LINQ To Google Image and Google Groups

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

namespace MChen.Linq.GoogleSearch.Common
{
    public abstract class Result
    {
        public int Rank { get; internal set; }
        public Uri Url { get; internal set; }
        public string Domain { get; internal set; }
        public string Description { get; internal set; }
    }

    internal abstract class QueryInfo
    {
        public List<string> AllWords = new List<string>();
        public List<string> OrWords = new List<string>();
        public List<string> NotWords = new List<string>();

        public string Domain { get; set; }

        #region private methods
        protected string GetDomain()
        {
            if (Domain == null) return "";
            return Domain;
        }

        protected string GetWords(List<string> list)
        {
            StringBuilder sb = new StringBuilder();
            foreach (string s in list)
                sb.AppendFormat("{0} ", s);
            return sb.ToString();
        }
        #endregion

        public abstract string GetUrl(int start);

        public override string ToString()
        {
            StringBuilder sb = new StringBuilder();
            sb.Append("All:         ");
            foreach (string s in AllWords) sb.AppendFormat("{0}, ", s);
            sb.Append("\n");
            sb.Append("Or:          ");
            foreach (string s in OrWords) sb.AppendFormat("{0}, ", s);
            sb.Append("\n");
            sb.Append("Not:         ");
            foreach (string s in NotWords) sb.AppendFormat("{0}, ", s);
            sb.Append("\n");
            sb.AppendFormat("Domian:      {0}\n", Domain);
            return sb.ToString();
        }
    }
}