Java继承和组合代码

class Student extends Person {
    protected int score;

    public Student(String name, int age, int score) {
        super(name, age); // 调用父类的构造方法Person(String, int)
        this.score = score;
    }
}

Person p = new Student(); 

class Student extends Person {
    protected Book book;
    protected int score;
}