Question

Had we assisted him , he ________ us a hand ________ today .

Answer 1

C

考查虚拟语气，had we assisted him="If" we had assisted him是虚拟条件句，主句是和现在相反，用could do，第二空in exchange，做为交换，句意是：如果我们帮助他，今天他就会帮我们做为交换了。选C。