I bent my head backward to drink in the stars, and clearly I heard a song so sweet and pure I had to hold myself to keep from breaking.

VOA: special.2009.02.14

we can run the engine backward and build a refrigerator, if you've got your lecture notes from last period your 8-9, well, they're labeled 8-9 lecture notes, I made an attempt to define something which was a little bit misguided.

现在我们可以把热机倒过来,制作一台制冷机，如果你们拿出上节课的笔记,也就是8-9节，好的，他们在8-9节，当时我试着,定义了一些,有些误导你们的物理量。

麻省理工公开课 - 热力学与动力学课程节选

If that's all it knows, then in that scenario there is no building or anything else; it continues a trajectory both forward in time and backward in time, and it says that whatever seconds, one second before you set your clock to 0, it would've been on the ground.

如果是这样,在那种模式下,没有楼房或者别的什么,物体的运动轨迹可以沿时间可以向后延伸,也可以向前延伸,不管时间取什么值,在零点前一秒时,物体就在地面上

耶鲁公开课 - 基础物理课程节选

He said the expulsion is obviously a matter of concern to the United States and a step backward,and that North Korea has only brought upon itself further isolation.

VOA: standard.2009.04.15

So it feels a little backward mentally perhaps, 1 but this is saying, "do this block of code as long as n is less than 1."

所以它感觉可能有点迟缓，但是它指明，“只要n小于,执行这段代码“

哈佛公开课 - 计算机科学课程节选