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.
一初产妇，宫缩15小时自娩一3000g女婴，现胎儿娩出已8分钟，胎盘尚未娩出，阴道无流血，此时的处理下列何项不当