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

I want to see the end of the internal combustion engine applied to personal mobility.

我想见证内燃机不在应用于,人们出行生活。

麻省理工公开课 - 固态化学导论课程节选

But rooted in free labor ideology is, among other ideas, this notion of mobility.

但是自由劳动意识体系起源于,在众多观点中,人口流动的概念

耶鲁公开课 - 美国内战与重建课程节选

It's going to change the very idea of mobility.

它将改变人口流动这一说法

耶鲁公开课 - 美国内战与重建课程节选