程序代码：

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

namespace test2010
{
    class Program
    {
        static void Main(string[] args)
        {

            birdTweetAdapter ch = new birdTweetAdapter(new chicken());
            ch.Showtype();
            ch.Tweet();
            Console.ReadLine();

        }
    }
    interface BirdSing
    {
        void Tweet();
    }

    class birdTweetAdapter:BirdSing
    {
        private Bird _bird;

        public birdTweetAdapter(Bird bird)
        {
            _bird = bird;
        }
        public void Showtype()
        {
            _bird.showtype();
        }

        public void Tweet()
        {
            Console.WriteLine("叫一下");
        }
    }
    class Bird
    {
        public string Name { get; set; }

        public void showtype()
        {
            Console.WriteLine(this.Name);
        }
    }

    class chicken:Bird
    {
        
        public chicken()
        {
            base.Name = "鸡";
        }
    }

    class durk : Bird
    {
        public durk()
        {
            base.Name = "鸭";
        }
    }
}