问题
选择题
(2013·高考江苏卷)I should not have laughed if I________ you were serious.
A．thought
B．would think
C．had thought
D．have thought
答案
答案：C
选C。句意：“如果我当时想到你是认真的，我就不会笑了。”根据主句中should not have laughed 可知，本句所讲的与过去事实相反。if引导非真实条件句表示与过去事实相反时，从句谓语结构为had done。