So, whether or not the email is addressed specifically to you in like the two field or if maybe you were BCC'd or it's a big email list of which you're just part, that could signify that this is in fact useful for you.

所以，不管这个邮件是不是,单独发给你的,或者这个邮件有一个大的邮件列表,而你正在其中，其实这也暗示了,这个邮件对你是有用的。

哈佛公开课 - 计算机科学课程节选

Conversely, if you get an answer and it doesn't seem to make sense, then you've got to go back and ask, am I violating some of the assumptions, and here you will find the assumption that the particle had that acceleration a is true as long it's freely falling under gravity but not when you hit the ground.

反过来说,如果你得到一个结果,发现似乎是错的,那么你就应该回过头来问问自己,我是不是违反某些前提了,这个模型中,你就发现,只要质点在重力作用下自由下落,质点具有加速度a的前提是正确的,但是落地后就不成立了

耶鲁公开课 - 基础物理课程节选