—This returned Chinese scholar has become one of the top experts in this field .

    —Yes , I know him very well . He  ____in Africa with wild animals for eight years .

   A．has worked         B．had worked       C．worked     D．has been working

----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 eight years.

A、has worke B、had worked C、worked D、has been working

—This returned Chinese scholar has become one of the top experts in this field .

—Yes , I know him very well . He         in Africa with wild animals for eight years .

A．has worked                B．had worked         C．worked               D．has been working

—This returned Chinese scholar has become one of the top experts in this field.

    —Yes , I know him very well. He ___________ in Africa with wild animals for eight years.

A.has worked           B.had worked        C.worked                   D.has been working

---This returned Chinese scholar has become one of the top experts in this field.

---Yes , I know him very well. He ______ in Africa with wild animals for eight years.

1. A.
   has worked
2. B.
   had worked
3. C.
   worked
4. D.
   has been working