写出下列程序段的运行结果abstract class Shape {abstract void display();}class Circle extends Shape {void display() {System.out.println("Circle");}}class Rectangle extends Shape {void display() {System.out.println("Rectangle");}}class Triangle extends Shape {void display() {System.out.println("Triangle");}}public class AbstractClassDemo{public static void main(String args[]){(new Circle()).display();(new Rectangle()).display();(new Triangle()).display();}}