c# rdf-sparql . dotNetRDF. don't work

<?xml version='1.0' encoding='UTF-8'?>

<rdf:RDF
  xmlns:rdf='http://www.w3.org/1999/02/22-rdf-syntax-ns#'
  xmlns:vCard='http://www.w3.org/2001/vcard-rdf/3.0#'
   >

  <rdf:Description rdf:about="http://somewhere/JohnSmith/">
    <vCard:FN>John Smith</vCard:FN>
    <vCard:N rdf:parseType="Resource">
    <vCard:Family>Smith</vCard:Family>
    <vCard:Given>John</vCard:Given>
    </vCard:N>
  </rdf:Description>

  <rdf:Description rdf:about="http://somewhere/RebeccaSmith/">
    <vCard:FN>Becky Smith</vCard:FN>
    <vCard:N rdf:parseType="Resource">
    <vCard:Family>Smith</vCard:Family>
    <vCard:Given>Rebecca</vCard:Given>
    </vCard:N>
  </rdf:Description>

  <rdf:Description rdf:about="http://somewhere/SarahJones/">
    <vCard:FN>Sarah Jones</vCard:FN>
    <vCard:N rdf:parseType="Resource">
    <vCard:Family>Jones</vCard:Family>
    <vCard:Given>Sarah</vCard:Given>
    </vCard:N>
  </rdf:Description>

  <rdf:Description rdf:about="http://somewhere/MattJones/">
    <vCard:FN>Matt Jones</vCard:FN>
    <vCard:N
    vCard:Family="Jones"
    vCard:Given="Matthew"/>
  </rdf:Description>

</rdf:RDF>

using System;
using VDS.RDF;
using VDS.RDF.Parsing;
using VDS.RDF.Query;

public class InMemoryTripleStoreExample
{
    public static void Main(String[] args)
    {
        IGraph g = new Graph();

        //Load some data into your Graph using the LoadFromFile() extension method
        g.LoadFromFile("1");

        //Use the extension method ExecuteQuery() to make the query against the Graph
        try
        {




            String q = @"PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX vCard: <http://www.w3.org/2001/vcard-rdf/3.0#>

SELECT * WHERE
 { 
   ?a rdf:type vCard:FN .
 }
 LIMIT 100";
            Object results = g.ExecuteQuery(q);

            if (results is SparqlResultSet)
            {
                //SELECT/ASK queries give a SparqlResultSet
                SparqlResultSet rset = (SparqlResultSet)results;
                foreach (SparqlResult r in rset)
                {
                    //Do whatever you want with each Result
                }
            }
            else if (results is IGraph)
            {
                //CONSTRUCT/DESCRIBE queries give a IGraph
                IGraph resGraph = (IGraph)results;
                foreach (Triple t in resGraph.Triples)
                {
                    //Do whatever you want with each Triple
                }
            }
            else
            {
                //If you don't get a SparqlResutlSet or IGraph something went wrong 
                //but didn't throw an exception so you should handle it here
                Console.WriteLine("ERROR");
            }
        }
        catch (VDS.RDF.Query.RdfQueryException queryEx)
        {
            //There was an error executing the query so handle it here
            Console.WriteLine(queryEx.Message);
        }
    }
}