关于#java#的问题：java编程

请问各位如何去写出来呀，刚刚学完一点头绪都没有。是java的。这学期刚刚学java

public interface speakable {
    public void speak0();
}

public abstract class Animal implements speakable {
}

public class Cat extends Animal {
    @Override
    public void speak0() {
        System.out.println("mew");
     }

    public static void main(String[] args) {
        Cat cat=new Cat();
        cat.speak0();
    }
}

public class Dog extends Animal {
    @Override
    public void speak0() {
        System.out.println("wow");
    }

    public static void main(String[] args) {
        Dog dog =new Dog();
        dog.speak0();
    }
}