问题补充：
---Excuse me, sir, is this seat taken?
---.
A. Sure, you may take it
B. Certainly. Help yourself
C. No. I don’t think so
D. No. I don’t hope so
答案：
A. Sure, you may take it
B. Certainly. Help yourself
(答案→)C. No. I don’t think so
D. No. I don’t hope so
解析：可联系答.案.网客服索取。
