Implementation of Type of Association

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

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

    public class BiologyDempartment
    {
        private IList<Teacher> teachers;

        public BiologyDempartment(IList<Teacher> teachers)
        {
            this.teachers = teachers;
        }

    }

    public class Teacher
    {
        string teacherName;
        public Teacher(string teacherName)
        {
            this.teacherName = teacherName;
        }

    }

    public class Car
    {
        private Wheel wheel;
        private Engine engine;

        public Car(Wheel wheel,Engine engine)
        {
            this.wheel = wheel;
            this.engine = engine;
        }
    }

    public class Wheel
    { 
    }

    public class Engine
    { 
    }
}