---Hi Mary, haven’t seen you for a long time.
--- Fine. What about you?
A. How are you doing?
B. What are you doing?
C. How do you do.
D. What do you do?
网友回答
(答案→)A. How are you doing?
B. What are you doing?
C. How do you do.
D. What do you do?
解析：考查交际用语：A. How are you doing?你怎么样？B. What are you doing?你在干什么？ C. How do you do.你好。回答也是：How do you do？D. What do you do?你是干什么的？句意：--你好，玛丽，很长时间没看见你了。你好吗？--很好，你呢？选A。