职称英语考试真题及答案(卫生类A级)2016年职称英语考试真题及答案(卫生类A级)掌握好每一个知识点，考试才能有恃无恐。下面是百分网小编精心为大家整理的卫生类的2016年职称英语考试真题及答案，希望对大家有帮助，更多内容请关注应届毕业生网!阅读判断DeforestationandDesertification(沙漠化)TheSahelzoneliesbetweentheSaharadesertandthefertilesavannahs(热带大草原)ofnorthernNigeriaandSouthSudan.ThewordsahelcomesfromArabicandmeansmarginalortransitional,andthisisagooddescriptionofthesemi-arid(半干旱)lands,whichoccupymuchoftheWesternAfricancountriesofMail,Mauritania,Niger,andChad.Unfortunately,overthelastcenturytheSaharadeserthassteadilycreptsouthwardseatingintoonceproductiveSahellands.UnitedNationssurveysshowthatover70percentofthedrylandinagricultureuseinAfricahasdeterioratedoverthelast30years.Droughtshavebecomemoresevere,themostrecentlastingovertwentyyearsinpartsoftheSahelregion.ThesameprocessofdesertificationistakingplaceacrosssouthernAfricaastheKalaharidesertadvancesintoBotswanaandpartsofSouthAfrica.Oneofthemajorcausesofthisdesertadvanceispooragriculturallanduse,drivenbythepressuresofincreasingpopulation.Overgrazing一keepingtoomanyfarmanimalsontheland一meansthatgrassesandotherplantscannotrecover,andscarcewatersuppliesareexhausted.Overcultivation一tryingtogrowtoomanycropsonpoorland一resultsinthesoilbecomingevenlessfertileanddrier,andbeginningtobreakup.Soilerosion(侵蚀)follows,andthelandturnsintodesert.Anothercauseofdesertificationislossoftreecover.Treesarecutdownforuseasfuelandtoclearlandforagriculturaluse.Treerootshelptobindthesoiltogether,toconservemoisture,andtoprovideahabitatforherplantsandanimals.Whentreesarecutdown,thesoilbeginstodryandloosen,windandrainerosionincrease,otherplantspeciesdie,andeventuallythefertiletopsoilmaybealmostentirelylost,leavingonlybarerockanddust.Theeffectsoflossoftopsoilandincreaseddroughtareirreversible.Theyare,however,preventable.Carefulconservationoftreecoverandsustainableagriculturallandusehavebeenshowntohaltdeteriorationofsoilsandlessentheeffectsofshortageofrainfall.OneprojectinKitainsouth-westMalifundedbyUNDPhasinvolvedlocalcommunitiesinsustainablemanagementofforest,