—How did your mathematics exam go？—I thought I           ，but in fact I fell beh

题型：不详难度：来源：

—How did your mathematics exam go？
—I thought I           ，but in fact I fell behind in the class.

A．should have been the top 10	B．could have been the top 10
C．may have been the top 10	D．need have been the top 10

答案

B

解析

考查虚拟语气。句意：你的数学考试怎么样？——我认为我能进前十名，但是实际上我在班里名落孙山。表示对过去事情的假设，意思是本来能够做某事而没有做，用“could+have+done”，故选B。