Dear___________,

　　I am terribly sorry to tell you that_________,andI am writing this letter to show my deepregret.Please accept my sincere apology withgratitude.I hope you will understand my situationand excuse me for___________.

　　The reason why__________isthat__________.Under thatcircumstance,____________.Therefore,it was notmy power to___________.

　　If possible,I would like to suggest that___________.I shall be obliged if you will kindly writeand tell me___________.I am looking forward to seeing you again.

　　Yours,

　　________