A lot of times when people draw them, they even only draw the big lobe just to keep their paper looking nicer, but there is that little tiny lobe on the other side.

很多时候当人们画它时，为了使图更加美观,他们甚至只画大叶，但另外一面是有一个小叶的。

麻省理工公开课 - 化学原理课程节选