51.假设你叫李华，在 2008 年暑假期间成为了北京奥运会的一名志愿者，请你用英语给美国的笔友 Tom 写一封 100 字左右的信，谈谈你当志愿者的心得体会。要点如下：
1 ．志愿者工作艰辛而快乐；
2 ．锻炼了英语口语；
3 ．增强了合作精神和责任感；
4 ．你感到很骄傲，并将珍藏这份记忆。
注意：
1 ．信件的开头和结尾都已给出，不记人总词数。
2 ．可适当增加细节以使行文连贯。
One possible version:
Dear Tom
How is everything going?
This summer I worked as an Olympic volunteer. It’s a valuable experience for me. In order to provide better service for the Beijing Olympics I made every effort to practice my spoken English and have made great progress. Second as a volunteer I worked very hard and felt the happiness that went with my voluntary work. What’s more I learnt more about cooperation and responsibility which will benefit me a lot in the future.
I’m proud of becoming an Olympic volunteer. It’s an opportunity of my lifetime and I will cherish this beautiful memory forever.
Looking forward to your reply. Take care.
Yours ，
Li Hua