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

—In order to prepare for tomorrow’s meeting.

A．if he works hard

B．why he stays up so late

C．that he is so busy

D．when he will stop working

烟支布带纹形成斜纹皱＞3条，且总长度＞（）烟支长为烟支不合格。

A.1/2

B.1/3

C.1/4

D.1/5