11级四级模拟试题Word格式文档下载.docx

11级四级模拟试题Word格式文档下载.docx

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Forthispart,youareallowed30minutestowriteαshortessαyentitledCompetitonandCooperation.Youshouldwriteatleast120wordsfollowingtheoutlinegivenbelow:

1、竞争与合作都很重要;

2、竞争与合作相辅相成。

CompetitionandCooperation

PartIIReadingComprehension（SkimmingandScanning）

Directions:

Inthispartyouwillhave15minutestogooverthepassagequicklyandanswerthequestionsonAnswerSheetI.Forquestions1-7,choosethebestanswerfromthefourchoicesmarkedA）,B）,C）andD）.Forquestions8-10,completethesentenceswiththeinformationgiveninthepassage.

HowtoSolveThreePuzzles

Newknowledgeandsophisticateddiagnostictechniquesarehelpingdoctorsrecognizeearlysignsofautism（孤独症）,Alzheimer’sdisease（痴呆症）andheartproblemsinwomen.Harvardexpertsreportontheadvancesthataregivingpatientshope.

DetectingAutism

Earlydiagnoses（诊断）ofautismiscriticalbecauseeducationalprogramsthatbuilduponachild’sstrengthensandimprovesocialskillsmayhelpsculptthedevelopingbrain,minimizingtheimpactoftheillnesslaterinlife.Butspottingthedisorderishardsincethereisnotestforit,althoughscientistsareslowlyuncoveringgeneabnormalitiesthatmakechildrenvulnerabletoautismLastweekTheNewEnglandJournalofMedicinereportedthataspecificlocationonchromosome（染色体）16wasthesiteofmutationsresponsibleforsomecasesofautism.

Fornow,diagnosisdependsonobservingachild’sbehavior.It’sacompleteprocess,sincenotwocasesarealikeandsignsrangefrommildtosevere.Indeed,eventhoughsignsofautismmaybeapparentbeforetheirfirstbirthday,mostchildrenaren’tdiagnoseduntiltheageof3.Thatmakesparents,whoaresointimatelyfamiliarwiththeirchild’sbehavior,perhapsthemosteffectivediagnostic“tools”.TheAmericanAcademyofPediatricsrecentlyissuedscreeningguidelinesrecommendingthatpediatriciansengageparentsinevaluatinginfantsforautism.Evenbabiesdevelopingtypically,theguidelinessay,shouldbescreenedatsetintervals,suchasduringthe9-,18-and24-monthvisits.

Healthyinfantsasyoungas6or8monthsdocommunicateandrespondnonverballytosocialcues.Mostlookuporturnatthesoundoftheirname.By12monthstheytypicallybabbleandpointatobjects.By16monthstheysaysinglewordsby24months,two-wordphrases.Incontrast,childrenwithautismseldommakemeaningfuleyecontactorrespondtofamiliarvoices.Theymayneverspeak.Theirplayisoftenrepetitiveandcharacterizedbylimitedimagination（neatlyarrangingcrayonsinsteadofcoloringwiththem）.Othersmaysimplyflaptheirhandsinexcitementordisappointment.

Ontheirown,noneofthesesignsmeansthatachildhasautismoranotherdevelopmentaldisorder.Nevertheless,ifyourchildhasanyofthesesigns,heorshemeritsevaluation.Althoughnotreatmentsarecurative,theycanhelpchildrenlearntheskillstheyneedtocopeinanormalenvironment,achievegreaterindependenceandhavebrighterfutures.

TheAlzheimer’sMystery

Alzheimer’sdisease,whichbeginsyears,evendecades,beforeitcausessymptoms,isaquietlytickingtimebomb.Butuntilrecentlydoctorshadnodiagnostictestthatcould“heart”theticking.Unfortunately,itdidn’tmattermuchthatAlzheimer’scouldn’tbespottedearly—atastagecalledmildcognitiveimpairment,orMCI-sincetherewerenotreatments.Today,however,therearenewdiagnosticteststhatcandetectAlzheimer’satanearlystage,andseveraldisease-modifyingdrugsareinadvancedclinicaltrials.

Thebrainshrinkage（萎缩）causedbyAlzheimer’scannowbemeasuredwithvolumetricmagneticresonanceimaging（MRI）.ThistechniquetakesaseriesofMRIbrainscansandtheusessophisticatedmathematicalmodelstoanalyzetheresults.Mostimportant,volumetricMRIenablesresearcherstoidentifysubtleshrinkageinbrainareasfirstaffectedbyAlzheimer’s,suchasthehippocampus,whichisinvolvedinmemory.

Anothertechnologyinlimitedclinicaluseisfluro-deoxy-glucosepositronemissiontomography（FDGPET）.ImagesproducedbyFDG-PETrevealpatternsofglucosemetabolism（葡萄糖新陈代谢）inthecerebralcortex,thesiteofabstractthought,reasoningandlearning.Becauseactiveneuronsguzzleglucoseforenergy,diminisheduptakeinaspecificpatterncandenoteAlzheimer’s.Intheresearchsetting,scientistshaveevenusedFDG-PETtoidentifypeoplewhodonotyethaveAlzheimer’sbutareatriskfordevelopingit,orfordevelopingmildcognitiveimpairment.

AdifferentkindofPET-scantechnologybuildsonrecentdiscoveriesaboutamyloidplaquesandtautangles,theneuron-killingproteinsthataccumulateinthebrainsofAlzheimer’spatients.ResearchersattheUniversityofPittsburghhavedevelopedPittsburghCompoundB,orPIB.Wheninjectedintotheblood,thiscompoundbindstoamyloidplaquesinthebrain,allowingthemtobedetectedonPETscansPETscanswithPIBclearlydistinguishpeoplewithAlzheimer’sfromhealthypeople.TheymayalsohelpidentifypeoplewiththeprogressiveformofMCI.

Takingadifferentapproach,otherresearchersareidentifyingearlychangesinthelevelsofparticularbrainproteinsincerebrospinalfluid.（Theclearspinalfluidconstantlybathesthebrainandspinalcord.）Spinal-fluidlevelsoftheproteintauaretypicallyelevatedinAlzheimer’s,andanalteredversionofthetauprotein,knownasphosphorylatedtau,canbedetectedearlyinAlzheimer’s.Loweredspinal–fluidconcentrationsofanalteredversionofbeta-amyloid,calledAB42,aretypicalinAlzheimer’sandcanalsohelpidentifypeoplewithmildcognitiveimpairmentwhoaremostlikelytoprogresstoAlzheimer’s

Althoughallthesenewimagingandbiochemicaldevelopmentsareindividuallypromising,thecombinationofseveraldifferentimagingtestsandbiochemicalmarkersmayyieldthemostaccuratediagnosis.Forexample,scientistsattheNewYorkUniversitySchoolofMedicinehavereportedthatcombiningvolumetricMRIofthehippocampuswithspinal–fluidmeasuresofphosphorylatedtauandisoprostane–amarkerofoxidativestress—improveddiagnosticaccuracyinidentifyingpeoplewithmilcognitiveimpairmentwhoaremostlikelytoprogresstoAlzheimer’s.

HeartDiseaseinWomen

Whenitcomestodiagnosingthemostcommonkindofheartdisease,somecardiologistsshareHenryHiggins’slamentin“MyFairLady”:

“Whycan’tawomanbemorelikeaman?

”That’sbecausemanywomendon’thavethetypicalsymptoms,likecrushingchestpainandshortnessofbreathbroughtonbyphysicalactivityorstress.Instead,theyhavediffusediscomforttinthetest,unusualexhaustionordepressionwithoutanapparentreason.Tomakemattersworse,thetestsconsideredbestatdiagnosingcoronary-arterydiseasegenerallydon’tworkaswellforwomenastheydoformen.Asaresult,analarmingnumberofwomenwithheartdiseasegoundiagnosedanduntreateddespiterepeatedvisitstothedoctorandtheemergencyroom.

Bloodflowstoheartmusclefirstthroughlargearteries（thecoronaryarteries）andthemthroughabranchingnetworkofsmallerbloodvesselsThesymptomsofheartdisease,inmenorwomen,oftenresultfromcholesterol-filledplaquesthatcanslowandcompletelyblocktheflowofbloodtotheheartmuscle.Thistypeofheartdisease,whichhasbeenrecognizedforacentury,canbeseenwithtestssuchascoronaryangiograms（orarteriogram）and,lesswell,withnoninvasivetestssuchasspecialCTandMRIscans.

Injustthepastdecade,researchershavelearnedthatmanywomenwithchestpainandothersymptomsofheartdiseasehaveaconditioncalledcoronarymicrovasculardisease,whichaffectstheheart’ssmallestarteries.Thisfundamentallydifferentformofheartdiseaseisascommonandascostlyasallfemale-specificcancerscombined,affectingasmanyas3millionAmericanwomen.Itaffectsmen,too,butnotnearlyasoften.

Manydoctorshavenotyetheardaboutcoronarymicro-vasculardisease.Currently,themostdefinitivetestinvolvesmeasuringcoronary-arteryflowreserveofcoronaryreactivity.Itinvolvesthreadinganultrathinwirewithblood-flowsensorsatthetipdeepintoacoronaryartery.Bloodflowinthearteryisthenmeasuredbeforeandafterinjectionsofoneormoremedicationsthatshouldcausethemicro-vesselstodilate.Analternative,noninvasivewayofdetectingmicro-vasculardiseaseiswithcardiacMRI.Thisscanmeasurestheamountofbloodflowingintotheheartmusclebeforeandaftertheheartisinfusedwithadrugthatdilatesthemicro-vessels.Aswiththecoronary-reactivitytest,ifbloodflowdoesnotincrease,thereisdiseaseofthemicro-vessels.

Ifyouareawomanwithrecurrentchestpainordiscomfort,shortnessofbreath,unexplainableexhaustionanddepression,youmayneedspecialevaluationevenifyouhavecleararteriesonanangiogram.Ifyourdoctorsaysthere’snothingwrong,askforasecondopinionatoneofagrowingnumberofwomen’scardiovascular-carecenters.Youmayhavecoronarymicro-vasculardisease.

1.Accordingtothepassage,heartproblemsnowadaysaremedicaldifficulties,especiallywhentheyoccurin_____

A）menB）womenC）theyoungD）theold

2.Whyisitsohardtodiagnosetheautism?

A）Becausetherestillexistsnotestfordiagnosesbynow.

B）Becausediagnosisofthesameautismcasesaredifferent.

C）Becausescientistsmakenoprogressinuncoveringthegeneticfactors.

D）Becauseoneofthesignsofautismisobvioustobediagnosed.

3.Howoldarethosebabieswithoutautismwhentheystarttosaysinglewords?

A）by6or8monthsB）by12months

C）by16monthsD）by24months

4.ThebrainshrinkagecausedbyAlzhe