银川是一个怎样的城市？ 本文首发于公众号：地道风物（didaofengwu）银川，超乎你对大西北的所有想象，但依旧西北。鸟瞰贺兰山及…
英语作文《沙漠化》 DesertificationDesertification is becoming a serious problem in recent years.A table shows the trend of desertification in a region in two aspects.According to the table，area of 560 square kilometers was deserted in the 1980s.In the 1990s，the area of desertification took a leap to 810 square kilometers.In the following ten years，the number raised slowly than the first ten years.The area of deserted land finally reached 980 square kilometers.The table also shows the frequency of sandstorms in the region.From 1980s to 1990s，the frequency of sandstorms raised sharply.Because the area of desertification took a turn to rise slowly，the frequency went up to 16，by about 30 percent only.Desertification is obviously an international problem now.It is caused by the decrease of woods and vegetation.The water in the ground is kept by the plants，so the land may turn to desert without enough plants.Desertification can cause bad weather like sandstorms and even change the climate of a region。.
求环保的资料，图片，文章，要图片和资料哦 最近，62616964757a686964616fe59b9ee7ad9431333234333361英国《自然》杂志刊登了剑桥大学和设菲尔德大学的科学家的文章。科学家们认为，全球每年应该拿出3000亿美元用于保护野生动植物，这个价格其实很划算。科学家有说：\"我们粗略估算了一下，3000亿美元同各国政府'不恰当'的补贴相比，其实是个小数目。'不恰当'的补贴占用于鼓励各国农业生产、能源利用、道路运输、淡水消费、商业捕鱼等，这些补贴每年在9500―14500亿美元之间。'不恰当'的补贴使资源的价格低于市场经济水平，淡化了人们'资源有价'的意识，实际上是在鼓励人们过度开发自然资源。现在，科学家、环境专家和一些国家政府越来越对自然资源估价感兴趣。环境保护、社会安全、教育和国防等诸领域，经常在财政上争饭吃，令政府首脑们头痛。而自然资源估价正被看成是一种有效的方法，用于检验政府投资的正确性，以及确定最应优先保护的环境领域。科学家们认为，地球生态系统为人们提供淡水资源，过滤和吸附污染物质，消纳温室气体，提供渔业资源和旅游资源，其价值应为33万亿美元。剑桥大学土地经济系的亚历山大？詹姆斯深有感触地说：\"我们每年为保护地球野生动植物仅投入60亿美元，真是大少了。摘自。
