这个java题怎么做呀

Question

定义动物类Animal及它的子类Cat和Dog,然后在Zoo类中分别创建各个子类对象，并调用子类覆盖父类Cry（）方法。

Answer 1

class Animal{
    public void cry() {
        System.out.println("动物会发出叫声");
    }
}
class Dog extends Animal{
    public void cry() {
        System.out.println("狗发出汪汪...的叫声");
    }
}
class Cat extends Animal{
    public void cry() {
    System.out.println("猫发出喵喵...的叫声");
    }
}
public class Zoo {

    public static void main(String[] args) {
    Animal h1=new Animal();
    Dog h2=new Dog();
    Cat h3=new Cat();
    h1.cry();
    h2.cry();
    h3.cry();
    h1=h2;
    System.out.println("----------------------------");
    h1.cry();
    }

}