using System.Collections.Generic;
public static void Main()
Console.Write("Hello World");
public abstract class Airplane
Console.WriteLine("my plane " + Make + Model + "is flying");
public abstract void Load();
public class Passenger_Plane : Airplane
public override void Load()
Console.WriteLine("Passanger loading");
public class Cargo_Plane : Airplane
public override void Load()
Console.WriteLine("Cargo loading");
List<Airplane> Airplanes_List = new List<Airplane>();
public void Add(Airplane A)
public Airport(string n, string c)
Console.WriteLine("Airport is being created" + Name + City);