研究生英语作文范文

1研究生英语作文范文为了在不久的将来，成为一名会英语的研究生，我们从现在就开始看英语作文积累词汇。下面是给大家整理的研究生英语作文范文，供大家参阅!Sleepisveryancient.Intheelectroencephalographicsenseweshareitwithalltheprimatesandalmostalltheothermammalsandbirds:itmayextendbackasfarasthereptiles.Thereissomeevidencethatthetwotypesofsleep,dreaminganddreamless,dependonthelife-styleoftheanimal,andthatpredatorsarestatisticallymuchmorelikelytodreamthanprey,whichareinturnmuchmorelikelytoexperiencedreamlesssleep.Indreamsleep,theanimalispowerfullyimmobilizedandremarkablyunresponsivetoexternalstimuli.Dreamlesssleepismuchshallower,andwehaveallwitnessedcatsordogscockingtheirearstoasoundwhenapparentlyfastasleep.Thefactthatdeepdreamsleepisrareamongpreytodayseemsclearlytobeaproductofnaturalselection,anditmakessensethattoday,whensleepishighlyevolved,thestupidanimalsarelessfrequentlyimmobilizedby2deepsleepthanthesmartones.Butwhyshouldtheysleepdeeplyatall?Whyshouldastateofsuchdeepimmobilizationeverhaveevolved?Perhapsoneusefulhintabouttheoriginalfunctionofsleepistobefoundinthefactthatdolphinsandwhalesandaquaticmammalsingeneralseemtosleepverylittle.Thereis,byandlarge,noplacetohideintheocean.Coulditbethat,ratherthanincreasingananimal'svulnerability,thefunctionofsleepistodecreaseit?WilseWebboftheUniversityofFloridaandRayMeddisofLondonUniversityhavesuggestedthistobethecase.Itisconceivablethatanimalswhoaretoostupidtobequietontheirowninitiativeare,duringperiodsofhighrisk,immobilizedbytheimplacablearmofsleep.Thepointseemsparticularlyclearfortheyoungofpredatoryanimals.Thisisaninterestingnotionandprobablyatleastpartlytrue.全文翻译：睡眠的进化睡眠是古老的。从脑电图上看，我们人类和所有灵长目动物以及几乎所有的哺乳动物和鸟类都一样需要睡眠;甚至爬行类动物也有睡眠。有证据显示，有梦睡眠和无梦睡眠这两种类型的睡眠取决于该动物的生活方式。从统计上看，食肉动物比被捕食动物有更多的有梦睡眠，而被捕食动物更多地无梦睡眠。3动物在有梦睡眠时，被有效地解除动作能力，并且对外界刺激缺乏反应。无梦睡眠则要浅得多。我们都看到过猫和狗在显然的酣睡中，有一点响动耳朵就会竖起来。被捕食动物很少有深度的有梦睡眠，这看来显然是自然选择的结果。而且这一点是有道理的：当睡眠高度进化以后，愚笨的动物比聪明的动物更少在深度睡眠状态下丧失动作能力。但是动物为什么要进入深度睡眠呢?为什么这样的无动作状态也会进化出来呢?海豚、鲸鱼以及水生哺乳动物睡眠都极少，这一事实可以给睡眠的根本功能提供有用的线索。海洋中是没有藏身之处的。会不会是这样，睡眠不但不增加动物受伤害的可能性，反而是减少了这种可能性呢?佛罗里达大学的WilseWebb和伦敦大学的RayMeddis认为情况就是如此。可以想像得出，在危险的时刻，那些由于太愚笨而不能自动保持安静的动物，会不由自主地变得动弹不得。这一点在食肉动物的幼兽身上表现得特别明显。这是一个很有意思的看法，它至少部分是正确的。研究生英语作文范文：TheHistoricalSignificanceofAmericanRevolutionThewaysofhistoryaresointricateandthemotivationsofhumanactionssocomplexthatitisalwayshazardoustoattempttorepresenteventscoveringanumberofyears,amultiplicityofpersons,anddistantlocalitiesastheexpressionofoneintellectualorsocialmovement;yetthehistoricalprocesswhichculminatedintheascentofThomas4Jeffersontothepresidencycanberegardedastheoutstandingexamplenotonlyofthebirthofanewwayoflifebutofnationalismasanewwayoflife.TheAmericanRevolutionrepresentsthelinkbetweentheseventeenthcentury,inwhichmodernEnglandbecameconsciousofitself,andtheawakeningofmodernEuropeattheendoftheeighteenthcentury.ItmayseemstrangethatthemarchofhistoryshouldhavehadtocrosstheAtlanticOcean,butonlyintheNorthAmericancoloniescouldastruggleforciviclibertyleadalsotothefoundationofanewnation.Here,inthepopularrisingagainsta"tyrannical"government,thefruitsweremorethanthesecuringofafreerconstitution.Theyincludedthegrowthofanationborninlibertybythewillofthepeople,notfromtherootsofcommondescent,ageographicentity,ortheambitionsofkingordynasty.WiththeAmericannation,forthefirsttime,anationwasborn,notinthedimpastofhistorybutbeforetheeyesofthewholeworld.全文翻译：美国革命的历史意义历史的进程是如此错综复杂，人类行为的动机是如此令人费解，以至于想把那些时间跨度大，涉及人数多，空间范围广的事件描述成5为一个智者或一场社会运动的表现的企图是危险的。然而以托马斯;杰弗逊登上总统宝座为高潮的那一段历史过程可以被视为一个特殊的例子。在这段历史时期里不仅诞生了新的生活方式，而且民族主义成为了一种新的生活方式。美国独立战争成为联结17世纪现代英格兰的自我意识和18世纪末现代欧洲的觉醒的纽带。历史的行程需要跨越大西洋，这看起来似乎有些奇怪，但却只有在北美殖民地为民权和自由的斗争才能导致新国家的建立。这里，反对"暴政"的民众起义的成果不仅是获得一个包含更多自由的宪法，还包括了一个依照人民的意愿诞生在自由中的国家的成长。这个国家不是基于血缘、地理、君主或王朝的野心。由于有了美国，第一次一个国家的诞生不是发生在历史模糊的过去，而是在全世界人们的眼前。研究生英语作文范文：Children'sNumericalSkillsPeopleappeartobeborntocompute.Thenumericalskillsofchildrendevelopsoearlyandsoinexorablythatitiseasytoimagineaninternalclockofmathematicalmaturityguidingtheirgrowth.Notlongafterlearningtowalkandtalk,theycansetthetablewithimpressiveaccuracy--oneknife,onespoon,onefork,foreachofthefivechairs.Soontheyarecapableofnotingthattheyhaveplacedfiveknives,spoonsandforksonthetableand,abitlater,thatthisamountsto6fifteenpiecesofsilverware.Havingthusmasteredaddition,theymoveontosubtraction.Itseemsalmostreasonabletoexpectthatifachildweresecludedonadesertislandatbirthandretrievedsevenyearslater,heorshecouldenterasecond-grademathematicsclasswithoutanyseriousproblemsofintellectualadjustment.Ofcourse,thetruthisnotsosimple.Thiscentury,theworkofcognitivepsychologistshasilluminatedthesubtleformsofdailylearningonwhichintellectualprogressdepends.Childrenwereobservedastheyslowlygrasped--or,asthecasemightbe,bumpedinto--conceptsthatadultstakeforgranted,astheyrefused,forinstance,toconcedethatquantityisunchangedaswaterpoursfromashortstoutglassintoatallthinone.Psychologistshavesincedemonstratedthatyoungchildren,askedtocountthepencilsinapile,readilyreportthenumberofblueorredpencils,butmustbecoaxedintofindingthetotal.Suchstudieshavesuggestedthattherudimentsofmathematicsaremasteredgradua