问题
选择题
The calculations, had they been done by hand, ______all practical value by the time they were finished.
A．had lost
B．would lose
C．should have lost
D．would have lost
答案
答案：D
题目分析:句意：这些计算如果用手工进行的话，那么当他们完成后将失去所有的实际价值。句中had they been done是if they had been done的省略，是对过去的虚拟，所以主句谓语应该用would have done，选D。