package abc;

public class Dog extends Animal {

?@Override

public String toString() {

return "Dog [age=" + age + "]";

}

public int age=20;

?public void eat() {

?System.out.println("狗具有吃骨頭的能力");

?}

?public Dog() {

System.out.println("Dog執行了");

?}

?public void nb() {

? ? eat();

?}

}