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

It's about what we choose to perceive, what we choose to focus on.

重要的是我们选择领悟什么，精力集中的焦点是什么。

哈佛公开课 - 幸福课课程节选