问题补充：
．—
—Sorry, I don’t know．
A. Have you seen Mr．Smith?
B. Where has Mr．Smith gone?
C. How about Mr．Smith?
D. Hello, Mr．Smith．
答案：
A. Have you seen Mr．Smith?
(答案→)B. Where has Mr．Smith gone?
C. How about Mr．Smith?
D. Hello, Mr．Smith．
解析：情景对话题。A．Have you seen Mr．Smith? 你见过史密斯先生吗？ B．Where has Mr．Smith gone?史密斯先生先生去哪了C．How about Mr．Smith? 史密斯先生怎么样 D．Hello, Mr．Smith． 喂，史密斯先生
句意：斯密斯先生去哪了？对不起，不知道。 根据语境选B
