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

GCC hello c So you see two similarities between the first version, GCC hello.c, and the second version but obviously I've just added which part for that second line.

你将会在第一个版本,和第二个版本GCC，-o，hello，hello，c之间，看到两点相似之处,很显然我们在第二个版本的第二行添加了一些东西。

哈佛公开课 - 计算机科学课程节选