Bacterial cells are small, one to two microns in diameter and this shows a picture of a common bacterium called E. Coli.

细菌细胞很小,直径只有一到两个微米,这张图片是一种常见细菌,大肠杆菌

耶鲁公开课 - 生物医学工程探索课程节选

There are still some active smallpox virus specimens kept in the world, and there are two sources of small--two places where smallpox is stored now.

世界上仍有地方保存着,一些具有活性的天花病毒样本,有两个地方还储存着天花病毒样本

耶鲁公开课 - 生物医学工程探索课程节选

it was a small seminar-- I had groups of students proposing two novels actually for the end of the syllabus, and the exercise gets you to think very hard about what you think this period is all about.

是以小组研讨课的方式进行-,几组学生提出两本小说,作为教学大纲上最后一本读物，这样做的练习的目的是,让你去思考这个时期的意义。

耶鲁公开课 - 1945年后的美国小说课程节选

Therefore, you will produce enough profit to make it possible, so that these small farms, you should imagine as typically having one or two slaves playing a part in this experience.

因此,需要创造足够的利润,才能使每个只有,一两个奴隶的小农场,能够在那段时间得以维系下去

耶鲁公开课 - 古希腊历史简介课程节选

There are two points that we talked about -the hypothetical points that came out of the small group discussions that I suggested we might think about at the beginning of this talk.

我们已经讨论了两点,其中假设性的一点,在课程刚开始时,我提出划分小组进行讨论时,就已经讲到了

耶鲁公开课 - 金融市场课程节选

So, just, if you can take what I'm saying for a moment right now that in fact this should collapse in this very small time frame, we have to see that there's a problem with one of these two things, either the Coulomb force law or Newtonian mechanics. So, what do you guys think is probably the issue here?

所以如果你们考虑我,开始说的这个塌缩应该,发生在很短的时间里，那么这两者之一就有问题,要么是库伦定律,要么是牛顿力学,你们觉得应该是哪个的问题？

麻省理工公开课 - 化学原理课程节选

Every time you hit the enter key in Notepad or in Microsoft Word, small white lie, those two characters end up getting saved in the file.

在Notepad或Microsoft里，每当你敲回车键时，没有恶意哈，这两个字符,都会保存在文档里。

哈佛公开课 - 计算机科学课程节选