Why is my xml file having these after convert from excel?

Question

My xml file has these "x0020" after the first word and last word of a column in my excel file, any clue?

<root>
    <first_x0020_Name>John<first_x0020_Name>
    <last_x0020_Name>Doe<first_x0020_Name>
    <Age_x0020_Range>28<first_x0020_Name>
</root>

Here's my code to convert from excel to xml:

string PATH = @"C:file.xlsx";
        string connection = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + PATH + ";Extended Properties=Excel 12.0";
        OleDbConnection objConn = new OleDbConnection(connection);
        OleDbCommand objCmd = new OleDbCommand(string.Format(@"Select * From [Sheet1$]"), objConn);

        OleDbDataAdapter objDatAdap = new OleDbDataAdapter();
        objDatAdap.SelectCommand = objCmd;
        DataSet ds = new DataSet();
        objDatAdap.Fill(ds);
        string result;
        using (StringWriter sw = new StringWriter())
        {
            ds.DataSetName = "samples";
            DataTable ok = ds.Tables[0];
            ok.TableName = "sample";
            ds.WriteXml(sw);
            ds.WriteXml("C:/File.xml");
        }