2017考研数学真题解析（张宇）

我们先来看看大题。这个大题22题概率的大题。X是一个离散的随机变量，取的点的是1/2，1/2，Y的概率密度，Y大于0小于1，这是0，这是其他。那么一个离散一个连续，而且X与Y独立。那么这种问题，第一

2021年考研真题中，数学一第17题是关于函数极限计算的题，数学一第13题是欧拉方程。数二第1题高阶无穷小，第13题是高于二阶的常系数齐次线性微分方程求解问题，第15题是函数极限的计算，第20题是对

【导语】眼瞅着已经进入2020考研冲刺阶段，现阶段对于大部分2020考研新手来说肯定是无比紧张的，在这里无忧考网想提醒大家，稳住心态，冲到最后!距离考研初试时间所剩无几，如何能够更好地做好英语阅读呢?

新东方在线推荐：2018年考研一次顺利提分课程！！一科不过，全科免费ItispossibleforstudentstoobtainadvanceddegreesinEnglish

新东方在线推荐：2018年考研一次顺利提分课程！！一科不过，全科免费Proponentsofdifferentjazzstyleshavealwaysarguedthattheir

新东方在线推荐：2018年考研一次顺利提分课程！！一科不过，全科免费Investigatorsofmonkey’ssocialbehaviorhavealwaysbeenstruckbymonkeys’aggressivepotentialandtheconsequentneedforsocialcontroloftheiraggressivebehavior.Studiesdirectedatdescribingaggressivebehaviorandthesituationsthatelicitit,aswellasthesocialmechanismsthatcontrolit,werethereforeamongthefirstinvestigationsofmonkeys’socialbehavior.Investigatorsinitiallybelievedthatmonkeyswouldcompeteforanyresourceintheenvironment:hungrymonkeyswouldfightoverfood,thirstymonkeyswouldfightoverwater,and,ingeneral,attimemorethanonemonkeyinagroupsoughtthesameincentivesimultaneously,adisputewouldresultandwouldberesolvedthroughsomeformofaggression.However,themotivatingforceofcompetitionforincentivesbegantobedoubtedwhenexperimentslikeSouthwick’sontherectionofspaceorthewithholdingoffoodfailedtoprocemorethantemporaryincreasesinintragroupaggression.Indeed,fooddeprivationnotonlyfailedtoincreaseaggressionbutinsomecasesactuallyresultedindecreasedfrequenciesofaggression.Studiesofanimalsinthewildunderconditionsofextremefooddeprivationlikewiserevealedthatstarvingmonkeysdevotedalmostallavailableenergytoforaging,withlittleenergyremainingforaggressiveinteraction.Furthermore,accumulatingevidencefromlaterstudiesofavarietyofprimategroups,forexample,thestudyconctedbyBernstein,indicatesthatoneofthemostpotentstimuliforelicitingaggressionistheintroctionofanintruderintoanorganizedgroup.Suchintroctionsresultinfarmoreseriousaggressionthanthatprocedinanyothertypesofexperimentscontrivedtoprocecompetition.Thesestudiesofintruderssuggestthataltmembersofthesamespeciesintrocedtooneanotherforthefirsttimeshowconsiderablehostilitybecause,intheabsenceofasocialorder,onemustbeestablishedtocontrolinteranimalrelationships.Whenasinglenewanimalisintrocedintoanexistingsocialorganization,thenewcomermeetsevenmoreseriousaggression.Whereasinthefirstcaseaggressionestablishesasocialorder,inthesecondcaseresidentanimalsmobtheintruder,therebyinitiallyexcludingthenewanimalfromtheexistingsocialunit.Thesimultaneousintroctionofseveralanimalslessenstheeffect,ifonlybecausethegroupdividesitsattentionamongthemultipletargets.If,however,theseveralanimalsintrocedagroupconstitutetheirownsocialunit,eachgroupmayfighttheopposinggroupasaunit;but,again,noindivialissubjectedtomassattack,andtheverycohesionofthegroupsprecludesprolongedindivialcombat.Thesubmissionofthedefeatedgroup,ratherthanunleashinguncheckedaggressiononthepartofthevictoriousgroup,recesboththeintensityandfrequencyoffurtherattack.Monkeygroupsthereforeseemtobeorganizedprimarilytomaintaintheirestablishedsocialorderratherthantoengageinhostilitiesperse.1.Theauthorofthetextisprimarilyconcernedwith[A]advancinganewmethodologyforchangingamonkey’ssocialbehavior.[B]comparingthemethodsofseveralresearchstudiesonaggressionamongmonkeys.[C]explainingthereasonsforresearcher’sinterestinmonkey’ssocialbehavior.[D]discussingthedevelopmentofinvestigators’theoriesaboutaggressionamongmonkeys.2.Whichofthefollowingbestsummarizesthefindingsreportedinthetextabouttheeffectsoffooddeprivationonmonkeys’behavior?[A]Fooddeprivationhasnoeffectonaggressionamongmonkeys.[B]Fooddeprivationincreasesaggressionamongmonkeysbecauseoneofthemostpotentstimuliforelicitingaggressionisthecompetitionforincentives.[C]Fooddeprivationmayincreaselong-termaggressionamongmonkeysinalaboratorysetting,butitprocesonlytemporaryincreaseamongmonkeysinthewild.[D]Fooddeprivationmaytemporarilyincreaseaggressionamongmonkeys,butitalsoleadstoadecreaseinconflict.3.Thetextsuggeststhatinvestigatorsofmonkeys’socialbehaviorhavebeenespeciallyinterestedinaggressivebehavioramongmonkeysbecause[A]aggressionisthemostcommonsocialbehavioramongmonkeys.[B]successfulcompetitionforincentivesdeterminesthesocialorderinamonkeygroup.[C]situationthatelicitaggressivebehaviorcanbestudiedinalaboratory.[D]mostmonkeysarepotentiallyaggressive,yettheyliveinsocialunitsthatcouldnotfunctionwithoutcontroloftheiraggressiveimpulses.4.Thetextsuppliesinformationtoanswerwhichofthefollowingquestions?[A]Howdoestherectionofspaceaffectintragroupaggressionamongmonkeysinanexperimentalsetting?[B]Dofamilyunitswithinamonkeysocialgroupcompetewithotherfamilyunitsforfood?[C]Whatarethemechanismsbywhichthesocialorderofanestablishedgroupofmonkeyscontrolsaggressionwithinthatgroup?[D]Howdomonkeysengagedinaggressionwithothermonkeyssignalsubmission?5.Whichofthefollowingbestdescribestheorganizationofthesecondparagraph?[A]Ahypothesisisexplainedandcounterevidenceisdescribed.[B]Atheoryisadvancedandspecificevidencesupportingitiscited.[C]Fieldobservationsaredescribedandaconclusionabouttheirsignificanceisdrawn.[D]Twotheoriesareexplainedandevidencesupportingeachofthemisdetailed.

新东方在线推荐：2018年考研一次顺利提分课程！！一科不过，全科免费Musiccomesinmanyforms;mostcountrieshaveastyleoftheiro

新东方在线推荐：2018年考研一次顺利提分课程！！一科不过，全科免费ThefamilyisthecenterofmosttraditionalAsians'lives.Ma

新东方在线推荐：2018年考研一次顺利提分课程！！一科不过，全科免费Generallyspeaking,aBritishiswidelyregardedasaquiet,shy