By 1860 there were approximately 4,000,000 slaves in the United States, the second largest slave society slave population--in the world.

截至1860年,美国大约有,四百万的奴隶,也因此使之成为了,世界历史上的第二大奴隶社会

耶鲁公开课 - 美国内战与重建课程节选

We live in a world in which almost 50% of the population is under 35.

我们生活在这样一个世界,几乎50%的人口的年龄不到35岁。

普林斯顿公开课 - 人性课程节选

First, to measure what a whole population eats, how in the world could you know that?

首先,去测量人群总体吃什么,到底该如何做

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

I want to say a little bit about the cost of vaccines because this is a part of what makes it difficult to accomplish what's usually our goal in a vaccine development, which is deliver the vaccine to every population in the world.

我想谈谈关于疫苗的成本,因为这是令我们的疫苗发展目标,无法得以实现的困难之一,这个目标就是将疫苗送至世界上每一个人

耶鲁公开课 - 生物医学工程探索课程节选