Well, this one works:
static void Main(string[] args)
{
var xmlDoc = new XmlDocument();
XMLDoc.Load("XMLFile1.xml");
XmlNamespaceManager manager = new XmlNamespaceManager(xmlDoc.NameTable);
manager.AddNamespace("ns", "http://ebc.mssb.com");
XmlNode root = xmlDoc.DocumentElement;
const string xpath = "//ns:Office";
if (root != null)
{
var xmlNodeList = root.SelectNodes(xpath, manager);
if (xmlNodeList == null) return;
foreach (XmlNode ele1 in xmlNodeList)
Console.WriteLine(ele1.InnerXml);
}
}