The area of deert in the world i growing every year. Many part of the world which once had large population and produced plenty of crop, have become deert. Dunhuang in China, deep in the heart of the Gebi Deert, wa once a great city.
Cattle are one caue of the problem. In good year, famer increae the number of their cattle. Then one year, the rain fail to come. The farmer do not want to kill any of their cattle, o the cattle eat ail the gra and anything that grow on poorer land. If thi continue for everal year, the gra never grow again and the land become a deert. One uggeted anwer i for farmer to limit the number of their cattle.
Another problem i that good oil i gradually lot. When tree are cut down, there i nothing to hold the oil in place on the hillide. So when if rain, the oil i wahed down the hill and into the river. h2 wind can alo blow away the valuable oil that lie on the top of the field.
地球本是多方位，包罗万象的，但作者从地球的沙漠化方面考虑，列举了造成此情况的原因，暗示人类要注意这个严重的问题。
这是一篇很好的原因 结果式文章。先陈述结果，后列举原因。
地球
世界上沙漠的面积每年都在扩大，许多地区曾经人口众多，五谷丰登，而今却成了沙漠。中国的敦煌曾经是一个大城市，而现在却深深陷入戈壁滩的腹地。[由www.haoZuowen.Com整理]
造成戈壁滩的原因之一是牲畜问题。年景好时，农民就增加牲畜饲养的头数。后来有一年天没有下雨，农民又不想把牲畜杀掉。因此，牲畜就把草和更加贫瘠的土地上所长的任何东西全都吃光。这种情况如果继续几年，那么，草就再也长不出来了，土地也就变成了沙漠。有人提出的解决办法是让农民限制饲养牲畜的数量。
另外一个问题就是沃土逐渐流失。树木被砍伐了，山坡上就没有什么东西能够把土壤保持住了。因此，下雨的时候，土壤从山上被冲刷下来，流到河里去了。大风也可能把田地表面的肥沃土壤刮走。
Earth Hour tarted in Autralia with million of home and buinee turning their light off for one hour. Now it ha grown to become one of the world’ bigget climate change initiative. People are all joining together in a global effort to how that it’ poible to take action on global warming.
Earth Hour ha brought about ome new change to our live. The iconic Bird’ Net National Stadium and the nearby Water Cube National Aquatic Center, uually illuminated by floodlight, went dark at 8:30 p.m., while dozen of hotel, office building, hopping mall and retaurant alo witched ome light off. People join activitie uch a candle-lit dinner and tar-gazing partie a a repone to the call for going dark. However, ome critic have dimied the event a imply a gimmick that will not make any difference.
From my point of view, Earth Hour i a global call to action to every individual, every buine and every community. A call to tand up, to take reponibility and to get involved in working toward a utainable future. Earth Hour i a meage of hope and a meage of action. Everyone can make a difference.
Topic:
Environmental problem are a big a not for individual country or individual people to addre. In other word, we have reached the tage that environmental problem be olved for international view. To what extent do you agree or diagree?
In recent year, many nation have become more aware of the environmental iue each nation face, uch a air and water pollution. The quetion i, are the environmental iue a national problem or an international problem? It i my belief that the environmental iue have grown to the point of becoming an international problem needing international cooperation to reolve.
Becaue of the difference in environmental policie, reource and technology, international cooperation could provide quicker reult and have a greater impact on bringing reolution to environmental problem for nation of differing environmental policie and of leer reource and technology. By pooling international reource and technology to addre the environmental problem, the diadvantaged nation are provided the aitance needed. Otherwie their environmental condition deteriorate ultimately affecting the reource and environment of the world a a whole.
One of the difficulitie to an international reolution to environmental iue i the difference in individual nation view and policie toward environmental protection. In order for international cooperation to occur and ucceed, the nation of the world mut ubmit themelved to international tandard and uperviion by an international commiion elected by the participating nation of the world. All member mut agree to abide by the tandard etablihed.
The environmental iue facing each country are not unrelated to the well being of the ret of the world. The impact i long term and international in cope. Without international cooperation and agreement to addre uch environmental iue a glacial melting at the South Pole, depletion of the ozone layer, water pollution, air polution, etc., the environmental condition of the world will deteriorate to the detriment of every nation, not jut thoe that ignore or lack the reource and technology to reolve their individual environmental problem.
A part of the ame planet, it i the reponibility of each individual and nation to protect the global environment. Only international cooperation will provide the timely olution and the effectivene needed to top the deteriorating global environment.