首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
考研
Conventional wisdom says trees are good for the environment. They absorb carbon dioxide—a greenhouse gas—from the atmosphere and
Conventional wisdom says trees are good for the environment. They absorb carbon dioxide—a greenhouse gas—from the atmosphere and
admin
2010-06-17
67
问题
Conventional wisdom says trees are good for the environment. They absorb carbon dioxide—a greenhouse gas—from the atmosphere and store it as carbon while releasing oxygen. The roots of trees have been thought to trap sediments and nutrients in the soil, keeping nearby rivers free flowing. Trees have also been credited with steadying the flow of these rivers, keeping it relatively constant through wet and dry seasons, thus preventing both drought and flooding. Pernicious nonsense, conclude two pieces of research published this week.
The first, a four-year international study led by researchers at the University of Newcastle, in Britain, and the Free University of Amsterdam, identifies several myths about the link between forests and water. For example, in arid and semi-arid areas, trees consume far more water than they trap. And it is not the trees that catch sediment and nutrients, and steady the flow of the rivers, but the fact that the soil has not been compressed.
The World Commission on Water estimates that the demand for water will increase by around 50% in the next 30 years. Moreover, around 4 billion people—one half of the world’s population—will live in conditions of severe water stress, meaning they will not have enough water for drinking and washing to stay healthy, by 2025.
The government of South Africa has been taking a tough approach to trees since it became the first to treat water as a basic human right in 1998. In a scheme praised by the hydrologists, the state penalizes forestry companies for preventing this water reaching rivers and underground aquifers. In India, large tree-planting schemes not only lose valuable water but dim the true problem identified by the hydrologists: the unregulated removal of water from aquifers to irrigate crops. Farmers need no permit to drill a borehole and, as most farmers receive free electricity, there is little economic control on the volume of water pumped. So a report of Britain’s Department for International Development concludes that there is no scientific evidence that forests increase or stabilize water flow in arid or semi-arid areas. It recommends that, if water shortages are a problem, governments should impose limits on forest plantation.
The second piece of research looked at how long the forests of the Amazon basin cling on to carbon. Growing trees consume carbon dioxide and it was thought that only when the tree died, perhaps hundreds of years later, would the carbon be returned to the atmosphere. No such luck. In a paper published in Nature this week, a team of American and Brazilian scientists found that trees were silently returning the carbon after just five years. Before taking an axe to trees, however, consider the merits of the tropical rainforests.
选项
A、can improve the quality of atmosphere.
B、may lead to slow flowing of rivers.
C、will help wet and dry seasons to be unchanged.
D、are able to remove carbon from the soil.
答案
A
解析
推理判断题。第一段围绕conventional wisdom展开,列举了人们对树木的传统认识,与题干中的 traditionally对应,第二句叙述了树木对空气的影响,吸收二氧化碳并释放氧气,所以选项A正确;选项Bslow flowing是对第三句中free flowing的错误理解;第四句是说树木可以保持河流在干旱和潮湿季节的流量,选项C错误;选项D文中未提及。
转载请注明原文地址:https://kaotiyun.com/show/n444777K
0
考研英语一
相关试题推荐
Asmanypeoplehitmiddleage,theyoftenstarttonoticethattheirmemoryandmentalclarityarenotwhattheyusedtobe.We
IftheInternetwastheinformationsuperhighway,5Gisafuturewhereeverystreetisahighway:nospeedlimits,nodatabottl
WarrenBuffett,whowillhostBerkshireHathaway’sannualshareholders’meetingonMay3rd,isaniconofAmericancapitalism.A
Withmanynationstryingtocreatetheirowninnovationeconomy,oneofthemoreanticipatedeventsalmosteveryyearisthelat
Nottoomanydecadesago,itseemed"obvious"bothtothegeneralpublicandtosociologiststhatmodernsocietyhaschangedpeo
Thereis,writesDanieleFanelliinarecentissueofNature,somethingrotteninthestateofscientificresearch—anepidemico
"What’sthedifferencebetweenGodandLarryEllison?"asksanoldsoftwareindustryjoke.Answer:Goddoesn’tthinkhe’sLarry
"What’sthedifferencebetweenGodandLarryEllison?"asksanoldsoftwareindustryjoke.Answer:Goddoesn’tthinkhe’sLarry
Foryears,highschoolstudentshavereceivedidenticaltextbooksastheirclassmates.Evenasstudentshavedifferentlearning
Musicproducesprofoundandlastingchangesinthebrain.Schoolsshouldaddmusicclasses,notcutthem.Nearly20yearsago,a
随机试题
社会工作者小李计划采用个案研究方法对随迁老人的需求进行研究,通过深度访淡、观察、量表等方法收集资料,分析某街道辖区随迁老人的需求,从而为这一群体的服务方案设计提供策略性建议。关于个案研究特点的说法,正确的有()。
仅满足lNF的关系模式会存在哪些问题?
抽样推断中,抽取样本需要遵循的基本原则是()
下列药材粉碎原则中不正确者是
牛股膝关节前方具有
近年来,许多不法商贩将工业明胶卖给企业制成药用空胶囊,最终流入药品企业,进入患者腹中。由于皮革在工业加工时,要使用含铬的鞣制剂,因此这样制成的胶囊,往往重金属铬超标。经有关部门检测,多家药厂的多个批次药品,所用胶囊重金属铬含量超标,“毒胶囊”事件引起了社
甲公司为电子设备生产公司,在上海证券交易所上市,为增值税一般纳税人,适用的增值税税率为27%,适用的所得税税率为33%,按税后利润的10%提取法定盈余公积,按5%提取法定公益金(06年教材中取消了法定公益金)。甲公司2004年度所得税汇算清缴于2005年3
在完全竞争市场上,厂商的需求曲线()。
阅读材料,根据要求完成教学设计。材料一《普通高中物理课程标准(2017年版)》关于“导体的电阻”的内容标准为:“通过实验,探究并了解金属导体的电阻与材料、长度和横截面积的定量关系。会测量金属丝的电阻率。”材料二高中物理某教科书“
外事警察是负责维护我国边境地区的社会治安,处理边境涉外事务的人民警察。()
最新回复
(
0
)