C# - 从现有词典创建列表

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

class Program
{
    static void Main()
    {
        Dictionary<string, string> words = new Dictionary<string, string>
        {
            { "apple", "a fruit" },
            { "banana", "a fruit" },
            { "carrot", "a vegetable" },
            { "orange", "a fruit" },
            { "grape", "a fruit" },
            { "pear", "a fruit" },
            { "tomato", "a vegetable" },
            { "potato", "a vegetable" },
            { "onion", "a vegetable" },
            { "garlic", "a vegetable" }
        };

        List<string> wordList = words.Select(word => word.Key).ToList();

        foreach (string word in wordList)
        {
            Console.WriteLine(word);
        }
    }
}