If you have some plain text, some message that you want to send, well, you can encrypt it or you can scramble it using a key, a secret key, which might be a physical machine like the Enigma 13 or it might be a number like 13.

如果你有没有加密的文本，你想要寄送的一些消息,你就可以加密它,或者你可以用一个密钥使其变得混乱，那就像一个英格玛的物理装置,或者他就是一个数字。

哈佛公开课 - 计算机科学课程节选

There can be fighting without war but there can be no war without an organization that makes it something more than just plain fighting.

就算没有战争,争斗同样可以存在,但没有组织,便没有战争,组织使的战争的意义超出了单纯的争斗

耶鲁公开课 - 古希腊历史简介课程节选