一般情况下空气中含氧量在()左右。

A、10%
B、15%
C、21%
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正确答案:

C

答案解析:

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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

Milk,butter,andcheeseare____herefromthefarms.

A、imported
B、transferred
C、transformed
D、transported

Passage3

Questions11to15arebasedonthefollowingpassage:

UnliketheirAmericanorEuropeancounterparts,carsalesmeninJapanworkhardtogetabuyer.Insteadoflyinglazilyaroundshowroomswaitingforcustomerstodropby,manyJapanesecarsalesmenstillgoouttogetthem.Theywalkwearilyalongthestreetscarsdoor-to-door.Newcustomersarehuntedwithfruitandcakesontheirbirthdays.Butlifeisgettingtough,andnotjustbecausenew-carsalesarefalling.

WithmoreJapanesewomen(whooftencontrolthehouseholdbudget)goingouttowork,thesalesmenincreasinglyfindnobodyathomewhentheycall.Thatmeansanothervisitintheeveningortheweekend.Thentheyfaceanextraproblem:morepeople,especiallytheyoung,prefertochooseanewcarfromashowroomwheretheycancomparedifferentmodels.

Evenaslateasthemid-1980ssome90%ofnewcarsweresolddoor-to-door.Insomeruralareasmostnewcarsarestillsoldthisway.Butinthebigcitiesmorethanhalfthenewcarsarenowsoldfromshowrooms.

AlthoughinvestinginshowroomsisexpensivebecauseofthehighcostofJapaneseland,dealershavelittlechoice.AlaborshortageandhigheramongJapan’sworkforcearemakingitdifficulttohiredoor-to-doorsalesmen.MostofaJapanesecarsalesman’sworkingdayisspentdoingfavorsforcustomers,likearranginginsuranceorpickingupvehiclesforservicing,ratherthanactuallyselling.

Japan’sdoorstepcarsalesmenarenotabouttovanish.Thepersonalservicetheyprovideissodeep-rootedinJapanthattheyarelikelytooperatealongsidetheglitteringnewshowrooms.Thetwosystemsevencomplementeachother.Whatincreasinglyhappensisthattheshowroomattractstheinterestofapotentialbuyer,givingthefootsoresalesmenafirmleadtofollowupwithahomevisit.

11.Japanesecarsalesusuallydonotwaitatshowroomsforcustomerstodropby;instead,.

A.theysellcarsdoor-to-door

B.theybuypresentsfortheircustomers

C.theyenjoythemselvesinrecreationcenters

D.theygoouttodomarketresearches

12.Impliedbutstated:thecompetitionincarmarketis.

A.lightB.moderateC.fierceD.unfair

13.Youngpeopleliketobuyanewcar.

A.athomeB.fromashowroom

C.madeintheU.S.A.D.madeinJapan

14.ThesquadronofJapanesecarsalesmenisreducingbecauseof.

A.alaborshortage

B.higherexpectationsamongJapan’sworkforce

C.highcostland

D.bothAandB

15.Japanesecarsalesmentotheircustomersmanyfavorssuchas.

A.showingthemaroundinanexhibition

B.arranginginsurance

C.payingthemavisitonweekends

D.sellingolecarsforthem

Recentresearchhasclaimedthatanexcessofpositiveionsintheaircanhaveanilleffectonpeople’sphysicalorpsychologicalhealth.Whatarepositiveions?Well,theairisfullofions,electricallychargedparticles,andgenerallythereisaroughbalancebetweenthepositiveandthenegativecharged.Butsometimesthisbalancebecomesdisturbedandalargerproportionofpositiveionsarefound.Thishappensnaturallybeforethunderstorm,earthquakeswhenwindssuchastheMistral,HamsinorSharavareblowingincertaincountries.Oritcanbecausedbyabuild-upofstaticelectricityindoorsfromcarpetsorclothingmadeofman-madefibres,orfromTVsets,duplicatorsorcomputerdisplayscreens.

Whenalargenumberofpositiveionsarepresentintheairmanypeopleexperienceunpleasanteffectssuchasheadaches,fatigue,irritability,andsomesensitivepeoplesuffernauseaorevenmentaldisturbance.Animalsarealsoaffected,particularlybeforeearthquakes,snakeshavebeenobservedtocomeoutofhibernation,ratstofleefromtheirburrows,dogshowlandcatsjumpaboutunaccountably.ThishasledtheUSGeographicalSurveytofundanetworkofvolunteerstowatchanimalsinanefforttoforeseesuchdisastersbeforetheyhitvulnerableareassuchasCalifornia.

Conversely,whenlargenumbersofnegativeionsarepresent,thenpeoplehaveafeelingofwell-being.Naturalconditionsthatproducetheselargeamountsarenearthesea,closetowaterfallsorfountains,orinanyplacewherewaterissprayed,orformsaspray.Thisprobablyaccountsforthebeneficialeffectofaholidaybythesea,orinthemountainswithtumblingstreamsorwaterfalls.

Toincreasethesupplyofnegativeionsindoors,somescientistsrecommendtheuseofionisers:smallportablemachines,whichgeneratenegativeions.Theyclaimthationisersnotonlycleanandrefreshtheairbutalsoimprovethehealthofpeoplesensitivetoexcesspositiveions.Ofcourse,therearethedetractors,otherscientists,whodismisssuchclaimsandareskepticalaboutnegative/positiveionresearch.Thereforepeoplecanonlymakeuptheirownmindsbyobservingtheeffectsonthemselves,oronothers,ofanegativerichorpoorenvironment.Afterallitisdebatablewhetherdependingonseismicreadingstoanticipateearthquakesismoreeffectivethanwatchingthecat.

1.Whateffectdoesexceedingpositiveionizationhaveonsomepeople?

A.Theythinktheyareinsane.

B.Theyfeelratherbad-temperedandshort-fussed.

C.Theybecomeviolentlysick.

D.Theyaretootiredtodoanything.

2.Inaccordancewiththepassage,staticelectricitycanbecausedby___.

A.usinghome-madeelectricalgoods.

B.wearingclothesmadeofnaturalmaterials.

C.walkingonartificialfloorcoverings.

D.copyingTVprogramsonacomputer.

3.Ahighnegativeioncountislikelytobefound___.

A.nearapoundwithawaterpump.

B.closetoaslow-flowingriver.

C.highinsomebarrenmountains.

D.byarotatingwatersprinkler.

4.Whatkindofmachinecangeneratenegativeionsindoors?

A.Ionisers.

B.Air-conditioners.

C.Exhaust-fans

D.Vacuumpumps.

5.Somescientistsbelievethat___.

A.watchinganimalstoanticipateearthquakesismoreeffectivethandependingonseismography.

B.theunusualbehaviorofanimalscannotbetrusted.

C.neitherwatchingnorusingseismographsisreliable.

D.earthquake

翻译:

如今,中国正步入老龄化社会,因此独生子女一代面临着巨大的工作和生活压力。中国政府开始适当调整计划生育政策,允许一些家庭在特殊情况下生育二胎。但调查显示,很多夫妻迫于不断加重的经济压力,放弃生育二胎。因此,要从根本上解决老龄化的问题不能依靠出生率的上升,最有效的办法是建立有效的社会保障制度。

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