读趣百科

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.

Whichissafer-stayingathome，travelingtoworkonpublictransport，orworkingintheoffice?Surprisingly，eachofthesecarriesthesamerisk，whichisverylow.However，whataboutflyingcomparedtoworkinginthechemicalindustry?Unfortunately，theformeris65timesriskierthanthelatter!Infact，theaccidentrateofworkersinthechemicalindustryislessthanthatofalmostanyofhumanactivity，andalmostassafeasstayingathome.

Thetroublewiththechemicalindustryisthatwhenthingsgowrongtheyoftencausedeathtothoselivingnearby.Itisthiswhichmakeschemicalaccidentssonewsworthy.Fortunately，theyareextremelyrare.ThemostfamousoneshappenedatTexasCity(1947)，Flixborough(1974)，Seveso(1976)，Pemex(1984)andBhopal(1984)。

Someofthesearealwaysinthemindsofthepeopleeventhoughthelossoflifewassmall.NoonediedatSeveso，andonly28workersatFlixborough.TheworstaccidentofallwasBhopal，whereupto3，000werekilled.TheTexasCityexplosionoffertilizerkilled552.ThePemexfireatastorageplantfornaturalgasinthesuburbsofMexicoCitytook542lives，justamonthbeforetheunfortunateeventatBhopal.

Someexpertshavediscussedtheseaccidentsandusedeachaccidenttoillustrateaparticulardanger.ThustheTexasCityexplosionwascausedbytonsofammoniumnitrate(硝酸铵)，whichissafeunlessstoredingreatquantity.TheFlixboroughfireballwasthefaultofmanagement，whichtookriskstokeepproductiongoingduringessentialrepairs.TheSevesoaccidentshowswhathappensifthelocalauthoritieslackknowledgeofthedangerontheirdoorstep.Whenthepoisonousgasdriftedoverthetown，localleaderswereincapableoftakingeffectiveaction.ThePemexfirewasmadeworsebyanoverloadedsiteinanovercrowdedsuburb.Thefiresetoffachainreactionosexplodingstoragetanks.Yet，byamiracle，thetwolargesttanksdidnotexplode.Hadthesecaughtfire，then3，000strongrescueteamandfirefighterswouldallhavedied.

1.Chemicalaccidentsareusuallyimportantenoughtobereportedasnewsbecause____.

A.theyareveryrare

B.theyoftencauselossoflife

C.theyalwaysoccurinbigcities

D.theyarousetheinterestofallthereaders

2.Whichofthefollowingstatementsistrue?

A.Workingattheofficeissaferthanstayingathome.

B.Traverllingtoworkonpublictransportissaferthanworkingattheoffice.

C.Stayingathomeissaferthanworkinginthechemicalindustry.

D.Workinginthechemicalindustryissaferthantravelingbyair.

3.Accordingtopassage，thechemicalaccidentthatcausedbythefaultofmanagementhappenedat____.

A.TexascityB.FlixboroughC.SevesoD.MexicoCity

4.Fromthediscussionamongsomeexpertswemaycocludethat____.

A.toavoidanyaccidentsweshouldnotrepairthefacilitiesinchemicalindustry

B.thelocalauthoritiesshouldnotbeconcernedwiththeproductionofthechemicalindustry

C.alltheseaccidentscouldhavebeenavoidedorcontrolledifeffectivemeasurehadbeentaken

D.naturalgasstoredinverylargetanksisalwayssafe

5.Fromthepassageweknowthatammoniumnitrateisakindof____.

A.naturalgas，whichcaneasilycatchfire

B.fertilizer，whichcan'tbestoredinagreatquantity

C.poisonoussubstance，whichcan'tbeusedinovercrowdedareas

D.fuel，whichisstoredinlargetanks

翻译：

Cultureshockiscausedbytheanxietythatresultsfromlosingallfamiliarsignsandsymbolsofsocialintercourse.(PassageFour)

翻译：

Asthesourceofaluminumisalmostinexhaustible,wecanexpectthatmoreandmoreuseswillbefoundforthisversatilemetal.(PassageTwo)

翻译：

Bymakingvehicleslighterinweightaluminumhasgreatlyreducedtheamountoffuelneededtomovethem,(PassageTwo)