Well, it apparently is not so obvious because in the Americas, before Columbus came-- " pre-Columbian America-- there were no wheeled vehicles anywhere.

好吧，从表面上看这似乎不那么显而易见,因为在美洲大陆，在哥伦布到来之前-,在“前哥伦比亚美洲-,根本没有任何轮式交通工具存在。

耶鲁公开课 - 金融市场课程节选

Smallpox affected world history hundreds of years ago, and it was a disease that was common in Europe, but not common in the Americas until the Americas were colonized.

天花影响了几个世纪前的历史,这种病在欧洲很常见,但在美国不多见,直到美国成为殖民地

耶鲁公开课 - 生物医学工程探索课程节选

Every major African-American writer of the twentieth century, at least until your lifetime, when black writers in this country are now born and raised in cities, in California or Minneapolis or New York or and in modern Atlanta and they come from all the same places other Americas do.

二十世纪的每一个主流的非裔美籍作家,至少到你们这一辈子所能接触到的,这个国家的黑人作家,现在,都生于城市长于城市,在加州,明尼阿波利斯市或者纽约市,或者现代亚特兰大,他们从和其他美国人来自同一个地方

耶鲁公开课 - 美国内战与重建课程节选