abstract class Animal
{
public abstract void eat();
}
class Cat extends Animal
{
public void eat()
{
  System.out.println("猫吃鱼");
}
public void catchMouse()
{
  System.out.println("抓老鼠");
}
}
class Dog extends Animal
{
public void eat()
{
  System.out.println("吃骨头");
}
public void kanJia()
{
  System.out.println("看门");
}
}
class Pig extends Animal
{
public void eat()
{
  System.out.println("吃饲料");
}
public void gongDi()
{
  System.out.println("拱地");
}
}

class DuoTaiDemo
{
public static void main(String[] args)
{
  //Animal a=new Cat();
  //a.eat();
  function(new Cat());
  function(new Dog());
  function(new Pig());
  
  //System.out.println("Hello World!");
}
public static void function(Animal a)
{
  a.eat();
}
}

abstract class Animal
{
public abstract void eat();
}
class Cat extends Animal
{
public void eat()
{
  System.out.println("猫吃鱼");
}
public void catchMouse()
{
  System.out.println("抓老鼠");
}
}
class Dog extends Animal
{
public void eat()
{
  System.out.println("吃骨头");
}
public void kanJia()
{
  System.out.println("看门");
}
}
class Pig extends Animal
{
public void eat()
{
  System.out.println("吃饲料");
}
public void gongDi()
{
  System.out.println("拱地");
}
}

class DuoTaiDemo
{
public static void main(String[] args)
{
  //Animal a=new Cat();
  //a.eat();
  function(new Cat());
  function(new Dog());
  function(new Pig());
  
  //System.out.println("Hello World!");
}
public static void function(Animal a)
{
  a.eat();
}
}