易百教程

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Demo {
   class Son : Father {
      public void DisplayTwo() {
         Console.WriteLine("Son.. ");
      }

      static void Main(string[] args) {
         Son s = new Son();
         s.Display();
         s.DisplayOne();
         s.DisplayTwo();
         Console.Read();
      }
   }

   class Grandfather {
      public void Display() {
         Console.WriteLine("Grandfather...");
      }
   }

   class Father : Grandfather {
      public void DisplayOne() {
         Console.WriteLine("Father...");
      }
   }
}