Question

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

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

Answer 1

A

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。