In fact, once you think about it, and not all that long, you can see the answer's got to be no.

事实上,只要你想一想,不用太久,你就会知道答案是否定的

耶鲁公开课 - 死亡课程节选

But for those of you that have been here for 30 seconds or longer see if you can get the right answer in here.

但那些已经来了30秒以上的同学,看看你们能不能得到正确的答案。

麻省理工公开课 - 化学原理课程节选

Compare after 30 or 60 seconds with the person next to you and see if before I reveal the answer we can't get everyone on to the exact same page.

和你身边的人比较30到60秒钟,看看是否在我揭露答案之前，我们不能使每个人,得到一个完全相同的页面。

哈佛公开课 - 计算机科学课程节选