using System;

using System.Linq;

using System.Collections.Generic;           

​

public class Program

{

    public static void Main()

    {

        var ma = new Dictionary<string, string>();

        ma.Add("Enable", "true");

        var cm = new Dictionary<string, string>();

        cm.Add("Enable", "false");

        cm.Concat(ma).ToDictionary(dict => dict.Key, dict => dict.Value);

    }

}