职称英语卫生A阅读理解真题及答案.docx

职称英语卫生 A 阅读理解真题及答案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 Mali, Mauritania,Niger, and Chad.Unfortunately, over the last century the Sahara desert has steadily crept southwards eating into once productive Sahellands. 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 asfuel 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, otherplant species die, and eventually the fertile top soil 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 south-west Mali funded by UNDP has involved local communities in sustainable management off or rest, 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.36. 【题干】 The Sahel zone is an area which .【选项】A. is covered with sad and grassB. has a long historyC. occupies much of South NigeriaD. belongs to Sudan【答案】 A【解析】37. 【题干】 What is the situation about the desertification in Africa?【选项】A. The deserts are replaced with grasslandsB. The deserts are expandingC. the deserts are moving northwardsD. the deserts are being deserted【答案】 B【解析】38. 【题干】 The word “ deteriorated ” in paragraph2 means .【选项】A.deepened B.sufferedC.slipped D.worsened【答案】 D【解析】39. 【题干】 What is the root cause of desertification?【 选 项 】 A.poor farming B.overpopulationC.radical climate change D.disappearance of rare plant species【答案】 A【解析】40. 【题干】 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 supportD.converting agricultural land into forest【答案】 B【解析】。