Mr. Mao whoas a construction worker for over 8 years is now a distinguished lawyer in th

问题补充：

Mr. Mao, whoas a construction worker for over 8 years, is now a distinguished lawyer in this country.

A. has worked

B. had worked

C. worked

D. has been working

答案：

A. has worked

B. had worked

(答案→)C. worked

D. has been working

解析：句意：毛先生，曾经作为一名建筑工人工作了8年，现在是这个国家著名的律师。表示发生在过去的事情，故用一般过去时，选C。