A lot of people are intimidated by multiple strand necklaces, but it's actually very easy to do."

VOA: special.2009.05.18

And thanks to our equation simplified here, it's very easy for us to figure out what actually the allowed energy levels are.

由于有了简化的方程，我们很容易看出,这些允许的能级在那里。

麻省理工公开课 - 化学原理课程节选