সি# AddRange

using System;
namespace MyApplication {
  class Program {
    static void Main(string[] args) {

    var numbers = new List<int> { 10, 15, 10, 25 };
    var amounts = new List<int> { 10, 15, 20, 25 };

    numbers.AddRange(amounts);

    foreach (var number in numbers) {
        Console.WriteLine(number);
    }

    }
  }
}