题目内容：
Questionsarebasedonthefollowingpassage. “Humansshouldnottrytoavoidstressanymorethantheywouldshunfood,loveorexercise.”SaidDr.HansSelye,thefirstphysiciantodocumenttheeffectsofstressonthebody.Whilehere’sonquestionthatcontinuousstressisharmful,severalstudiessuggestthatchallengingsituationsinwhichyou’reabletorisetotheoccasioncanbegoodforyou.
Ina2001studyof158hospitalnurses,thosewhofacedconsiderableworkdemandsbutcopedwiththechallengeweremorelikelytosaytheywereingoodhealththanthosewhofelttheystressthatyoucanmanagealsoboostimmune（免疫的）function.InastudyattheAcademicCenterforDentistryinAmsterdam,researchersputvolunteersthroughtwostressfulexperiences.Inthefirst,atimedtaskthatrequiredmemorizingalistfollowedbyashorttest,subjectsthroughagory（血淋淋的）videoonsurgicalprocedures.ThosewhodidwellonthememorytesthadanincreaseinlevelsofimmunoglobulinA,anantibodythat’sthebody’sfirstlineofdefenseagainstgerms.Thevideo-watchersexperiencedadownturnintheantibody.
Stresspromptsthebodytoproducecertainstresshormones.Inshortburststhesehormoneshaveapositiveeffect,includingimprovedmemoryfunction.“Theycanhelpnervecellshandleinformationandputitintostorage,”saysDr.BruceMcEwenofRockefellerUniversityinNewYork.Butinthelongrunthesehormonescanhaveaharmfuleffectonthebodyandbrain.
“Sustainedstressisnotgoodforyou,”saysRichardMorimoto,aresearcheratNorthwesternUniversityinIllinoisstudyingtheeffectsof
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