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
How deserts are formed A. A desert refers to a barren section of land, mainly in arid and semi-arid areas, where there is al
How deserts are formed A. A desert refers to a barren section of land, mainly in arid and semi-arid areas, where there is al
admin
2022-01-29
78
问题
How deserts are formed
A. A desert refers to a barren section of land, mainly in arid and semi-arid areas, where there is almost no precipitation, and the environment is hostile for any creature to inhabit. Deserts have been classified in a number of ways, generally combining total precipitation, how many days the rainfall occurs, temperature, humidity, and sometimes additional factors. In some places, deserts have clear boundaries marked by rivers, mountains or other landforms, while in other places, there are no clear-cut borders between desert and other landscape features.
B. In arid areas where there is not any covering of vegetation protecting the land, sand and dust storms will frequently take place. This phenomenon often occurs along the desert margins instead of within the deserts, where there are already no finer materials left. When a steady wind starts to blow, fine particles on the open ground will begin vibrating. As the wind picks up, some of the particles are lifted into the air. When they fall onto the ground, they hit other particles which will then be jerked into the air in their turn, initiating a chain reaction.
C. There has been a tremendous deal of publicity on how severe desertification can be, but the academic circle has never agreed on the causes of desertification. A common misunderstanding is that a shortage of precipitation causes the desertification—even the land in some barren areas will soon recover after the rain falls. In fact, more often than not, human activities are responsible for desertification. It might be true that the explosion in world population, especially in developing countries, is the primary cause of soil degradation and desertification. Since the population has become denser, the cultivation of crops has gone into progressively drier areas. It’s especially possible for these regions to go through periods of severe drought, which explains why crop failures are common. The raising of most crops requires the natural vegetation cover to be removed first; when crop failures occur, extensive tracts of land are devoid of a plant cover and thus susceptible to wind and water erosion. All through the 1990s, dryland areas went through a population growth of 18.5 per cent, mostly in severely impoverished developing countries.
D. Livestock farming in semi-arid areas accelerates the erosion of soil and becomes one of the reasons for advancing desertification. In such areas where the vegetation is dominated by grasses, the breeding of livestock is a major economic activity. Grasses are necessary for anchoring barren topsoil in a dryland area. When a specific field is used to graze an excessive herd, it will experience a loss in vegetation coverage, and the soil will be trampled as well as be pulverised, leaving the topsoil exposed to destructive erosion elements such as winds and unexpected thunderstorms. For centuries, nomads have grazed their flocks and herds to any place where pasture can be found, and oases have offered chances for a more settled way of living. For some nomads, wherever they move to, the desert follows.
E. Trees are of great importance when it comes to maintaining topsoil and slowing down the wind speed. In many Asian countries, firewood is the chief fuel used for cooking and heating, which has caused uncontrolled clear-cutting of forests in dryland ecosystems. When too many trees are cut down, windstorms and dust storms tend to occur.
F. What’s worse, even political conflicts and wars can also contribute to desertification. To escape from the invading enemies, the refugees will move altogether into some of the most vulnerable ecosystems on the planet. They bring along their cultivation traditions, which might not be the right kind of practice for their new settlement.
G. In the 20th century, one of the states of America had a large section of farmland that had turned into desert. Since then, actions have been enforced so that such a phenomenon of desertification will not happen again. To avoid the reoccurring of desertification, people shall find other livelihoods which do not rely on traditional land uses, are not as demanding on local land and natural resource, but can still generate viable income. Such livelihoods include but are not limited to dryland aquaculture for the raising of fish, crustaceans and industrial compounds derived from microalgae, greenhouse agriculture, and activities that are related to tourism. Another way to prevent the reoccurring of desertification is bringing about economic prospects in the city centres of drylands and places outside drylands. Changing the general economic and institutional structures that generate new chances for people to support themselves would alleviate the current pressures accompanying the desertification processes.
H. In nowadays society, new technologies are serving as a method to resolve the problems brought by desertification. Satellites have been utilised to investigate the influence that people and livestock have on our planet Earth. Nevertheless, it doesn’t mean that alternative technologies are not needed to help with the problems and process of desertification.
Reading Passage has eight paragraphs, A-H.
Which paragraph contains the following information?
Write the correct letter, A-H, in boxes on your answer sheet.
NB You may use any letter more than once.
the influence of migration on desertification
选项
答案
D
解析
迁徙对沙漠化的影响。关键词migration。D段主要讲的是畜牧业对沙漠化形成所产生的影响。这一段的倒数第2句提到了游牧民族的生活习惯,接着最后1句…wherever they move to,the desert follows是总结,牧民所到之处便会形成沙漠,体现了本题题干migration这个关键词。因此,本题的正确答案为D。
转载请注明原文地址:https://kaotiyun.com/show/HBAO777K
本试题收录于:
雅思阅读题库雅思(IELTS)分类
0
雅思阅读
雅思(IELTS)
相关试题推荐
ThepolarlightsknownasaurorasareproducedwhenchargedsubatomicLineparticles,suchasprotonsandelectronsflowingfro
Educatorswhostudytheinfluencesofgeographicaldifferencesoneducationalsuccesshaveconcludedthatenvironmentisnot___
Ironically,thewritersowaryof(i)______was(ii)______withinkandpaper,hisnovelrunningto2,500shagreen-boundfoliopages
Notwithstandingtheir______regardingotherissues,townshipresidentshaveconsistentlypassedtheboardofeducation’sannualb
Themassiveinfluxofwomencyclists—makingupatleastathirdofthetotalmarket—wasperhapsthemoststrikingandprofound
Thispassageisadaptedfrommaterialpublishedin2001.In1998scientistsusingtheneutrinodetectorinKamioka,Japan,were
Readersofhistoryoftenmarvelthat(i)______eventsweretriggeredbyactionsthatseemed(ii)______atthetime.
IntheredNamibiandesertofDemarala,about100blackrhinosstillmanageto(i)______eventhoughtheterrainisextraordinari
Muchofthisauthor’swork,unfortunately,is(i)______with(ii)______chapteroftenimmediatelyfollowingasublimeone.
Therecentlyannounceddiscoveryofthefirstknownplanetorbitingapulsar(theultradense,pulsatingremnantoffthesupernov
随机试题
下列关于证据收集的说法,错误的是:()
A、胃小弯十二指肠后壁B、胃大弯C、胃小弯D、幽门附近、胃和十二指肠前壁E、胃窦胃癌多位于_______。
津液输布的主要通道是
周先生,49岁,患慢性痢疾,医嘱给予0.5%新霉素溶液保留灌肠,不正确的操作是
城市化进程中城市发展与经济结构转型过程,形成()四个阶段。
会计人员在工作中“都是熟人不会错”的不良习惯,违背了会计职业道德规范中的()的具体内容。
收益性物业预算是物业管理中经营计划的核心,预算中包括()。
富士于薄红中醒来。请将眼睛下移,红霞早已罩在最北面的大山顶上了。接着,很快________到足柄山,又转移到箱根山。看吧,黎明正脚步匆匆________着黑夜。红追而蓝奔,伊豆的连山早已一派桃红。依次填入画横线部分最恰当的一项是()。
唐朝时的“朋党之争”所反映的矛盾是( )。
许多企业深受目光短浅之害,它们太关注立竿见影的结果和短期目标,以至于无法高瞻远瞩,往往使企业陷于被动甚至导致破产。因此,企业领导层的决策和行动应该以长期目标为主,不需过分关注短期目标。以下哪项如果为真,将最有力地削弱上述论证?
最新回复
(
0
)