植物开花与光照时间的关系
地球的公转与自转，带来了地球上日照长短的周期性变化。由于分布在地球各地的动植物长期生活在具有一定昼夜变化格局的环境中，借助于自然选择和进化，而形成了各类生物所特有的对日照长度变化的反应方式，这就是在生物中普遍存在的光周期现象。例如植物在一定光照条件下的开花、落叶和休眠以及动物的迁移、生殖、冬眠、筑巢和换毛换羽等。
植物的开花有时与日照时间有很大关系，根据这个特点，一般将植物分为长日照植物、短日照植物和日中性植物三类。长日照植物，一般是指每天光照时间在14个小时以上才能开花的植物，否则便只进行营养生长，不能形成花芽。而且光照时间越长，开花越早。典型的长日照植物有包括：凤仙花、石榴、茉莉等，作物中有冬小麦、大麦、油菜、菠菜等。它们的花期通常在每年的5-10月。短日照，一般是指每天光照时间在8小时以内，通常是深秋、冬季和早春日照的时间。典型的短日照植物有：长寿、秋菊、秋播的叶菜类，如白菜、油菜、生菜等，早春开花的一些木本，如桃树、杏树、紫荆、丁香等。它们的花期多在秋、冬、春三季。
日中性植物，它们的开花与日照时间长度没有任何联系，可以说有常年开花的特性。常见的植物有：黄瓜、蒲公英辣椒、矮牛、太阳花等。它们的通常具有边生长边开花的习性，如辣椒，进入秋季，枝头上仍有不少花蕾。光周期对植物的地理分布有较大影响。短日照植物大多数原产地是日照时间短的热带、亚热带；长日照植物大多数原产于温带和寒带，在生长发育旺盛的夏季，一昼夜中光照时间长。如果把长日照植物栽培在热带，由于光照不足，就不会开花。同样，短日照植物栽培在温带和寒带也会因光照时间过长而不开花。
【英文题源】
Short-dayandlong-dayplant
Tounderstandplantflowering,weneedtogetahandleon"photoperiodism,"oramountoflightanddarknessaplantisexposedto.Theamountofuninterrupteddarknessiswhatdeterminestheformationofflowersonmosttypesofplants,explainedAnnMarieVanDerZanden,horticulturistwiththeOregonStateUniversityExtensionService.
Botanistsusedtothinkthatthelengthofdaylightaplantwasexposedtodeterminewhetheraplantwouldformflowers.Butexperimentsprovedotherwise.Itisthelengthofdarknessthataplantexperiencesthatplaysthemostcrucialrole.
Aplantthatrequiresalongperiodofdarkness,istermeda"shortday"(longnight)plant.Short-dayplantsformflowersonlywhendaylengthislessthanabout12hours.Manyspringandfallfloweringplantsareshortdayplants,includingchrysanthemums,poinsettiasandChristmascactus.Iftheseareexposedtomorethan12hoursoflightperday,bloomformationdoesnotoccur.Otherplantsrequireonlyashortnighttoflower.Thesearetermed"longday"plants.Thesebloomonlywhentheyreceivemorethan12hoursoflight.Manyofoursummerbloomingflowersandgardenvegetablesarelongdayplants,suchasasters,coneflowers,Californiapoppies,lettuce,spinachandpotatoes.Theseallbloomwhenthedaysarelong,duringourtemperatesummers.
Andsomeplantsformflowersregardlessofdaylength.Botanistscallthese"dayneutral"plants.Tomatoes,corn,cucumbersandsomestrawberriesareday-neutral.Someplants,suchaspetuniasdefycategorization,saidVanDerZanden."Theyflowerregardlessofdaylength,butflowerearlierandmoreprofuselywithlongdays,"shesaid.
Horticulturistsandhomegardenersmanipulatethedayandnightlength(indoorswithlights)togetplantstobloomattimesotherthantheywouldnaturally.Forexample,chrysanthemums,shortdayplants,naturallysetflowerandbloomwiththelongnightsofspringorfall.Butbymakingthedaysshorterbycoveringthechrysanthemumsforatleast12hoursadayforseveralweeksoverthelatespringandearlysummer,youcansimulatethelightanddarknesspatternofspringorfall,therebystimulatingsummerblooming.
Oryoucanbringalong-dayplantintobudformationandeventualbloomearlybeforeourdaylengthssurpass12hours,forexample,byputtingtheplantundergrowlightsforafewhoursadaybeyondnaturaldaylengthforafewweeks.Addingsupplementaldaylengthtostimulateearlybloomingisamonpracticeinthenurseryandfreshflowerindustry,especiallythistimeofyear,forValentine'sDayandEasterflowers.
【托福高频词】
handle
exposed
uninterrupted
crucial
termed
regardlessof
neutral
manipulate
simulate
blooming
surpass
supplemental
【长难句分析】
Butbymakingthedaysshorterbycoveringthechrysanthemumsforatleast12hoursadayforseveralweeksoverthelatespringandearlysummer,youcansimulatethelightanddarknesspatternofspringorfall,therebystimulatingsummerblooming.
【机经简述及学科知识】
印加古国的书写系统
据考古发掘，印加帝国有青铜器皿和刀、镰、斧等劳动工具，其冶炼铸造技术相当精巧。印加人也有发达的农业灌溉系统，绵延的驿道等。印加人的建筑技术、医学、织布和染色技巧也相当发达。印加人有自己的语言，可是却没有一套书写文字的系统。印加人利用绳结记录法来代替文字，这就是所谓的“奇普”。一直以来，科学家们就对这些绳结困惑不已——大多数文明早期都使用象形文字或图像，然而印加人留下的却是棉线和绳结。难道印加帝国没有任何形式的书写方式？若是这样，那国家大量的数据信息将如何保存和传递？
大部分科学家拒绝承认“奇谱”是一种书面文件，而认为这些绳子是一种保存记忆的设备，即一种个人化的记忆辅助工具，顶多是一种纺织品算盘，而没有任何统一的含义。然而，随着研究的深入，一些研究学者越来越怀疑这个结论的正确性。
哈佛大学考古学家格里·乌尔顿及其同事通过电脑对这些绳索的各种元素进行长期的分析和研究，结果发现，奇谱代表的数字记录方式，并成功破译了第一个印加文字—印加的宫殿所在地：普鲁楚柯城。
奇谱是一种与众不同的三维立体的书写体系，记载着5500公里帝国的信息。科学家为每一块“奇谱”都创建了相应的数据库，详细记录了它们的各种情况：绳索的大孝长度与颜色，垂挂的穗的数量，绳结数目，每股绳的旋转方向与次数、年代等，第一次系统地对奇谱进行分解与分析。他希望通过数据分析找到某些规律。
这一发现有助于理解那些绳子中所蕴含的文字信息。例如在陵墓中发现的奇谱还用作日历。印加统治者凭借广大的道路系统和政府体制就可以将食物、人力和原料从安第斯山脉的首都库斯本运送到其他众多下级城市。对奇谱的深入分析将有助于揭开其生活细节，他们希望根据奇谱能告诉科学家这是否是骆驼、劳工或其他贡品。但遗憾的是，目前还没有其他更令人信服的证据去证明“奇谱”的文字功能。
【英文题源】
In1532,theSpanishexplorerFranciscoPizarro"discovered"theIncaEmpire,knowntoitsinhabitantsasTawantinsuyu.TheTawantinsuyuEmpirestretchedatotallengthof2485miles,essentiallythelengthoftheSouthAmericancontinentbetweentheAncasmayoRiverattheborderofmoderndayColombiaandEcuador,allthewaytoSantiago,Chile.
Tawantinsuyuwasdividedintofourprovinces,eachwithitsowngovernor.Kingsheldtheirpositionbydivineright;ancestorworshipwasveryelaborateindeed.Theeconomicbaseoftheempirewasmaizeandllamas;anextensivetradeworkwasinplace,withstateartisansworkingingold,textiles,andpolychromeceramics,forselectivedistribution.Themassiveempirewasconnectedbyaplexseriesofroads,over18,000milesofroadsinfact,supportedbyasmanyas2000waystations.ThemonumentalandmunalarchitectureoftheIncaincludessomeofthemostbeautifulandtechnicallyamazingstructuresonthepl,suchasOllantaytambo,andthefamouscityofthecloudsMachuPicchu.Irrigationcanals,suspensionbridges,pavedandbuttressedroads,andspectacularterracesareallcharacteristicsoftheIncaarchitecturalstyle.TheIncaEmpirewassubstantial,sophisticated,andsuccessful.
Butitdidnothavewhatmostoftherestoftheworldwouldrecognizeasawritingsystem.Nocarvedstone,nopapyrus,nowedgespressedintoclay,nolinespaintedonpotsherds.Nothinglikethat.
Ifyouthinkaboutit,aworkingempirewithoutawritingsystemwouldtrulybeanamazingfeat.Empiresrequireaccountants.Whoowestaxes,whoisnextinlineforthethrone,wherearethebestagriculturalfieldsandhowmuchdotheyproduce?Howmanypeopleliveineachsegmentofthesociety?Whatistheweatherlikeinonesectionandhowdoweprotectthepeoplefromdroughtorfamine?Whenshouldweexpectthewinter?Whenisagoodtimetoplant?Howdowekeepallthosepeople,spreadoutsofaralongtheAndes,inlineandinmunicationwiththecenters?Furthermore,whataboutoriginmyths?Whataboutthethousandsofstoriesthataregeneratedbypeoplethatformtheirreligion,theirsociety,theirculturalmemories?Forasocietytofunction,thisinformationmustbekeptsomewhere.
Andsureenough,therewas,infact,awritingsystemamongtheInca;butonesostrangethatitisgoingtotakemealloftheremainingwordsofthisarticletoconvinceyouofthefacts.TheIncakepttheiraccounts,theirgenealogy,theirastronomicalcalculations,and(probably)theirstoriesonaplicatedsystemofcordsandknots,calledquipu(alsospelledkhipu).
WeknowthisinpartbecauseoncetheJesuitmissionariesoftheSpanishInquisitionrecognizedtherangeoffunctionofthequipu,theydidtheirbesttodestroyasmanyashumanlypossible.Thedescriptionofthequipuas"asystemofcordsandknots"doesnotdojusticetotheirplexity;anditisthatplexitythatissoconvincing.Quipushaveinformationstoredinthemusingcordcolor,cordlength,knottype,knotlocation,cordtwistdirection.Cordsareoftenplaitedinbinedcolors;cordssometimeshavesinglethreadsofdistinctivelycottonorwoolwovenin.Cordsareconnectedmostlyfromasinglehorizontalstrand;butsubsidiarycordseofftheverticalstrandsinobliquedirections.
ThereareonlyafewhundredIncaperiodkhipuleft,andintheinterveningcenturies,muchoftheabilitytodecipherthemeaningoftheknotsandcolorshasdisappeared.ArecentcollectionofarticlesinanewbookcalledNarrativeThreads,editedbyJeffreyQuilterandGaryUrton,describeshowahandfulofscholarsareworkingtowardscrackingthecode.Mostexciting,recentexcavationsatthenewlydiscoveredancientcivilizationofCaralhaveidentifiedtheoldestknownquipu,datedto4600yearsago.
【托福高频词】
stretched
elaborate
sophisticated
substantial
function
convince
plaited
dyed
intervening
decipher
cracking
【长难句分析】
TheTawantinsuyuEmpirestretchedatotallengthof2485miles,essentiallythelengthoftheSouthAmericancontinentbetweentheAncasmayoRiverattheborderofmoderndayColombiaandEcuador,allthewaytoSantiago,Chile.
Themassiveempirewasconnectedbyaplexseriesofroads,over18,000milesofroadsinfact,supportedbyasmanyas2000waystations.
ThereareonlyafewhundredIncaperiodkhipuleft,andintheinterveningcenturies,muchoftheabilitytodecipherthemeaningoftheknotsandcolorshasdisappeared.
【机经简述及学科知识】
英国农业的发展：
17世纪至19世纪英国农业生产方式发生巨大变革的过程。包括圈地运动、机械化、四轮作、良种培育等，其结果是农业生产效率大大提高。
在这段时期里，欧洲出现了圈地运动（enclosuremovement）。英国的圈地运动最为典型，规模也最大。15世纪后，英国毛纺制呢业迅猛发展，市场上的羊毛价格开始猛涨，使养羊变得有利可图，但需要大片的土地。于是，贵族们把原来租种他们土地的农民赶走，把可以养羊的土地圈占起来发展养羊业。
新航路开辟的影响。新航路开辟后，扩大了世界各地区、各民族之间的经济和文化交往。英国地处大西洋航运的中心线上，对外贸易急剧扩大，从而进一步刺激了英国羊毛出口业和毛织业的发展，推动了养羊业的发展。利润的刺激。英国的封建的习惯地租与资本主义地租之间的差别极大，使地主看到把土地租给农业资本家比对农民进行封建剥削更为有利可图，从而刺激了圈地运动的发展。
18世纪末，英国的农业已经在欧洲居领先地位。在轻视农业的政策的诱导下，农业逐步衰退，英国在食品供应方面严重依赖世界市常二战期间，由于德国潜艇击毁英国远洋商船，粮食进口运输受阻，使国内粮食供应发生困难。英国政府不得不实行食品配给制，转而加强对农业的干预，采取重视农业的许多措施，如：奖励垦荒、对开垦荒地的农户发给奖金；扩大耕地面积；提高农业机械化水平；大幅度提高农产品价格；各地区普遍建立农业生产管理委员会，对农业生产进行监督。战后，英国花了近15年的时间，扭转了农业衰退的局面，逐步实现了农业现代化。
注：十八世纪初，英国农民采用效率更高的耕种方法，改三田制为圈地，休耕为轮流耕种。
旧方法：三田制新方法：圈地
旧方法：休耕新方法：轮流耕种
【英文题源】
TheDevelopmentofBritishAgriculture
InEnglishsocialandeconomichistory,enclosureistheprocesswhichendstraditionalrightssuchasmowingmeadowsforhay,orgrazinglivestockonmonlandformerlyheldintheopenfieldsystem.Onceenclosed,theseusesofthelandberestrictedtotheowner,anditceasestobemonland.Underenclosure,suchlandisfencedandorentitledtooneormoreowners.TheprocessofenclosurebegantobeawidespreadfeatureoftheEnglishagriculturallandscapeduringthe16thcentury.Bythe19thcentury,unenclosedmonshadbelargelyrestrictedtoroughpastureinmountainousareasandtorelativelysmallpartsofthelowlands.
Theprocessofenclosurehassometimesbeenapaniedbyforce,resistance,andbloodshed,andremainsamongthemostcontroversialareasofagriculturalandeconomichistoryinEngland.ThiscreatedalandlessworkingclassthatprovidedthelaborrequiredinthenewindustriesdevelopinginthenorthofEngland.
LargerfarmersandlandownersinitiallybenefitedfromthegreatlandsalesthatfollowedtheDissolutionoftheMonasteriesinthe1530s,whilemostfarmersgainedfromrisingpricesandfavorableleases.Agriculturalproductivity–particularlyofgrain–wasspurredbyadoublingofpopulationfrombetween2.5and3milliontoover5millionby1660,andanassociatedriseingrainprices.After1650,afallingrainprices,ariseincattlepricesanddemandfromLondonandothergrowingurbanmarkets,ledtoariseincattlerearinginthenorthofEngland,andofthedairyindustryandspecializedproduce(suchashopsandcider)inotherareas.Improvementsintransport,includingthecoastalandrivertrade,providedaccesstonewmarkets.Newrotationsandcrops,particularlyclover,grassesandturnips,hadbeestablishedbytheendofthisperiodonthelightsoilsofEastAngliaandadoptedwithvaryingsuccessinotherpartsofthecountry.Thisperiodisstronglymarkedbythecontinuingprocessofenclosureandtherelatedprocessofexchangeandconsolidationoffarmholdings,thegrowthoffarmsize(especiallyincorn-producingareas),largeestatesandthewidespreaddevelopmentofalandlord–tenantsystem.Landowners,notablythecountygentry,emergedasinfluentialpioneersofnewcropsandnewsystemsoffarming.Theconsolidationofestatesandholdingsarereflectedinthecontinuing–andinmoreancientlyenclosedareasoftenthefinal–phaseofenclosure.Thenationalmarketbecamemoreintegratedfromthelater17thcentury,intandemwiththeemergenceofspecializedregionaleconomies.This,andthedevelopmentandstrengtheningoflocalbuildingtraditions,arealsoreflectedinthelayoutanddesignofbothfarmhousesandmoresubstantialfarmbuildings.
Agriculturalproductivitysustainedamassiveincreaseinpopulation,whichhadrisenfromaround6millionin1750toover16.7millionby1851and26millionin1881.Thiswasthemostimportantperiodoffarmbuildingdevelopment,monlydividedbyagriculturalhistoriansintotwoperiods:beforeandafter1840.Probablyunder25%ofthelandareaofEnglandremainedunenclosedby1750,andbetween1760and1815asmuchas18%ofthislandwasenclosed.ThiswasaprocessatfirstconcentratedontheMidlandclays(forthemanagementoflandaspastureforfattening)andthen–fromthestartoftheNapoleonicWarsinthe1790s–ontheexpansionofthecultivatedareaontopoorerandlightersoilssuchasthenorthernmoorlandsandthesoutherndownlands,andpoorly-drainedlandsuchastheFensandtheLancashiremosses.
Inthe‘HighFarming’yearsofthe1840sto1870s,high-inputorhigh-outputsystems–basedontheavailabilityofimportedartificialfertilizersandmanures(superphosphates,nitrates,guanoandbones)andfeedssuchasoilcakebroughtontothefarm–replacedthe‘closedcircuit’methodsthatreliedonfarm-producedfeedsandmanure.Amajordevelopment–asobservedbytheagriculturaljournalistJamesCairdwritinginthe1850s–wasanincreaseddistinctionbetweentheintensivelycroppedlandscapesoftheeasternhalfofthecountry,andthewetterandmorepastoral-basedeconomiesofthewesternhalf.
【托福高频词】
entitled
apaniedby
ceases
initially
spurred
associated
produce
rotations
notably
substantial
artificial
sustained
cultivated
distinction
【长难句分析】
InEnglishsocialandeconomichistory,enclosureistheprocesswhichendstraditionalrightssuchasmowingmeadowsforhay,orgrazinglivestockonmonlandformerlyheldintheopenfieldsystem.
Theprocessofenclosurehassometimesbeenapaniedbyforce,resistance,andbloodshed,andremainsamongthemostcontroversialareasofagriculturalandeconomichistoryinEngland.
ThiscreatedalandlessworkingclassthatprovidedthelaborrequiredinthenewindustriesdevelopinginthenorthofEngland.
LargerfarmersandlandownersinitiallybenefitedfromthegreatlandsalesthatfollowedtheDissolutionoftheMonasteriesinthe1530s,whilemostfarmersgainedfromrisingpricesandfavorableleases.
Newrotationsandcrops,particularlyclover,grassesandturnips,hadbeestablishedbytheendofthisperiodonthelightsoilsofEastAngliaandadoptedwithvaryingsuccessinotherpartsofthecountry.
ThiswasaprocessatfirstconcentratedontheMidlandclays(forthemanagementoflandaspastureforfattening)andthen–fromthestartoftheNapoleonicWarsinthe1790s–ontheexpansionofthecultivatedareaontopoorerandlightersoilssuchasthenorthernmoorlandsandthesoutherndownlands,andpoorly-drainedlandsuchastheFensandtheLancashiremosses.
2011年1月21日
【机经简述及学科知识】
婴幼儿的记忆能力
记忆是人脑对过去经验的反映，记忆过程由四个部分构成，它包括识记、保持、再认和回忆四个基本环节。识记是获得知识经验和巩固知识经验的过程。例如，幼儿初次认字，要通过反复多次的认识，才把字记住，这是识记过程。保持是跟随识记过程的，只要记住的字，总可保持一段时间。但保持的效果怎样，则要通过再认和回忆来检验。再认是经历过的事物再次出现时，感到熟悉，能够识别，再认识。例如，认过的字，再次出现能认识。回忆是经历过的事物不在眼前时，根据一定的条件能把它重新反映出来。比如幼儿把玩具藏起来时会做个标记，然后通过会议这些标记找到所藏的东西。幼儿记忆就是由这样四个相互联系的过程组成的。
据研究表明，记忆的效果，随年龄和经验的增长而增长，随记忆材料性质的不同而不同，一般到少年期达到高峰。有人做过这样的实验：用三组不同的材料，考察孩子的记忆能力，第一组材料是画有具体实物图形的图片，第二组材料是画有抽象图形的图片，第三组材料是词。结果表明，对具体实物图形的记忆能力在小学高年级时达到高峰，对抽象图形和词的记忆能力到初中阶段，就是少年时期达到高峰。
人们一般认为幼儿的记忆比成人更好，但事实上这是一种错觉。例如，成人的生活领域广阔，获取经验的范围极广，工作、学习、生活中需要记忆的事情很多，为了保证记住主要的事情，常常对—些琐碎的小事忽略而记不住；而孩子生活环境和经验范围很小，活动中需要记住的事情相对较少，同时某些琐碎小事反而常常是孩子感兴趣的事情。如一些生活中的小物品，常常是孩于喜欢玩弄的，所以，当成人忘记某些小东西的存放地点时，孩子就能告诉成人。
【英文题源】
Duringearliertimestherewasaconflictofbeliefbetweenparentsandresearchersaboutmemorystatusandskillstolearninchildren.Thoughparentsalwaysthoughtthatthechildlearnsandremembersatallages,butresearcherswereoftheopinionthatthechildhasnomemoryskilluptothetimethechildisofeightorninemonths.
Studyhasalsorevealedthatthechildhasmemoryevenwhenatthestageoffetus.Achildcanrememberanimpulsefromtenminutestotwentyfourhoursatdifferentstagesofdevelopmentasafetus.
Whatpsychologistshavedone,though,isexaminetheemergenceofmemoryinourfirstfewyearswithaseriesofnowclassicexperiments.Ifmemoriesreallycanbelaiddownearlyinlifethenitiscertainlypossibleintheoryforadultstorememberveryearlyexperiences.Oneclassicexperiment,devisedbyProfessorCarolynRovee-Collierandcolleaguesinthe1960s,providesusaninsightintowhatinfantscanremember.Thismethodhasproducedsomegreatevidenceabouthowandwheninfants'memoriesdevelop.Intheirexperiment,Roveehadinfantsofbetween9and12weekslayfortablyintheircribsathomelookingupatamobilecoveredwithbrightlycolouredwoodenfigures.Acordwasthenattachedtotheirfootconnectingittothemobile.Thismeantthatiftheinfantskickedoutthemobilewouldmove.And,iftheykickedouthard,thewoodenfigureswouldbumpintoeachotherandmakeapleasantknockingsound.Themorethelittlekidskick,themoreofakicktheygetfromthemobile.
Ifyou'restartingtogetawhiffofPavlovandhissalivatingdogthenyou'reontherightlines.Thisexperimentisallaboutseeingifaninfantcanbeconditionedtokicktheirfoottomakethemobilemove.Researchersfirstmeasureinfants'baselinelevelsofkicking(withmobileunattached),thenparethistokickingthatproducesanexcitingresponse.WhatRoveefoundwasthateveninfantsasyoungas8weeksoldcouldlearntheassociationbetweenkickingandthemobilemovement.Thislearningwasstillevidentovera45-55minutesperiod.
Whilethisinitialfindingisfairlymodest,theuseofthisprocedurehasledtoallsortsofnewfindingsaboutinfants'memories.Forexample,subsequentstudieshavelatersubstitutedadifferentmobilefortheoriginaltoseeiftheinfantscanspotthedifference,therebytestingwhetherornottheyreallyremember.
Inoneexperimentinfantsonly8-weeks-oldweretrainedwiththemobileoveraperiodof3daysfor9minuteseachday.Twenty-fourhourslatertheinfantsonlykickedatabovetheirbaselinelevelswhenthesamemobilewasabovetheirheads.Thisshowedtheyrememberedtheparticularmobiletheyhadbeentrainedwithandnotjustanyoldmobile.Itwasanespeciallyexcitingfindingbecauseithadpreviouslybeenthoughtthatlong-termmemory(and24hoursislong-termforpsychologists)didn'temergeuntilaslateas8or9months.
Becauseofthisexperimentandotherslikeit,wenowknowmuchmoreaboutinfantmemory.Ourmemorysystemsactuallyworkquitewellfromveryearlyon.Infants'memoriesalsoseemtoworkinmuchthesamewayasadultmemories-it'sjustthatinfantmemoriesaremuchmorefragile.
Roveearguesitisdoubtfulwhetherinfantileamnesiareallyexists.Itcertainlyappearsourbrainscanlaydownlong-termmemorieseveninthefirstyearoflife.Thereasonitisunusualtoretainmemoriesfromthattimeintoadulthoodisprobablybecauseofthelimitedcapacityofourearlymemorysystemsandtheinterveningyearsduringwhichweinevitablyforget.
【托福高频词】
Subsequent
revealed
devised
attached
conditioned
modest
mobile
previously
intervening
inevitably
【长难句分析】
Subsequentresearchhasestablishedthatthebabyhasmemoryandcanretainathinginmemoryforadayattheageofsixweeksanduptoaperiodoffourmonthswhenattheageofeighteenmonths.
Thisexperimentisallaboutseeingifaninfantcanbeconditionedtokicktheirfoottomakethemobilemove.
Thereasonitisunusualtoretainmemoriesfromthattimeintoadulthoodisprobablybecauseofthelimitedcapacityofourearlymemorysystemsandtheinterveningyearsduringwhichweinevitablyforget.
