全國(guó)英語(yǔ)六級(jí)考試閱讀臨考沖刺題

全國(guó)英語(yǔ)六級(jí)考試閱讀臨考沖刺題

全國(guó)英語(yǔ)六級(jí)考試閱讀臨考沖刺題

Wesometimesthinkhumansareuniquelyvulnerableto

anxiety,butstressseemstoaffecttheimmunedefensesoflower

animalstoo.Inoneexperiment,forexample,behavioral

immunologist（免疫學(xué)家）MarkLaudenslager,attheUniversity

ofDenver,gavemildelectricshocksto24rats.Halfthe

animalscouldswitchoffthecurrentbyturningawheelintheir

enclosure,whiletheotherhalfcouldmot.Theratsinthetwo

groupswerepairedsothateachtimeoneratturnedthewheel

itprotectedbothitselfanditshelplesspartnerfromtheshock.

Laudenslagerfoundthattheimmuneresponsewasdepressedbelow

normalinthehelplessratsbutnotinthosethatcouldturn

offtheelectricity.Whathehasdemonstrated,hebelieves,is

thatlackofcontroloveranevent,nottheexperienceitself,

iswhatweakenstheimmunesystem.

Otherresearchersagree.JayWeiss,apsychologistatDuke

UniversitySchoolofMedicine,hasshownthatanimalswhoare

allowedtocontrolunpleasantstimulidontdevelopsleep

disturbancesorchangesinbrainchemistrytypicalofstressed

rats.Butiftheanimalsareconfrontedwithsituationsthey

havenocontrolover,theylaterbehavepassivelywhenfaced

withexperiencestheycancontrol.Suchfindingsreinforce

千里之行，始于足下。

psychologistssuspicionsthattheexperienceorperceptionof

helplessnessisoneofthemostharmfulfactorsindepression.

Oneofthemoststartlingexamplesofhowthemindcanalter

theimmuneresponsewasdiscoveredbychance.In1975

psychologistRobertAderattheUniversityofRochesterSchool

ofMedicineconditioned(使形成條件反射)micetoavoid

saccharin(糖精)bysimultaneouslyfeedingthemthesweetener

andinjectingthemwithadrugthatwhilesuppressingtheir

immunesystemscausedstomachupsets.Associatingthe

saccharinwiththestomachpains,themicequicklylearnedto

avoidthesweetener.Inordertoextinguishthisdislikefor

thesweetener,Aderreexposedtheanimalstosaccharin,this

timewithoutthedrug,andwasastonishedtofindthatthose

micethathadreceivedthehighestamountsofsweetenerduring

theirearlierconditioningdied.Hecouldonlyspeculatethat

hehadsosuccessfullyconditionedtheratsthatsaccharin

alonenowservedtoweakentheirimmunesystemsenoughtokill

them.

11.Laudenslagersexperimentshowedthattheimmunesystem

ofthoseratswhocouldturnofftheelectricity.

A)wasstrengthened

B)wasnotaffected

C)wasaltered

D)wasweakened

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12.Accordingtothepassage,theexperienceof

helplessnesscausesratsto.

A)trytocontrolunpleasantstimuli

B)turnofftheelectricity

C)behavepassivelyincontrollablesituations

D)becomeabnormallysuspicious

13.ThereasonwhythemiceinAdersexperimentavoided

saccharinwasthat.

A)theydislikeditstaste

B)itaffectedtheirimmunesystems

C)itledtostomachpains

D)theyassociateditwithstomachaches

14.Thepassagetellsusthatthemostprobablereasonfor

thedeathofthemiceinAdersexperimentwasthat.

A)theyhadbeenweakenedpsychologicallybythesaccharin

B)thesweetenerwaspoisonoustothem

C)theirimmunesystemshadbeenalteredbythemind

千里之行，始于足下。

D)theyhadtakentoomuchsweetenerduringearlier

conditioning

15.Itcanbeconcludedfromthepassagethattheimmune

systemsofanimals.

A)canbeweakenedbyconditioning

B)canbesuppressedbydruginjections