【题目】Had I known about this computer program, a huge amount of time and energy__A__.
A. would have been saved B. had been saved
C. will be saved D. was saved
在线课程【答案】A
【解析】
根据句子的倒装特征判断此处是省略了if的虚拟语气, 原形是：If I had known about this computer program, a huge amount of time and energy .故选择A。句意为：如果我早知道这个电脑程序, 就可以节省大量的时间和精力了。