第一段：称呼
dear mr. president,
第二段：引出写信的目的
主题句： this letter comes to you from one of your students.
扩展句： in it, some opinions are put forward for you to reflect upon
第三段：对学校食堂的看法
主题句：as you know, our students are the main customers of the university canteen. but unfortunately, we don't find the service there satisfying sometimes.
扩展句：
1、the food is not as nutritious as it should be. (举例) as a result, some of us become thinner and weaker at university.
2、besides, sometimes the canteen people just bring us steamed bread with their dirty bare hands.
3、and what's more, the fare is also a little higher at university.
第四段：别人对食堂看法
主题句：some people may argue that measures have been taken and things are improving there.
扩展句：
1、for instance, ic cards have taken the place of money in the canteed, and the attitude of the service people is also changing.
2、but in my opinon, progress is not so quick and thorough.
第五段：结尾，表明自己看法
结尾句：to be belief, though a bit dissatisfied with the present canteen conditions,
扩展句：i do believe that, with the efforts of all people concerned, we can solved the problems there. thanks.
第三部分、范文
dear mr. president,
this letter comes to you from one of your students.in it, some opinions are put forward for you to reflect upon.
as you know, our students are the main customers of the university canteen. but unfortunately, we don't find the service there satisfying sometimes.the food is not as nutritious as it should be. as a result, some of us become thinner and weaker at university.besides, sometimes the canteen people just bring us steamed bread with their dirty bare hands.and what's more, the fare is also a little higher at university.
some people may argue that measures have been taken and things are improving there.for instance, ic cards have taken the place of money in the canteed, and the attitude of the service people is also changing.but in my opinon, progress is not so quick and thorough