He says this advice is for professional writers as well as school children writing papers.

VOA: special.2009.10.12

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

I don't know how much you've seen, but quite often the way you learned physics earlier on in high school is probably different from the way professional physicists think about it.

我不知道你们对物理有多少了解,但你们以前在高中所学的物理知识,和资深物理学家们的看法,常常是很不一样的

耶鲁公开课 - 基础物理课程节选

Two years later, he decided to leave school and become a professional musician.

VOA: special.2009.05.03

Professional cooks around the country will adopt a local school.

VOA: special.2010.06.07