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离心泵的容积损失有___泄漏损失____泄漏损失和级间泄漏损失。

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密封环,平衡机构

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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___.

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B.theunusualbehaviorofanimalscannotbetrusted.

C.neitherwatchingnorusingseismographsisreliable.

D.earthquake

Sheaskedthatshe_____allowedtoseehersoninpolicecustody.

PartIVTranslation

Thesubjectsinhisexperimentwere75collegestudents.TheyrepresentedalllevelsofabilityinEnglish:beginning,intermediate,andnative-speakingstudents.(PassageTwo)

PartIReadingComprehension

Directions:Inthisparttherearefourpassages.Eachpassageisfollowedbyfourcomprehensionquestions.Readthepassageandanswerthequestions.ThenmarkyouranswerontheAnswerSheet.

Passage1

Questions1to5arebasedonthefollowingpassage:

Someyearsagothecaptainofashipwasveryinterestedinmedicine.Healwaystookmedicinebookstoseaandlikedtotalkaboutdifferentdiseases.

Onedayalazysailoronhisshippretendedtobeill.Helayonhisbunk(铺)andgroanedasifhewereverysick.Thecaptaincametoseehimandwasverypleasedtohaveapatienttolookafter.Hetoldthemantorestforafewdaysandmadetheothersailorsdohiswork.Threedayslateranothersailorpretendedthathehadsomethingwrongwithhischest.Oncemorethecaptainlookedinhismedicalbooksandtold“sick”mantohavearest.

Theothersailorswereveryangrybecausetheyhadmoreworktodo.Thepatientshadthebestfoodandlaughedattheirfriendswhenthecaptainwasnotlooking.Atlastthemate(船长副手)decidedtocurethe“sick”men.Hemixedupsomesoap,soot(烟灰),glue(胶水)andotherunpleasantthings.Thenheobtainedpermissionfromthecaptaintogivehismedicinetothe“sick”men.Whentheytastedthemedicine,theyreallydidfeelill.Itwassohorriblethatoneofthepatientsjumpedoutofhibunk,ranupondeskandclimbedthehighestmastontheship.Hedidnotwantanymoremedicine.

Thematetoldbothofthementhattheymusttakethemedicineeveryhalfanhour,nightandday.Thissooncuredthem.Theybothsaidtheyfeltbetterandwantedtostartwordagain.Thecaptainrealizedthatthementriedtodeceivehimsohemadethemworkveryhardfortherestofthevoyage.

1.Thefirstsailorpretendedtobeillbecausehewantedto.

A.testthecaptain’sknowledgeofmedicineB.befreefromwork

C.havethebestfoodontheshipD.playajokeonhisfriends

2.Whenthecaptainknewasailorwasill,he.

A.didn’tcaremuchB.sentforadoctor

C.lookedafterhimandtoldhimtohavearestD.gavehimsomemedicine

3.Thepatientsfeltbetterquicklybecause.

A.theyhadbeengivenpropermedicine

B.theylearnedthatthecaptainhadfoundoutthetruth

C.theywerelaughedatbytheirfriends

D.themedicinethemategavewashorrible

4.Whenthecaptainknewhehadbeendeceived,he.

A.toldthemnottodosoagainB.losthistemper

C.madethemworkharderD.firedthem

5.Whichofthefollowingbestsummarizesthepassage?

A.AsuddenCure.B.TwoPatients.C.CaptainandSailors.D.ADifficultVoyage.

PartIVTranslation:

Inordertolearntobeone’strueself,itisnecessarytoobtainawideandextensiveknowledgeofwhathasbeensaidanddoneintheworld.(PassageTwo)

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