题目

题型：不详难度：来源：

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

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

答案

A

解析

试题分析：考查虚拟语气，表示与过去事实相反的情况。其句型为“ if + 主语 + 动词的过去完成式，主语 +would / could / should / might + have + 动词的过去分词”。这道题里从句Had I known about this computer program是省略了if 然后倒装的="If" I had known about this computer program. 主句中a huge amount of time and energy和save是被动关系，所以用would have been saved.句意：如果我（早）知道这计算机程序，就能节约大量短时间和精力了，选A。
点评：虚拟过去时是表示与过去事实相反的假设，if 从句的谓语形式用过去完成时即had＋过去分词，主句用would / should / could / might + have +过去分词，有时可以把含有助动词、情态动词、be或have的虚拟条件句中的连词if 省去，而将had , should, were 等词提到主语之前，即用倒装结构。这题就是用的这个形式。