Dear Tom,
I＇m very glad  to know you are interested in stamps and are starting to collect them now.
You are asking for advice on stamp-collecting. I think first you should collect as many stamps as you can and trade the stamps you don＇t want with other people. I don＇t think you should collect the envelope unless it is unusual or it is a“first day cover”. Then you have to decide whether you want to collect a certain kind of stamp, such as stamps with a bird design. You＇d better join a group. Other people will help you learn more about stamps and they will soon trade stamps with you. Have you thought of going to stamp sales and buy whatever you can afford? But at the beginning, you should buy used stamps.
Stamp-collecting is fun and you may enjoy the unusual and beautiful designs of stamps.
Good luck!
                                                                                                                              Love,
                                                                                                                      Uncle Fred
【写法指要】
这封信写得很圆满。像一篇短文一样，有引言段、扩充段和结尾段。在扩充段中有主题句和铺垫部分：第一句是主题句，其中“stamp-collecting”是王题，“advice”是制约思想；铺垫部分围绕制约思想写了三层意思，第一层意思以“first”为标记，第二层意思以“Then”开头，第三层意思以问句“Have you thought of…?”启发对方。这样，Uncle Fred就为Tom提供了三条集邮的建议供其参考。在结尾段里，作者指出集邮的好处。