下列对胸痛的表述错误的是

下列哪项不是胎盘剥离征象

PartIVTranslation

Bymakingvehicleslighterinweightaluminumhasgreatlyreducedtheamountoffuelneededtomovethem,(PassageTwo)

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.

Passage4

Questions16to20arebasedonthefollowingpassage:

Thenewglobalsatellitecommunicationssystemswillofferthreekindsservice,whichmayoverlapinmanydifferentkindsofreceivers.

VOICE.SatellitetelephoneswillbeabletomakecallsfromanywhereontheEarthtoanywhereelse.Thatcouldmakethemespeciallyusefultoremote,thirdworldvillages(someofwhichalreadyusestationarysatellitetelephones),explorersanddisaster-reliefteams.Today’smobiletelephonesdependonearth-boundtransmitters,wheretechnicalstandardsvaryfromcountrytocountry.Sobusinesstravelerscannotusetheirmobilephonesoninternationaltrips.Satellitetelephoneswouldmakethatpossible.

MESSAGING.Satellitemassagershavethesameglobalcoverageassatellitetelephones,butcarrytextalone,whichcouldbeusefulforthosewithlaptopcomputers.Equippedwithasmallscreenliketoday’spapers,satellitemassagerswillalsoreceiveshortmessages.

TRACKING.Voiceandmessagingsystemswillalsotelltheiruserswheretheyaretowithinafewhundredmeters.Combinedwiththemessagingservice,thelocationservicecouldhelprescueteamstofindstrandedadventurers,thepolicetofindstolencars,exporterstofollowtheprogressofcargoes,andhaulagecompaniestocheckthatdriversarenotdetouringthepub.America’smilitaryGlobalPositioningSystem(GPS)satellitewillprovidebetterpositioninginformationtoanyonewhohasareceiverfortheirsignals,butGPSdoesnotcarrymessages,sosuchareceivercannotbeusedonitsownfortrackingorrescue.Bythemid-1990s,GPSreceiverswillbeabletotellpeoplewheretheyaretowithin70metersanywhereintheworld,andtowithinameterorsoinareaswheretheserviceissupplementedbyground-basedtransmitter.

16.Globalsatellitecommunicationssystemswillbeusefulto.

A.laptopcomputerusers

B.remotevillages

C.disaster-reliefteams

D.allabove

17.Satellitetelephonewillmake.

A.businesstravelersusemobilephonesoninternationaltrips

B.possiblecallsfromanywhereonearthtoanywhereelse

C.explorershappy

D.allabove

18.Whichofthefollowingistrue?

A.ThepositioningprecisionofthevoicesystemisbetterthanthatofGPS.

B.ThepositioningprecisionofGPSisBetterthanthatofthevoicesystem.

C.ThepositioningprecisionofthemessagingsystemisbetterthanofGPS.

D.Thepositioningprecisionofvoicesystemisbetterthanthatofthemessagingsystem.

19.Whatcanwesayaboutthenewglobalsatellitecommunicationssystems?

A.Theyarewidelyused.

B.Theyareveryhelpful.

C.Theyarecostly.

D.BothAandB.

20.Whichofthefollowingmaybethebesttitleforthepassage?

A.GlobalSatelliteCommunications

B.NewVoiceandMessagingSystem

C.NewGenerationSatellite

D.AlwaysinTouch