Thank you for all your hard work last week.I don't think we ___ it without you.A can manage B could have managedC could manageD can have managed这题为什么选B,为什么用虚拟语气现在完成时态啊?

问题描述:

Thank you for all your hard work last week.I don't think we ___ it without you.
A can manage
B could have managed
C could manage
D can have managed
这题为什么选B,为什么用虚拟语气现在完成时态啊?