--Hello is Mr. David in? ---.A. Who's callingB. Who are youC. I’m DavidD. Are you Lucy?

问题补充：

--Hello, is Mr. David in? ---.

A. Whos calling

B. Who are you

C. I’m David

D. Are you Lucy?

答案：

(答案→)A. Whos calling

B. Who are you

C. I’m David

D. Are you Lucy?

解析：这是电话用语，Whos calling/Who is that?意思是：你是哪一位？