He told students it was time for them to learn what it means to be a human being on Earth at a time when every living system was failing.

VOA: special.2009.06.05

OK, we're going to do this reversibly, which means we're going to slowly change the external pressure very, very slightly at a time, so that at every point we're basically in equilibrium, p2/ until the pressure reaches a new smaller pressure p2.

整个过程保持可逆，外界压强,变化得很慢，每一个瞬间,都保持平衡，直到压强减小到末态值。

麻省理工公开课 - 热力学与动力学课程节选

It looks like a tautology because you're never able to show me something that moves forever at a constant velocity, because every time you don't find such a thing, I give an excuse, namely, a force is acting.

这听上去像个死循环,因为你不可能,找到永远匀速运动下去的物体,因为每当你找不到这样的物体时,我就会给出一个理由,也就是,有力作用在上面

耶鲁公开课 - 基础物理课程节选

At the time,Irma was a single mother, working at every opportunity to support her four children.

VOA: standard.2009.12.25

So, that's sort of the mathematically how we get to a, but we can also just look at the graph here, because every time we go one wavelength we can see that we're back in a maximum.

这是就我们得到a的数学,办法，但我们可以直接,从图上看，因为每次我们,经过一个波长，都回到一个最大值。

麻省理工公开课 - 化学原理课程节选