Scatteredthroughtheseasoftheworldarebillionsoftonsofsmallplantsandanimalscalledplankton.Mostoftheseplantsandanimalsaretoosmallforthehumaneyetosee.Theydriftaboutlazilywiththecurrents,providingabasicfoodformanylargeranimals.Planktonhasbeendescribedastheequivalentofthegrassesthatgrowonthedrylandcontinents,andthecomparisonisanappropriateone.Inpotentialfoodvaluehowever,planktonfaroutweighsthatofthelandgrasses.Onescientisthasestimatedthatwhilegrassesoftheworldproduceabout49billiontonsofvaluablecarbohydrateseachyear.Thesea’splanktongeneratesmorethantwiceasmuch.

Despiteitsenormousfoodpotential,littleeffortwasmadeuntilrecentlytofarmplanktonaswefarmgrassesonland.Nowmarinescientistshaveatlastbeguntostudythispossibility,especiallyasthesea’sresourcesloomevenmoreimportantasameansoffeedinganexpandingworldpopulation.

Nooneyethasseriouslysuggestedthat“planktonburgers”maysoonbecomepopulararoundtheworld.Asapossiblefarmedsupplementaryfoodsource,however,planktonisgainingconsiderableinterestamongmarinescientists.

Onetypeofplanktonthatseemstohavegreatharvestpossibilitiesisatinyshrimplikecreaturecalledkrill.Growingtotwoorthreeincheslong,krillprovidethemajorfoodforthegiantbluewhale,thelargestanimalevertoinhabittheEarth.Realizingthatthiswhalemaygrow100feetandweigh150tonsatmaturity,itisnotsurprisingthateachonedevoursmorethanonetonofkrilldaily.

Krillswimaboutjustbelowthesurfaceinhugeschoolssometimesmileswide,mainlyinthecoldAntarctic.Becauseoftheirpinkcolor,theyoftenappearasasolidreddishmasswhenviewedfromashiporfromtheair.Krillareveryhighinfoodvalue.Apoundofthesecrustaceanscontainsabout460calories—aboutthesameasshrimporlobster,towhichtheyarerelated.

Ifthekrillcanfeedsuchhugecreaturesaswhales,manyscientistsreason,theymustcertainlybecontendersasnewfoodsourceforhumans.

1.Whichofthefollowingbestportraystheorganizationofthepassage?

A.Theauthorpresentstheadvantagesanddisadvantagesofplanktonasafoodsource.

B.Theauthorquotespublicopiniontosupporttheargumentforfarmingplankton.

C.Theauthorclassifiesthedifferentfoodsourcesaccordingtoamountofcarbohydrate.

D.Theauthormakesageneralstatementaboutplanktonasafoodsourceandthenmovestoaspecificexample.

2.Accordingtothepassage,whyisplanktonregardedtobemorevaluablethanlandgrasses?

A.Itiseasiertocultivate.

B.Itproducesmorecarbohydrates.

C.Itdoesnotrequiresoil.

D.Itismorepalatable.

3.Whydoestheauthormention“planktonburgers”?

A.Todescribetheappearanceofonetypeofplankton.

B.Toillustratehowmuchplanktonawhaleconsumes.

C.Tosuggestplanktonasapossiblefoodsources.

D.Tocomparethefoodvaluesofbeefandplankton.

4.Whatismentionedasoneconspicuousfeatureofkrill?

A.Theyarethesmallestmarineanimals.

B.Theyarepinkincolor.

C.Theyaresimilarinsizetolobsters.

D.Theyhavegrasslikebodies.

5.Theauthormentionsallofthefollowingasreasonswhyplanktoncouldbeconsideredahumanfoodsourceexceptthatitis___.

A.highinfoodvalue.

B.inabundantsupplyintheoceans.

C.anappropriatefoodforotheranimals.

D.freeofchemicalsandpollutants.

Withoutregularsuppliesofsomehormonesourcapacitytobehavewouldbeseriouslyimpaired;withoutotherswewouldsoondie.Tinyamountsofsomehormonescanmodifymoodsandactions,ourinclinationtoeatordrink,ouraggressivenessorsubmissiveness,andourreproductiveandparentalbehavior.Andhormonesdomorethaninfluenceadultbehavior;earlyinlifetheyhelptodeterminethedevelopmentofbodilyformandmayevendetermineanindividual’sbehavioralcapacities.Laterinlifethechangingoutputsofsomeendocrineglandsandthebody’schangingsensitivitytosomehormonesareessentialaspectsofthephenomenaofaging.

Communicationwithinthebodyandtheconsequentintegrationofbehaviorwereconsideredtheexclusiveprovinceofthenervoussystemuptothebeginningofthepresentcentury.TheemergenceofendocrinologyasaseparatedisciplinecanprobablybetracedtotheexperimentsofBaylissandStarlingonthehormonesecretion.Thissubstanceissecretedfromcellsintheintestinalwallswhenfoodentersthestomach;ittravelsthroughthebloodstreamandstimulatesthepancreastoliberatepancreaticjuice,whichaidsindigestion.Byshowingthatspecialcellssecretchemicalagentsthatareconveyedbythebloodstreamandregulatedistanttargetorgansortissues.Baylissandstarlingdemonstratedthatchemicalintegrationcouldoccurwithoutparticipationofthenervoussystem.

Theterm“hormone”wasfirstusedwithreferencetosecretion.StarlingderivedthetermfromtheGreekhormone,meaning“toexciteorsetinmotion.Theterm“endocrine”wasintroducedshortlythereafter“Endocrine”isusedtorefertoglandsthatsecretproductsintothebloodstream.Theterm“endocrine”contrastswith“exocrine”,whichisappliedtoglandsthatsecrettheirproductsthoughductstothesiteofaction.Examplesofexocrineglandsarethetearglands,thesweatglands,andthepancreas,whichsecretspancreaticjuicethroughaductintotheintestine.Exocrineglandsarealsocalledductglands,whileendocrineglandsarecalledductless.

1.Whatistheauthor’smainpurposeinthepassage?

A.Toexplainthespecificfunctionsofvarioushormones.

B.Toprovidegeneralinformationabouthormones.

C.Toexplainhowtheterm“hormone”evolved.

D.Toreportonexperimentsinendocrinology.

2.Thepassagesupportswhichofthefollowingconclusions?

A.Thehumanbodyrequireslargeamountsofmosthormones.

B.Synthetichormonescanreplaceaperson’snaturalsupplyofhormonesifnecessary.

C.Thequantityofhormonesproducedandtheireffectsonthebodyarerelatedtoaperson’sage.

D.Theshortchildoftallparentsverylikelyhadahormonedeficiencyearlyinlife.

3.ItcanbeinferredfromthepassagethatbeforetheBaylissandStarlingexperiments,mostpeoplebelievedthatchemicalintegrationoccurredonly___.

A.duringsleep.

B.intheendocrineglands.

C.undercontrolofthenervoussystem.

D.duringstrenuousexercise.

4.Theword“liberate”couldbestbereplacedbywhichofthefollowing?

A.EmancipateB.DischargeC.SurrenderD.Save

5.Accordingtothepassageanothertermforexocrineglandsis___.

A.ductglands

B.endocrineglands

C.ductlessglands

D.intestinalglands.

Passage2

Questions6to10arebasedonthefollowingpassage:

Thefoodweeatseemstohaveprofoundeffectsonourhealth.Althoughsciencehasmadeenormousstepsinmakingfoodmorefittoeat,ithas,atthesametime,mademanyfoodsunfittoeat.Someresearchhasshowntat40percentofcancerisrelatedtothedietaswell,especiallycancerofthecolon.Differentculturesatemorepronetogetcertainillnessesbecauseofthefoodthatischaracteristicinthesecultures.Thatfoodisrelatedtoillnessisnotanewdiscovery.In1945,governmentresearchersrealizedthatnitratesandnitrites,commonlyusedtopreservecolorinmeats,andotherfoodadditives,causedcancer.Yetthesecarcinogenicadditivesremaininourfood,anditbecomesmoredifficultallthetimetoknowwhichthingsonthepackaginglabelsofprocessedfoodarehelpfulorharmful.Theadditivesthatweeatarenotallsodirect.Farmersoftengivepenicillintobeefandpoultry,andbecauseofthis,penicillinhasbeenfoundinthemilkoftreatedcows.Sometimessimilardrugsareadministeredtoanimalsnotformedicinalpurposes,butforfinancialreasons.Thefarmersaresimplytryingtofattentheanimalsinordertoobtainahigherpriceonthemarket.AlthoughtheFoodandDrugAdministration(FDA)hastriedrepeatedlytocontroltheseprocedures,thepracticescontinue.

6.Howhassciencedoneadisservicetomankind?

A.Becauseofscience,mostofthefoodsweeattodayarecontaminated.

B.Ithascausedalackofinformationconcerningthevalueoffood.

C.Asaresultofscientificintervention,somepotentiallyharmfulsubstanceshasbeenaddedtoourfood.

D.Thescientistshavepreservedthecolorofmeats,butnotofvegetables.

7.Whatarenitratesusedfor?

A.Theypreservesflavorinpackagedfoods.

B.Theypreservethecolorofmeats.

C.Theyaretheobjectsofresearch.

D.Theycausetheanimalstobecomefatter.

8.TheFDAhastriedrepeatedlytocontrol.

A.theattempttofattentheanimals

B.theattempttocuresickanimals

C.theusingofdrugstoanimals

D.theusingofadditivestopreservethedoloroffood

9.Theword“carcinogenic”meansmostnearlythesameas.

A.trouble-makingB.color-retaining

C.money-savingD.cancer-causing

10.WhichofthefollowingstatementsisNOTtrue?

A.Drugsarealwaysgiventoanimalsformedicalreasons.

B.Someoftheadditivesinourfoodareaddedtothefooditselfandsomearegiventothelivinganimals.

C.Researchershaveknownaboutthepotentialhazardsofthefoodadditivesforoverthirty-fiveyears.

D.Foodmaycausefortypercentofcancerintheworld.

Theywillneverreconcilethemselvesto____.

ThediscoveryoftheAntarcticnotonlyprovedoneofthemostinterestingofallgeographicaladventures,butcreatedwhatmightbecalled“theheroicageofAntarcticexploration”.Bytheirtremendousheroism,mensuchasShakleton,Scott,andAmundsencausedanewcontinenttoemergefromtheshadows,andyetthatheroicage,littlemorethanacenturyold,isalreadypassing.Modernscienceandinventionsarerevolutionizingtheendurance,futurejourneysintotheseicywasteswillprobablydependonmotorvehiclesequippedwithcaterpillartractionratherthanonthedogsthatearlierdiscoverersfoundsoinvaluableandhardlycomparable.

FewrealizethatthisAntarcticcontinentisalmostequalinsizetoSouthAmerica,andenormousfieldofworkawaitsgeographersandprospectors.Thecoastsofthiscontinentremaintobeaccuratelycharted,andthemapingofthewholeoftheinteriorpresentsaformidabletasktothecartographerswhoundertakethework.Oncetheirlaborsarecompleted,itwillbepossibletoprospectthevastnaturalresourceswhichscientistsbelievewillfurnishoneofthelargesttreasurehoardsofmetalsandmineralstheworldhasyetknown,andalmostinexhaustiblesourcesofcopper,coal,uranium,andmanyotheroreswillbecomeavailabletoman.SuchdiscoverieswillusherinaneraofpracticalexploitationoftheAntarcticwastes.

Thepolardarknesswhichhidesthiscontinentforthesixwintermonthswillbedefeatedbyhugebatteriesoflight,andmakepossibletheestablishingofair-fieldsforthefutureinter-continentalairservicesbymakingtheseareasaslightasday.Presentflyingrouteswillbecompletelychanged,fortheAntarcticrefuelingbaseswillmakeflightsfromAustraliatoSouthAmericacomparativelyeasyoverthe5,000milesjourney.

Theclimateisnotlikelytoofferaninsuperableproblem,fortheexplorerAdmiralByrdhasshownthattheclimateispossibleevenformencompletelyuntrainedforexpeditionsintothosefrozenwastes.Someofhispartiesweremenwhohadneverseensnowbefore,andyetherecordsthattheysurvivedtherigorsoftheAntarcticclimatecomfortably,sothat,providedthattheappropriateinstallationsaremade,wemayassumethathumanbeingsfromallcountriescouldlivetheresafely.Byrdevenaffirmsthatitisprobablythemosthealthyclimateintheworld,fortheintensecoldofthousandsofyearshassterilizethiscontinent,andrendereditabsolutelygermfree,withtheconsequencesthatordinaryandextraordinarysicknessanddiseasesfromwhichmansuffersinotherzoneswithdifferentclimatesarehereutterlyunknown.Thereexistnoproblemsofconservationandpreservationoffoodsupplies,forthelatterkeepindefinitelywithoutanysignsofdeterioration;itmayevenbethatlatergenerationswillcometoregardtheAntarcticasthenaturalstorehouseforthewholeworld.

Plansarealreadyonfoottosetuppermanentbasesontheshoresofthiscontinent,andwhatsofewyearsagowasregardedasa“deadcontinent”nowpromisestobeamostactivecenterofhumanlifeandendeavor.

1.WhendidmanbegintoexploretheAntarctic?

A.About100yearsago.

B.Inthiscentury.

C.Atthebeginningofthe19thcentury.

D.In1798.

2.Whatmusttheexplorersbe,eventhoughtheyhavemodernequipmentandtechniques?

A.Braveandtough

B.Stubbornandarrogant.

C.Well-likedandhumorous.

D.Stoutandsmart.

3.Themosthealthyclimateintheworldis___.

A.inSouthAmerica.

B.intheArcticRegion.

C.intheAntarcticContinent.

D.intheAtlanticOcean.

4.WhatkindofmetalsandmineralscanwefindintheAntarctic?

A.Magnetite,coalandores.

B.Copper,coalanduranium.

C.Silver,naturalgasanduranium.

D.Aluminum,copperandnaturalgas.

5.Whatisplannedforthecontinent?

A.Buildingdamsalongthecoasts.

B.Settingupseveralsummerresortsalongthecoasts.

C.Mappingthecoastandwholeterritory.

D.Settinguppermanentbasesonthecoasts.