c#中的“接口”问题，代码摆出。请帮我解答一下。100分奉上

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;namespace Hello_World
{
    interface IStorable
    {
        void Read();
        void Write();
    }    public class Document : IStorable
    {
        public Document(string s)
        {
            Console.WriteLine("{0}",s);
        }        public virtual void Read()
        {
            Console.WriteLine("Document_Read");
        }        public virtual void Write()
        {
            Console.WriteLine("Document_Write");
        }
       
    }    public class Note : Document
    {
        public Note(string s):base(s)
        {
            Console.WriteLine("this is Note");
        }        public override void Read()
        {
            //base.Read();
            Console.WriteLine("Note_Read");
        }        public new void Write()
        {
            //base.Write();
            Console.WriteLine("Note_write");
        }
    }     class Program
    {
        static void Main(string[] args)
        {
          
            Note note2 = new Note("seond test");
            IStorable isNote2 = note2 as IStorable;
            if (isNote2 != null)
            {
                //isNote2.Read();
                isNote2.Write();
            }
            //5note2.Read();
            note2.Write();
            
        }
    }
}
这个是我根据书上的例子简化的代码，我想知道为什么两个 Write 方法的输出不一样，为什么接口的write方法调用的是基类方法？请帮忙解惑。