北京市延庆县2016高考英语暑假阅读理解选练（8）阅读下列四篇短文，从每小题后所给的A,B,C或D四个选项中，选出最佳选项。Riversmaybeasignificantsourceofthegreenhousegasnitrousoxide(一氧化二氮),scientistsnowfind.TheircalculationsuggeststhatacrosstheglobethewaterwayscontributethreetimestheamountofnitrousoxidetotheatmosphereashadbeenestimatedbytheInternationalPanelonClimateChange(IPCC),theUnitedNationsscientificbodychargedwithreviewingclimatechangeresearch.Theyfoundthattheamountofnitrousoxideproducedinstreamsisrelatedtohumanactivitiesthatreleasenitrogen(氮)intotheenvironment,suchasfertilizeruseandsewagedischarges.“Humanactivities,includingfossilfuelcombustionandintensiveagriculture,haveincreasedtheavailabilityofnitrogenintheenvironment,”saidJakeBeaulieuoftheUniversityofNotreDameandtheU.S.EnvironmentalProtectionAgencyinCincinnati,Ohio,andleadauthorofthepaperpublishedthisweekinthejournalProceedingsoftheNationalAcademyofSciences.“Muchofthisnitrogenistransportedintoriverandstreamnetworks,”Beaulieusaid.There,microbes(微生物)convertthenitrogenintonitrousoxide(alsocalledlaughinggas)andaninertgascalleddinitrogen(二氮).Thefindingisimportant,theresearcherssay,becausenitrousoxideisapowerfulgreenhousegasthatcontributestoclimatechangeanddestructionofthestratosphere’sozonelayer,whichprotectsusfromthesun’sharmfulultraviolet(紫外线)radiation.Comparedwithcarbondioxide,nitrousoxideis300-foldmorepowerfulintermsofitswarmingpotential,thoughcarbondioxideisafarmorecommongreenhousegas.Scientistsestimatenitrousoxideaccountsforabout6percentofhuman-inducedclimatechange.Beaulieuandcolleaguesmeasurednitrousoxideproductionratesin72streams.Whensummedacrosstheglobe,theresultsshowedriversandstreamsarethesourceofatleast10percentofhuman-causednitrousoxideemissionstotheatmosphere.“Changesinagriculturalandland-usepracticesthatresultinlessnitrogenbeingdeliveredtostreamswouldreducenitrousoxideemissionsfromrivernetworks,”Beaulieusaid.1.Fromthesecondparagraphwecanlearn.A.actuallyriversgiveoffmuchmorenitrousoxidethanexpectedB.scientists’calculationistotallywrongC.humanactivitiesreleasenitrousoxideintotheriversD.thereisnonitrogeninfertilizer2.WhichofthefollowingisNOTthesourceofnitrogen?A.Fertilizeruse.B.Sewagedischarges.C.Fossilfuelcombustion.D.Climatechange.3.Nitrousoxideisapowerfulgreenhousegasbecause.A.itcanprotectusfromthesun’sharmfulultravioletradiationB.itistoblameformostofhuman-inducedclimatechangeC.itisafarmorecommongreenhousegasD.ithasmuchmorewarmingpotentialthancarbondioxide4.Whatdoesthepassagemainlytellsus?A.Riversmaybeasourceofthegreenhousegasnitrousoxide.B.It’shumanactivitiesthatreleasenitrogenintotheenvironment.C.HowtoreducenitrousoxideemissionsfromrivernetworksDWhattodowiththeclimatechangecausedbynitrousoxide.【参考答案】1—4、ADDA【2013界广东深圳市第二次调研考试】Allofusshouldkeepakitchendiary,showinghowmuchfoodareleftuneatenasgarbage.Weallwastefood,youandmemillionsoftonsofit.InChina,enoughfoodiswastedinrestaurantseveryyeartofeed200millionpeople.IntheUnitedStates,40percentoffoodiswastedfromfarmtofork.Eachyear,theamountoffoodthrownawayinrichcountriesisalmostthesameasthatproducedinsub–SaharanAfrica.Thisraisessomeimportantquestions.Indevelopingcountries,foodislostbecausefarmersdonothaveappropriatecooling,storageormarketaccessfortheircrops.Theirgrains,fruitsandvegetablesdryupandrotaway.Indevelopedco...
