"Humansshouldnottrytoavoidstressanymorethantheywouldshunfoodloveorexercise."saidDr．HansSelyethefirstphysiciantodocumenttheeffectsofstressonthebody．Whilehere'snoquestionthatcontinuousstres

　　"Humansshouldnottrytoavoidstressanymorethantheywouldshunfoodloveorexercise."saidDr．HansSelyethefirstphysiciantodocumenttheeffectsofstressonthebody．Whilehere'snoquestionthatcontinuousstressisharmfulseveralstudiessuggestthatchallengingsituationsinwhichyou'reabletorisetotheoccasioncanbegoodforyou．

　　Ina2001studyof158hospitalnursesthosewhofacedconsiderableworkdemandsbutcopedwith（设法处理）thechallengeweremorelikelytosaytheywereingoodhealththanthosewhofelttheycouldn'tgetthejobdone．

　　Stressthatyoucanmanagemayalsoboostimmune（免疫的）function．InastudyattheAcademicCenterforDentistryinAmsterdamresearchersputvolunteersthroughtwostressfulexperiences．Inthefirstatimedtaskthatrequiredmemorizingalistfollowedbyashorttestsubjectsbelievedtheyhadcontrolovertheoutcome．Inthesecondtheyweren'tincontrol:Theyhadtositthroughagory（血淋淋的）videoonsurgicalprocedures．ThosewhodidgoonthememorytesthadanincreaseinlevelsofimmunoglobulinAanantibodythat'sthebody'sfirstlineofdefenseagainstgermsThevideo-watchersexperiencedadowntumintheantibody．

　　Stresspromptsthebodytoproducecertainstresshormones（荷尔蒙）.Inshortburststhesehormoneshaveapositiveeffectincludingimprovedmemoryfunction．"Theycanhelpnervecellshandleinformationandputitintostorage"saysDr．BruceMcEwenofRockefellerUniversityinNewYork．Butinthelongrunthesehormonescanhaveaharmfuleffectonthebodyandbrain．

　　"Sustainedstressisnotgoodforyou"saysRichardMorimotoaresearcheratNorthwesternUniversityinIllinoisstudyingtheeffectsofstressonlongevity（长寿）"It'stheoccasionalburstofstressorbriefexposuretostressthatcouldbeprotective．"

　　1．Thepassageismainlyabout .

　　A．thebenefitsofmanageablestress

　　B．howtoavoidstressfulsituations

　　C．howtocopewithstresseffectively

　　D．theeffectsofstresshormonesonmemory

　　2．Theunderlinedword"shun"（LinelPara．l）mostprobablymeans .

　　A．cutdownon B．stayawayfrom

　　C．runouto