C ＃ learning about abstract classes

The following code covers the cases of abstract class learning

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

namespace ConsoleApp3
{
    
   abstract class Fruits
    {
    
        public string name;

        public abstract void Bad();

        public virtual void Test()
        {
    

        }
    }

    class Apple : Fruits
    {
    
        public override void Bad()
        {
    
            Console.WriteLine(" The apple has rotted away ");
        }


    }

    class SuperApple:Apple
    {
    
        public override void Bad()
        {
    
            Console.WriteLine(" The super apple is rotten ");
        }

        public override void Test()
        {
    
            Console.WriteLine(" Super apple Test");
        }
    }





    class Program
    {
    
        static void Main(string[] args)
        {
    
            Fruits fruits = new Apple();
            fruits.Bad();

            Fruits myfruits = new SuperApple();
            myfruits.Test();
        }
    }
}