当你询问”他们正在干什么”时，说：请选择ABC;_.{1`3P8Z1v*m7x(^3},D:V1e7Y(h(p
A. What are they doing ?1e7Y(h(p
B. When do they go home ?1e7Y(h(p
C. Where are they going ?1e7Y(h(p