①表达歉意
►I sincerely apologize to you for…
►I am indeed very sorry for …, but believe I had no intention to…
► I am writing this letter to apologize to you for my failing to…
② 解释苦衷
► …due to my toothache/traffic accident/traffic jam
►… as the things is quite beyond my power to do
► …because I have to deal with the urgent business assigned by my boss
③ 提出补偿建议+再次道歉
►I want to know if we could…
►I wonder whether it is possible that I make up the loss by…
►Please forgive me for/accept my deepest apology for …
►I do hope that you can understand my situation and accept my apology.