问题补充：
I don’t think he could have done such a stupid thing last night，?
A. do I
B. could he
C. did he
D. has he
答案：
A. do I
B. could he
(答案→)C. did he
D. has he
解析：陈述部分为主从句的复合句，且主句的主语和谓语是I think，I suppose，I believe，I imagine等结构时，附加疑问句的人称和数往往要与从句的人称和数保持一致，并要注意否定的转移。
