But that was less than they fell at the end of two thousand eight compared to a year earlier.

VOA: special.2009.05.29

You see the African-American individuals have a somewhat lower risk, although not a lot, from the white people individuals in this study, but the Mexican-Americans have elevated risk compared to the other two races.

非裔美国人患病风险相对较低,尽管在这项研究中,他们与白人之间的差异并不显著,但与这两个种族相比,墨西哥裔美国人患病风险则比较高

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

We know there is no thing called a massless rope, but most ropes have a mass, but maybe negligible compared to the two blocks you are pulling, so we'll take the idealized limit where the mass of the rope is 0.

我们都知道无质量的绳子是不存在的,是绳子就有质量,但是相比于这两个物体就可以忽略不计了,所以我们有了这个理想的条件,即绳子的质量都是 0

耶鲁公开课 - 基础物理课程节选