Joy as a language teacher in China for two years before she went back to London.A. had wo

问题补充：

Joy as a language teacher in China for two years before she went back to London.

A. had worked

B. was working

C. worked

D. has worked

答案：

(答案→)A. had worked

B. was working

C. worked

D. has worked

解析：句意：乔伊去伦敦之前，已经在中国做了两年的语言老师了。作为语言老师这个动作发生在went back回去之前，所以用过去完成时，故选A