If you have ever visited, you might have noticed the popular license plates on many D.C.cars.

VOA: special.2009.03.20

And if you noticed earlier that these are what we'd call powers of ten, these are just powers of two.

四位，八位吗？,如果你想想之前学习的十的次方，这些就是二的次方。

哈佛公开课 - 计算机科学课程节选

I don't know if you noticed it, but there are many, many examples.

这里有很多例子。

耶鲁公开课 - 1945年后的美国小说课程节选

If you noticed it, you got to stop.

如果注意到了,你应该打断我

耶鲁公开课 - 基础物理课程节选

If you've ever noticed, Mac OS has its Apple menu on the top left and Windows has its start menu in the bottom left, really for no compelling reason.

如果你注意到，你会发现，Mac操作系统,在其左上角是Apple菜单，Windows却把它的开始菜单,放在左下角，毫无理由可言。

哈佛公开课 - 计算机科学课程节选

In Franny and Zooey, what did you notice? Tell me what you noticed, at first bat, if any of you have read it.

在《弗兰尼与佐伊》里，你们注意到了什么，告诉我，首先问一下，你们有谁读了它吗。

耶鲁公开课 - 1945年后的美国小说课程节选