现象重要性比较结构描述 + 转折提出问题 + 写作目的阐述
Perhaps no any other resource is more important than the land which gives birth to the plants in various colors that constitutes capacity allows in that irrigation， farming machinery， electricity power， pesticides such as DDT， herbicides， and chemical fertilizers all come into being. These techniques significantly surge the crop yields. As a result， the food surplus， together with other favorable elements， naturally brings about population booms.
The increase in population， on the other hand， exercises considerable adverse impacts on the land resource. A large world population means more places to live. Urbanization as a consequence slips into high gear. People start to invade and intrude the primitive land which the creator leaves for other animals and plants. Humans use the land to build roads， houses， schools， and factories. As a result， trees have been cut， amphibians such as frog and toads are forced to move away from their habitats and finally extinct， and biodiversity becomes no longer as rich and complex as it was before. Land becomes commerce as the automobiles are purchased for an endless of purposes that go directly against the natures law.
Industrial activities， for another， must be an overwhelming factor that drives the resource of land to go with the wind. Land nourishes people. Ironically， people undermine it. Factoriesormanufacturing centers not only occupy an immense area of land which otherwise fosters and forges a perfect ecosystem balance， but also pollute the unrecyclable land. Take the manufacturing factories as a typical case in point. In Shiyan city， Hubei， Chian， where the Second Automobiles Works is located， ninety percent of the land is used to produce cars and parts of cars. This city was established half a century ago. But before 1960s， there was neither city nor cars there and the land was untapped， pristine， and pure. Today， however， the land is almost totally polluted， unable to give birth to a beautiful landscape.
All the reasons that ruin the land are independent and interacted. What human beings are supposed to commit themselves tois neither to stop developing agricultureorindustry， nor to totally weaken the land. Rather it is to achieve a balance between developing and maintaining the health of land.