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Intheearlieststagesofman'sdevelopmenthehadnomoreneedofmoneythananimalshave.Hewascontentwithverysimpleformsofshelter,madehisownroughtoolsandweaponsandcouldprovidefoodandclothingforhimselfandhisfamilyfromnaturalmaterialsaroundhim.Ashebecamemorecivilized,however,hebegantowantbettershelter,moreefficienttoolsandweapons,andmorecomfortableandmorelastingclothingthancouldbeprovidedbyhisownneighborhoodorbytheworkofhisownunskilledhands.Forthesethingshehadtoturntotheskilledpeoplesuchassmiths,leatherworkersorcarpenters.Itwasthenthatthequestionofpaymentarose.
Atfirsthegotwhathewantedbyasimpleprocessofexchange.Thesmithwhohadnotthetimetolookafterlandorcattlewasgladtotakemeatorgrainfromthefarmerinexchangeforanaxeoraplough.Butasmoreandmoregoodswhichhadnofixedexchangevaluecameonthemarket,exchangebecametoocomplicatedtobesatisfactory.Anotherproblemarosewhenthosewhomadethingswantedtogetstocksofwoodorleather,oriron,buthadnothingtoofferinexchangeuntiltheirfinishedgoodswereready.Thusthedifficultiesofexchangeledbydegreestotheinventionofmoney.Insomecountrieseasilyhandledthingslikeseedsorshellsweregivenacertainvalueandthefarmer,insteadofpayingthesmithforanewaxebygivinghimsomemeatorgrain,gavehimsomanyshells.Ifthesmithhadanyshellsleftwhenhehadboughthisfood,hecouldgetstocksoftherawmaterialsofhistrade.Insomecountriesquitelargethingssuchascowsorcamelsorevenbigflatstoneswereusedfortrade.Later,piecesofmetal,bearingvaluesaccordingtotherarityofthemetalandthesizeofthepieces,orcoinswereused.Moneyasweknowithadarrived.
1.Exchangeofgoodsbecamedifficultbecause_________.
Amanbecamemorecivilized
Bsmithsbegantolookafterlandorcattleintheirsparetime
Cmoreandmoregoodswhichhadnofixedexchangealuescametothemarker
Dfarmershadn'tenoughgrainormeattoprovidefor
skilledworkers
2.Moneywasnotuseduntil_______.
Apaperwasinvented
Bpeoplepracticedasimpleprocessofexchange
CnothingcouldbeofferedinexchangeDtheexchangeofonethingforanotherbecametoocomplicated
3.Thebesttitleforthispassageis_____.
AWhatismoney
BWhataremoney'sfunctions.
CTheimportanceofmoney
DThebeginningofmoney
Roguetheoryofsmellgetsaboost
1.Acontroversialtheoryofhowwesmell,whichclaimsthatourfinesenseofodourdependsonquantummechanics,hasbeengiventhethumbsupbyateamofphysicists.
2.CalculationsbyresearchersatUniversityCollegeLondon(UCL)showthattheideathatwesmellodourmoleculesbysensingtheirmolecularvibrationsmakessenseintermsofthephysicsinvolved.
3.That'sstillsomewayfromprovingthatthetheory,proposedinthemid-1990sbybiophysicistLucaTurin,iscorrect.Butitshouldmakeotherscientiststaketheideamoreseriously.
4."Thisisabigstepforward,"saysTurin,whohasnowsetuphisownperfumecompanyFlexitralinVirginia.Hesaysthatsincehepublishedhistheory,"ithasbeenignoredratherthancriticized."
5.Mostscientistshaveassumedthatoursenseofsmelldependsonreceptorsinthenosedetectingtheshapeofincomingmolecules,whichtriggersasignaltothebrain.Thismolecular'lockandkey'processisthoughttoliebehindawiderangeofthebody'sdetectionsystems:itishowsomepartsoftheimmunesystemrecogniseinvaders,forexample,andhowthetonguerecognizessometastes.
6.ButTurinarguedthatsmelldoesn'tseemtofitthispictureverywell.Moleculesthatlookalmostidenticalcansmellverydifferent—suchasalcohols,whichsmelllikespirits,andthiols,whichsmelllikerotteneggs.Andmoleculeswithverydifferentstructurescansmellsimilar.Moststrikingly,somemoleculescansmelldifferent—toanimals,ifnotnecessarilytohumans—simplybecausetheycontaindifferentisotopes(atomsthatarechemicallyidenticalbuthaveadifferentmass).
7.Turin'sexplanationforthesesmellyfactsinvokestheideathatthesmellsignalinolfactoryreceptorproteinsistriggerednotbyanodourmolecule'sshape,butbyitsvibrations,whichcanenourageanelectrontojumpbetweentwopartsofthereceptorinaquantum-mechanicalprocesscalledtunnelling.Thiselectronmovementcouldinitiatethesmellsignalbeingsenttothebrain.
8.Thiswouldexplainwhyisotopescansmelldifferent:theirvibrationfrequenciesarechangediftheatomsareheavier.Turin'smechanism,saysMarshallStonehamoftheUCLteam,ismorelikeswipe-cardidentificationthanakeyfittingalock.
9.Vibration-assistedelectrontunnellingcanundoubtedlyoccur—itisusedinanexperimentaltechniqueformeasuringmolecularvibrations."Thequestioniswhetherthisispossibleinthenose,"saysStoneham'scolleague,AndrewHorsfield.
10.StonehamsaysthatwhenhefirstheardaboutTurin'sidea,whileTurinwashimselfbasedatUCL,"Ididn'tbelieveit".But,headds,"becauseitwasaninterestingidea,IthoughtIshouldproveitcouldn'twork.Ididsomesimplecalculations,andonlythenbegantofeelLucacouldberight."NowStonehamandhisco-workershavedonethejobmorethoroughly,inapapersoontobepublishedinPhysicalReviewLetters.
11.TheUCLteamcalculatedtheratesofelectronhoppinginanosereceptorthathasanodorantmoleculeboundtoit.Thisratedependsonvariouspropertiesofthebiomolecularsystemthatarenotknown,buttheresearcherscouldestimatetheseparametersbasedontypicalvaluesformoleculesofthissort.
12.Thekeyissueiswhetherthehoppingratewiththeodorantinplaceissignificantlygreaterthanthatwithoutit.Thecalculationsshowthatitis—whichmeansthatodouridentificationinthiswayseemstheoreticallypossible.
13.ButHorsfieldstressesthatthat'sdifferentfromaproofofTurin'sidea."Sofarthingslookplausible,butweneedproperexperimentalverification.We'rebeginningtothinkaboutwhatexperimentscouldbeperformed."
14.Meanwhile,Turinispressingaheadwithhishypothesis."AtFlexitralwehavebeendesigningodorantsexclusivelyonthebasisoftheircomputedvibrations,"hesays."Oursuccessrateatodorantdiscoveryistwoordersofmagnitudebetterthanthecompetition."Attheveryleast,heisputtinghismoneywherehisnoseis.
Questions5-9
Completethesentencesbelowwithwordsfromthepassage.UseNOMORETHANTHREEWORDSforeachanswer.
5.Thehypothesisthatwesmellbysensingthemolecularvibrationwasmadeby______.
6.Turin'scompanyisbasedin______.
7.Mostscientistsbelievedthatournoseworksinthesamewayasour______.
8.Differentisotopescansmelldifferentwhen______weighdifferently.
9.AccordingtoAudrewHorsfield,itisstilltobeprovedthat______couldreallyoccurinhumannose.
