So Roman slavery and the freedom of that was actually one way that a few people in the Ancient World recognized some kind of social mobility, which was very rare in the Roman Empire.

所以罗马奴隶制以及奴隶释放制,被古代部分人认为是,某种社会阶级流动，在罗马帝国很少见。

耶鲁公开课 - 新约课程节选

You reach Egypt, and of course, Egypt is one of the great empires of antiquity going back into, perhaps, certainly into the fourth millennium, possibly into the fifth, by no means as powerful as it used to be, far from it.

你来到了埃及的领地,当然,埃及是古代最伟大的帝国之一,它有近四千年,甚至五千年的历史,毫无疑问,古埃及达到了空前绝后的强大

耶鲁公开课 - 古希腊历史简介课程节选