She the opportunity，but unfortunately she just let it go.
A. should have taken
B. must have taken
C. needn't have taken
D. can't have taken
网友回答
(答案→)A. should have taken
B. must have taken
C. needn't have taken
D. can't have taken
解析：A 考查情态动词＋have done。句意：她本该抓住这个机会，但是不幸的是，她让机会溜走了。should have done本该做某事(而事实上并没有做)，表示对过去动作的虚拟。must have done一定做了(表示推测)；needn't have done本不必做某事(而事实上做了某事)；can't have done肯定没做某事(表示推测)。根据句意选A。