用字母编写的3D电影，很震撼的啊。还有文字打印，实现文字单个跳出，还有鼠标云彩环绕-3D movie, very shocking letter written ah. Text printing text a single jump, there are mouse clouds surround

Point3D继承Point2D，实例化两个2D、两个3D点，并随机打印2D或3D点 Point3D继承Point2D，实例化两个2D、两个3D点，并随机打印2D或3D点Point3D继承Point2D，实例化两个2D、两个3D点，并随机打印2D或3D点-//Write a program that implements the concept of an abstract class.)