Because nutrition is going to be one of the big problems of your generation; how to have enough nutritious food for the population as it grows.

因为营养,对你们这一代人是个大问题,怎样才能确保食物的质和量,能够满足日益增长人口的需求

耶鲁公开课 - 生物医学工程探索课程节选

Then from 1820 to 1860, the forty years before the war, an estimated roughly two million American slaves were sold to satisfy the need of slave labor in the great cotton kingdom of the growing Southwest.

之后从1820年到1860年,这战争前的四十年间,据粗略统计有大约两百万美国奴隶被出售,以满足西南部,这个日益增长的棉业帝国对奴隶劳工的需求

耶鲁公开课 - 美国内战与重建课程节选