Equipped with modern facilities,today's libraries differ greatly from ( ).

问题描述:

Equipped with modern facilities,today's libraries differ greatly from ( ).
为什么不选 the past 或者the past one

the past表示过去,而题目的意思是说与过去的图书馆不同,而不是与过去不同;the past one是特指,而这里是泛指过去的图书馆,所以以上两个都不行.应该是past ones