It was so nice of you to e to our aid. I don’t think we it without you.
A. can manage
B. could have managed
C. must have managed
D. could manage
网友回答
A. can manage
(答案→)B. could have managed
C. must have managed
D. could manage
解析：句意：你能来帮助我们真是太好了，我认为没有你我们不可能已经完成它。Could have done:可能已经做了某事 must have done:一定已经做了某事 根据句意可知表达一种对过去情况进行虚拟，故用could/would/might/should+have done。故选B。