回复感谢信
We greatly appreciate your letter describing the assistance you received in solving your air-conditioning problems. We are now in our fifty year of operation, and we receive many letters like your indicating a high level of customer satisfaction with our installation. We are pleased that our technical staff assisted you so capably. We would like you to know that it you need to contact us at any time in the future. Our engineers will be equally responsive to your request for assistance. If we can be of service to you again, please let us know. Thank you again for your very kind letter.