TPO 22.docx
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TPO22
TPO22
1.Accordingtoparagraph1,eachofthefollowingistrueofSpartinaalrernifloraEXCEPT:
A.Itrarelyflowersinsaltmarshes.
B.Itgrowswellinintertidalzones.
C.Itiscommonlyreferredtoascordgrass.
D.ItoccursnaturallyalongtheGulfCoastandtheAtlanticcoastoftheUnitedStates.
2.Accordingtoparagraph2,amajorreasonwhynaturalsaltmarshesaresoproductiveisthattheyare
A.inhabitedbylong-livedseaweedandmarshgrassesthatreproducegradually
B.keptclearofexcessplantmaterialbythetides
C.regularlysuppliedwithhighlevelsofnutrients
D.hometoawidevarietyofdifferentspeciesofgrasses
3.Whichofthesentencesbelowbestexpresstheessentialinformationinthehighlightedsentenceinthepassage?
Incorrectchoiceschangethemeaninginimportantwaysorleaveoutessentialinformation.
A.Insectsfeedonlyondeadcordgrass,whilemostothermarshinhabitantsfeedonlivecordgrass.
B.Themarshisagoodhabitatforinsects,butarelativelypooroneforbirdsandanimals.
C.Althoughcordgrassprovidesfoodforbirdsandanimals,itgivesinsectsbothfoodandaplacetolive.
D.Cordgrassprovidesfoodfornumerousinsects,birds,andotheranimals.
4.Whatistheorganizationalstructureofparagraph3?
A.ItmakesageneralclaimaboutSpartinaandthenprovidesspecificevidencetodefendthatclaimagainstobjectionstotheclaim.
B.ItpresentsageneralcharacterizationofSpartinaandthendescribesparticularfeaturesonwhichthischaracterizationisbased.
C.ItreportsawidelyheldviewaboutSpartinaandthenconsidersevidencebothforandagainstthatview.
D.ItpresentsageneralhypothesisaboutSpartinaandthenlistsspecificevidencethatdisputesthathypothesis.
5.Theword"exceedingly"inthepassageisclosestinmeaningto
A.unusually
B.dangerously
C.surprisingly
D.highly
6.Accordingtoparagraph3,onereasonthatSpaninaisabletocompeteinmarshenvironmentssosuccessfullyisitsabilityto
A.alterthesubstrateinwhichitgrows
B.convertsulfidesintoausableformofsulfur
C.growandproduceseedswhilefloatingonthesurfaceofthewater
D.producecarbondioxidewithgreatefficiency
7.Paragraph4suggeststhatwhereSpaninaoccursnaturally,anestablishedstandofitwilleventually
A.createconditionsinwhichitcannolongersurvive
B.getwashedawaybywaterflowingthroughthedeepchannelsthatformaroundit
C.becomeadaptedtobrackishwater
D.takeoverothergrassspeciesgrowinginthearea
8.Accordingtoparagraph4,initsnaturalhabitats,Spaninahelpsestuariesby
A.controllingmarshlanddecline
B.decreasingthesubstrateelevation
C.reducingthebrackishnessofthewater
D.increasingtheflowofwaterintotheestuary
9.Theword"modifies"inthepassageisclosestinmeaningto
A.creates
B.changes
C.growson
D.breaksdown
10.Theword"Efforts"inthepassageisclosestinmeaningto
A.Laws
B.Suggestions
C.Attempts
D.Failures
11.Accordingtoparagraph5,Spaninanegativelyaffectswildlifeinestuariesby
A.trappingfishandwaterfowlinsediment
B.preventingoystersfromtransplantingsuccessfully
C.turningmudflatsintohighmarshesandsaltmeadows
D.expandingthemarshyfringesofsaltmeadows
12.Accordingtoparagraph6,eachofthefollowingmethodshasbeenusedinattemptstocontrolSpaninaEXCEPT
A.floodingplants
B.cuttingplantsdownrepeatedly
C.applyingherbicides
D.introducingpredatoryinsects
13.Lookatthefoursquares[Ⓐ][Ⓑ][Ⓒ]and[Ⓓ]thatindicatewherethefollowingsentencecouldbeaddedtothepassage.
Spartinaisparticularlyabletotoleratehighsalinitiesbecausesaltglandsonthesurfaceoftheleavesremovethesaltfromtheplantsap.
Wherewouldthesentencebestfit?
14.
Spaninaalrerniflora,orcordgrass,isthedominantnativespeciesinsaltmarshesalongtheAtlanticcoastandtheGulfCoastoftheUnitedStates.
Clickon3answers.
A.Spartinaisverywelladaptedtoconditionsinsaltmarshes,whereitplaysavaluableroleinstabilizingthemandmakingthemhighlyproductivemarinehabitats.
B.Spartinaexpandsbygrowingrootsystemsthatfloatonthewater’ssurfaceanddescendunderground,whereitfindsthenutrientsthatitneedstogerminate.
C.AsaresultofitsspreadinWashingtonStateoverthepasthundredyears.Spartinahasnowbecomeathreattonativeoystersbyreleasingsedimentsthatcontainsulfidesintothewaters.
D.ThedeadleavesofSpartinabecomefoodforawidevarietyofmarineorganisms.
E.Outsideitsnativeregions,Spartinacanposeseriousproblemsbyturningmudflatsintohighmarshesthatareinhospitabletomanynativefishandbirds.
F.Spartinahasphysiologicaladaptationsthatallowittogrowinenvironmentswhereotherplantscannot,makingitaverystrongcompetitorthatisdifficulttocontrolonceitisestablished.
Spartina
Spartinaalterniflora,knownascordgrass,isadeciduous,perennialfloweringplantnativetotheAtlanticcoastandtheGulfCoastoftheUnitedStates.Itisthedominantnativespeciesofthelowersaltmarshesalongthesecoasts,whereitgrowsintheintertidalzone(theareacoveredbywatersomepartsofthedayandexposedothers).
Thesenaturalsaltmarshesareamongthemostproductivehabitatsinthemarineenvironment.Nutrient-richwaterisbroughttothewetlandsduringeachhightide,makingahighrateoffoodproductionpossible.Astheseaweedandmarshgrassleavesdie,bacteriabreakdowntheplantmaterial,andinsects,smallshrimplikeorganisms,fiddlercrabs,andmarshsnailseatthedecayingplanttissue,digestit,andexcretewasteshighinnutrients.Numerousinsectsoccupythemarsh,feedingonlivingordeadcordgrasstissue,andredwingblackbirds,sparrows,rodents,rabbits,anddeerfeeddirectlyonthecordgrass.Eachtidalcyclecarriesplantmaterialintotheoffshorewatertobeusedbythesubtidalorganisms.
Spartinaisanexceedinglycompetitiveplant.Itspreadsprimarilybyundergroundstems;coloniesformwhenpiecesoftherootsystemorwholeplantsfloatintoanareaandtakerootorwhenseedsfloatintoasuitableareaandgerminate.Spartinaestablishesitselfonsubstratesrangingfromsandandsilttogravelandcobbleandistolerantofsalinitiesrangingfromthatofnearfreshwater(0.05percent)tothatofsaltwater(3.5percent).Becausetheylackoxygen,marshsedimentsarehighinsulfidesthataretoxictomostplants.Spartinahastheabilitytotakeupsulfidesandconvertthemtosulfate,aformofsulfurthattheplantcanuse;thisabilitymakesiteasierforthegrasstocolonizemarshenvironments.AnotheradaptiveadvantageisSpartina’sabilitytousecarbondioxidemoreefficientlythanmostotherplants.
ThesecharacteristicsmakeSpartinaavaluablecomponentoftheestuarieswhereitoccursnaturally.Theplantfunctionsasastabilizerandasedimenttrapandasanurseryareaforestuarinefishandshellfish.Onceestablished,astandofSpartinabeginstotrapsediment,changingthesubstrateelevation,andeventuallythestandevolvesintoahighmarshsystemwhereSpartinaisgraduallydisplacedbyhigher-elevation,brackish-waterspecies.Aselevationincreases,narrow,deepchannelsofwaterformthroughoutthemarsh.AlongtheeastcoastSpartinaisconsideredvaluableforitsabilitytopreventerosionandmarshlanddeterioration;itisalsousedforcoastalrestorationprojectsandthecreationofnewwetlandsites.
SpartinawastransportedtoWashingtonStateinpackingmaterialsforoysterstransplantedfromtheeastcoastin1894.Leavingitsinsectpredatorsbehind,thecordgrasshasbeenspreadingslowlyandsteadilyalongWashington’stidalestuariesonthewestcoast,crowdingoutthenativeplantsanddrasticallyalteringthelandscapebytrappingsediment.Spartinamodifiestidalmudflats,turningthemintohighmarshesinhospitabletothemanyfishandwaterfowlthatdependonthemudflats.ItisalreadyhamperingtheoysterharvestandtheDungenesscrabfishery,anditinterfereswiththerecreationaluseofbeachesandwaterfronts.SpartinahasbeentransplantedtoEnglandandtoNewZealandforlandreclamationandshorelinestabilization.InNewZealandtheplanthasspreadrapidly,changingmudflatswithmarshyfringestoextensivesaltmeadowsandreducingthenumberandkindsofbirdsandanimalsthatusethemarsh.
EffortstocontrolSpartinaoutsideitsnaturalenvironmenthaveincludedburning,flooding,shadingplantswithblackcanvasorplastic,smotheringtheplantswithdredgedmaterialsorclay,applyingherbicide,andmowingrepeatedly.LittlesuccesshasbeenreportedinNewZealandandEngland;WashingtonState’smanagementprogramhastriedmanyofthesemethodsandispresentlyusingtheherbicideglyphosphatetocontrolitsspread.Workhasbeguntodeterminethefeasibilityofusinginsectsasbiologicalcontrols,buteffectivebiologicalcontrolsareconsideredyearsaway.Evenwithamassiveeffort,itisdoubtfulthatcompleteeradicationofSpartinafromnonnativehabitatsispossible,forithasbecomeanintegralpartoftheseshorelinesandestuariesduringthelast100to200years.
Spartinaisanexceedinglycompetitiveplant.ⒶItspreadsprimarilybyundergroundstems;coloniesformwhenpiecesoftherootsystemorwholeplantsfloatintoanareaandtakerootorwhenseedsfloatintoasuitableareaandgerminate.ⒷSpartinaestablishesitselfonsubstratesrangingfromsandandsilttogravelandcobbleandistolerantofsalinitiesrangingfromthatofnearfreshwater(0.05percent)tothatofsaltwater(3.5percent).ⒸBecausetheylackoxygen,marshsedimentsarehighinsulfidesthataretoxictomostplan