We look at what emails you reply to if you reply in theory that suggests this user must care about whoever sent this email or the topic they are in.

我们看看哪些邮件要回复,如果你回复了,理论上来说这表明了用户一定很关心,发件人以及邮件的主题。

哈佛公开课 - 计算机科学课程节选

If you have any questions, anything that's not clear, if you agree or disagree with something, email me or email your TF and we'll always respond.

如果你有任何问题或不明白的地方，如果你同意或反对什么观点，请给我或助教写邮件,我们一定会回复的。

哈佛公开课 - 幸福课课程节选