主题 卫生A代码12

 卫生A代码12   1.we are worried++changeable   2.the umrella was ++cleverly   3.compentitors must ++obey   4.the details of ++real   5.she is an ++bear   6.the new garment ++clothes   7.the way she++ ?   8.some newspapers in++especially   9.the coastal area ++warm   10.they have++water   11.he wore++old   12.his answers++unclear   13.only people++qualifred   14.the weather++pleasant   15.the latest++lists   16.a new++wrong   17.cardlac arrest++right   18.defibrillators are ++wrong   19.the new computer++wrong   20.the non-linear++wrong   21.the early-warning++not   22.the researchers++right   23.paragraph2++defin the   24.paragraph3++turn off   25.paragraph4++keep   26.paragraph5++take   27.the tiredness++low   28.sleeping++poor   29.a lower++exposure   30.a strong ++the   31.according to the++more   32.peopli++lung   33.according to theachman,couples++eat   34.according to theachman,single++their expectation   35.techman++the participants were   36.the sahel++occuples   37.what is the situation++the deserts are expanding   38.the world++worsened   39.what is the root++overpopulation   40.in orde to++developing   41.Dr ++not been proved   42.the clinical ++both calcium   43.the findings++only   44.the adverse++forgetfulness   45.according to++the amount   补全短文   46.an extra   47.a few   48.the cardiovascular   49.the body   50.pregnant   完形填空   51.through   52.valued   53.provide   54.surveyors   55.available   56.effective   57.fallen   58.which   59.prevented   60.access   61.in   62.soon   63.weigh   64.losses   65.with

主题 作者: 27.219.58.* 2016-03-28 13:24:27
1 楼 阅读 第二篇 Deforestation and Desertification(沙漠化)

第二篇 Deforestation and Desertification(沙漠化)   TheSahel zone lies between the Saharadesert and the fertile savannahs(热带大草原)ofnorthern Nigeria and South Sudan. The word sahel comes from Arabic and means marginal or transitional ,andthis is a good description of thesesemi-arid(半干旱)lands,whichoccupy much of the Western African countries of Mail,Mauritania,Niger,and Chad.   Unfortunately, over the last century theSahara desert has steadily crept southwards eating into once productive Sahellands. United Nations surveys show that over 70 percent of the dry land inagriculture use in Africa has deterioratedover the last 30 years. Droughts have become more severe, the most recentlasting over twenty years in parts of the Sahel region. The same process ofdesertification is taking place across southern Africa as the Kalahari desertadvances into Botswana and parts of South Africa.   One ofthe major causes of this desert advance ispoor agricultural land use, driven by the pressures of increasing population.Overgrazing一 keeping too many farm animals on the land一means that grasses and other plants cannot recover, and scarce water suppliesare exhausted. Overcultivation一 tryingto grow too many crops on poor land一 resultsin the soil becoming even less fertile and drier, and beginning to break up. Soilerosion (侵蚀) follows, and the land turns into desert.   Another cause of desertification is loss of tree cover. Trees are cutdown for use as fuel and to clear land for agricultural use. Tree roots help tobind the soil together, to conserve moisture, and to provide a habitat forother plants and animals. When trees are cut down, the soil begins to dry andloosen, wind and rain erosion increase, other plant species die, and eventuallythe fertile top soil may be almost entirely lost, leaving only bare rock anddust.   The effects of loss of topsoil and increased drought are irreversible. Theyare,however, preventable. Careful conservation of tree cover and sustainableagricultural land use have been shown to halt deterioration of soils and lessenthe effects of shortage of rainfall. One project in Kita in south-west Malifunded by UNDP has involved local communities in sustainable management offorest,while at the same time providing a viable(有活力的)agriculturaleconomy. This may be a model for similar projects in otherWest African countries.      36.The Sahel zone is an area which ___.   A. is covered with sad and grass   B. has a long history   C. occupies much of South Nigeria   D. belongs to Sudan   答案:a   37. What is the situation about thedesertification in Africa?   A. The deserts are replaced withgrasslands   B. The deserts are expanding   C. the deserts are moving northwards   D. the deserts are being deserted   答案:b   38. The word “deteriorated ” in paragraph2 means ___.   A. deepened   B. suffered   C. slipped   D. worsened   答案:d   39. What is the root causeof desertification?   A. poor farming   B. overpopulation   C. radical climate change   D. disappearance of rare plant species   答案:a   40. In order to prevent desertification,the author proposes ___.   A. making good use of international aids   B. developing a sustainableagricultural economy   C. gaining international support   D. converting agricultural land intoforest   答案:b

作者: 27.219.58.*   2016-03-28 14:09:01
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