I don't know if you know how a spark plug works, but for the electrical current to fly into operation in a spark plug, the two points of contact have to be gapped.

我不知道你们是否知道,火花塞是怎样工作的，在电流通入火花塞中使它运转之前，两个接触点之间需要有空隙。

耶鲁公开课 - 文学理论导论课程节选

You take a throttle valve, which consists of some sort of porous plug between two cylinders that is insulated. There is insulation here.

有一个节流阀，它由一些多孔的塞子组成,这些多孔塞在两个绝热的汽缸之中,这里是绝热的，底下也是绝热的。

麻省理工公开课 - 热力学与动力学课程节选

If you think about what happens when we go from hydrogen to helium, now instead of one electron, we have to describe two electrons, so now we have six position variables that we need to plug into our Schrodinger equation.

如果你们考虑,当我们从氢到氦会发生些什么，现在我们不是要描述一个电子，我们将要描述两个电子，所有我们现在将有6个位置变量,需要加入至薛定谔方程。

麻省理工公开课 - 化学原理课程节选