Collections Data Structure C#

using System;
using System.Collections;
using System.Collections.Generic;
using System.Text;
class Program {
    static void Main(string[] args) {
        Queue alphabet = new Queue();
        alphabet.Enqueue("A");
        alphabet.Enqueue("B");
        alphabet.Enqueue("C");
        Console.Write("First Iteration: ");
        foreach (string item in alphabet) {
            Console.Write(item);
        }
        Console.WriteLine("\nItem pulled from collection: " +
           alphabet.Dequeue().ToString());
        Console.Write("Second iteration: ");
        foreach (string item in alphabet) {
            Console.Write(item);
        }
    }
}