1、ships of desert-exposition,exposition,Exposition is explanatory writing. Its purpose is to explain or clarify a point Patterns of exposition: exemplification ;process analysis ;cause effect analysis; comparison and contrast; classification ;analogy; definition.,Organization,Part 1 (para. 1-8): the l
2、ist of the images of environmental destruction: the drying up of the Aral; deforestation; air pollution Part 2 (para. 9-16): analysis of the global threats posed by the environmental destruction and the common cause-the change in the relationship between human civilization and the earths natural bal
3、ance Part 3 (para. 17-26): the solution to environmental destructions- reinventing and healing the relationship between civilization and the earth,Loss of biodiversity,Biodiversity（生物多样性） Definition：Biological diversity (biodiversity) refers to a range of diverse living organisms (animals, plants, m
4、icro-organisms) on a regular basis constituted by the combination of stable ecological complexes.,Value of biodiversity and its significance ： Direct value： （1） biodiversity provides food, fiber, building materials and furniture, and other industrial raw materials for human beings.,（2）Biodiversity a
5、lso have aesthetic value（美学价值）, we can cultivate our sentiments and beautify peoples lives. In addition, biodiversity can also stimulate inspiration for literary and artistic creation.,winter sweet,chrysanthemum,bamboo,（3）Biodiversity has an important ecological function. No matter what kind of ecos
6、ystem, wildlife is one of the essential components. Wildlife once reduced, the ecosystem stability would be destroyed, the survival environment of mankind would also be affected.,the potential value: as far as the medicinal properties, 80% of the populations in developing countries rely on plants or
7、 animals, to ensure the basic health.,Causes of biodiversity reduction: 1、The rapid increase in population.,The population keeps increasing, so arable land must be expanded to meet demands of eating, this becomes the direct threat to the natural eco-systems.,2、Overexploitation,Environmental pollution,killing,No!,Are these problems difficult to be solved?,As long as we can start out small.,Thank you !,
