题干
-----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.
-----Yes, I know him very well. He _____ in Africa with wild animals for eight years.
A：is working
B：had worked
C：worked
D：has been working
答案(点此获取答案解析）
C
