–I as the manager in this company. –May I know since when?A. workedB. had workedC. have w

问题补充：

–I as the manager in this company.

–May I know since when?

A. worked

B. had worked

C. have worked

D. am working

答案：

A. worked

B. had worked

(答案→)C. have worked

D. am working

解析：考查时态。本题的关键词是since when.根据since when,可知使用完成时。