To whom it may concern,I am delighted to learn that_写信的原因. And I am writing this letter to express my suggestions on 话题.To begin with, I would like to suggest 建议内容一(that+包含should的句子). In addition, It is necessary / beneficial for you to 建议内容二.Terminally, you’re supposed to建议内容三 ,which is a good way to improve_______.I would appreciate it a lot if these suggestions are seriously taken into consideration. Thank you for your time and attention to this letter.Yours sincerely,Li Ming