因果链分析说明:焚烧树叶对人有害-Burning Is Har

焚烧树叶对人有害
【内容提示】
根据内容提示写一篇提醒人们不要焚烧树叶的文章，说明焚烧树叶产生的烟雾，会污染环境，有害于人们的身体健康。
内容梗概：
前几天你去火车站给朋友送行，路上看到清洁工人正在烧树叶，你由此联想到老师曾讲过树叶燃烧的烟尘会对大气造成污染，并直接影响人体健康，导致癌症。你在文中呼吁人们不要烧树叶。
【作文示范】
Burning Is Harmful to People
A few days ago, I went to the railway station to see my friend off. On the way I saw street-cleaners burning dry leaves. What they do is wrong.
Burning things does harm to people. I remembered that our teachers once told us that burning dry leaves would give off smoke and dust which in turn pollute air. And what is more, it would be harmful to people's health. When people breathe the air with smoke, the smoke might lead to cancer. As a result, the cancer would cause people to die.
As we all know, leaves can make very good fertilizer. It would be better to collect them for the fields.
【词语解释】
fertilizer['f+:tilaiz+] n．肥料
【写法指要】
本文分析焚烧树叶的害处。引言段最后一句是全文的篇题。扩充段第一句是主题句，下面分析说：人燃烧树叶，树叶产生烟尘，烟尘污染空气，空气被人吸入，人得癌症，癌症致人死亡。这样就构成了一种因果链。所以我们说，本文是因果链分析说明文。结尾段中，作者提出自己的建议。