Had I known about this computer program a huge amount of time and energy.A. would have be

问题补充：

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：

(答案→)A. would have been saved

B. had been saved

C. will be saved

D. was saved

解析：句意：如果我了解电脑的话，大量时间和精力都会省下来了。如果省略if，那么把had,should,were提前，由从句的谓语动词可以看出这是对过去的虚拟，所以主句用would have done，故选A。