Question

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

Answer 1

A

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。