When you're teenagers, you don't quite know what to write on there. Little Os and Xs for kisses and things like that.

VOA: special.2010.02.08

Now, in the world of Linux and Unix more generally, both of which are our operating systems that had been around for many, many years, Mac OS is based on one of-- one version thereof.

在Linux和Unix里更广泛，对了，这两个都是历史悠久的,操作系统，就连Mac操作系统,都是基于它的一个版本设计出来的。

哈佛公开课 - 计算机科学课程节选

If you've ever noticed, Mac OS has its Apple menu on the top left and Windows has its start menu in the bottom left, really for no compelling reason.

如果你注意到，你会发现，Mac操作系统,在其左上角是Apple菜单，Windows却把它的开始菜单,放在左下角，毫无理由可言。

哈佛公开课 - 计算机科学课程节选