I suppose people's tempers are getting a little bit frayed, and hopefully we won't see more of this but there seems every chance that we might."

VOA: standard.2010.06.22

This is a course, a version of which I've taught almost every year for the last twenty years and it evolves a little bit every year.

诚如你们所见,在过去二十年中,几乎每年我都要讲授这门课,这门课程每年都会与时俱进

耶鲁公开课 - 生物医学工程探索课程节选