C# new关键字和override

using System;class MyBaseClass{    virtual public void Print()    {Console.WriteLine("This is the 鸡 class.");}}class MyDerivedClass:MyBaseClass{    override public void Print()    {Console.WriteLine("This is the derived 派生的 class.");}}class SecondDerived : MyDerivedClass {     new public void Print() {       //这里关键字是override呢？         Console.WriteLine("This is the second derived class.");      }   }      class Program {      static void Main()                                    // Main      {         SecondDerived derived = new SecondDerived();       // Use SecondDerived.         MyBaseClass mybc = derived;      // Use MyBaseClass.         //也可以写成MyBaseClass mybc=(MyBaseClass)derived;            derived.Print();         mybc.Print();      }   }