植物開花與光照時(shí)間的關(guān)系

地球的公轉(zhuǎn)與自轉(zhuǎn)，帶來了地球上日照長(zhǎng)短的周期性變化。由于分布在地球各地的動(dòng)植物長(zhǎng)期生活在具有一定晝夜變化格局的環(huán)境中，借助于自然選擇和進(jìn)化，而形成了各類生物所特有的對(duì)日照長(zhǎng)度變化的反應(yīng)方式，這就是在生物中普遍存在的光周期現(xiàn)象。例如植物在一定光照條件下的開花、落葉和休眠以及動(dòng)物的遷移、生殖、冬眠、筑巢和換毛換羽等。

植物的開花有時(shí)與日照時(shí)間有很大關(guān)系，根據(jù)這個(gè)特點(diǎn)，一般將植物分為長(zhǎng)日照植物、短日照植物和日中性植物三類。長(zhǎng)日照植物，一般是指每天光照時(shí)間在14個(gè)小時(shí)以上才能開花的植物，否則便只進(jìn)行營(yíng)養(yǎng)生長(zhǎng)，不能形成花芽。而且光照時(shí)間越長(zhǎng)，開花越早。典型的長(zhǎng)日照植物有包括：鳳仙花、石榴、茉莉等，作物中有冬小麥、大麥、油菜、菠菜等。它們的花期通常在每年的5-10月。短日照，一般是指每天光照時(shí)間在8小時(shí)以內(nèi)，通常是深秋、冬季和早春日照的時(shí)間。典型的短日照植物有：長(zhǎng)壽、秋菊、秋播的葉菜類，如白菜、油菜、生菜等，早春開花的一些木本，如桃樹、杏樹、紫荊、丁香等。它們的花期多在秋、冬、春三季。

日中性植物，它們的開花與日照時(shí)間長(zhǎng)度沒有任何聯(lián)系，可以說有常年開花的特性。常見的植物有：黃瓜、蒲公英辣椒、矮牛、太陽花等。它們的通常具有邊生長(zhǎng)邊開花的習(xí)性，如辣椒，進(jìn)入秋季，枝頭上仍有不少花蕾。光周期對(duì)植物的地理分布有較大影響。短日照植物大多數(shù)原產(chǎn)地是日照時(shí)間短的熱帶、亞熱帶；長(zhǎng)日照植物大多數(shù)原產(chǎn)于溫帶和寒帶，在生長(zhǎng)發(fā)育旺盛的夏季，一晝夜中光照時(shí)間長(zhǎng)。如果把長(zhǎng)日照植物栽培在熱帶，由于光照不足，就不會(huì)開花。同樣，短日照植物栽培在溫帶和寒帶也會(huì)因光照時(shí)間過長(zhǎng)而不開花。

【英文題源】

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.

【托福高頻詞】

handle

exposed

uninterrupted

crucial

termed

regardlessof

neutral

manipulate

simulate

blooming

surpass

supplemental

【長(zhǎng)難句分析】

Butbymakingthedaysshorterbycoveringthechrysanthemumsforatleast12hoursadayforseveralweeksoverthelatespringandearlysummer,youcansimulatethelightanddarknesspatternofspringorfall,therebystimulatingsummerblooming.

【機(jī)經(jīng)簡(jiǎn)述及學(xué)科知識(shí)】

印加古國(guó)的書寫系統(tǒng)

據(jù)考古發(fā)掘，印加帝國(guó)有青銅器皿和刀、鐮、斧等勞動(dòng)工具，其冶煉鑄造技術(shù)相當(dāng)精巧。印加人也有發(fā)達(dá)的農(nóng)業(yè)灌溉系統(tǒng)，綿延的驛道等。印加人的建筑技術(shù)、醫(yī)學(xué)、織布和染色技巧也相當(dāng)發(fā)達(dá)。印加人有自己的語言，可是卻沒有一套書寫文字的系統(tǒng)。印加人利用繩結(jié)記錄法來代替文字，這就是所謂的“奇普”。一直以來，科學(xué)家們就對(duì)這些繩結(jié)困惑不已——大多數(shù)文明早期都使用象形文字或圖像，然而印加人留下的卻是棉線和繩結(jié)。難道印加帝國(guó)沒有任何形式的書寫方式？若是這樣，那國(guó)家大量的數(shù)據(jù)信息將如何保存和傳遞？

大部分科學(xué)家拒絕承認(rèn)“奇譜”是一種書面文件，而認(rèn)為這些繩子是一種保存記憶的設(shè)備，即一種個(gè)人化的記憶輔助工具，頂多是一種紡織品算盤，而沒有任何統(tǒng)一的含義。然而，隨著研究的深入，一些研究學(xué)者越來越懷疑這個(gè)結(jié)論的正確性。

哈佛大學(xué)考古學(xué)家格里·烏爾頓及其同事通過電腦對(duì)這些繩索的各種元素進(jìn)行長(zhǎng)期的分析和研究，結(jié)果發(fā)現(xiàn)，奇譜代表的數(shù)字記錄方式，并成功破譯了第一個(gè)印加文字—印加的宮殿所在地：普魯楚柯城。

奇譜是一種與眾不同的三維立體的書寫體系，記載著5500公里帝國(guó)的信息?？茖W(xué)家為每一塊“奇譜”都創(chuàng)建了相應(yīng)的數(shù)據(jù)庫(kù)，詳細(xì)記錄了它們的各種情況：繩索的大孝長(zhǎng)度與顏色，垂掛的穗的數(shù)量，繩結(jié)數(shù)目，每股繩的旋轉(zhuǎn)方向與次數(shù)、年代等，第一次系統(tǒng)地對(duì)奇譜進(jìn)行分解與分析。他希望通過數(shù)據(jù)分析找到某些規(guī)律。

這一發(fā)現(xiàn)有助于理解那些繩子中所蘊(yùn)含的文字信息。例如在陵墓中發(fā)現(xiàn)的奇譜還用作日歷。印加統(tǒng)治者憑借廣大的道路系統(tǒng)和政府體制就可以將食物、人力和原料從安第斯山脈的首都庫(kù)斯本運(yùn)送到其他眾多下級(jí)城市。對(duì)奇譜的深入分析將有助于揭開其生活細(xì)節(jié)，他們希望根據(jù)奇譜能告訴科學(xué)家這是否是駱駝、勞工或其他貢品。但遺憾的是，目前還沒有其他更令人信服的證據(jù)去證明“奇譜”的文字功能。

【英文題源】

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.

【托福高頻詞】

stretched

elaborate

sophisticated

substantial

function

convince

plaited

dyed

intervening

decipher

cracking

【長(zhǎng)難句分析】

TheTawantinsuyuEmpirestretchedatotallengthof2485miles,essentiallythelengthoftheSouthAmericancontinentbetweentheAncasmayoRiverattheborderofmoderndayColombiaandEcuador,allthewaytoSantiago,Chile.

Themassiveempirewasconnectedbyaplexseriesofroads,over18,000milesofroadsinfact,supportedbyasmanyas2000waystations.

ThereareonlyafewhundredIncaperiodkhipuleft,andintheinterveningcenturies,muchoftheabilitytodecipherthemeaningoftheknotsandcolorshasdisappeared.

【機(jī)經(jīng)簡(jiǎn)述及學(xué)科知識(shí)】

英國(guó)農(nóng)業(yè)的發(fā)展：

17世紀(jì)至19世紀(jì)英國(guó)農(nóng)業(yè)生產(chǎn)方式發(fā)生巨大變革的過程。包括圈地運(yùn)動(dòng)、機(jī)械化、四輪作、良種培育等，其結(jié)果是農(nóng)業(yè)生產(chǎn)效率大大提高。

在這段時(shí)期里，歐洲出現(xiàn)了圈地運(yùn)動(dòng)（enclosuremovement）。英國(guó)的圈地運(yùn)動(dòng)最為典型，規(guī)模也最大。15世紀(jì)后，英國(guó)毛紡制呢業(yè)迅猛發(fā)展，市場(chǎng)上的羊毛價(jià)格開始猛漲，使養(yǎng)羊變得有利可圖，但需要大片的土地。于是，貴族們把原來租種他們土地的農(nóng)民趕走，把可以養(yǎng)羊的土地圈占起來發(fā)展養(yǎng)羊業(yè)。

新航路開辟的影響。新航路開辟后，擴(kuò)大了世界各地區(qū)、各民族之間的經(jīng)濟(jì)和文化交往。英國(guó)地處大西洋航運(yùn)的中心線上，對(duì)外貿(mào)易急劇擴(kuò)大，從而進(jìn)一步刺激了英國(guó)羊毛出口業(yè)和毛織業(yè)的發(fā)展，推動(dòng)了養(yǎng)羊業(yè)的發(fā)展。利潤(rùn)的刺激。英國(guó)的封建的習(xí)慣地租與資本主義地租之間的差別極大，使地主看到把土地租給農(nóng)業(yè)資本家比對(duì)農(nóng)民進(jìn)行封建剝削更為有利可圖，從而刺激了圈地運(yùn)動(dòng)的發(fā)展。

18世紀(jì)末，英國(guó)的農(nóng)業(yè)已經(jīng)在歐洲居領(lǐng)先地位。在輕視農(nóng)業(yè)的政策的誘導(dǎo)下，農(nóng)業(yè)逐步衰退，英國(guó)在食品供應(yīng)方面嚴(yán)重依賴世界市常二戰(zhàn)期間，由于德國(guó)潛艇擊毀英國(guó)遠(yuǎn)洋商船，糧食進(jìn)口運(yùn)輸受阻，使國(guó)內(nèi)糧食供應(yīng)發(fā)生困難。英國(guó)政府不得不實(shí)行食品配給制，轉(zhuǎn)而加強(qiáng)對(duì)農(nóng)業(yè)的干預(yù)，采取重視農(nóng)業(yè)的許多措施，如：獎(jiǎng)勵(lì)墾荒、對(duì)開墾荒地的農(nóng)戶發(fā)給獎(jiǎng)金；擴(kuò)大耕地面積；提高農(nóng)業(yè)機(jī)械化水平；大幅度提高農(nóng)產(chǎn)品價(jià)格；各地區(qū)普遍建立農(nóng)業(yè)生產(chǎn)管理委員會(huì)，對(duì)農(nóng)業(yè)生產(chǎn)進(jìn)行監(jiān)督。戰(zhàn)后，英國(guó)花了近15年的時(shí)間，扭轉(zhuǎn)了農(nóng)業(yè)衰退的局面，逐步實(shí)現(xiàn)了農(nóng)業(yè)現(xiàn)代化。

注：十八世紀(jì)初，英國(guó)農(nóng)民采用效率更高的耕種方法，改三田制為圈地，休耕為輪流耕種。

舊方法：三田制新方法：圈地

舊方法：休耕新方法：輪流耕種

【英文題源】

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.

【托福高頻詞】

entitled

apaniedby

ceases

initially

spurred

associated

produce

rotations

notably

substantial

artificial

sustained

cultivated

distinction

【長(zhǎng)難句分析】

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

【機(jī)經(jīng)簡(jiǎn)述及學(xué)科知識(shí)】

嬰幼兒的記憶能力

記憶是人腦對(duì)過去經(jīng)驗(yàn)的反映，記憶過程由四個(gè)部分構(gòu)成，它包括識(shí)記、保持、再認(rèn)和回憶四個(gè)基本環(huán)節(jié)。識(shí)記是獲得知識(shí)經(jīng)驗(yàn)和鞏固知識(shí)經(jīng)驗(yàn)的過程。例如，幼兒初次認(rèn)字，要通過反復(fù)多次的認(rèn)識(shí)，才把字記住，這是識(shí)記過程。保持是跟隨識(shí)記過程的，只要記住的字，總可保持一段時(shí)間。但保持的效果怎樣，則要通過再認(rèn)和回憶來檢驗(yàn)。再認(rèn)是經(jīng)歷過的事物再次出現(xiàn)時(shí)，感到熟悉，能夠識(shí)別，再認(rèn)識(shí)。例如，認(rèn)過的字，再次出現(xiàn)能認(rèn)識(shí)?；貞浭墙?jīng)歷過的事物不在眼前時(shí)，根據(jù)一定的條件能把它重新反映出來。比如幼兒把玩具藏起來時(shí)會(huì)做個(gè)標(biāo)記，然后通過會(huì)議這些標(biāo)記找到所藏的東西。幼兒記憶就是由這樣四個(gè)相互聯(lián)系的過程組成的。

據(jù)研究表明，記憶的效果，隨年齡和經(jīng)驗(yàn)的增長(zhǎng)而增長(zhǎng)，隨記憶材料性質(zhì)的不同而不同，一般到少年期達(dá)到高峰。有人做過這樣的實(shí)驗(yàn)：用三組不同的材料，考察孩子的記憶能力，第一組材料是畫有具體實(shí)物圖形的圖片，第二組材料是畫有抽象圖形的圖片，第三組材料是詞。結(jié)果表明，對(duì)具體實(shí)物圖形的記憶能力在小學(xué)高年級(jí)時(shí)達(dá)到高峰，對(duì)抽象圖形和詞的記憶能力到初中階段，就是少年時(shí)期達(dá)到高峰。

人們一般認(rèn)為幼兒的記憶比成人更好，但事實(shí)上這是一種錯(cuò)覺。例如，成人的生活領(lǐng)域廣闊，獲取經(jīng)驗(yàn)的范圍極廣，工作、學(xué)習(xí)、生活中需要記憶的事情很多，為了保證記住主要的事情，常常對(duì)—些瑣碎的小事忽略而記不??；而孩子生活環(huán)境和經(jīng)驗(yàn)范圍很小，活動(dòng)中需要記住的事情相對(duì)較少，同時(shí)某些瑣碎小事反而常常是孩子感興趣的事情。如一些生活中的小物品，常常是孩于喜歡玩弄的，所以，當(dāng)成人忘記某些小東西的存放地點(diǎn)時(shí)，孩子就能告訴成人。

【英文題源】

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.

【托福高頻詞】

Subsequent

revealed

devised

attached

conditioned

modest

mobile

previously

intervening

inevitably

【長(zhǎng)難句分析】

Subsequentresearchhasestablishedthatthebabyhasmemoryandcanretainathinginmemoryforadayattheageofsixweeksanduptoaperiodoffourmonthswhenattheageofeighteenmonths.

Thisexperimentisallaboutseeingifaninfantcanbeconditionedtokicktheirfoottomakethemobilemove.

Thereasonitisunusualtoretainmemoriesfromthattimeintoadulthoodisprobablybecauseofthelimitedcapacityofourearlymemorysystemsandtheinterveningyearsduringwhichweinevitablyforget.