So if you've ever seen or used an old school typewriter, you might recall that when you're typing something out on an old mechanical typewriter, - when you like hit the char-- when you hit the enter key to move the head back to the left hand side to the next line or you would pull down some lever, it was really a two part process.

如果你们有谁曾经看过或用过老式打字机，可能还记得，当你在,这种老式打字机上打字的时候，当你-,敲入回车键，跳转到,下一行的最左边，或者,拉一下杆，这个需要两步走。

哈佛公开课 - 计算机科学课程节选

Every time you hit the enter key in Notepad or in Microsoft Word, small white lie, those two characters end up getting saved in the file.

在Notepad或Microsoft里，每当你敲回车键时，没有恶意哈，这两个字符,都会保存在文档里。

哈佛公开课 - 计算机科学课程节选