Write a note according to the situation described. You are returning by post a friend’s book you have kept for too long. Write a note to him/her, apologizing for and explaining the delay.(70-100 words)
I am terribly sorry for not returning the book you lent me last year until now because I’ve been in use of it all the time. I had tried to find another book of the kind in order to return yours in an early time, but failed. I found it so helpful to my paper writing that I think I couldn’t have accomplished my task without it. It must have caused you some inconvenience in your study. Please accept my apologies.