假如你是高中生李华，有感于校园中存在的随地吐痰（to spit）和乱丢垃圾（to litter）等不文明行为，请用英语给校长写一封信，信中应包括以下内容：
1．说明写信目的；
2．对这些行为进行批评；
3．提出建议（至少两点）；
注意：1．可根据内容要点适当发挥，但不要逐条翻译。
2．词数150左右。
3．信的抬头、落款及信的第一句已给出（不计词数）。
November 15, 2012
Mr. Headmaster,
I'm Li Hua, a student from Class 1, Senior II. I am writing to draw your attention to some improper behaviour among us students: spitting and littering. It makes our school dirty and unpleasant, and does hard to the image of our school.
I always feel ashamed whenever I see this. It is clearly not appropriate for a student to spit and litter about. I wonder if the school could place more dustbins around and set up specific rules against such behaviour. At the same time, students should be encouraged to develop good habits and better behave themselves. I believe that, with the joint efforts of both teachers and students, our school will become a more enjoyable place in the near future.
Thank you for your consideration.
Your faithfully,
Li Hua
题目分析：这是一封信的写作，内容要点已给出，我们需要用正确的英语把给出的要点表达出来.写作时注意准确运用时态，上下文意思连贯，符合逻辑关系，尽量使用自己熟悉的单词句式，同时也要注意使用高级词汇和高级句型使文章显得更有档次。
点评：议论文的写作，观点，例证，结论，建议要清晰，平时多积累单词和句型，多读一些范文。