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

— Maybe he has to study for a test.

A．if he works hard

B．who he is studying with

C．what he is busy with

D．when he will stop working

香附、乌药、木香共同的功效是（）

A.降逆止呃

B.疏肝解郁

C.行气止痛

D.行气导滞

E.消肿散结