In valence bond theory, the focus is on discussing the bonds, but it should look very familiar to you, because there's two types of bonds that we want to discuss here.

在价电子成键理论中，所关注的是讨论成键，但这对于你们来说应该很熟悉，因为这是我们要讨论的两种键。

麻省理工公开课 - 化学原理课程节选

So those are our three types of bonds in ethene.

这就是乙烷里的三种间。

麻省理工公开课 - 化学原理课程节选

So that's two of our types of bonds in benzene, and we have one type left, that's going to actually be the double bond or the pi bond that So we can have one bond here between this carbon's p orbital and this carbon's p orbital.

这就是苯环里的两种键，我们还剩一种，那就是这些p轨道之间，形成的双键或者π键,我们可以在这个碳的p轨道,和这个碳的p轨道之间有个键。

麻省理工公开课 - 化学原理课程节选