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Question31-40Completethenotesbelow.WriteONEWORDONLYforeachanswer.EarlyhistoryofkeepingcleanPrehistorictimes:waterwasusedtowashoff31AncientBabylon:soap-likematerialfoundin32cylindersAncientGreece:peoplecleanedthemselveswithsandandothersubstancesusedastrigil—scrapermadeof33washedclothesinstreamsAncientGermanyandGaul:usedsoaptocolourtheir34AncientRome:animalfat,ashesandclaymixedthroughactionofrain,usedforwashingclothesfromabout312BC,watercarriedtoRoman35byaqueductsEuropeinMiddleAges:declineinbathingcontributedtooccurrenceof 3637begantobeaddedtosoapEuropefrom17thcentury:1600s:cleanlinessandbathingstartedbecomingusual1791:Leblancinventedawayofmakingsodaashfrom38early1800s:Chevreulturnedsoapmakingintoa39from1800s,therewasnolongera40onsoap
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Question11-12ChooseTWOletters,A-E.AccordingtoMegan,whataretheTWOmainadvantagesofworkingintheagricultureandhorticulturesectors?
Question1-10Completethenotesbelow.WriteONEWORDAND/ORANUMBERforeachanswer.JUNIORCYCLECAMPThecoursefocusesonskillsandsafety.•CharliewouldbeplacedinLevel5.•Firstofall,childrenatthislevelaretakentopractiseina1 .Instructors•Instructorswear2 shirts.•A3 isrequiredandtrainingisgiven.Classes•Thesizeoftheclassesislimited.•Therearequiettimesduringthemorningfora4 oragame.•Classesareheldevenifthereis5 .Whattobring•achangeofclothing•a6 •shoes(notsandals)•Charlies7 Day1•Charlieshouldarriveat9.20amonthefirstday.•Beforetheclass,his8 willbechecked.•Heshouldthengotothe9 tomeethisclassinstructor.Cost•Thecoursecosts$10 perweek.
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AttitudestowardsArtificialIntelligenceAArtificialintelligence(AI)canalreadypredictthefuture.Policeforcesareusingittomapwhenandwherecrimeislikelytooccur.Doctorscanuseittopredictwhenapatientismostlikelytohaveaheartattackorstroke.ResearchersareeventryingtogiveAIimaginationsoitcanplanforunexpectedconsequences.Manydecisionsinourlivesrequireagoodforecast,andAIisalmostalwaysbetteratforecastingthanweare.Yetforallthesetechnologicaladvances,westillseemtodeeplylackconfidenceinAIpredictions.RecentcasesshowthatpeopledontlikerelyingonAIandprefertotrusthumanexperts,eveniftheseexpertsarewrong.IfwewantAItoreallybenefitpeople,weneedtofindawaytogetpeopletotrustit.Todothat,weneedtounderstandwhypeoplearesoreluctanttotrustAIinthefirstplace.BTakethecaseofWatsonforOncology,oneoftechnologygiantIBMssupercomputerprograms.TheirattempttopromotethisprogramtocancerdoctorswasaPRdisaster.TheAIpromisedtdelivertop-qualityrecommendationsonthetreatmentof12cancersthataccountedfor80%oftheworldscases.ButwhendoctorsfirstinteractedwithWatson,theyfoundthemselvesinaratherdifficultsituation.Ontheonehand,ifWatsonprovidedguidanceaboutatreatmentthatcoincidedwiththeirownopinions,physiciansdidnotseemuchpointinWatsonsrecommendations.Thesupercomputerwassimplytellingthemwhattheyalreadyknew,andtheserecommendationsdidnotchangetheactualtreatment.Ontheotherhand,ifWatsongeneratedarecommendationthatcontradictedtheexpertsopinion,doctorswouldtypicallyconcludethatWatsonwasntcompetent.Andthemachinewouldntbeabletoexplainwhyitstreatmentwasplausiblebecauseitsmachine-learningalgorithmsweresimplytoocomplextobefullyunderstoodbyhumans.Consequently,thishascausedevenmoresuspicionanddisbelief,leadingmanydoctorstoignoretheseeminglyoutlandishAIrecommendationsandsticktotheirownexpertise.CThisisjustoneexampleofpeopleslackofconfidenceinAIandtheirreluctancetoacceptwhatAIhastooffer.Trustinotherpeopleisoftenbasedonourunderstandingofhowothersthinkandhavingexperienceoftheirreliability.Thishelpscreateapsychologicalfeelingofsafety.AI,ontheotherhand,isstillfairlynewandunfamiliartomostpeople.Evenifitcanbetechnicallyexplained(andthatsnotalwaysthecase),AIsdecision-makingprocessisusuallytoodifficultformostpeopletocomprehend.Andinteractingwithsomethingwedontunderstandcancauseanxietyandgiveusasensethatwerelosingcontrol.ManypeoplearealsosimplynotfamiliarwithmanyinstancesofAIactuallyworking,becauseitoftenhappensinthebackground.Instead,theyareacutelyawareofinstanceswhereAIgoeswrong.EmbarrassingAIfailuresreceiveadisproportionateamountofmediaattention,emphasisingthemessagethatwecannotrelyontechnology.Machinelearningisnotfoolproof,inpartbecausethehumanswhodesignitarent.DFeelingsaboutAIrundeep.Inarecentexperiment,peoplefromarangeofbackgroundsweregivenvarioussci-fifilmsaboutAItowatchandthenaskedquestionsaboutautomationineverydaylife.Itwasfoundthat,regardlessofwhetherthefilmtheywatcheddepictedAIinapositiveornegativelight,simplywatchingacinematicvisionofourtechnologicalfuturepolarisedtheparticipantsattitudes.OptimistsbecamemoreextremeintheirenthusiasmforAIandscepticsbecameevenmoreguarded.ThissuggestspeopleuserelevantevidenceaboutAIinabiasedmannertosupporttheirexistingattitudes,adeep-rootedhumantendencyknownas“confirmationbias”.AsAIisrepresentedmoreandmoreinmediaandentertainment,itcouldleadtoasocietysplitbetweenthosewhobenefitfromAIandthosewhorejectit.Morepertinently,refusingtoaccepttheadvantagesofferedbyAIcouldplacealargegroupofpeopleataseriousdisadvantage.EFortunately,wealreadyhavesomeideasabouthowtoimprovetrustinAI.SimplyhavingpreviousexperiencewithAIcansignificantlyimprovepeoplesopinionsaboutthetechnology,aswasfoundinthestudymentionedabove.Evidencealsosuggeststhemoreyouuseothertechnologiessuchastheinternet,themoreyoutrustthem.AnothersolutionmaybetorevealmoreaboutthealgorithmswhichAIusesandthepurposestheyserve.Severalhigh-profilesocialmediacompaniesandonlinemarketplacesalreadyreleasetransparencyreportsaboutgovernmentrequestsandsurveillancedisclosures.AsimilarpracticeforAIcouldhelppeoplehaveabetterunderstandingofthewayalgorithmicdecisionsaremade.FResearchsuggeststhatallowingpeoplesomecontroloverAIdecision-makingcouldalsoimprovetrustandenableAItolearnfromhumanexperience.Forexample,onestudyshowedthatwhenpeoplewereallowedthefreedomtoslightlymodifyanalgorithm,theyfeltmoresatisfiedwithitsdecisions,morelikelytobelieveitwassuperiorandmorelikelytouseitinthefuture.WedontneedtounderstandtheintricateinnerworkingsofAIsystems,butifpeoplearegivenadegreeofresponsibilityforhowtheyareimplemented,theywillbemorewillingtoacceptAIintotheirlives.Question33-35Choosethecorrectletter,A,B,CorD.Writethecorrectletterinboxes33-35onyouranswersheet.
Plant“thermometertriggersspringtimegrowthbymeasuringnight-timeheatAphotoreceptormoleculeinplantcellshasbeenfoundtohaveasecondjobasathermometerafterdark-allowingplantstoreadseasonaltemperaturechanges.ScientistssaythediscoverycouldhelpAAninternationalteamofscientistsledbytheUniversityofCambridgehasdiscoveredthatthe“thermometermoleculeinplantsenablesthemtodevelopaccordingtoseasonaltemperaturechanges.Researchershaverevealedthatmoleculescalledphytochromes-usedbyplantstodetectlightduringtheday-actuallychangetheirfunctionindarknesstobecomecellulartemperaturegaugesthatmeasuretheheatofthenight.Thenewfindings,publishedinthejournalScience,showthatphytochromescontrolgeneticswitchesinresponsetotemperatureaswellaslighttodictateplantdevelopment.BAtnight,thesemoleculeschangestates,andthepaceatwhichtheychangeisdirectlyproportionaltotemperature,sayscientists,whocomparephytochromestomercuryinathermometer.Thewarmeritis,thefasterthemolecularchange-stimulatingplantgrowth.CFarmersandgardenershaveknownforhundredsofyearshowresponsiveplantsaretotemperature:warmwinterscausemanytreesandflowerstobudearly,somethinghumanshavelongusedtopredictweatherandharvesttimesforthecomingyear.Thelatestresearchpinpointsforthefirsttimeamolecularmechanisminplantsthatreactstotemperature-oftentriggeringthebudsofspringwelongtoseeattheendofwinter.DWithweatherandtemperaturessettobecomeevermoreunpredictableduetoclimatechange,researcherssaythediscoverythatthislight-sensingmoleculealsofunctionsastheinternalthermometerinplantcellscouldhelpusbreedtoughercrops.Itisestimatedthatagriculturalyieldswillneedtodoubleby2050,butclimatechangeisamajorthreattoachievingthis.Keycropssuchaswheatandricearesensitivetohightemperatures.Thermalstressreducescropyieldsbyaround10%foreveryonedegreeincreaseintemperature,saysleadresearcherDrPhilipWiggefromCambridgesSainsburyLaboratory.Discoveringthemoleculesthatallowplantstosensetemperaturehasthepotentialtoacceleratethebreedingofcropsresilienttothermalstressandclimatechange.EIntheiractivestate,phytochromemoleculesbindthemselvestoDNAtorestrictplantgrowth.Duringtheday,sunlightactivatesthemolecules,slowingdowngrowth.Ifaplantfindsitselfinshade,phytochromesarequicklyinactivated-enablingittogrowfastertofindsunlightagain.Thisishowplantscompetetoescapeeachothersshade.Light-drivenchangestophytochromeactivityoccurveryfast,inlessthanasecond,saysWigge.Atnight,however,itsadifferentstory.Insteadofarapiddeactivationfollowingsundown,themoleculesgraduallychangefromtheiractivetoinactivestate.Thisiscalleddarkreversion.Justasmercuryrisesinathermometer,therateatwhichphytochromesreverttotheirinactivestateduringthenightisadirectmeasureoftemperature,saysWigge.FThelowerthetemperature,theslowertherateatwhichphytochromesreverttoinactivity,sothemoleculesspendmoretimeintheiractive,growth-suppressingstate.Thisiswhyplantsareslowertogrowinwinter.Warmtemperaturesacceleratedarkreversion,sothatphytochromesrapidlyreachaninactivestateanddetachthemselvesfromtheplantsDNA-allowinggenestobeexpressedandplantgrowthtoresume.Wiggebelievesphytochromethermo-sensingevolvedatalaterstage,andco-optedthebiologicalnetworkalreadyusedforlight-basedgrowthduringthedowntimeofnight.GSomeplantsmainlyusedaylengthasanindicatoroftheseason.Otherspecies,suchasdaffodils,haveconsiderabletemperaturesensitivity,andcanflowermonthsinadvanceduringawarmwinter.Infact,thediscoveryofthedualroleofphytochromesprovidesthesciencebehindawell-knownrhymelongusedtopredictthecomingseason:oakbeforeashwellhaveasplash,ashbeforeoakwereinforasoak.Wiggeexplains:Oaktreesrelymuchmoreontemperature,likelyusingphytochromesasthermometerstodictatedevelopment,whereasashtreesrelyonmeasuringdaylengthtodeterminetheirseasonaltiming.Awarmerspring,andconsequentlyahigherlikelinessofahotsummer,willresultinoakleafingbeforeash.Acoldspringwillseetheopposite.AstheBritishknowonlytoowell,acoldersummerislikelytobearain-soakedone.HThenewfindingsaretheculminationoftwelveyearsofresearchinvolvingscientistsfromGermany,ArgentinaandtheUS,aswellastheCambridgeteam.Theworkwasdoneinamodelsystem,usingamustardplantcalledArabidopsis,butWiggesaysthephytochromegenesnecessaryfortemperaturesensingarefoundincropplantsaswell.Recentadvancesinplantgeneticsnowmeanthatscientistsareabletorapidlyidentifythegenescontrollingtheseprocessesincropplants,andevenaltertheiractivityusingprecisemolecular“scalpels”,addsWigge.Cambridgeisuniquelywell-positionedtodothiskindofresearchaswehaveoutstandingcollaboratorsnearbywhoworkonmoreappliedaspectsofplantbiology,andcanhelpustransferthisnewknowledgeintothefield.Question27-32DothefollowingstatementsagreewiththeinformationgiveninReadingPassage3?Inboxes27-32onyouranswersheet,writeTRUEifthestatementagreeswiththeinformationFALSEifthestatementcontradictstheinformationNOTGIVENifthereisnoinformationonthis
Question21-26Whatdidfindingsofpreviousresearchclaimaboutthepersonalitytraitsachildislikelytohavebecauseoftheirpositioninthefamily?ChooseSIXanswersfromtheboxandwritethecorrectletter,A–H,nexttoQuestions21–26.Positioninfamily21theeldestchild 21 22amiddlechild 22 23theyoungestchild 23 24atwin 24 25anonlychild 25 26achildwithmucholdersiblings 26 PersonalityTraitsA.outgoingB.selfishC.independentD.attention-seekingE.introvertedF.co-operativeG.caringH.competitive
【参考范例六】
Nutmeg–avaluablespiceAThenutmegtree,Myristicafragrans,isalargeevergreentreenativetoSoutheastAsia.Untilthelate18thcentury,itonlygrewinoneplaceintheworld:asmallgroupofislandsintheBandaSea,partoftheMoluccas–orSpiceIslands–innortheasternIndonesia.Thetreeisthicklybranchedwithdensefoliageoftough,darkgreenovalleaves,andproducessmall,yellow,bell-shapedflowersandpaleyellowpear-shapedfruits.Thefruitisencasedinafleshyhusk.Whenthefruitisripe,thishusksplitsintotwohalvesalongaridgerunningthelengthofthefruit.Insideisapurple-brownshinyseed,2–3cmlongbyabout2cmacross,surroundedbyalacyredorcrimsoncoveringcalledan‘aril’.Thesearethesourcesofthetwospicesnutmegandmace,theformerbeingproducedfromthedriedseedandthelatterfromthearil.BNutmegwasahighlyprizedandcostlyingredientinEuropeancuisineintheMiddleAges,andwasusedasaflavouring,medicinal,andpreservativeagent.Throughoutthisperiod,theArabsweretheexclusiveimportersofthespicetoEurope.TheysoldnutmegforhighpricestomerchantsbasedinVenice,buttheyneverrevealedtheexactlocationofthesourceofthisextremelyvaluablecommodity.TheArab-Venetiandominanceofthetradefinallyendedin1512,whenthePortuguesereachedtheBandaIslandsandbeganexploitingitspreciousresources.CAlwaysindangerofcompetitionfromneighbouringSpain,thePortuguesebegansubcontractingtheirspicedistributiontoDutchtraders.ProfitsbegantoflowintotheNetherlands,andtheDutchcommercialfleetswiftlygrewintooneofthelargestintheworld.TheDutchquietlygainedcontrolofmostoftheshippingandtradingofspicesinNorthernEurope.Then,in1580,PortugalfellunderSpanishrule,andbytheendofthe16thcenturytheDutchfoundthemselveslockedoutofthemarket.Aspricesforpepper,nutmeg,andotherspicessoaredacrossEurope,theydecidedtofightback.DIn1602,DutchmerchantsfoundedtheVOC,atradingcorporationbetterknownastheDutchEastIndiaCompany.By1617,theVOCwastherichestcommercialoperationintheworld.Thecompanyhad50,000employeesworldwide,withaprivatearmyof30,000menandafleetof200ships.Atthesametime,thousandsofpeopleacrossEuropeweredyingoftheplague,ahighlycontagiousanddeadlydisease.Doctorsweredesperateforawaytostopthespreadofthisdisease,andtheydecidednutmegheldthecure.Everybodywantednutmeg,andmanywerewillingtosparenoexpensetohaveit.NutmegboughtforafewpenniesinIndonesiacouldbesoldfor68,000timesitsoriginalcostonthestreetsofLondon.Theonlyproblemwastheshortsupply.Andthat’swheretheDutchfoundtheiropportunity.ETheBandaIslandswereruledbylocalsultanswhoinsistedonmaintaininganeutraltradingpolicytowardsforeignpowers.ThisallowedthemtoavoidthepresenceofPortugueseorSpanishtroopsontheirsoil,butitalsoleftthemunprotectedfromotherinvaders.In1621,theDutcharrivedandtookover.OncesecurelyincontroloftheBandas,theDutchwenttoworkprotectingtheirnewinvestment.Theyconcentratedallnutmegproductionintoafeweasilyguardedareas,uprootinganddestroyinganytreesoutsidetheplantationzones.Anyonecaughtgrowinganutmegseedlingorcarryingseedswithouttheproperauthoritywasseverelypunished.Inaddition,allexportednutmegwascoveredwithlimetomakesuretherewasnochanceafertileseedwhichcouldbegrownelsewherewouldleavetheislands.TherewasonlyoneobstacletoDutchdomination.OneoftheBandaIslands,asliveroflandcalledRun,only3kmlongbylessthan1kmwide,wasunderthecontroloftheBritish.Afterdecadesoffightingforcontrolofthistinyisland,theDutchandBritisharrivedatacompromisesettlement,theTreatyofBreda,in1667.Intentonsecuringtheirholdovereverynutmeg-producingisland,theDutchofferedatrade:iftheBritishwouldgivethemtheislandofRun,theywouldinturngiveBritainadistantandmuchlessvaluableislandinNorthAmerica.TheBritishagreed.ThatotherislandwasManhattan,whichishowNewAmsterdambecameNewYork.TheDutchnowhadamonopolyoverthenutmegtradewhichwouldlastforanothercentury.FThen,in1770,aFrenchmannamedPierrePoivresuccessfullysmugglednutmegplantstosafetyinMauritius,anislandoffthecoastofAfrica.SomeofthesewerelaterexportedtotheCaribbeanwheretheythrived,especiallyontheislandofGrenada.Next,in1778,avolcaniceruptionintheBandaregioncausedatsunamithatwipedouthalfthenutmeggroves.Finally,in1809,theBritishreturnedtoIndonesiaandseizedtheBandaIslandsbyforce.TheyreturnedtheislandstotheDutchin1817,butnotbeforetransplantinghundredsofnutmegseedlingstoplantationsinseverallocationsacrosssouthernAsia.TheDutchnutmegmonopolywasover.GToday,nutmegisgrowninIndonesia,theCaribbean,India,Malaysia,PapuaNewGuineaandSriLanka,andworldnutmegproductionisestimatedtoaveragebetween10,000and12,000tonnesperyear.
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Plant“thermometertriggersspringtimegrowthbymeasuringnight-timeheatAphotoreceptormoleculeinplantcellshasbeenfoundtohaveasecondjobasathermometerafterdark-allowingplantstoreadseasonaltemperaturechanges.ScientistssaythediscoverycouldhelpAAninternationalteamofscientistsledbytheUniversityofCambridgehasdiscoveredthatthe“thermometermoleculeinplantsenablesthemtodevelopaccordingtoseasonaltemperaturechanges.Researchershaverevealedthatmoleculescalledphytochromes-usedbyplantstodetectlightduringtheday-actuallychangetheirfunctionindarknesstobecomecellulartemperaturegaugesthatmeasuretheheatofthenight.Thenewfindings,publishedinthejournalScience,showthatphytochromescontrolgeneticswitchesinresponsetotemperatureaswellaslighttodictateplantdevelopment.BAtnight,thesemoleculeschangestates,andthepaceatwhichtheychangeisdirectlyproportionaltotemperature,sayscientists,whocomparephytochromestomercuryinathermometer.Thewarmeritis,thefasterthemolecularchange-stimulatingplantgrowth.CFarmersandgardenershaveknownforhundredsofyearshowresponsiveplantsaretotemperature:warmwinterscausemanytreesandflowerstobudearly,somethinghumanshavelongusedtopredictweatherandharvesttimesforthecomingyear.Thelatestresearchpinpointsforthefirsttimeamolecularmechanisminplantsthatreactstotemperature-oftentriggeringthebudsofspringwelongtoseeattheendofwinter.DWithweatherandtemperaturessettobecomeevermoreunpredictableduetoclimatechange,researcherssaythediscoverythatthislight-sensingmoleculealsofunctionsastheinternalthermometerinplantcellscouldhelpusbreedtoughercrops.Itisestimatedthatagriculturalyieldswillneedtodoubleby2050,butclimatechangeisamajorthreattoachievingthis.Keycropssuchaswheatandricearesensitivetohightemperatures.Thermalstressreducescropyieldsbyaround10%foreveryonedegreeincreaseintemperature,saysleadresearcherDrPhilipWiggefromCambridgesSainsburyLaboratory.Discoveringthemoleculesthatallowplantstosensetemperaturehasthepotentialtoacceleratethebreedingofcropsresilienttothermalstressandclimatechange.EIntheiractivestate,phytochromemoleculesbindthemselvestoDNAtorestrictplantgrowth.Duringtheday,sunlightactivatesthemolecules,slowingdowngrowth.Ifaplantfindsitselfinshade,phytochromesarequicklyinactivated-enablingittogrowfastertofindsunlightagain.Thisishowplantscompetetoescapeeachothersshade.Light-drivenchangestophytochromeactivityoccurveryfast,inlessthanasecond,saysWigge.Atnight,however,itsadifferentstory.Insteadofarapiddeactivationfollowingsundown,themoleculesgraduallychangefromtheiractivetoinactivestate.Thisiscalleddarkreversion.Justasmercuryrisesinathermometer,therateatwhichphytochromesreverttotheirinactivestateduringthenightisadirectmeasureoftemperature,saysWigge.FThelowerthetemperature,theslowertherateatwhichphytochromesreverttoinactivity,sothemoleculesspendmoretimeintheiractive,growth-suppressingstate.Thisiswhyplantsareslowertogrowinwinter.Warmtemperaturesacceleratedarkreversion,sothatphytochromesrapidlyreachaninactivestateanddetachthemselvesfromtheplantsDNA-allowinggenestobeexpressedandplantgrowthtoresume.Wiggebelievesphytochromethermo-sensingevolvedatalaterstage,andco-optedthebiologicalnetworkalreadyusedforlight-basedgrowthduringthedowntimeofnight.GSomeplantsmainlyusedaylengthasanindicatoroftheseason.Otherspecies,suchasdaffodils,haveconsiderabletemperaturesensitivity,andcanflowermonthsinadvanceduringawarmwinter.Infact,thediscoveryofthedualroleofphytochromesprovidesthesciencebehindawell-knownrhymelongusedtopredictthecomingseason:oakbeforeashwellhaveasplash,ashbeforeoakwereinforasoak.Wiggeexplains:Oaktreesrelymuchmoreontemperature,likelyusingphytochromesasthermometerstodictatedevelopment,whereasashtreesrelyonmeasuringdaylengthtodeterminetheirseasonaltiming.Awarmerspring,andconsequentlyahigherlikelinessofahotsummer,willresultinoakleafingbeforeash.Acoldspringwillseetheopposite.AstheBritishknowonlytoowell,acoldersummerislikelytobearain-soakedone.HThenewfindingsaretheculminationoftwelveyearsofresearchinvolvingscientistsfromGermany,ArgentinaandtheUS,aswellastheCambridgeteam.Theworkwasdoneinamodelsystem,usingamustardplantcalledArabidopsis,butWiggesaysthephytochromegenesnecessaryfortemperaturesensingarefoundincropplantsaswell.Recentadvancesinplantgeneticsnowmeanthatscientistsareabletorapidlyidentifythegenescontrollingtheseprocessesincropplants,andevenaltertheiractivityusingprecisemolecular“scalpels”,addsWigge.Cambridgeisuniquelywell-positionedtodothiskindofresearchaswehaveoutstandingcollaboratorsnearbywhoworkonmoreappliedaspectsofplantbiology,andcanhelpustransferthisnewknowledgeintothefield.Question38-40Completethesentencesbelow.ChooseNOMORETHANTWOWORDSfromthepassageforeachanswer.Writeyouranswersinboxes38–40onyouranswersheet.Daffodilsarelikelytoflowerearlyinresponseto38 weather.lfashtreescomeintoleafbeforeoaktrees,theweatherin39 willprobablybewet.Theresearchwascarriedoutusingaparticularspeciesof40 .
Plant“thermometertriggersspringtimegrowthbymeasuringnight-timeheatAphotoreceptormoleculeinplantcellshasbeenfoundtohaveasecondjobasathermometerafterdark-allowingplantstoreadseasonaltemperaturechanges.ScientistssaythediscoverycouldhelpAAninternationalteamofscientistsledbytheUniversityofCambridgehasdiscoveredthatthe“thermometermoleculeinplantsenablesthemtodevelopaccordingtoseasonaltemperaturechanges.Researchershaverevealedthatmoleculescalledphytochromes-usedbyplantstodetectlightduringtheday-actuallychangetheirfunctionindarknesstobecomecellulartemperaturegaugesthatmeasuretheheatofthenight.Thenewfindings,publishedinthejournalScience,showthatphytochromescontrolgeneticswitchesinresponsetotemperatureaswellaslighttodictateplantdevelopment.BAtnight,thesemoleculeschangestates,andthepaceatwhichtheychangeisdirectlyproportionaltotemperature,sayscientists,whocomparephytochromestomercuryinathermometer.Thewarmeritis,thefasterthemolecularchange-stimulatingplantgrowth.CFarmersandgardenershaveknownforhundredsofyearshowresponsiveplantsaretotemperature:warmwinterscausemanytreesandflowerstobudearly,somethinghumanshavelongusedtopredictweatherandharvesttimesforthecomingyear.Thelatestresearchpinpointsforthefirsttimeamolecularmechanisminplantsthatreactstotemperature-oftentriggeringthebudsofspringwelongtoseeattheendofwinter.DWithweatherandtemperaturessettobecomeevermoreunpredictableduetoclimatechange,researcherssaythediscoverythatthislight-sensingmoleculealsofunctionsastheinternalthermometerinplantcellscouldhelpusbreedtoughercrops.Itisestimatedthatagriculturalyieldswillneedtodoubleby2050,butclimatechangeisamajorthreattoachievingthis.Keycropssuchaswheatandricearesensitivetohightemperatures.Thermalstressreducescropyieldsbyaround10%foreveryonedegreeincreaseintemperature,saysleadresearcherDrPhilipWiggefromCambridgesSainsburyLaboratory.Discoveringthemoleculesthatallowplantstosensetemperaturehasthepotentialtoacceleratethebreedingofcropsresilienttothermalstressandclimatechange.EIntheiractivestate,phytochromemoleculesbindthemselvestoDNAtorestrictplantgrowth.Duringtheday,sunlightactivatesthemolecules,slowingdowngrowth.Ifaplantfindsitselfinshade,phytochromesarequicklyinactivated-enablingittogrowfastertofindsunlightagain.Thisishowplantscompetetoescapeeachothersshade.Light-drivenchangestophytochromeactivityoccurveryfast,inlessthanasecond,saysWigge.Atnight,however,itsadifferentstory.Insteadofarapiddeactivationfollowingsundown,themoleculesgraduallychangefromtheiractivetoinactivestate.Thisiscalleddarkreversion.Justasmercuryrisesinathermometer,therateatwhichphytochromesreverttotheirinactivestateduringthenightisadirectmeasureoftemperature,saysWigge.FThelowerthetemperature,theslowertherateatwhichphytochromesreverttoinactivity,sothemoleculesspendmoretimeintheiractive,growth-suppressingstate.Thisiswhyplantsareslowertogrowinwinter.Warmtemperaturesacceleratedarkreversion,sothatphytochromesrapidlyreachaninactivestateanddetachthemselvesfromtheplantsDNA-allowinggenestobeexpressedandplantgrowthtoresume.Wiggebelievesphytochromethermo-sensingevolvedatalaterstage,andco-optedthebiologicalnetworkalreadyusedforlight-basedgrowthduringthedowntimeofnight.GSomeplantsmainlyusedaylengthasanindicatoroftheseason.Otherspecies,suchasdaffodils,haveconsiderabletemperaturesensitivity,andcanflowermonthsinadvanceduringawarmwinter.Infact,thediscoveryofthedualroleofphytochromesprovidesthesciencebehindawell-knownrhymelongusedtopredictthecomingseason:oakbeforeashwellhaveasplash,ashbeforeoakwereinforasoak.Wiggeexplains:Oaktreesrelymuchmoreontemperature,likelyusingphytochromesasthermometerstodictatedevelopment,whereasashtreesrelyonmeasuringdaylengthtodeterminetheirseasonaltiming.Awarmerspring,andconsequentlyahigherlikelinessofahotsummer,willresultinoakleafingbeforeash.Acoldspringwillseetheopposite.AstheBritishknowonlytoowell,acoldersummerislikelytobearain-soakedone.HThenewfindingsaretheculminationoftwelveyearsofresearchinvolvingscientistsfromGermany,ArgentinaandtheUS,aswellastheCambridgeteam.Theworkwasdoneinamodelsystem,usingamustardplantcalledArabidopsis,butWiggesaysthephytochromegenesnecessaryfortemperaturesensingarefoundincropplantsaswell.Recentadvancesinplantgeneticsnowmeanthatscientistsareabletorapidlyidentifythegenescontrollingtheseprocessesincropplants,andevenaltertheiractivityusingprecisemolecular“scalpels”,addsWigge.Cambridgeisuniquelywell-positionedtodothiskindofresearchaswehaveoutstandingcollaboratorsnearbywhoworkonmoreappliedaspectsofplantbiology,andcanhelpustransferthisnewknowledgeintothefield.Question33-37ReadingPassage3haseightsections,A-H.Whichsectioncontainsthefollowinginformation?Writethecorrectletter,A-H,inboxes33-37onyouranswersheet.
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Question11-16Choosethecorrectletter,A,BorC.StreetPlaySchemeQuestion17-18ChooseTWOletters,A-E.Question19-20ChooseTWOletters,A-E.
IcontainmultitudesWendyMoorereviewsEdYongsbookaboutmicrobesMicrobes,mostofthembacteria,havepopulatedthisplanetsincelongbeforeanimallifedevelopedandtheywilloutliveus.Invisibletothenakedeye,theyareubiquitous.Theyinhabitthesoil,air,rocksandwaterandarepresentwithineveryformoflife,fromseaweedandcoraltodogsandhumans.And,asYongexplainsinhisutterlyabsorbingandhugelyimportantbook,wemesswiththematourperil.Everyspecieshasitsowncolonyofmicrobes,calledamicrobiome,andthesemicrobesvarynotonlybetweenspeciesbutalsobetweenindividualsandwithindifferentpartsofeachindividual.Whatisamazingisthatwhilethenumberofhumancellsintheaveragepersonisabout30trillion,thenumberofmicrobialonesishigher-about39trillion.Atbest,Yonginformsus,weareonly50percenthuman.Indeed,somescientistsevensuggestweshouldthinkofeachspeciesanditsmicrobesasasingleunit,dubbedaholobiont.Ineachhumantherearemicrobesthatliveonlyinthestomach,themouthorthearmpitandbyandlargetheydosopeacefully.Sobadmicrobesarejustmicrobesoutofcontext.Microbesthatsitcontentedlyinthehumangut(wheretherearemoremicrobesthantherearestarsinthegalaxy)canbecomedeadlyiftheyfindtheirwayintothebloodstream.Thesecommunitiesareconstantlychangingtoo.Therighthandsharesjustonesixthofitsmicrobeswiththelefthand.And,ofcourse,wearesurroundedbymicrobes.Everytimeweeat,weswallowamillionmicrobesineachgramoffood;wearecontinuallyswappingmicrobeswithotherhumans,petsandtheworldatlarge.ItsafascinatingtopicandYong,ayoungBritishsciencejournalist,isanextraordinarilyadeptguide.Writingwithlightnessandpanache,hehasaknackofexplainingcomplexscienceintermsthatarebotheasytounderstandandtotallyenthralling.Yongisonamission.Leadingusgentlybythehand,hetakesusintotheworldofmicrobes-abizarre,alienplanet-inabidtopersuadeustolovethemasmuchashedoes.Bytheend,wedo.Formostofhumanhistorywehadnoideathatmicrobesexisted.ThefirstmantoseetheseextraordinarilypotentcreatureswasaDutchlens-makercalledAntonyvanLeeuwenhoekinthe1670s.Usingmicroscopesofhisowndesignthatcouldmagnifyupto270times,heexaminedadropofwaterfromanearbylakeandfounditteemingwithtinycreatureshecalledanimalcules.ItwasntuntilnearlytwohundredyearslaterthattheresearchofFrenchbiologistLouisPasteurindicatedthatsomemicrobescauseddisease.ItwasPasteursgermtheorythatgavebacteriathepoorimagethatendurestoday.Yongsbookisinmanywaysapleaformicrobialtolerance,pointingoutthatwhilefewerthanonehundredspeciesofbacteriabringdisease,manythousandsmoreplayavitalroleinmaintainingourhealth.Thebookalsoacknowledgesthatourattitudetowardsbacteriaisnotasimpleone.Wetendtoseethedangersposedbybacteria,yetatthesametimewearesoldyoghurtsanddrinksthatsupposedlynurturefriendlybacteria.Inreality,saysYong,bacteriashouldnotbeviewedaseitherfriendsorfoes,villainsorheroes.Insteadweshouldrealisewehaveasymbioticrelationship,thatcanbemutuallybeneficialormutuallydestructive.Whatthendothesemillionsoforganismsdo?Theanswerisprettymucheverything.Newresearchisnowunravellingthewaysinwhichbacteriaaiddigestion,regulateourimmunesystems,eliminatetoxins,producevitamins,affectourbehaviourandevencombatobesity.Theyactuallyhelpusbecomewhoweare,saysYong.Butwearefacingagrowingproblem.Ourobsessionwithhygiene,ouroveruseofantibioticsandourunhealthy,low-fibredietsaredisruptingthebacterialbalanceandmayberesponsibleforsoaringratesofallergiesandimmuneproblems,suchasinflammatoryboweldisease(IBD).Themostrecentresearchactuallyturnsacceptednormsupsidedown.Forexample,therearestudiesindicatingthattheexcessiveuseofhouseholddetergentsandantibacterialproductsactuallydestroysthemicrobesthatnormallykeepthemoredangerousgermsatbay.Otherstudiesshowthatkeepingadogasapetgiveschildrenearlyexposuretoadiverserangeofbacteria,whichmayhelpprotectthemagainstallergieslater.ThereadersofYongsbookmustbepreparedforadecidedlyunglamorousworld.Amongthelessappealingcasestudiesisoneaboutafungusthatiswipingoutentirepopulationsoffrogsandthatcanbehaltedbyararemicrobialbacterium.Anotherisaboutsquidthatcarryluminescentbacteriathatprotectthemagainstpredators.However,ifyoucanovercomeyourdistasteforsomeoftheinvestigations,thereasonsforYongsenthusiasmbecomeclear.Themicrobialworldisaplaceofwonder.Already,inanattempttostopmosquitoesspreadingdenguefever-adiseasethatinfects400millionpeopleayear-mosquitoesarebeingloadedwithabacteriumtoblockthedisease.Inthefuture,ourabilitytomanipulatemicrobesmeanswecouldconstructbuildingswithusefulmicrobesbuiltintotheirwallstofightoffinfections.Justimagineaneonatalhospitalwardcoatedinaspeciallymixedcocktailofmicrobessothatbabiesgetthebeststartinlife.Question21-26DothefollowingstatementsagreewiththeclaimsofthewriterinReadingPassage2?Inboxes21-26onyouranswersheet,writeTRUEifthestatementagreeswiththeclaimsofthewriterFALSEifthestatementcontradictstheclaimsofthewriterNOTGIVENifitisimpossibletosaywhatthewriterthinksaboutthis