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
外语
Deforestation and Desertification(沙漠化) The Sahel zone lies between the Sahara desert and the fertile savannahs(热带大草原)of nort
Deforestation and Desertification(沙漠化) The Sahel zone lies between the Sahara desert and the fertile savannahs(热带大草原)of nort
admin
2016-08-16
40
问题
Deforestation and Desertification(沙漠化)
The Sahel zone lies between the Sahara desert and the fertile savannahs(热带大草原)of northern Nigeria and South Sudan. The word "sahel" comes from Arabic and means marginal or transitional, and this is a good description of these semi-arid(半干旱)lands,which occupy much of the Western African countries of Mail, Mauritania, Niger, and Chad.
Unfortunately, over the last century the Sahara desert has steadily crept southwards eating into once productive Sahel lands. United Nations surveys show that over 70 percent of the dry land in agriculture use in Africa has deteriorated over the last 30 years. Droughts have become more severe, the most recent lasting over twenty years in parts of the Sahel region. The same process of desertification is taking place across southern Africa as the Kalahari desert advances into Botswana and parts of South Africa.
One of the major causes of this desert advance is poor agricultural land use, driven by the pressures of increasing population. Overgrazing—keeping too many farm animals on the land—means that grasses and other plants cannot recover, and scarce water supplies are exhausted. Over cultivation—trying to grow too many crops on poor land—results in the soil becoming even less fertile and drier, and beginning to break up. Soil erosion(侵蚀)follows, and the land turns into desert.
Another cause of desertification is loss of tree cover. Trees are cut down for use as fuel and to clear land for agricultural use. Tree roots help to bind the soil together, to conserve moisture, and to provide a habitat for other plants and animals. When trees are cut down, the soil begins to dry and loosen, wind and rain erosion increase, other plant species die, and eventually the fertile topsoil may be almost entirely lost, leaving only bare rock and dust.
The effects of loss of topsoil and increased drought are irreversible. They are, however, preventable. Careful conservation of tree cover and sustainable agricultural land use have been shown to halt deterioration of soils and lessen the effects of shortage of rainfall. One project in Kita in southwest Mali funded by UNDP has involved local communities in sustainable management of forest, while at the same time providing a viable(有活力的)agricultural economy. This may be a model for similar projects in other West African countries.
In order to prevent desertification, the author proposes______.
选项
A、making good use of international aids
B、developing a sustainable agricultural economy
C、gaining international support
D、converting agricultural land into forest
答案
B
解析
根据第五段Careful conservation of tree cover and sustainable agricultural land use havebeen shown to halt deterioration of soils and lessen the effects of shortage of rainfall可知,为了阻止沙漠化,作者建议保护植被和可持续的农业土地利用。故选B。
转载请注明原文地址:https://kaotiyun.com/show/EhGd777K
本试题收录于:
职称英语理工类A级题库职称英语分类
0
职称英语理工类A级
职称英语
相关试题推荐
ANewFindingBritishcancerresearchershavefoundthatchildhoodleukaemiaiscausedbyaninfectionandclustersofcase
InternationalTradeSincetheendofWorldWarII,internationaltradehasdevelopeddramatically.Allcountriesinthemo
ChangesinMuseumsMuseumshavechanged.Theyarenolongerplacesthatone“should”visit,theyareplacestoenjoyandl
TheEffectsofGlobalWarmingonWeatherTherearehiddenfactorswhichscientistscall“feedbackmechanisms”.Nooneknow
GeographyandMovementTounderstandhowastrologyworks,weshouldfirsttakeaquicklookatthesky.Althoughthestars
DisfigurementofBusinessmanIntherelationshipofeducationtobusinessweobservetodayafinestateofparadox.Onthe
Bydescribingatypicalsituationofalostdriverontheroad,theauthorintendto______.Ofthefollowingfunctions,which
TheauthorcouldnotgotosleeppartlybecauseWhatdidthecouchrepresent?
Intelligence:aChangedView1.Intelligencewasbelievedtobeafixedentity(存在,实体),somefacultyofthemindthatweallposs
Theideawasquitebrilliant.
随机试题
根据增值税法律制度的规定,一般纳税人提供下列应税服务,可以选择适用简易计税方法计税的有()。
急性阑尾炎可发生的并发症不包括下列哪项()(1998年)
男性,50岁,病人15年来,无事实根据的认为单位上下合伙谋害他,反复到各级信访机关及公安局上访告状,劝说无效
《中国药典》一部收载的内容包含有
下列关于会计政策变更的处理中,正确的是()。
下列各项中,关于仲裁的各项表述正确的是()。
阅读关于“地球的圈层结构”的图文资料,按要求完成教学设计任务。材料一《普通高中地理课程标准(实验)》的内容要求:“说出地球的圈层结构,概括各圈层的主要特点。”材料二某版本教科书中关于“地球的圈层结构”的部分内容。地球具有圈层结构,从
李五欲自己出资设立一个有限责任公司,向杨律师进行咨询,杨律师提供的下列咨询意见中,不正确的是()。
ThecompletionofthenewTownHallhasbeen______owingtoastrike.
Whyisitsodifficulttofallasleepwhenyouareovertired?Thereisnooneanswerthat【C1】______toeveryindividual.Butman
最新回复
(
0
)