Hold on, I'm getting another call.

稍等，我有其他电话进来。

youdao

Hey, I gotta call you back, I'm getting another call.

我待会给你打回去吧，我现在要接个电话。

youdao

Why then do we use music as a first port of call in getting to know another person?

那么为什么我们会利用音乐作为了解他人的第一个中途站点呢？

youdao

I just doubled the indentation each time so you can see it. So each successive call, notice what's happening. The argument is getting reduced. And we're going another level in. When we get down to this point, we're calling it with just a string of length one.

因此每次成功调用注意它的过程,我们的命题不断简化，而且我们不断深入嵌套,当我们走到这一步的时候,我们就是在调用它处理，仅有一个元素的字符串了。

麻省理工公开课 - 计算机科学及编程导论课程节选