I should not have laughed if I________yo

问题选择题

I should not have laughed if I________you were serious.

A．thought	B．would think
C．had thought	D．have thought

答案

解析　考查虚拟语气。句意为：如果我当时想到你是认真的，我就不会笑了。由句意知，此句是与过去事实相反的虚拟语气，故从句结构为had done。