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大学英语四级改革适用（阅读）模拟试卷280(总分：60.00，做题时间：90分钟)一、ReadingComprehension(总题数：6，分数：60.00)1.PartIIIReadingComprehension（分数：10.00）__________________________________________________________________________________________解析：2.SectionC（分数：10.00）__________________________________________________________________________________________解析：Howdoesfoodaffectmoodandmind?Theanswermaylieinthechemistryofthebrainandnervoussystem.Moleculescalledneurotransmitters(神经传递素)arechemicalmessengers.Theycarryanerveimpulseacrossthegapbetweennervecells.Thereleaseofneurotransmittermoleculesfromoneneuronandtheirattachmenttoreceptorsitesonanotherkeepanerveimpulsemoving.Nerveimpulsescarrymessagesfromtheenvironmenttothebrain,forexample,thepainyoufeelwhenyoustub(踢碰)yourtoe.Theyalsocarrymessagesintheotherdirection,fromthebraintothemuscles.That'swhyyoubackawayfromtheobstaclethatinitiatedthepainsignalandexclaim,Ouch!Manyneurotransmittersarebuiltfromthefoodsweeat,saysneuroscientistEricChudleroftheUniversityofWashington.Toolittleortoomuchofaparticularnutrientinthedietcanaffecttheirproduction,Chudlersays.Forexample,tryptophanfromfoodssuchasyogurt,milk,bananas,andeggsisrequiredfortheproductionoftheneurotransmitterserotonin.Phenylalaninefrombeets,almonds,eggs,meat,andgrainsgoesintomakingtheneurotransmitterdopamine.Dozensofneurotransmittersareknown;hundredsmayexist.Theireffectsdependontheiramountsandwheretheyworkinthebrain.Theneurotransmitterserotonin,forexample,isthoughttoproducefeelingsofcalmness,relaxation,andcontentment.Drugsthatpreventitfrombeingtakenagain(intotheneuronthatreleasedit)areprescribedtotreatdepression.Inatleastsomehealthy,nondepressedpeople,carbohydratefoodsseemtoenhanceserotoninproductionandproducesimilareffects.Itisthebalancebetweendifferentneurotransmittersthathelpsregulatemood,Chudlersays.Propernutritionmayalsoenhancebrainpower.CholineisasubstancesimilartotheBvitamins.It'sfoundineggyolks,wholewheat,peanuts,milk,greenpeas,liver,beans,seafood,andsoybeans.Thebrainusesittomaketheneurotransmitteracetylcholine.Totesttheeffectsofcholineonmemoryandlearning,researchersattheMassachusettsInstituteofTechnologygavememoryteststocollegestudentsbeforeincreasingtheamountofcholineintheirsubjects'diets.Later,theyretested.Ontheaverage,memorieswerebetter,andthestudentslearnedalistofunrelatedwordsmoreeasily.（分数：10.00）(1).Thefunctionofneurotransmitterscanbebestcomparedtothatof_____.（分数：2.00）A.atransportvehicle√B.aprotectiveshieldC.apowerplantD.afoodfactory解析：解析：从第1段第3句末的messenger和第4句中的carry…across可以知道neurotransmitters就像传递信息的信使，有“运输、输送”信息的功能，因此，本题应选A。(2).Accordingtothesecondparagraph,messagessentfromthebraintothemusclesmakeyou_____.（分数：2.00）A.feelthepainB.stubyourtoeC.seeanobstacleD.exclaimOuch√解析：解析：第2段第3句开头的That'swhy…表明当信息从大脑传到肌肉的时候，会使你躲开障碍物并发出“哎哟”的叫声，D就是这两个动作的其中之一，故为答案。A最具干扰性，因为pain一词在第3句也有提及，但根据本段第一句可知A应属于“信息从肌肉传到大脑”的过程，和题干中的fromthebraintothemuscles正好相反，因此，A并不正确。(3).Whenisdepressionresulted?（分数：2.00）A.Whenthelevelofserotoninislow.√B.Whenthelevelofserotoninishigh.C.Whenserotoninisreleasedfromneurons.D.Whenpeopleeatcarbohydratefoods.解析：解析：第4段第5句末的similareffects指的是“同样可以使人不再情绪低落”，由此可见，本句指出了serotonin的含量高，情绪就不会低落，反过来说，serotonin的含量低就会导致情绪低落，这就是A的内容。C项具有干扰性，但原文并没有依据表明神经元细胞释放serotonin时人的情绪就会低落，故不选。(4).ResearchersattheMassachusettsInstituteofTechnologyintendedtofindout_____.（分数：2.00）A.howcholineisproducedoutoffoodsB.howcholineisconvertedintoacetylcholineC.iftheimprovementofbrainpowerisrelatedtocholine√D.iftheimprovementofbrainpowerisrelatedtoproperdiets解析：解析：最后一段第5句开头的Totesttheeffectsofcholineonmemoryandlearning明确表明了麻省理工学院的研究目的是为了找到choline对学生记忆和学习的影响，记忆和学习都与“脑力”有关，由此可见，C是对这个研究目的的正确描述，为本题答案。(5).Whatisthemessagetheauthorintendstoconvey?（分数：2.00）A.Thechemistryofthebrainandnervoussystem.B.Theinfluenceoffoodsonourmoodandmind.√C.Thefunctionsofneurotransmitters.D.Theimportanceofabalanceddiet.解析：解析：本文首句提出的问题是全文要解答的问题，也就是说，全文围绕这个问题展开讨论，由此可见，本文是为了说明食物对情绪和思维的影响，因此，本题应选B。A可以说是第1段至第4段的主要内容，C是第1段的内容，均没有全面概括全文内容。D中的balanceddiet在文中不断提及，但本文的重点不是为了说明均衡饮食的重要性，而是饮食和情绪、思维的关系。Likeaneedleclimbingupabathroomscale,thenumberkeepsrising.In1991,15%ofAmericanswereobese(肥胖的);by1999,thatproportionhadgrownto27%.Youngsters,whoshouldhaveageandactivityontheirside,aregrowinglargeraswell:19%ofAmericansunder17areobese.Waistbandshavebeenpoppinginotherwesterncountriestoo,asphysicalactivityhasdeclinedanddietshaveexpanded.Byandlarge,peopleintherichworldseemtohavelostthefightagainstflab(松弛).Meanwhile,poorernationshaveenjoyedsomesuccessintheirbattlesagainstmalnutritionandfamine.But,accordingtoresearchpresentedattheannualmeetingoftheAmericanAssociationfortheAdvancementofScience,itismoreacaseofbeingoutofthefryingpanandintothefire.ThemoststrikingexampleactuallyinthepoorworldcomesfromthePacificislands,homeoftheworld'smostobesecommunities.In1966,14%ofthemenonthisislandwereobesewhile100%ofmenundertheageof30in1996wereobese.Thisincreaseinweighthasbeenunevenaswellasfast.Asaresult,undernourishedandover-nourishedpeoplefrequentlylivecheekbyjowl(面颊).Themixcanevenoccurwithinasinglehousehold.AstudyoffamiliesinIndonesiafound