辽宁省高考英语二轮：阅读理解训练5及答案

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1、2016辽宁省高考英语二轮：阅读理解训练（5）及答案阅读下列四篇短文，从每小题后所给的AZBZC或D四个选项中，选出最佳选项。Riversmaybeasign讦icantsourceofthegreenhousegasnitrousoxide（一氧彳匕二氮），scientistsnowfind.TheircalculationsuggeststhatacrosstheglobethewaterwayscontributethreetimestheamountofnitrousoxidetotheatmosphereashadbeenestimatedbytheInt

2、ernationalPanelonClimateChange（IPCC）,theUnitedNationsscientificbodychargedwithreviewingclimatechangeresearch・Theyfoundthattheamountofnitrousoxideproducedinstreamsisrelatedtohumanactivitiesthatreleasenitrogen（氮）intotheenvironment,suchasfertilizeruseandsewagedischarges・"Humanactivities,i

3、ncludingfossilfuelcombustionandintensiveagriculture,haveincreasedtheavailabilityofnitrogenintheenvironment/saidJakeBeaulieuoftheUniversityofNotreDameandtheU.S.EnvironmentaiProtectionAgencyinCincinnati,Ohio,andleadauthorofthepaperpublishedthisweekinthejournalProceedingsoftheNationalAcad

4、emyofSciences."Muchofthisnitrogenistransportedintoriverandstreamnetworks/Beaulieusaid.There,microbes（微生扌勿）convertthenitrogenintonitrousoxide（alsocalledlaughinggas）andaninertgascalleddinitrogen（二氮）.Thefindingisimportant,theresearcherssay,becausenitrousoxideisapowerfulgreenhousegasthatco

5、ntributestoclimatechangeanddestructionofthestratosphere'sozonelayer,whichprotectsusfromthesurfsharmfulultraviolet（紫夕卜纟戋）radiation.Comparedwithcarbondioxide,nitrousoxideis300-foldmorepowerfulintermsofitswarmingpotential,thoughcarbondioxideisafarmorecommongreenhousegas・Scientistsestimate

6、nitrousoxideaccountsforabout6percentofhuman-inducedclimatechange.Beaulieuandcolleaguesmeasurednitrousoxideproductionratesin72streams・Whensummedacrosstheglobe,theresultsshowedriversandstreamsarethesourceofatleast10percentofhumarrcausednitrousoxideemissionstotheatmosphere."Changesinagric

7、ulturalandIand-usepracticesthatresultinlessnitrogenbeingdeliveredtostreamswouldreducenitrousoxideemissionsfromrivernetworks/Beaulieusaid.1.Fromthesecondparagraphwecanlearn.A.actuallyriversgiveoffmuchmorenitrousoxidethanexpectedB.scientists"calculationistotallywrongC.humanactivitiesre