【正确答案】Dear Sirs,
   We have received with pleasure your letter dated August 20, knowing that you are interested in our products and market for agricultural cars．
   Being in this line of business for many years, we can assure you that our products are of best quality． To acquaint you with the products we deal in, we are sending you a copy of our catalogue of the main items for export now for your reference．
   If you are interested in items not mentioned on the list, please don't hesitate to let us know． We shall do what we can, upon receipt of your detailed requirements, to get the said items for you．
   We are looking forward to your early reply．
   Yours sincerely,