Math and Graph and China

I answered a question in my math class. I'm actually super proud of myself right now, mostly because the class is in China, conducted in Chinese. And I was able to explain, on the fly, my answer to a math question in Chinese so that the teacher and my classmates understood what I said. He didn't go rephrase for me, so I hope my classmates understood! The question was to explain what a bipartite graph is. （谁可以介绍偶图是什么？）
 Basically, a bipartite graph is a graph where you can take the points (vertices) and split them into two groups. If two points are in the same group, there isn't a line directly connecting them. If they're in different groups, there could be a line connecting them. [A graph is a bunch of points with lines connecting some pairs. A point can be unconnected to any other points, or to all the points, or anything in between.]
 And minus the explanation of what a graph is, plus using slightly more mathy words for things, that's pretty much what I said in Chinese.
 如果一个图是偶图，那么可以把顶点分开，放在两部分。如果两个顶点再一样的一部分，这双顶点没有边。如果两个顶点再不同的部分，可以（不一定）有边。