. that; because he is ill

B. that; because of his illness

C. why; for he is ill

(答案→)D. why; that he is ill

解析： he hasn’t come是定语从句，先行词The reason在定从中作原因状语，用why引导；is后是表语从句，不能用for引导，所以选D。