Write a letter to the mayor(市长) to show you want to be a volunteer foe the 2010 World Expo

Dear Mayor:
Have a nice day!I am xxx,from the xxx Middle school.I am writing this letter for that I want to be a volunteer for the 2010 World Expo.
First,I am good at English,I can do the communicaton with foreigners fluently.When they need the help,I can do my best to give the foreigners the best services.
Second,I have been the volunteers during the 2008 Olympic Games in Beijing.With the successful experice,I believe I can be the appropriate volunteer.
Thank you!I am waiting for your reply!
Best Regards
xxx