but for应该加什么时态?But for my classmates' help,I ____ the work in time DA) could not finish B) would not have finished

问题描述:

but for应该加什么时态?
But for my classmates' help,I ____ the work in time D
A) could not finish B) would not have finished

答案B
这是一个虚拟语气.与过去事实相反.用would 来说明

B.
But for = If not for = 如果不是因为
如果不是因为同学的帮助,我根本不可能完成了功课