The flip side is there are going to be a couple of lectures now where it is not going to be on the test, so I think you will deal with it.

现在这种对立面将是,一些现在的课程,这些不会在考试上出现，所以我想你能处理好的。

麻省理工公开课 - 固态化学导论课程节选

This is what's called the Bohr radius, and we'll explain - hopefully we'll get to it today where this Bohr radius name comes from, but for now what you need to know is just that it's a constant, just treat it like a constant, and it turns out to be equal to or about 1/2 an angstrom.

它叫做玻尔半径，我们后面会解释,希望我们今天可以讲到,波尔半径这个名称的由来，但现在你们只要记住,它是一个常数，只要把它当做一个常数对待，它等于,或者是1/2埃。

麻省理工公开课 - 化学原理课程节选