Dear Mr. Wang,
I am writing to apologize for my late homework. The paper which you have assigned to us last Monday was due this Friday, but to my regret, I haven't even started it yet. I feel really sorry for not handing in the paper on time and for the inconvenience it would bring to you.
I have caught a serious cold last week and the doctor asked me to stay in bed for a week since I was very weak and the weather was very cold these days. Therefore, I couldn't go to the library to get the necessary referential information which was needed for my paper. As a result of this, I have not started writing the paper yet and could not hand it in on time.
Fortunately I have finally fully recovered. I will finish the paper as soon as I can and try my best to hand in homework on time in the future.
Sincerely yours,
Li Ming
