专业八级分类模拟55.docx

专业八级分类模拟55.docx

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专业八级分类模拟55

READINGCOMPREHENSION

Daylightsavingtime（DST）istheconventionofadvancingclockssothat

afternoonshavemoredaylightandmorningshaveless.Typicallyclocksare

adjustedforwardonehournearthestartofspringandareadjustedbackward

inautumn.ModernDSTwasfirstproposedin1907byWilliamWillett.Many

countrieshaveuseditsincethen;detailsvarybylocationandchange

occasionally.

Generalagreementabouttheday'slayoutconferssomanyadvantagesthat

astandardDSTscheduleusuallyoutrankseffortstogetupearlier,evenfor

peoplewhopersonallydisliketheDSTschedule.Thepracticeismixedblessing,

however.

Forinstance,retailers,sportinggoodsmakers,andotherbusinesses

benefitfromextraafternoonsunlight,asitinducescustomerstoshopand

toparticipateinoutdoorafternoonsports.Asthe1984Fortunemagazine

estimatedthataseven-weekextensionofDSTwouldyieldanadditional$30

millionfor7-Elevenstores,andtheNationalGolfFoundationestimatedthe

extensionwouldincreasegolfindustryrevenues$200millionto$300million.

Conversely,DSTcanadverselyaffectfarmersandotherswhosehoursareset

bythesun.Forexample,grainharvestingisbestdoneafterdewevaporates,

sowhenfieldhandsarriveandleaveearlierinsummertheirlaborisless

valuable.DSTalsohurtsprime-timebroadcastratingsanddrive-inandother

theaters.

Clockshiftscorrelatewithdecreasedeconomicefficiency.In2000the

daylight-savingeffectimpliedanestimatedone-daylossof$31billionon

U.S.stockexchanges.ClockshiftsandDSTrulechangeshaveadirecteconomic

cost,sincetheyentailextraworktosupportremotemeetings,computer

applicationsandthelike.Forexample,a2007NorthAmericanrulechange

costanestimated$500millionto$1billion.

Extraafternoondaylightissaidtoreducetrafficfatalities.In1975

theU.S.DOTconservativelyidentifieda0.7%reductionintrafficfatalities

duringDST,andestimatedtherealreductiontobe1.5%to2%,butthe1976

NBSreviewoftheDOTstudyfoundnodifferencesintrafficfatalities.In

1995theInsuranceInstituteforHighwaySafetyestimatedareductionof1.2%,

includinga5%reductionincrashesfataltopedestrians.Othershavefound

similarreductions.Single/DoubleSummerTime（SDST）,avariantwhereclocks

areonehouraheadofthesuninwinterandtwoinsummer,hasbeenprojected

toreducetrafficfatalitiesby3%to4%intheUK,comparedtoordinaryDST.

AcorrelationbetweenclockshiftsandaccidentshasbeenobservedinNorth

AmericabutnotinSweden.Ifthiseffectexists,itisfarsmallerthanthe

overallreductioninfatalities.

However,theeffectofDSToncrimeislessclear.Inthe1970stheU.S.

LawEnforcementAssistanceAdministration（LEAA.foundareductionof10%

to13%inWashington,D.C.'sviolentcrimerateduringDST.However,theLEAA

didnotfilteroutotherfactors,anditexaminedonlytwocitiesandfound

crimereductionsonlyinoneandonlyinsomecrimecategories;theDOTdecided

itwas"impossibletoconcludewithanyconfidencethatcomparablebenefits

wouldbefoundnationwide".Outdoorlightinghasamarginalandsometimes

evencontradictoryinfluenceoncrimeandfearofcrime.

DSTalsohasmixedeffectsonhealth.Insocietieswithfixedworkschedules

itprovidesmoreafternoonsunlightforoutdoorexercise.Italterssunlight

exposure;whetherthisisbeneficialdependsonone'slocationanddaily

schedule,assunlighttriggersvitaminDsynthesisintheskin,butoverexposure

canleadtoskincancer.Sunlightstronglyinfluencesseasonalaffective

disorder.DSTmayhelpindepressionbycausingindividualstoriseearlier,

butsomearguethereverse.TheRetinitisPigmentosaFoundationFighting

Blindness,chairedbyblindsportsmagnateGordonGund,successfullylobbied

in1985and2005forU.S.DSTextensions,butDSTcanhurtnightblindness

sufferers.

Clockshiftsdisruptsleepandreduceitsefficiency.Effectsonseasonal

adaptationofthecircadianrhythmcanbesevereandlastforweeks.The

governmentofKazakhstancitedhealthcomplicationsduetoclockshiftsas

areasonforabolishingDSTin2005.

AlthoughtheDSTincreasesopportunitiesforoutdoorleisureactivities

duringafternoonsunlighthours,obviouslyitdoesnotchangethelengthof

theday;thelongerdaysnearerthesummersolsticeinhighlatitudesmerely

offermoreroomtoshiftapparentdaylightfrommorningtoevening.Andthe

DSTiscommonlynotobservedduringmostofwinter,becauseitsmorningsare

darker:

workersmayhavenosunlitleisuretime,andchildrenmayneedto

leaveforschoolinthedark.

1、Accordingtothepassage,theDST______.

A.offersonemorehourintheafternoonbothintheseasonsofsummerand

winter

B.causespeopletogetuponehourearlierinsummerbu