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.

PartIIICloze

Directions:Therearetwentyblanksinthefollowingpassage.Foreachblanktherearefourchoices.ChoosetheonethatbestfitsintothepassageandthenmarksyouranswerontheAnswerSheet.

Therearetwofactorswhichdetermineanindividual’sintelligence.Thefirstisthesortofbrainheisborn61.Humanbrainsdifferconsiderably,62beingmorecapablethanothers.63nomatterhowgoodabrainhehastobeginwith,anindividualwillhavealoworderofintelligence64hehasopportunitiestolearn.Sothesecondfactoriswhat65totheindividual—thesortofenvironmentinwhichheisbrought66.Ifanindividualishandicapped(受阻碍)67,itislikelythathisbrainwill68todevelopandhewill69attainthelevelofintelligenceofwhichheis70.

Theimportanceofenvironmentindetermininganindividual’sintelligencecanbe71bythecasehistoryoftheidenticaltwins,PeterandJohn.Whenthetwinswerethreemonthsold,theirparentsdied,andtheyareplacedin72foster(寄养)homes.Peterwasrearedbyparentsoflowintelligenceinan73communitywithpooreducational74.John,75,waseducatedinthehomeofwell-to-doparentswhohasbeentocollege.Thisenvironmental76continueduntilthetwinswere77theirlateteens,78theyweregiventeststo79theirintelligence.John’sI.Q.(智商)was125,twenty-fivepointshigherthanthe80andfullyfortypointshigherthanhisidenticalbrother.

61.A.forB.byC.withD.in

62.A.mostB.someC.manyD.few

63.A.ButB.ForC.StillD.And

64.A.ifB.thoughtC.asD.unless

65.A.refersB.appliesC.happensD.concerns

66.A.aboutB.upC.forwardD.forth

67.A.relativelyB.intelligentlyC.regularlyD.environmentally

68.A.failB.helpC.manageD.stop

69.A.everB.neverC.evenD.nearly

70.A.ableB.capableC.availableD.acceptable

71.A.demonstratedB.deniedC.neglectedD.ignored

72.A.separateB.similarC.remoteD.individual

73.A.omittedB.isolatedC.enclosedD.occupied

74.A.possibilitiesB.opportunitiesC.capacitiesD.responsibilities

75.A.moreoverB.consequentlyC.thenD.however

76.A.exceptionB.divisionC.differenceD.alteration

77.A.inB.byC.atC.for

78.A.whileB.sinceC.whenD.because

79.A.estimateB.countC.decideD.measure

80.A.averageB.commonC.usualD.ordinary

AccordingtoStevenYoung,ifscientistsgetthedatathat________,theywouldpetitionforfasttrackstatus.

Nearlyallthefamiliescanmanagetomeetthesoaringtuitioncoststhroughvariousinvestmentplans.

Theareagets________________(年降雨量不足五厘米).