Recently, American experts held a three-week training class in Ukraine about pain control.

VOA: special.2009.02.10

There's a whole vast scholarship on this and two or three of the teaching assistants in this class are real experts on it.

荣誉的学问是很深的,这门课有两三位助教,对这方面很有研究

耶鲁公开课 - 美国内战与重建课程节选

So imagine there were three people in the class, and imagine that they chose 25,5, and 60.

假如有三个人,他们分别选了25,5,60

耶鲁公开课 - 博弈论课程节选

Actually three of our graduates or current students are teaching fellows in this class.

我们有三名毕业生或在读生,是这门课的助教。

哈佛公开课 - 幸福课课程节选

The clicker does not have any identifying information on it, so you're one of you know, three-hundred people in the class or so, and your response will show up but we won't know whose-- who it came from so there's no intent to use it in any kind of way of identifying people.

表决器上没有任何的标识,所以你们要知道,课堂上大约有三百人,你们回答了我的问题,我却不知道,是谁回答的,所以绝对不会存在暴露身份的问题

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选