问如何在C#中将字典内容复制到新字典？

EN

Dictionary<string, string> d = new Dictionary<string, string>();
Dictionary<string, string> d2 = new Dictionary<string, string>(d);

Dictionary<string, string> d = new Dictionary<string, string>();
Dictionary<string, string> d2 = d;

using System;
using System.Collections.Generic;

class Program
{
    static void Main(string[] args)
    {
        Dictionary<string, string> first = new Dictionary<string, string>()
        {
            {"1", "One"},
            {"2", "Two"},
            {"3", "Three"},
            {"4", "Four"},
            {"5", "Five"},
            {"6", "Six"},
            {"7", "Seven"},
            {"8", "Eight"},
            {"9", "Nine"},
            {"0", "Zero"}
        };

        Dictionary<string, string> second = new Dictionary<string, string>();
        foreach (string key in first.Keys)
        {
            second.Add(key, first[key]);
        }

        first["1"] = "newone";
        Console.WriteLine(second["1"]);
    }
}

var second = first.Keys.ToDictionary(_ => _, _ => first[_]);