—Thelightinhisofficeisstillon.Doyouknow

问题详情：

—The light in his office is still on. Do you know _____________?

               —In order to prepare for the coming exams.

               A. if he works hard                                           

               B. when he will stop working

               C. why is he so busy    

               D. why he stays up so late

【回答】

D

知识点：宾语从句

题型：选择题