题目

题型：不详难度：来源：

Tom _____ full marks, but he was too careless and made a spelling mistake.

A．could gain

B．could have gained

C．must have gained

D．must gain

答案

B

解析

试题分析：句意：汤姆本可以得到满分的，但是他太粗心了，犯了一个拼写错误。从but he was too careless and made a spelling mistake.可知是说明的过去的事情，排除AD，could have done“本可以做而没有做”是虚拟语气，符合句意，must have done过去一定做了，不符合句意，所以选B。