问题补充：
---Can I speak to Tom, please? ---Yes. .
A. I am Tom
B. Tom is here
C. That’s Tom. Who are you?
D. This is Tom speaking
答案：
A. I am Tom
B. Tom is here
C. That’s Tom. Who are you?
(答案→)D. This is Tom speaking
解析：这是电话用语, 回电话的是本人时,用This is XXX (speaking), who’s that?
