DOM操作XML的数据结果存在疑惑

string xmlData =  "<Class>" +
                              " <student id=\"tcs001\">" +
                              "  <name>AAA</name>" +
                              "  <age>25</age>" +
                              "  <contact>" +
                              "    <mobile>13401012345</mobile>" +
                              "    <telphone>010-12345678</telphone>" +
                              "  </contact>" +
                              "  <className>Tcs242</className>" +
                              " </student>" +
                              " <student id=\"tcs002\">" +
                              "  <name>BBB</name>" +
                              "  <age>23</age>" +
                              "  <contact>" +
                              "    <mobile>13401054321</mobile>" +
                              "    <telphone>010-87654321</telphone>" +
                              "  </contact>" +
                              "  <className>Tcs242</className>" +
                              " </student>" +
                              " <student id=\"tcs003\">" +
                              "  <name>CCC</name>" +
                              "  <age>23</age>" +
                              "  <contact>" +
                              "    <mobile>134010456789</mobile>" +
                              "    <telphone>010-9876543</telphone>" +
                              "  </contact>" +
                              "  <className>Tcs242</className>" +
                              " </student>" +
                              "</Class>";
                      myClass.LoadXml(xmlData);
     XmlNodeList list = .GetElementsByTagName("*");
 Program.OutputNodeNameValue(list); static void OutputNodeNameValue(XmlNodeList list)
        {
            foreach (XmlNode child in list)
            {
                Console.WriteLine("节点名：{0}，节点值：{1}", child.Name, child.Value);
                Program.OutputNodeNameValue(child.ChildNodes);
            }
        }为啥输出结果的结果是：
节点名：Class，节点值：
节点名：student，节点值：
节点名：name，节点值：
节点名：#text，节点值：AAA……
这个#text从哪来的呢？
XMLDOM