儿子傻笑了一下，厌倦的摇了摇头，我们以前就谈论过这个话题好多次，他低下头转动着眼珠。我的充满母性的劝解又成了他的耳旁风。

He smirked and shook his head with boredom, we talked this many times before, he lowed his head and rolled his eyes, I knew my panic and maternal words were fall of his deaf ears again.

youdao

还记得几周以前我们谈论的一个掠过地球的天体吗？今天就是这一天。

Remember weeks ago we talk about an astro that flied by the earth, today is the day.

youdao

现在我们能公开谈论以前讳言不提的艾滋病问题。

We can now talk openly about AIDS which we couldn't before.

youdao

And, of course, there's this-- another acoustical phenomenon here we've talked about before, what's the relationship within an octave?

当然,就是这个,我们以前谈论过的,另一种声学现象,八度的内部联系是什么呢

耶鲁公开课 - 聆听音乐课程节选