问题补充：
—Are you going to the concert tonight?
—I should have told you that I won’t, ?
A. haven’t you
B. shouldn’t you
C. are you
D. will you
答案：
A. haven’t you
B. shouldn’t you
(答案→)C. are you
D. will you
解析：第一句问：Are you going to the concert tonight? 第二句说他本应告诉对方他不去，但是没有。第三句再次问对方要不要去。应理解为：Are you going to the concert tonight?此处为省略后部分所以选C
