让学员吐血的类的封装继承

using System;

namespace P74
{
    class Person
    {
        private string name;
        private uint age;

        public Person(string name, uint age)
        {
            this.name=name;
            this.age=age;
        }
        public override string ToString() //去掉override试试
        {
            return String.Format("{0},今年{1}岁",this.name,this.age);
        }
    }

    class Student :Person
    {
        private string school;
        //public,internal(,protected,private)
        internal Student(string name, uint age, string school)
            :base(name,age)    //调用基类的构造函数
        {
            this.school=school;
        }
        //下面的代码管用吗
        public new string ToString()
        {
            return  base.ToString() + String.Format("在{0}就读。",this.school);
        }

    }

    class myApp
    {
        static void Main_p74(string[] args)
        {
            Student s =new Student("许明会",2,"北大青鸟");
            Console.WriteLine(s); //省去ToString效果就不一样了
            //修改ToString方法的override为new或者空，输出什么？
            Person p = s;
            Console.WriteLine(p);
        }
    }
}
/**//*
许明会,今年2岁
许明会,今年2岁 * */