Isn't the distinction between friend and enemy ? based on a kind of knowledge, on a perception of ? who is your friend and who is your enemy?

朋友与敌人之间的差别,不是根据知识吗，或是你对,谁是朋友或敌人的看法？

耶鲁公开课 - 政治哲学导论课程节选

If you'd like to ask who your friend's best friend is,

如果你想知道你朋友认为的最好的朋友是谁，

Who 课堂 - SpeakingMax英语口语达人

Ask yourself who is your best friend at Yale.

问一下自己，你们在耶鲁最好的朋友是谁。

耶鲁公开课 - 心理学导论课程节选

Who is your best friend?

你最好的朋友是谁？

Who 课堂 - SpeakingMax英语口语达人