Dear Bob,
I am the Chinese student who stayed in your apartment during my vacation in Canada. Now I have returned home in China and the purpose of my writing this letter is to express my sincere apology for the stupid mistake I have made.
Upon arriving home, I found the music CD which belongs to you in my luggage. I am in great worry because I know this your birthday present from your wife. Your CD will be sent immediately through EMS in the very near future. I have been told it will take about a week to reach Canada .
Once again, please accept my sincere apology for any inconveniences I have caused. Thank you for your understanding and please send me a reply at your earliest convenience.
Sincerely
Li Ming