【1】
Dear,
I am writing this letter to express my apology that .
I feel terribly sorry about this. Once again, I am very sorry for any inconvenience caused.
I will be really appreciated if you can accept my apologies and understand my situation.
Yours Sincerely
亲爱的，(对方姓名)
我写这封信以表达我的道歉(道歉原因)。
对此我深感抱歉。我再次对给您造成的任何不便深感歉意，希望您能理解我的处境并接受我的.道歉。
谨启(自己姓名)
【2】
Dear Anne,
Thank you for your invitation to dinner at your home tomorrow evening.
Unfortunately, it is much to my regret that I cannot join you and your family, because I will be fully occupied then for an important exam coming the day after tomorrow.
I feel terribly sorry for missing the chance of such a happy get-together, and I hope that all of you enjoy a good time.
Is it possible for you and me to have a private meeting afterward? If so, please don't hesitate to drop me a line about your preferable date. I do long for a pleasant chat with you.
Please allow me to say sorry again.
Regards, Li Ming
【3】
Dear Bob,
I'm writing to apologize for having forgotten to return the "the Beatles" CD to you when I left Canada,I was in such a hurry that I packed everything in my luggage without checking carefully.Had I paid more attention then,I wouldn't have made such a stupid mistake.
Now something must be done to solve the problem because I understand you cherish the CD enormously.I can either send it to you by express mail or alternatively compensate you at a reasonable price.If you do not mind,I may bring it back to you next time I go to Canada.
Please let me know which solution you prefer at your earliest convenience.I really hope you will accept my sincere apology.
Faithfully yours,
Li ming