Remember the way dictionary works, this is the key. Is the key of a value.

记住这个字典的工作原理，这是关键，它是值的关键。

麻省理工公开课 - 计算机科学及编程导论课程节选

Again, each of them seems to represent, in a superior way, the key components of the human soul, the appetitive, the war-like or spirited, and the rational.

每一位角色，似乎都代表着，较优秀的人类灵魂的关键构成要素，欲望，战士精神，以及理性。

耶鲁公开课 - 政治哲学导论课程节选