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PrimeronSmellInadditiontobringingout1theflavoroffood,whatdoesthesenseofsmelldoforus?Smell“givesusinformationaboutplace,aboutwhereweare,”saysRandallReed,aJohnsHopkinsUniversityprofessorwhosespecialtyisthesenseofsmell.___1___“Whetherwerealizeitornot,wecollectalotofinformationaboutwhoisaroundusbasedonsmell,”saysReed.Evenatadistance,odorscanwarnusof2trouble—spoiledfood,leakinggas,orfire.“It’sagreatalert,”offersDonaldLeopold,adoctoratJohnsHopkins.Forexample,ifsomethingintheovenisburning,everyoneinthehouseknowsit.Withjustasimplescent,smellcanalsoevokeveryintenseemotion.Let’ssay,forexample,thatthesmellispurplepetunias.___2___Nowlet’simaginethatyourmotherdiedwhenyouwerethree,andsheusedtohaveaflowergarden.Youwouldn’tneedtoidentifythesmellortohaveconsciousmemoriesofyourmotherorhergarden.Youwouldfeelsadassoonasyousmelledthatspicyodor.Comparedwith3animals,howwelldopeopledetectsmelts?Thatdependsonwhatyoumeanby“howwell”.Wearelowonreceptorcells：currentestimatessaythathumanshaveroughlyfivemillionsmell-receptorcells,aboutasmanyasamouse.___3___Reedsaysthat,acrossspecies,thereisarelativelygoodcorrelationbetweenthenumberofreceptorcellsandhowstrongthesenseofsmellis.“Youcanhardlyfindtheolfactorybulbinahumanbrain——it’sapea-sizedobject.Inamouse,it’salittlebigger.It’sbean-sizedinarat,aboutthesizeofyourlittlefingerinarabbit,andthesizeofyourthumbinabloodhound.”Doesthatmeanthatoursenseofsmellisnotveryacute?Notexactly.Whilewemaynothavetheolfactoryrangeofothercreatures,thereceptorswedohaveareassensitiveasthoseofanyanimal.___4___Atrained“nose”,suchasthatofaprofessionalintheperfumebusiness,cannameanddistinguishabout10,000odors.Reedsaysthataperfumeexpertcansniffamodemscentthathasahundreddifferentodorantsinit,gointothelab,andlisttheingredients.“Inamodestamountoftime,hecomesbackwithwhattoyouormewouldsmelllikeaperfectimitationofthatperfume.It’samazing.”Whathappensto4oursenseofsmellasweage?Manypeoplecontinuetohavegoodolfactoryfunctionastheygetolder.___5___Leopoldsaysthatsmellisgenerallyhighestinchildhood,staysthesamefromtheteensthroughthe50s,anddropsstartingatabout60forwomenand65formen.“Theaverage80-year-oldisonlyabletosmellthingshalfaswellastheaverage20-year-old,”saysLeopold.词汇：scent/sent/n.气味，香味petunia/pə'tju:niə/n.喇叭花olfactory/ɔl'fækt(ə)ri/adj.嗔觉的，味道的sniff/snif/v.嗅，闻，用力吸注释：1.bringout：使……显出，使……变得明显2.warnof：发出关于……的警告。warnsb.ofsth.：警告某人某事3.comparewith：与……相比4.happento：发生于，发生在练习：ATheseflowershavearichspicinessthatnootherpetuniahas.BOdors,orsmells,canwarnusabouttrouble.CThat’snottherule,however.DAndsmelltellsusaboutpeople.EWecanalsothink,andwemakeconscious(andsuccessful)effortstotellthedifferencebetweenonesmellandanother.FArathassome10million,arabbit20million,andabloodhound100million.答案与题解：1.D根据后文提到的“我们能够根据气味收集到有关人的很多信息”可以推断此处答案是D选项。2.A前文提到以紫喇叭花的香味举例，选项中只有A选项提到了喇叭花。3.F前文提到人类和小鼠的嗅觉受体细胞数量，可以推断此处应介绍其他物种的嗅觉受体细胞数量。4.E后文都在介绍人类可以区分味道的不同，所以此处E选项最符合原文意思。5.C后文介绍了不是每个人都随着年龄的增长嗅觉能力不发生变化，所以此处C选项最符合原文。参考译文第十四篇嗅觉入门嗅觉除了能让我们感受到食物的气味外，还能做什么？美国约翰霍普金斯大学研究嗅觉的专家RandallReed教授指出，气味能提供给我们关于位置，关于我们在哪儿，以及有关人的信息。“无论我们是否意识到，我们能根据气味收集到许多关于谁在我们身边的信息，”Reed讲道。即使还隔着一段距离，气味就能提醒我们注意很多麻烦：变质的食物，煤气泄漏，或是火灾。“它是一个很好的警告，”约翰霍普金斯大学的医生DonaldLeopold说道。比方说，烤箱中有东西烧焦了，屋内的每个人都会知道。仅仅是简单的气味，嗅觉就会引起强烈的情感。比如说那种气味就是紫喇叭花。它的气味中有一种其他喇叭花没有的香味。现在我们想象一下，你的母亲在你3岁时就去世了，她曾经拥有一座花园。你不必去辨认那种气味或者有意识地回忆起你的母亲或者她的花园，只要是你闻到那种紫喇叭花的香味，你就会感到伤感。与动物相比，人类感知气味的能力有多强？那要取决于你所谓的“多强”是什么意思。我们人类的受体细胞很少：目前估计人类有大概500万个嗅觉受体细胞，差不多和一只小鼠的一样多。一只大鼠大约有1000万个，一只兔子有2000万个，一只寻血犬有1亿个。Reed谈到，在不同的物种中，受体细胞的数量和嗅觉的强弱大体是正相关的。“人的大脑中是几乎找不到嗅球的，它像豌豆般大小。小鼠的脑中，嗅球大一点。大鼠的脑中，嗅球有蚕豆那么大，兔子脑中的有你的小手指那么大，而寻血犬脑中的有拇指那么大。”这是不是就意味着我们的嗅觉不够敏锐呢？不完全是。尽管我们的嗅觉范围可能没有其他生物的那么广，但是我们已有的受体细胞和其他动物的一样敏感。我们也可以认为，我们在有意（并且成功地〕努力区别不同的气味。受过培训的鼻子，比如研究香水的专家的鼻子就能够区分1万种气味并说出其名字。Reed说，一个香水专家可以在闻完一种含有100种不同香料的现代香水后，走进实验室，列出这些成分。“一段时间过后，他调制出来的气味对于你我来说都是那种香水气味的完美复制，太不可思议了。”随着年龄的增长，我们的嗅觉会发生什么变化？许多人年龄增大时还会有很好的嗅觉能力。但并不都是这样。指出，一个人的嗅觉在儿童时最强，在青少年时期一直到50多岁都保持不变，女人通常从60岁、男人从65岁开始下降。“通常来说，80岁的人能闻到的东西是20岁的人能闻到的一半，”Leopold说道。TheApgarTestThebabywasbornat3:36p.m.At3:37,shescored4outof10onherfirsttest.At3:41,shescored8outof10.Thedoctorwasglad.Anotherbaby,bornat8:24p.m.,scored3outof10onhisfirsttest.Hescored4outof10onhissecondtest.Hetookanothertestat8:34andscored5.___1___Hecalledforhelp1.ThesenewbornbabiestookatestcalledtheApgartest.Thistesthelpsdoctorsdiagnoseproblems.___2___Mostbabiestaketwotests.Thefirstisat1minuteafterbirth,andthesecondisat5minutesafterbirth.Ifababy’sscoreat5minutesislessthan6,thebabytakesanothertestat10minutesafterbirth.TheApgartestisnotanintelligencetest.It’satestthatshowsababy’shealthrightafteritisborn.TheApgartestmeasuresthingssuchasababy’scolor,heartrate,andbreathing.Thetesthasfiveparts,andthescoreforeachpartcanbe0,1,or2.___3___AdoctornamedVirginiaApgardevelopedthetest.ApgarwenttomedicalschoolatColumbiaUniversityinNewYorkCityin1929.Shefacedmanychallengesbecauseshewasthefirstwomanintheprogram.However,shewasoneofthebeststudentsinherclass.Aftermedicalschool,shestartedtreatingpatients2.Apgaralsobecamearesearcherinanesthesiology,anewtopicinmedicineatthetime3.Duringherstudies,shelearnedhowto