The institutions and the ideas therefore, that provide for freedom and improvement in the material conditions of life, cannot take root and flourish without an understanding of how they came about and what challenges they have had to surmount.

故此,这些机制和理念,为物质生活条件的自由和改善,提供了基础,但在不知道其根源且,无法预料的挑战之前,机制和理念是不可能扎根的

耶鲁公开课 - 古希腊历史简介课程节选

I take the difference in the x-values, squared, the difference in the y-values, squared, add them up, take the square root of that.

好，是毕达哥拉斯定力对不对？,求x坐标的差，然后平方，求y坐标的差，然后平方，把它们加起来，开平方。

麻省理工公开课 - 计算机科学及编程导论课程节选