But first,we talk to some Americans who have retired from their professional lives but still work hard to help others.

VOA: special.2010.07.16

We're trying to run a school here that has some professional standards.

我们试图运行一个学校,里面有些专业的标准。

麻省理工公开课 - 固态化学导论课程节选

We're trying to teach you some chemistry, but I'm also trying to teach you how to transform into a standalone professional.

我们会教化学，但是我也会教你们如何成为,一个独立的专业人士。

麻省理工公开课 - 固态化学导论课程节选