"This experience teaches me how to,more or less,teach teenagers, how to say 'OK, we're having a problem with this section, let's clap it,let's sing it.'" The orchestra performs for free but receives donations that help pay for necessities like sheet music.

VOA: special.2010.06.21

So that's where it's easy to get lost, but let's see if these lines in the picture help us stay on track.

这就是容易迷惑的地方，下面看看,这幅图中的这些线能否帮助我们追踪。

哈佛公开课 - 计算机科学课程节选

Let's bind z eh let's bind z to the-- f if I could type it would help-- say, f of 3. OK?

让我们给z赋值--如果我能打字就好了-,比方说？

麻省理工公开课 - 计算机科学及编程导论课程节选