So, as they're very quietly handing out your class notes, let's think about what this bond is here, this boxed bond, is it a pi bond or a sigma bond?

在他们发讲义的同时，我们来看看这个键，方框里的这个键，它是sigma键还是π键？

麻省理工公开课 - 化学原理课程节选

So, as they're very quietly handing out your class notes, let's think about what this bond is here, this boxed bond, is it a pi bond or a sigma bond?

在他们发讲义的同时，我们来看看这个键，方框里的这个键，它是sigma键还是π键？

麻省理工公开课 - 化学原理课程节选