------ Can I help you?
-------- No, thank you. I now.
A. have been served
B. have served
C. am being served
D. am serving
网友回答
A. have been served
B. have served
(答案→)C. am being served
D. am serving
解析：考察时态语态。根据can I help you?可知，该对话发生在商店里，所以I和serve之间是被动关系，排除BD。因为前面有NO，所以我现在正在有人招待了。