But, of course, what you saw in recitation, and hopefully, what you can now think very quickly by looking at this, is that this is not the only configuration of pi bonds that we could have in benzene.

当然，你们在习题课看到过，你们通过看这个可以很快的想到，这不是苯环里,唯一的π键构型。

麻省理工公开课 - 化学原理课程节选