We begin to know more about three or four hundred years down the road, when there appear buildings and settlements in the world later inhabited by the Greeks, as we know, to which we give the name Mycenaean.

约三四百年之后当这块希腊人聚居的土地,出现了建筑和住宅群,我们才开始对它有了更多的了解,并将其命名为今天人人皆知的"迈锡尼文明"

耶鲁公开课 - 古希腊历史简介课程节选

You all know that when you do dy/dx, you're not supposed to cancel that d.

你们都知道 当你算dy/dx时,你不能把d约掉

耶鲁公开课 - 基础物理课程节选