The number that you choose to rotate your letters by is what we call in cryptography, a key.

你选择的旋转字母的数量,就是所谓的加密学，一个密钥。

哈佛公开课 - 计算机科学课程节选

Your birthday and social security number is what you look up.

你的生日和社保号码才是你应该查的

耶鲁公开课 - 基础物理课程节选

You can call your broker and say, I'd like to short stock number one and what the broker will do is borrow the shares on your behalf and sell them and then you own negative shares.

你可以打电话给你的经纪人说，我要做空一号股票,经纪人就会在你的名下赊入这些股票,然后卖掉,这样你就拥有数量为负的股票了。

耶鲁公开课 - 金融市场课程节选