填空题 读下面程序,写出程序运行结果. class Point{ int x=1; public void show(){System.out.println(x);}} class SPoint extends Point{ int y=2; public void show(){System.out.println(x+","+y);}} class PPoint extends Point{ int z=3; public void show(){System.out.println(x+","+z);}} public class tempDemo{ public static void main(String []args){ Point p; p=new Point(); p.show(); p=new SPoint(); p.show(); p.x=2; p.show(); p=new PPoint(); p.show(); }} 运行结果为