2012-2013学年度第二学期高一半期英语能力测试姓名得分PAGE\*MERGEFORMAT3一．阅读短文回答下列问题80%AOverthepasthalfcentury,usingchemicalfertilizershasbecomeverycommoninfarming.Manyfarmerswelcomedthemasgreatwaytostopcropdiseaseandincreaseproduction.Recently,however,scientistshavebeenfindingthatlong-termuseofthesefertilizerscancausedamagetothelandand,evenmoredangerous,topeople’shealth.Whataresomeoftheproblemscausedbychemicalfertilizers?First,theydamagethelandbykillingthehelpfulbacteriaandpestsaswellastheharmfulones.Chemicalsalsostayinthegroundandundergroundwaterforalongtime.Thisaffectscropsand,therefore,animalsandhumans,sincechemicalsgetinsidethecropsandcannotjustbewashedoff.Thesechemicalsinthefoodsupplybuildupinpeople’sbodiesovertime.Manyofthesechemicalscanleadtocancerorotherillnesses.Inaddition,fruit,vegetablesandotherfoodgrownwithchemicalfertilizersusuallygrowtoofasttobefullofmuchnutrition.Theymaylookbeautiful,butinsidethereisusuallymorewaterthanvitaminsandminerals.Withthesediscoveries,somefarmersandmanycustomersarebeginningtoturntoorganicfarming.Organicfarmingissimplyfarmingwithoutusinganychemicals.Theyfocusonkeepingtheirsoilrichandfreeofdisease.Ahealthysoilreducesdiseaseandhelpscropsgrowstrongandhealthy.Organicfarmers,therefore,oftenpreferusingnaturalwastefromanimalsasfertilizer.Theyfeelthatthismakesthesoilintheirfieldsricherinmineralsandsomorefertile.Thisalsokeepstheair,soil,waterandcropsfreefromchemicals.Organicfarmersalsousemanyothermethodstokeepthesoilfertile.Theyoftenchangethekindofcropineachfieldeveryfewyears,forexample,growingcornorwheatandthenthenextyearpeasorsoybeans.Cropssuchaspeasorsoybeansputimportantmineralsbackintothesoil,makingitreadyforcropssuchaswheatorcornthatneedrichandfertilesoil.Organicfarmersalsoplantcropstousedifferentlevelsofsoil,forexample,plantingpeanutsthatusetheground’ssurfacefollowedbyvegetablesthatputdowndeeproots.Someorganicfarmerspreferplantinggrassbetweencropstopreventwindorwaterfromcarryingawaythesoil,andthenleavingitinthegroundtobecomeanaturalfertili