Now, we're going to go back to Roger Ibbotson at the School of Management. He did some path breaking work in terms of describing capital markets returns over reasonably long periods of time.

先讲回到管理学院的罗格·伊博森,所进行的开创性研究,描述了在相当长的时期内,资本市场的收益情况

耶鲁公开课 - 金融市场课程节选

Even if you imagine that slaves did the work, you would need a hell of a lot of them, over a long period of time, and you had to feed them, if nothing else.

哪怕你想象这个墓穴是由奴隶所建造,那也一定是成千上万的奴隶,经过了相当长的时间工作,至少,你还要养活这些奴隶

耶鲁公开课 - 古希腊历史简介课程节选

Soil was being eroded and wasted along the Eastern seaboard, and they were using up the great soils of the Mississippi Valley and over time that slave system just somehow wasn't going to work out.

东部沿海地区的土地因被侵蚀而荒废掉,密西西比河谷地区的土地资源即将被耗尽,但就在这种情况下,奴隶制依然能维持南方的经济

耶鲁公开课 - 美国内战与重建课程节选