阅读下面的程序,在不new Cat类的情况下,添加代码运行Demo的mian方法后执行Cat的eat()方法。 public class Demo { public static void main(String[] args) { Animal animal = new Cat(); ____; cat.eat(); } }class Animal{ public void eat(){ System.out.println("animal eat"); } } class Cat ____Animal{ public void eat(){ System.out.println("cat eat"); } }