一个问题.

using System;
public class EHClass
{
    static void Main()
    {
        string s1 = new string(new char[] { '.', 'n', 'e', 't' });
        string s2 = ".net";
        string s3 = ".net";
        Console.WriteLine(s1 == s2);
        Console.WriteLine(s2 == s3);
        Console.WriteLine((object)s1 == (object)s2);
        Console.WriteLine((object)s2 == (object)s3);
        Console.WriteLine(s1 == (object)s2);
        Console.WriteLine(s2 == (object)s3);
        Console.WriteLine((object)s1 == s2);
        Console.WriteLine((object)s2 == s3);
        Console.WriteLine(s1.Equals (s2));
        Console.ReadLine();
    }
}
结果是:true,true,false,true,false,true,false,true,true.  
有人知道第三个,第五个,还有第七个,为什么是"false".小弟谢过了!