They must have finished the work by the end of last month, ______? A．hadn’t they

题型：不详难度：来源：

They must have finished the work by the end of last month, ______?

A．hadn’t they

B．mustn’t they

C．haven’t they

D．didn’t they

答案

A

解析

试题分析：句意：他们上个月的月底一定已经完成了这项工作，不是吗？当情态动词must表推测时，其反义疑问句要根据实际情况来判断，本题的时间状语是by the end of last month,应与过去完成时连用，还原一下本题应为：They had finished the work by the end of last month.故选C。