一This returned Chinese scholar has become one of the top experts in this field.
—Yes,I know him very well , he in Africa with animals for ten years.
A. has worked B、had worked C.has been working D.worked
一This returned Chinese scholar has become one of the top experts in this field.
—Yes,I know him very well , he in Africa with animals for ten years.
A. has worked B、had worked C.has been working D.worked
D