HadIknownaboutthiscomputerprogram,ahugeamountoftimeande...

问题详情：

Had I known about this computer program, a huge amount of time and energy ________.

 A. would have been saved  B. had been saved    C. must be saved       D. was saved

【回答】

A

知识点：虚拟语气与情态动词

题型：选择题