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1TPO21Sample:Thearticleproposesseveralbenefitsofgrowinggeneticallymodifiedtrees,whilethespeakerpointsoutthepotentialproblemsandcostshiddenbehindthosebenefits.First,thearticleclaimsthatgeneticallymodifiedtreesarebetterabletosurvivebecausetheyaredesignedtobehardier.However,thespeakerpointsoutthat,sincenaturaltreescanensuretheirsurvivalwhenfacingthreateningconditionsduetotheirdiversityingenes,geneticallymodifiedones,becauseoftheiruniformityingenes,aremorelikelytodieoutwhenexposedtoenvironmentalchallenges.Second,thearticlearguesthatgeneticallymodifiedtrees,becauseoftheirfastgrowthandlargeamountofyield,areeconomicallybenefittopeoplegrowingthem.Ontheotherhand,thespeakerpointsoutthehiddencostsofgrowingsuchtrees,thatis,companieswouldchargemoreforseedsofgeneticallymodifiedtreesandeverytimetheyareplanted,theseedshavetobepaid.Thethirdbenefitproposedinthearticleisthat,becauseofthefeatureoffastgrowthandhighyield,geneticallymodifiedtreeswouldsatisfythedemandforwoodandthusprotectotherwildtrees.Thispoint,however,isrefutedbythespeaker,whopointsoutthat,becausegeneticallymodifiedtreestendtogrowaggressivelyamongnaturaltrees,theytendtooutcompetetheirnativecounterpartsforresourcesandcrowdthemoutintheend.TPO22Sample:Thearticleintroducesseveralreasonstoshowthatethanolisnotagoodalternativetogasoline.However,thespeakerfindsnoneofthereasonsconvincing.Thefirstreasonproposedbythearticleisthatethanolisnotmoreenvironmentallyfriendlythangasolinesinceitalsoreleasescarbondioxideintotheairwhenburnedforfuelandcontributestoglobalwarming.Butthespeakerpointsoutthatethanolfueldoesn’taddtoglobalwarmingsincethegrowingofitsrawmaterial–planssuchascorns,whichabsorbcarbondioxide-counteractsthenegativeeffectproducedbyburningethanol.Thesecondreasonsuggestedinthearticleisthattoproducelargeamountsofethanol,themajorityofthecorngrowninAmericawouldhavetobeutilizedandthefoodforanimalswoulddecreaserapidly.Incontrast,thespeakerarguesthattheproductionofethanoldoesn’thavetoreduceanimalfoodbecauseethanolcanbeattainedfromotherpartsoftheplantsthatarenoteatenbyanimals.ThethirdargumentmadebythearticleisthatethanolwillbelessadvantageousthangasolineinpriceiftheU.S.governmentremovesitstaxsubsidiesgiventoethanol2producers.Thispointisrefutedbythespeaker,whoarguesthatethanolwillbeabletocompetewithgasolineinpricewithouttheneedofsubsidysincetheincreaseofdemandofethanolwillstimulatetheincreaseofproductionandthesubsequentdecreaseofprice.TPO23Sample:Inthearticle,severalhypothesesareproposedtoexplainthesteadydeclineofyellowcedarinNorthAmericainthepastcentury.However,thespeakerfindsnoneoftheexplanationsadequate.Thefirsthypothesisintroducedinthearticleisthatthedeclinemaybecausedbyinsectparasitessuchasbarkbeetlewhichattackcedarsaggressivelyandwhoselarvaeeatthewood.Butthespeakerpointsoutthathealthycedarsarefullofchemicalsthatarepoisonoustoinsects.Soonlycedarsthataredamagedorsickcouldbeattackedbyinsects.Thesecondexplanationforthedeclineisthatbrownbearseatthetreebarkwhichcontainslargeamountofsugar,oneofbears’majordiets.However,thespeakerarguesthat,besidesonthemainland,thedeclineofcedarsisalsowitnessedontheislandsoffthecoast,wherenobearsarefound.Sobearscannotbecountedasareasonfortheoveralldeclineofcedars.Thethirdreasonproposedinthearticleisthefactthatchangesofclimatehaveforwardedthegrowthtimethefinerootsofcedarstolatewinter,whentheyarelikelytobedamagedbythefreezingweatherandunderminethehealthofthetress.Thispointisrefutedbythespeakerwhopointsoutthatmorecedarsdieinlowerelevations,wheretheclimateiswarmer,thaninhigherelevationswhereitiscolder,whichisoppositetotheargumentmadeinthereading.TPO24Sample:ThearticleproposesevidencestoshowthatthematerialsfoundinsidetheT.rex’slegbonemayberemainsofsomeofitsactualtissues.Thespeaker,however,findssuchargumentskeptical.First,thearticleclaimsthatthesoft,flexiblesubstanceinsidethesmallchannelsmaywellberemainsofT.rex’sbloodvesselsbecausethehollowsmayjustbetheplaceswherebloodvesselswereoncelocated.Incontrast,thespeakerarguesthattheyarenotnecessarilyremainsofbloodvessels,butcouldwellberesiduesleftbehindbysoft,moistbacteriaoncecolonizingthechannels.Second,thearticlearguesthatthespheresidentifiedintheinnerbonecouldbetheremainsofredbloodcells,becausetheyarefoundcontainingironanddarkredcenters,3whicharecloselyconnectedtoredbloodcells,andofthesamesizeofredbloodcells.However,thespeakerpointsoutthatsimilarspheresarealsofoundinotheranimalsdiscoveredinthesameplace,whichpossessnobloodcells.Theymaywellbepiecesofreddishminerals.Third,accordingtothearticle,collagenisfoundinthelegbone,whichisasignaloflivingbonetissue.Butthisisrefutedbythespeakerwhoarguesthatnocollagenhaseverbeenfoundinremainsolderthan1000years.Asaresult,thecollagenmightwellcomefrommuchmorerecentsources,suchastheskinsofresearcherswhohandledthebone.TPO25Sample:ThearticleproposesseveralargumentstocontradicttheclaimthattheancientclayjarsfoundinIraqservedaselectricbatteries.Butthespeakerfindssuchargumentsunconvincing.Thefirstargumentmadebythearticleisthatnoelectricityconductorssuchasmetalwireswerefoundattachedto