不能再简单的乒乓球游戏，你可以把它作为一个碰撞实例，如果把它做为一个真正的乒乓球游戏，那它太不完美了，甚至有点弱智。-Can no longer be a simple table tennis game, you can put it as an example of the collision, if it as a real table-tennis game, it too is not perfect, and even a little bit mentally.