Equipped with modern facilities, today' hospitals are quite different from _____ A. those of the past B. the past C. which of the pastD. these past答案为 A,C 为什么不行?which 不能代替前面出现的词么?which 不能代替复数复? 谢谢!
The Greek Empire constructed seven systerms to supply as much water per person as is provided in many industrial countries today. 请教老师此句as… as is 的含义。谢谢老师。