At most American colleges, undergraduate students choose one area of study, like English or biology, and focus on it for all four years of their education.

VOA: standard.2010.05.12

The more interesting four are the ones I'm going to focus on in this lecture because they're a bit more subtle and they may be things that you've never heard of before.

四个有趣因素,才是我要讲的重点,因为它们更加微妙,由此发生的事情，你不曾听闻过。

耶鲁公开课 - 心理学导论课程节选