I said, well, let's do something on, I don't know, pick a topic.

我说，好，让我们做点东西，我不知道，选一个课题。

麻省理工公开课 - 固态化学导论课程节选

I declare a variable called n. I'm not giving it a value yet, so I had better be careful.

我申明一个变量n，我先不给它赋值，所以我最好小心点。

哈佛公开课 - 计算机科学课程节选