The millions of calculations involved,had they been done by hand,__ all practical value by the time

题目

The millions of calculations involved,had they been done by hand,__ all practical value by the time theyhave finished.
A had lost
B would lose
C would have lost
D should have lost
请解释下选择哪个,其他的为什么不行

答案

选C吧,这是一句虚拟语气的句子,Had they been done by hand 是对过去事实的假设的一种特殊说法,省略if,had 倒装的句型,后面应该用should 或would have done.但是从语义上讲,应该表示推测,而不是应该做而实际没有做,...