C # using the word to open the document is too slow

Hi,
     When I open Word using C #, too slow, would have quickly open the Word function »

C # code is as follows:

  Microsoft.Office.Interop.Word.Application wor = new         Microsoft.Office.Interop.Word.ApplicationClass();
            Microsoft.Office.Interop.Word.Document doc = null ;
            try
            {
                Console.WriteLine("open file : " + fileFullPath);
               
                doc = wor.Documents.Open(
                ref fileFullPath,
                ref confirmConversion,
                ref readOnly,
                ref addtoRecentFiles,
                ref missing,
                ref missing,
                ref missing,
                ref missing,
                ref missing,
                ref missing,
                ref missing,
                ref missing,
                ref missing,
                ref missing,
                ref missing,
                ref missing);
         ........................