问题补充：
.－Would you mind my opening the window for some fresh air?
－
A. Why not?
B. Yes, help yourself.
C. Go ahead, please.
D. Yes, but you’d better not.
答案：
A. Why not?
B. Yes, help yourself.
(答案→)C. Go ahead, please.
D. Yes, but you’d better not.
解析：考查交际用语。Why not? 为什么不呢？Yes, help yourself.是的，请随便用，Go ahead, please. 请吧，Yes, but you’d better not.是的，你最好不要，根据问句你介意我打开窗户让新鲜空气进来吗，从四个选项中可看出C请打开吧，符合题意，故选C。
