当你询问”他们正在干什么”时，说： 请选择CBA)Y;@*?'s/n'j-I,l7h:e;?5S4A4U
A. What are they doing ?;?5S4A4U
B. When do they go home ?;?5S4A4U
C. Where are they going ?;?5S4A4U