C ＃ graphic tutorial (Fourth Edition) chapter7-7.6.1 virtual and override

using System;

namespace Chapter76_1_VirtualAndOverride
{
    class MyBaseClass
    {
       virtual public void Print()
        {
            Console.WriteLine("This is the base class,With Virtual ");
        }
    }
    class MyDerivedClass : MyBaseClass
    {
        override  public void Print()
        {
            Console.WriteLine("This is the derived class.With Override ");
        }
    }
    class Program
    {
        static void Main(string[] args)
        {
            //Console.WriteLine("Hello World!");
            MyDerivedClass derived = new MyDerivedClass();
            MyBaseClass mybc = (MyBaseClass)derived;
            derived.Print();
            mybc.Print();
        }
    }
}