—How long have you been in this office?—Just a few minutes.My cousins here together with

问题补充：

—How long have you been in this office?

—Just a few minutes.My cousins here together with me.

A. have walked

B. had walked

C. walked

D. have been walking

答案：

A. have walked

B. had walked

(答案→)C. walked

D. have been walking

解析：C 考察动词时态在交际英语中的应用。根据here together with me可知，我表弟来的行为发生在过去某一时间。因此选择一般过去时。