【正确答案】
With the aggressive conquering of nature, humans are now facing serious problem of desertification. In the past spring, more than ten disastrous sandstorms hit several major cities in North China. This has alarmed the whole nation about the devastating consequences of the development strategy which turned a blind eye on the environment.
There may be some major reasons which contribute to the problem. For one thing, the development of economy is carried out at the expense of environment. Excessive land reclamation, grazing and lumbering have consequently caused a great loss of precious vegetation, resulting in the topsoil's extreme vulnerability to erosion. Secondly, the rapid growth of population also accelerates the process of desertification. We can say that desertification is threatening people's life.
As the problem remains, it is imperative for us to take effective measures to combat desertification. First of all, laws and regulations should be passed to protect the existing natural plant cover. Secondly, the government should encourage farmers to return the reclaimed land to grasslands or forests. Thirdly, the general public should have the awareness to protect our living environment. In brief, our strategy to combat desertification will be a long-term goal and everyone should make contributions to it.

【答案解析】[解析] 本篇作文属于问题解决类型，主要适用于对存在的某种问题提出解决方案或建议的写作。这一模式可以具体描述为：开始段说明问题的存在，中间段分析原因或后果，结束段提出解决方案。