2012年考研真题及标准答案解析专题

合集下载

2012年考研真题及答案解析专题

2012年考研真题及答案解析专题一、单项选择题：1～65小题，每小题2分，共130分。

下列每题给出的四个选项中，只有一个选项是符合题目要求的。

请在答题卡上将所选项的字母涂黑。

1、下列选项中，不属于心理状态的是( )A、感觉B、想象C、注意D、记忆答案：D解析：感觉、想象、注意都是心理状态，记忆则不然。

2、大脑两半球之间传递信息的神经结构是( )A、杏仁核B、内囊C、边缘系统D、胼胝体答案：D解析：胼胝体位于大脑半球纵裂的底部，连接左右两侧大脑半球的横行神经纤维束，是大脑半球中最大的连合纤维。

3、神经系统最小的单位是( )A、突触B、轴突C、神经元D、胞体答案：C解析：神经系统结构和功能的最小单位是神经元。

4、大部分色盲不能区分( )A、红和青B、红和黄C、红和蓝D、红和绿答案：D解析：色盲以红绿色盲较为多见，蓝色盲及全色盲较少见。

5、感受性提高的感觉适应现象是( )A、触觉适应B、嗅觉适应C、暗适应D、明适应答案：D解析：在暗适应时是出现感受性提高，而明适应是感受性降低。

6、当人看到下图，一般都只看到一些乱点，经提示这是一幅骑马图片后，人们就觉得像所提示的内容。

这主要体现的知觉特性是( ) (图略)A、知觉整体性B、知觉理解性C知觉恒常性、D、知觉选择性答案：B解析：人在知觉过程中不是被动的把知觉对象的特点登记下来，而是以过去的知识经验为依据，力求对知觉对象做出某种解释，使它具有一定的意义。

该题目体现了知觉的理解性。

7、立体电影利用知觉的( )A、运动视差B、纹理梯度C、线条透视D、双眼视差答案：A解析：立体电影是利用人双眼的视角差和会聚功能制作的可产生立体效果的电影。

8、一名5岁小儿童向怀里抱的布娃娃讲妈妈曾给她讲过的故事，这种语言属于( )A、对话B、独白C、语言获得D、语言理解答案：B解析：独白是一个人自言自语，自问自答。

9、安德森提出语言产生三阶段，包括( )A、构造、转化、执行B、概念化、公式化、发音C、构造、转化、发音D、概念化、公式化、执行答案：A解析：安德森提出语言产生三阶段，包括，1.构造阶段，根据目的确定要表达的思想;2.转化阶段，运用句法规则将思想转换成语言的形式;3.执行阶段，将语言形式的信息说出或写出。

2012年考研政治真题(全部答案解析完整版)

2012年考研政治真题（全部答案解析完整版）一、单项选择题：1～16小题，每小题1分，共16分。

下列每题给出的四个选项中，只有一个选项是符合题目要求的。

请在答题卡上将所选项的字母涂黑。

1.恩格斯说：“鹰比人看得远得多，但是人的眼睛识别东西远胜于鹰。

狗比人具有敏锐得多的嗅觉，但是它连被人当做各种物的特定标志的不同气味的百分之一也辨别不出来。

”人的感官的识别能力高于动物，除了人脑及感官发育得更加完善之外，还因为A人不仅有感觉还有思维 B人不仅有理性还有非理性C人不仅有知觉还有想象 D人不仅有生理机能还有心理活动1.【答案】A【解析】人与动物的区别之一，从马哲角度上讲，人有思维，有意识，能对客观世界反映，发挥主观能动性，所以，本题正确答案是选项A。

2.有这样一道数学题：“90%×90%×90%×90%×90%=？其答案是约59%。

90分看似一个非常不错的成绩，然而，在一项环环相扣的连续不断的工作中，如果每个环节都打点折扣，最终得出的成绩就是不及格。

这里蕴含的辩证法道理是（）A肯定中包含否定B量变引起事变C必然性通过偶然性开辟道路D可能和现实是相互转化的2.【答案】A【解析】本题考查的知识点是量变质变规律，量变积累到一定程度必然发生质变，度是事物保持其质的量的界限，所以，本题正确答案是选项Ａ。

3、在资本主义社会里，资本家雇佣工人进行劳动并支付相应的工资。

资本主义工资的本质是（）A.工人所获得的资本家的预付资本B.工人劳动力的价值或价格C.工人所创造的剩余价值的一部分D.工人全部劳动的报酬3.【答案】B【解析】这是一道识记性考点，资本主义社会工人的工资就是劳动力的价格，劳动力已经成为一种特殊的商品，其使用价值是劳动，价值是工资。

所以，本题的正确选项是选项Ｂ。

4、2011年9月以来美国爆发的“占领华尔街”抗议活动中，示威者打出“我们是99%”的标语，向极富阶级表示不满。

2012年考研数学三真题及标准答案

２0１2年考研数学三真题一、选择题(１~8小题，每小题４分,共３2分。

下列每题给出的四个选项中,只有一个选项是符合题目要求的。

）(1)曲线y=x 2+xx2−1渐近线的条数为(Ａ)0 (B）1 (C)2 （D)3 【答案】C。

【解析】由limx→+∞y=limx→+∞x2+xx2−1=1=limx→−∞y=limx→−∞x2+xx2−1，得y=1是曲线的一条水平渐近线且曲线没有斜渐近线；由limx→1y=limx→1x2+xx−1=∞得x=1是曲线的一条垂直渐近线；由limx→−1y=limx→−1x2+xx−1=12得x=−1不是曲线的渐近线;综上所述，本题正确答案是C【考点】高等数学—一元函数微分学—函数图形的凹凸、拐点及渐近线(2)设函数f(x)=(e x−1)(e2x−2)⋯(e nx−n)，其中n为正整数，则f′(0)=（A）(−1)n−1(n−1)! (B)(−1)n(n−1)!（C)(−1)n−1(n)! (D）(−1)n(n)!【答案】A【解析】【方法1】令g (x )=(e 2x −2)⋯(e nx −n)，则f (x )=(e x −1)g (x )f ′(x)=e xg (x )+(e x −1)g′(x )f ′(0)=g (0)=(−1)(−2)⋯(−(n −1))=(−1)n−1(n −1)!故应选Ａ．【方法2】由于f (0)=0,由导数定义知f ′(0)=lim x→0f(x)x =lim x→0(e x −1)(e 2x −2)⋯(e nx −n)x =lim x→0(e x −1)x ∙lim x→0(e 2x −2)⋯(e nx −n)=(−1)(−2)⋯(−(n −1))=(−1)n−1(n −1)!.【方法3】排除法，令n =2,则f (x )=(e x −1)(e 2x −2)f ′(x )=e x (e 2x −2)+2e 2x (e x −1)f ′(0)=1−2=−1则（B)(C)（D)均不正确综上所述，本题正确答案是(A ）【考点】高等数学—一元函数微分学—导数和微分的概念(3)设函数f(t)连续，则二次积分∫dθπ20∫f(r 2)rdr 22cos θ= (A )∫dx 20∫√x 2+y 2f(x 2+y 2)dy √4−x 2√2x−x 2(Ｂ) ∫dx 20∫f(x 2+y 2)dy √4−x 2√2x−x 2。

2012考研数学一真题+答案解析

2
1 4 0
1 12
1 12
导航官网：地址：海淀区北大太平洋数码城 17 层(导航教育集团)
集团电话：4008-166-661
（Ⅱ）求 Cov( X − Y , Y )
（23）（本题满分 11 分）设随机变量 X 与 Y 相互独立分别服从正态分布 N ( µ , σ 2 ) 与 N ( µ , 2σ 2 ) ，其中 σ 是未知参数且 σ >0。设 Z = X −Y （Ⅰ）求 Z 的概率密度 f ( z , σ 2 ) 2 （Ⅱ）设 z1 , z2 , ⋅⋅⋅, zn 为来自总体 Z 的简单随机样本，求 σ 2 的最大似然估计量 σ 为 σ 2 的无偏估计量（Ⅲ）证明 σ
' x 2x
− 2)
(e nx − n) + (e x − 1)(2e 2 x − 2)
(e nx − n) +
(e x − 1)(e2 x − 2)
(nenx − n)
所以 f (0) = ( −1)
'
n −1
n!
（3）如果 f ( x, y ) 在 ( 0, 0 ) 处连续，那么下列命题正确的是（（A）若极限 lim
x →0 y →0
（C）若 f ( x, y ) 在 (0, 0) 处可微，则极限 lim
x →0 y →0
（D）若 f ( x, y ) 在 (0, 0) 处可微，则极限 lim
x →0 y →0
【答案】：
【解析】：由于 f ( x, y ) 在 ( 0, 0 ) 处连续，可知如果 lim
x →0 y →0
（2）设函数 y ( x = ) (e x − 1)(e 2 x − 2) ⋅⋅⋅ (e nx − n) ，其中 n 为正整数，则 y ' (0) = （A） (−1) n −1 (n − 1)! （B） (−1) n (n − 1)! （C） (−1) n −1 n ! （D） (−1) n n ! )

2012年考研政治真题(全部答案解析完整版

2012年考研政治真题（全部答案解析完整版）一、单项选择题：1～16小题，每小题1分，共16分。

下列每题给出的四个选项中，只有一个选项是符合题目要求的。

请在答题卡上将所选项的字母涂黑。

1.恩格斯说：“鹰比人看得远得多，但是人的眼睛识别东西远胜于鹰。

狗比人具有敏锐得多的嗅觉，但是它连被人当做各种物的特定标志的不同气味的百分之一也辨别不出来。

”人的感官的识别能力高于动物，除了人脑及感官发育得更加完善之外，还因为A人不仅有感觉还有思维B人不仅有理性还有非理性C人不仅有知觉还有想象D人不仅有生理机能还有心理活动1.【答案】A【解析】人与动物的区别之一，从马哲角度上讲，人有思维，有意识，能对客观世界反映，发挥主观能动性，所以，本题正确答案是选项A。

2.有这样一道数学题：“90%×90%×90%×90%×90%=？其答案是约59%。

90分看似一个非常不错的成绩，然而，在一项环环相扣的连续不断的工作中，如果每个环节都打点折扣，最终得出的成绩就是不及格。

3、在资本主义社会里，资本家雇佣工人进行劳动并支付相应的工资。

所以，本题的正确选项是选项Ｂ。

4、2011年9月以来美国爆发的“占领华尔街”抗议活动中，示威者打出“我们是99%”的标语，向极富阶级表示不满。

漫画所显示的美国社会财富占有的两极分化，是资本主义制度下（）A劳资冲突的集中体现B生产社会化的必然产物C资本积累的必然结果D虚拟资本泡沫化的恶果4.【答案】C【解析】资本主义制度下，资本积累的必然结果就是两极分化，剥削程度加深，人民生活水平降低，相对人口过剩。

2012年考研教育学真题及答案（完整版）

⼀、单项选择题：1～45⼩题，每⼩题2分，共90分。

下列每题给出的四个选项中，只有⼀个选项是符合题⽬要求的。

请在答题卡上将所选项的字母涂⿊。

对于题⽬的答案有疑义的，可以进⼊勤思考研论坛提问或者关注勤思考研的微博。

1.关注和探询“谁控制学校”、“谁制定学校管理的政策”、“谁决定教育的伦理、社会和经济⽬标”、“谁设置课程”的教育理论流派是A. 制度教育学B. 改造主义教育理论C. 存在主义教育理论D. 批判教育学【参考答案】D 【勤思考研解析】批判教育学是20世纪70年代之后兴起的⼀种教育思潮，主要代表⼈物是鲍尔斯、⾦蒂斯、阿普尔、吉鲁，法国的布厄迪尔等。

基本观点是：第⼀，当代资本主义的学校教育不是⼀种民主的建制和解放的⼒量，⽽是维护现实社会的不公平和不公正的⼯具，是造成社会差别、社会歧视和社会对⽴的根源；第⼆，教育是与社会相对应的，有什么样的社会政治、经济和⽂化，就有什么样的学校教育机构，社会的政治意识形态、⽂化样态、经济结构都强烈低制约着学校的⽬的、课程、师⽣关系、评价⽅式等，学校教育的功能就是再⽣产出占主导地位的社会政治意识形态、⽂化关系和经济结构；第三，批判教育学的⽬的就是要揭⽰看似⾃然事实背后的利益关系，帮助教师和学⽣对⾃⼰所处的教育环境及形成教育环境的诸多因素敏感起来，即对他们进⾏“启蒙”，以达到意识“解放”⽬的，从⽽积极地寻找克服教育及社会不平等和不公正的策略；第四，教育现象不是中⽴的和客观的，⽽是充满着利益纷争的，教育理论研究不能采取唯科学主义的态度和⽅法，⽽要采⽤实践批判的态度和⽅法。

从题⼲的⾓度出发，选择D。

2.如下现象属于教育范畴的是 A. 爸爸针对⼩明懦弱的个性设法训练⼩明如何以⽛还⽛报复欺侮者 B. 妈妈指导⼩明在与他⼈冲突中如何保护⾃⼰ C. ⽼师严格管理以保护⼩明等弱⼩学⽣不再受欺负 D. ⼩明在与同学的多次冲突中逐渐学会了如何与⼈和睦相处【参考答案】B 【勤思考研解析】教育的定义具有⼴义和狭义的区分，⼴义的教育指的是，凡是有⽬的的地增进⼈的知识技能，影响⼈的思想品德，增强⼈的体质的活动，不论是有组织的或是⽆组织的，系统的或是零碎的，都是教育。

2012年考研英语二真题全文翻译标准答案超详解析

20１2年全国硕士研究生入学统一考试英语(二）试题答案与解析Seｃtion I Use of English一、文章题材结构分析本文是一篇关于人物介绍的说明性文章，主要讲述了G．I. Joe由普通人成长为英雄,是美国特种兵敢死队的象征。

二、试题解析1．【答案】B【解析】本段开篇提出主题:Ｇ. I. Jｏe 这个名字对于参加过第二次世界大战的人来说意义非凡。

空格中需要填动词,在定语从句中做谓语,其主语是ｗho(指代meｎａnｄwoｍｅｎ)，动作发生的地点是ｉn ＷorlｄWar IＩ；空后的句子“theｐeoｐle they ｌiｂｅｒaｔed”中ｔhey也指代men and ｗoｍeｎ，他们有ｌiｂeratｅ的动作,由此推断“ｔhe men ａnd woｍｅｎ”指的应该是参加了第二次大战的男人和女人,即服役的军人。

只有serve 有“服兵役”的意思,所以选B。

A 项peｒfｏrｍ意为“表现;执行;表演”;C 项rebel 意为“造反，反抗”;Ｄ项beｔｒay意为”背叛,出卖”,皆不符合文意，为干扰项。

２．【答案】Ｂ【解析】空格处所指的人与下文的ｔhe poor farm kiｄ和tｈe ｇuy在含义上呼应,同时与空格后的“ｇrown intoherｏ”逻辑含义应保持一致,因此空内信息应该是与hero“英雄”意思相对,后面的分句说他背井离乡,经历了很多苦难，显然这里应该是说由普通人平凡人（commoｎman）成长为英雄,所以选B。

A 项actual 意为“实际上,事实上的”；C 项ｓpeｃｉａl 意为“特殊的,专门的”;Ｄ项normaｌ意为“正常的,常态的”；皆不符合上下文语意,为干扰项。

３．【答案】A【解析】本题考查的是词语的搭配关系，需要填入动词在定语从句中做谓语，先行词是ｗho（the gｕy)，宾语是aｌl thｅburdeｎs of baｔtle，要表达“承担战争带来的负担,应该用动词beaｒ或ｓｈｏｕldeｒ,所以这里选A，boｒe。

2012年考研(数学一)真题试卷(题后含答案及解析)

2012年考研（数学一）真题试卷(题后含答案及解析) 题型有：1. 选择题 2. 填空题 3. 解答题选择题下列每题给出的四个选项中，只有一个选项符合题目要求。

1．曲线渐近线的条数为( )．A．0B．1C．2D．3正确答案：C2．设函数f(x)＝(ex－1)(e2x－2)…(enx－n)，其中n为正整数，则fˊ(0)＝( )．A．(－1)n－1(n－1)!B．(－1)n(n－1)!C．(－1)n－1n!D．(－1)nn!正确答案：A3．如果函数f(x，y)在(0，0)处连续，那么下列命题正确的是( )．A．&nbspB．&nbspC．&nbspD．&nbsp正确答案：B4．设(k＝1，2，3)，则有( )．A．I1＜I2＜13B．I3＜I2＜I1C．I2＜I3＜I1D．I2＜I1＜I3正确答案：D5．设，其中c1，c2，c3，c4为任意常数，则下列向量组线性相关的为( )．A．α1，α2，α3B．α1，α2，α4C．α1，α3，α4D．α2，α3，α4正确答案：C6．设A为3阶矩阵，P为3阶可逆矩阵，且若P＝(α1，α2，α3)，Q＝(α1＋α2，α2，α3)，则Q－1AQ＝( )．A．&nbspB．&nbspC．&nbspD．&nbsp正确答案：B7．设随机变量X与Y相互独立，且分别服从参数为1与参数为4的指数分布，则P｜x＜y｜＝( )．A．1／5B．1／3C．2／5D．4／5正确答案：A8．将长度为1 m的木棒随机地截成两段，则两段长度的相关系数为( )．A．1B．1／2C．﹣1／2D．﹣1正确答案：D填空题9．若函数f(x)满足方程f〞(x)＋fˊ(x)－2f(x)＝0及fˊ(x)＋f(x)＝2ex，则f(x)＝__________．正确答案：齐次方程f〞(x)＋fˊ(x)－2f(x)＝0的特征方程为r2＋r－2＝0，得特征根为r1＝1，r2＝－2，则有通解f(x)＝c1ex＋c2e－2x，代人方程fˊ(x)＋f(x)＝2ex得2c1ex－c2e－2x＝2ex，则c1＝1，c2＝0．因此f(x)＝ex．10．正确答案：根据题意，令t＝x－1，则本题用到奇函数在对称区间上积为零的结论．11．正确答案：根据题意，令将点(2，1，1)代入，上式＝(1，1，1)．12．设∑＝｛(x，y，z)｜x＋y＋z＝1，x≥0，y≥0，z≥0｝，则y2dx＝________．正确答案：其中D为∑投影在xOy平面上的区域，D＝｛(x，y)｜x≥0，y ≥0，x＋y≤1｝13．设X为三维单位列向量，E为三阶单位矩阵，则矩阵E－XXT的秩为_________．正确答案：根据题意设X＝(1，0，0)T，14．设A、B、C是随机事件，A与C互不相容，P(AB)＝1／2，P（C）＝1／3，则P(AB｜C￣)＝________．正确答案：解答题解答应写出文字说明、证明过程或演算步骤。

2012年考研管综真题及答案

综合能力试题一、问题求解题：第1～15小题，每小题三分，共45分。

下列每题给出的(A )、(B )、(C )、(D )、(E )五个选项中，只有一项是符合试题要求的。

请在答题卡．．．上将所选的字母涂黑。

1.某商品的定价为200元，受金融危机的影响，连续两次降价20%后的售价为()．(A )114元(B )120元(C )128元(D )144元(E )160元2.如图1，△ABC 是直角三角形，1，2，3为正方形，已知，，分别是1，2，3的边长，则()．(A )=+(B )2=2+2(C )2=22+22(D )3=3+3(E )3=23+23S 3BCAS 1S 2图13.如图2，一个储物罐的下半部分是底面直径与高均是20m 的圆柱体、上半部分(顶部)是半球形的，已知底面与顶部的造价是400元/m 2，侧面的造价是300元/m 2,则该储物罐的造价是()．(π≈3.14)图2(A )56.52万元(B )62.8万元(C )75.36万元(D )87.92万元(E )100.48万元4.在一次商品促销活动中，主持人出示一个9位数，让顾客猜测商品的价格，商品的价格是该9位数中从左到右相邻的3个数字组成的3位数，若主持人出示的是513535319，则顾客一次猜中价格的概率是()．(A )17(B )16(C )15(D )27(E )135.某商店经营15种商品，每次在橱窗内陈列5种，若每两次陈列的商品不完全相同，则最多可陈列()．(A )3000次(B )3003次(C )4000次(D )4003次(E )4300次6.甲、乙、丙三个地区的公务员参加一次测评，其人数和考分情况如下表所示：三个地区按平均分由高到低的排名顺序为()。

(A )乙、丙、甲(B )乙、甲、丙(C )甲、丙、乙(D )丙、甲、乙(E )丙、乙、甲7.经统计，某机场的一个安检口每天中午办理安检手续的乘客人数及相应的概率如下表所示：乘客人数0~56~1011~1516~2021~2525以上概率0.10.20.20.250.20.05该安检口2天中至少有1天中午办理安检手续的乘客人数超过15的概率是()．(A)0.2(B)0.25(C)0.4(D)0.5(E)0.758.某人在保险柜中存放了M元现金，第一天取出它的23，以后每天取出前一天所取的13，共取了7次，保险柜中剩余的现金为()．(A)37元(B)36元(C)236元(D)[1−(23)7]元(E)[1−7×(23)7]元9.在直角坐标系中，若平面区域D中所有点的坐标(s p均满足：0≤≤6，0≤≤6，−≤3，2+2≥9，则D的面积是()．(A)94(1+4p(B)9(4−4)(C)9(3−4)(D)94(2+π)(E)94(1+π)10.某单位春季植树100颗，前2天安排乙组植树，其余任务由甲、乙两组用3天完成，已知甲组每天比乙组多植树4棵，则甲组每天植树()．(A)11棵(B)12棵(C)13棵(D)15棵(E)17棵11.在两队进行的羽毛球对抗赛中，每队派出3男2女共5名运动员进行5局单打比赛．如果女子比赛安排在第二局和第四局进行，则每队队员的不同出场顺序有()．(A)12种(B)10种(C)8种(D)6种(E)4种12.若3+2+B+能被2−3+2整除，则()．(A)=4,=4(B)=−4,=−4(C)=10,=−8(D)=−10,=8(E)=−2,=013.某公司计划运送180台电视机和110台洗衣机下乡，现在两种货车，甲种货车每辆最多可载40台电视机和10台洗衣机，乙种货车每辆最多可载20台电视机和20台洗衣机．甲、乙两种货车的租金分别是每辆400元和360元，则最少的运费是()．(A)2560元(B)2600元(C)2640元(D)2680元(E)2720元14.如图3所示，三个边长为1的正方形所覆盖区域(实线所围)的面积为()．图3(A)3−2(B)3−(C)3−3(D)3(E)315.在一次捐赠活动中，某市将捐赠的物品打包成件，其中帐篷和食品共320件，帐篷比食品多80件，则帐篷的件数是()件．(A)180(B)200(C)220(D)240(E)260二、条件充分性判断：第16～25小题，每小题3分，共30分。

2012考研数二真题及解析

2012年全国硕士研究生入学统一考试数学二试题解析一、选择题：1～8小题，每小题4分，共32分，下列每小题给出的四个选项中，只有一项符合题目要求的，请将所选项前的字母填在答题纸．．．指定位置上. （1）曲线221x x y x +=-渐近线的条数为（）（A ）0 （B ）1 （C ）2 （D ）3 【答案】：C【解析】：221lim 1x x xx →+=∞-，所以1x =为垂直的 22lim 11x x xx →∞+=-，所以1y =为水平的，没有斜渐近线故两条选C （2）设函数2()(1)(2)()x x nx f x e e e n =--- ，其中n 为正整数，则'(0)f = （A ）1(1)(1)!n n --- （B ）(1)(1)!n n -- （C ）1(1)!n n -- （D ）(1)!n n - 【答案】：C【解析】：'222()(2)()(1)(22)()(1)(2)()x x nx x x nx x x nx f x e e e n e e e n e e ne n =--+---+--- 所以'(0)f =1(1)!n n --（3）设a n >0(n =1,2,…)，S n =a 1+a 2+…a n ，则数列(s n )有界是数列（a n ）收敛的(A)充分必要条件. (B)充分非必要条件.（C ）必要非充分条件.（D ）即非充分地非必要条件.【答案】：(B)（4）设2kx keI e=⎰sin x d x (k=1,2,3),则有D（A ）I 1< I 2 <I 3. (B) I 2< I 2< I 3. (C) I 1< I 3 <I 1,(D) I 1< I 2< I 3.【答案】：(D) 【解析】：：2sin kx k eI e xdx =⎰看为以k 为自变量的函数，则可知()2'sin 0,0,k k I e k k π=≥∈，即可知2sin kx k eI e xdx =⎰关于k 在()0,π上为单调增函数，又由于()1,2,30,π∈，则123I I I <<，故选D（5）设函数f (x,y ) 可微，且对任意x ,y 都有(,)f x y x∂∂ >0,(,)f x y y ∂∂<0,f (x 1,y 1)<f(x 2,y 2)成立的一个充分条件是 (A) x 1> x 2, y 1< y 2. (B) x 1> x 2, y 1>y 1. (C) x 1< x 2, y 1< y 2.(D) x 1< x 2, y 1> y 2.【答案】：(D) 【解析】：(,)0f x y x ∂>∂，(,)0f x y y∂<∂表示函数(,)f x y 关于变量x 是单调递增的，关于变量y 是单调递减的。

2012年考研英语真题及答案完整解析

2012年全国硕士研究生入学统一考试英语（一）Section I Use of EnglishDirections:Read the following text. Choose the best word(s) for each numbered blank and mark A, B, C or D on ANSWER SHEET 1. (10 points)Read the following text. Choose the best word(s) for each numbered blank and mark A, B, C or D on ANSWER SHEET 1. (10 points)The ethical judgments of the Supreme Court justices have become animportant issue recently. The court cannot _1_ its legitimacy as guardian of therule of law _2_ justices behave like politicians. Yet, in several instances, justicesacted in ways that _3_ the court’s reputation for being independent andimpartial.Justice Antonin Scalia, for example, appeared at political events. That kind ofactivity makes it less likely that the court’s decisi ons will be _4_ as impartialjudgments. Part of the problem is that the justices are not _5_by an ethics code.At the very least, the court should make itself _6_to the code of conduct that _7_tothe rest of the federal judiciary.This and other similar cases _8_the question of whether there is still a_9_between the court and politics.The framers of the Constitution envisioned law _10_having authority apartfrom politics. They gave justices permanent positions _11_they would be free to_12_ those in power and have no need to _13_ political support. Our legal systemwas designed to set law apart from politics precisely because they are so closely_14_.Constitutional law is political because it results from choices rooted infundamental social _15_ like liberty and property. When the court deals withsocial policy decisions, the law it _16_ is inescapably political-which is why decisions split along ideological lines are so easily _17_ as unjust.The justices must _18_ doubts about the court’s legitimacy by making themselves _19_ to the code of conduct. That would make rulings more likely to be seen as separate from politics and, _20_, convincing as law.1. [A]emphasize [B]maintain [C]modify [D] recognize2. [A]when [B]lest [C]before [D] unless3. [A]restored [B]weakened [C]established [D] eliminated4. [A]challenged [B]compromised [C]suspected [D] accepted5. [A]advanced [B]caught [C]bound [D]founded6. [A]resistant [B]subject [C]immune [D]prone7. [A]resorts [B]sticks [C]loads [D]applies8. [A]evade [B]raise [C]deny [D]settle9. [A]line [B]barrier [C]similarity [D]conflict10. [A]by [B]as [C]though [D]towards11. [A]so [B]since [C]provided [D]though12. [A]serve [B]satisfy [C]upset [D]replace13. [A]confirm [B]express [C]cultivate [D]offer14. [A]guarded [B]followed [C]studied [D]tied15. [A]concepts [B]theories [C]divisions [D]conceptions16. [A]excludes [B]questions [C]shapes [D]controls17. [A]dismissed [B]released [C]ranked [D]distorted18. [A]suppress [B]exploit [C]address [D]ignore19. [A]accessible [B]amiable [C]agreeable [D]accountable20. [A]by all mesns [B]atall costs [C]in a word [D]as a resultSection II Reading ComprehensionPart ADirections:Read the following four texts. Answer the questions below each text by choosing A, B, C or D. Mark your answers on ANSWER SHEET 1. (40 points)Text 1Come on –Everybody’s doing it. That whispered message, half invitation and half forcing, is what most of us think of when we hear the words peer pressure. It usually leads to no good-drinking, drugs and casual sex. But in her new book Join the Club, Tina Rosenberg contends that peer pressure can also be a positive force through what she calls the social cure, in which organizations and officials use the power of group dynamics to help individuals improve their lives and possibly the word.Rosenberg, the recipient of a Pulitzer Prize, offers a host of example of the social cure in action: In South Carolina, a state-sponsored antismoking program called Rage Against the Haze sets out to make cigarettes uncool. In South Africa, an HIV-prevention initiative known as LoveLife recruits young people to promote safe sex among their peers.The idea seems promising，and Rosenberg is a perceptive observer. Her critique of the lameness of many pubic-health campaigns is spot-on: they fail to mobilize peer pressure for healthy habits, and they demonstrate a seriously flawed understanding of psychology.” Dare to be different, please don’t smoke!” pleads one billboard campaign aimed at reducing smoking amongteenagers-teenagers, who desire nothing more than fitting in. Rosenberg argues convincingly that public-health advocates ought to take a page from advertisers, so skilled at applying peer pressure.But on the general effectiveness of the social cure, Rosenberg is less persuasive. Join the Club is filled with too much irrelevant detail and not enough exploration of the social and biological factors that make peer pressure so powerful. The most glaring flaw of the social cure as it’s presented here is that it doesn’t work very well for very long. Rage Against the Haze failed once state funding was cut. Evidence that the LoveLife program produces lasting changes is limited and mixed.There’s no doubt that our peer groups exert enormous influence on our behavior. An emerging body of research shows that positive health habits-as well as negative ones-spread through networks of friends via social communication. This is a subtle form of peer pressure: we unconsciously imitate the behavior we see every day.Far less certain, however, is how successfully experts and bureaucrats can select our peer groups and steer their activities in virtuous directions. It’s like the teacher w ho breaks up the troublemakers in the back row by pairing them with better-behaved classmates. The tactic never really works. And that’s the problem with a social cure engineered from the outside: in the real world, as in school, we insist on choosing our own friends.21. According to the first paragraph, peer pressure often emerges as[A] a supplement to the social cure[B] a stimulus to group dynamics[C] an obstacle to school progress[D] a cause of undesirable behaviors22. Rosenberg holds that public advocates should[A] recruit professional advertisers[B] learn from advertisers’ experience[C] stay away from commercial advertisers[D] recognize the limitations of advertisements23. In the author’s view, Rosenberg’s book fails to[A] adequately probe social and biological factors[B] effectively evade the flaws of the social cure[C] illustrate the functions of state funding[D]produce a long-lasting social effect24. Paragraph 5shows that our imitation of behaviors[A] is harmful to our networks of friends[B] will mislead behavioral studies[C] occurs without our realizing it[D] can produce negative health habits25. The author suggests in the last paragraph that the effect of peer pressure is[A] harmful[B] desirable[C] profound[D] questionableText 2A deal is a deal-except, apparently ,when Entergy is involved. The company, a major energy supplier in New England, provoked justified outrage in Vermont last week when it announced it was reneging on a longstanding commitment to abide by the strict nuclear regulations.Instead, the company has done precisely what it had long promised it would not challenge the constitutionality of Vermont’s rules in the federal court, as part of a desperate effort to keep its Vermont Yankee nuclear powe r plant running. It’s a stunning move.The conflict has been surfacing since 2002, when the corporation bought Vermont’s only nuclear power plant, an aging reactor in Vernon. As a condition of receiving state approval for the sale, the company agreed to seek permission from state regulators to operate past 2012. In 2006, the state went a step further, requiring that any extension of the plant’s license be subject to Vermont legislature’s approval. Then, too, the company went along.Either Entergy never real ly intended to live by those commitments, or it simply didn’t foresee what would happen next. A string of accidents, including the partial collapse of a cooling tower in 207 and the discovery of an underground pipe system leakage, raised serious questions about both Vermont Yankee’s safety and Entergy’s management–especially after the company made misleading statements about the pipe. Enraged by Entergy’s behavior, the Vermont Senate voted 26 to 4 last year against allowing an extension.Now the company is suddenly claiming that the 2002 agreement is invalid because of the 2006 legislation, and that only the federal government has regulatory power over nuclear issues. The legal issues in the case are obscure: whereas the Supreme Court has ruled that states do have some regulatory authority over nuclear power, legal scholars say that Vermont case will offer a precedent-setting test of how far those powers extend. Certainly, there are valid concerns about the patchwork regulations that could result if every state sets its own rules. But had Entergy kept its word, that debate would be beside the point.The company seems to have concluded that its reputation in Vermont is already so damaged that it has noting left to lose by going to war with the state. But there should be consequences. Permission to run a nuclear plant is a poblic trust. Entergy runs 11 other reactors in the United States, including Pilgrim Nuclear station in Plymouth. Pledging to run Pilgrim safely, the company has applied for federal permission to keep it open for another 20 years. But as the Nuclear Regulatory Commission (NRC) reviews the company’s application, it should keep it mind what promises from Entergy are worth.26. The phrase “reneging on”(Line 3.para.1) is closest in meaning to[A] condemning.[B] reaffirming.[C] dishonoring.[D] securing.27. By entering into the 2002 agreement, Entergy intended to[A] obtain protection from Vermont regulators.[B] seek favor from the federal legislature.[C] acquire an extension of its business license .[D] get permission to purchase a power plant.28. According to Paragraph 4, Entergy seems to have problems with its[A] managerial practices.[B] technical innovativeness.[C] financial goals.[D] business vision29. In the author’s view, th e Vermont case will test[A] Entergy’s capacity to fulfill all its promises.[B] the mature of states’ patchwork regulations.[C] the federal authority over nuclear issues .[D] the limits of states’ power over nuclear issues.30. It can be inferred from the last paragraph that[A] Entergy’s business elsewhere might be affected.[B] the authority of the NRC will be defied.[C] Entergy will withdraw its Plymouth application.[D] Vermont’s reputation might be damaged.Text 3In the idealized version of how science is done, facts about the world are waiting to be observed and collected by objective researchers who use the scientific method to carry out their work. But in the everyday practice of science, discovery frequently follows an ambiguous and complicated route. We aim to be objective, but we cannot escape the context of our unique life experience. Prior knowledge and interest influence what we experience, what we think our experiences mean, and the subsequent actions we take. Opportunities for misinterpretation, error, and self-deception abound.Consequently, discovery claims should be thought of as protoscience. Similar to newly staked mining claims, they are full of potential. But it takes collective scrutiny and acceptance to transform a discovery claim into a mature discovery. This is the credibility process, through which the individual researcher’s me, here, now becomes the community’s anyone, anywhere, anytime. Objective knowledge is the goal, not the starting point.Once a discovery claim becomes public, the discoverer receives intellectual credit. But, unlike with mining claims, the community takes control of what happens next. Within the complex social structure of the scientific community, researchers make discoveries; editors and reviewers act as gatekeepers by controlling the publication process; other scientists usethe new finding to suit their own purposes; and finally, the public (including other scientists) receives the new discovery and possibly accompanying technology. As a discovery claim works it through the community, the interaction and confrontation between shared and competing beliefs about the science and the technology involved transforms an individual’s discovery claim into the community’s credible discovery.Two paradoxes exist throughout this credibility process. First, scientific work tends to focus on some aspect of prevailing Knowledge that is viewed as incomplete or incorrect. Little reward accompanies duplication and confirmation of what is already known and believed. The goal is new-search, not re-search. Not surprisingly, newly published discovery claims and credible discoveries that appear to be important and convincing will always be open to challenge and potential modification or refutation by future researchers. Second, novelty itself frequently provokes disbelief. Nobel Laureate and physiologist AlbertAzent-Gyorgyi once described discovery as “seeing what everybody has seen and thinking what nobody has thought.” But thinking what nobody else has thought and telling others what they have missed may not change their views. Sometimes years are required for truly novel discovery claims to be accepted and appreciated.In the end, credibility “happens” to a discovery claim – a process that corresponds to what philosopher Annette Baier has described as the commons of the mind. “We reason together, challenge, revise, and complete each other’s reasoning and each other’s conceptions of reason.”31. According to the first paragraph, the process of discovery is characterized by its[A] uncertainty and complexity.[B] misconception and deceptiveness.[C] logicality and objectivity.[D] systematicness and regularity.32. It can be inferred from Paragraph 2 that credibility process requires[A] strict inspection.[B]shared efforts.[C] individual wisdom.[D]persistent innovation.33.Paragraph 3 shows that a discovery claim becomes credible after it[A] has attracted the attention of the general public.[B]has been examined by the scientific community.[C] has received recognition from editors and reviewers.[D]has been frequently quoted by peer scientists.34. Albert Szent-Györgyi would most likely agree that[A] scientific claims will survive challenges.[B]discoveries today inspire future research.[C] efforts to make discoveries are justified.[D]scientific work calls for a critical mind.35.Which of the following would be the best title of the test?[A] Novelty as an Engine of Scientific Development.[B]Collective Scrutiny in Scientific Discovery.[C] Evolution of Credibility in Doing Science.[D]Challenge to Credibility at the Gate to Science.Text 4If the trade unionist Jimmy Hoffa were alive today, he would probably represent civil servant. When Hoffa’s Teamsters were in their prime in 1960, only one in ten American government workers belonged to a union; now 36% do. In 2009 the number of unionists in America’s public sector passed that of their fellow members in the private sector. In Britain, more than half of public-sector workers but only about 15% of private-sector ones are unionized.There are three reasons for the public-sector unions’ thriving. First, they can shut things down without suffering much in the way of consequences. Second, they are mostly bright and well-educated. A quarter of America’s public-sector workers have a university degree. Third, they now dominate left-of-centre politics. Some of their ties go back a long way. Britain’s Labor Party, as its name implies, has long been associated with trade unionism. Its current leader, Ed Miliband, owes his position to votes from public-sector unions.At the state level their influence can be even more fearsome. Mark Baldassare of the Public Policy Institute of California points out that much of the state’s budget is patrolled by unions. The teachers’ unio ns keep an eye on schools, the CCPOA on prisons and a variety of labor groups on health care.In many rich countries average wages in the state sector are higher than in the private one. But the real gains come in benefits and work practices. Politicians h ave repeatedly “backloaded” public-sector pay deals, keeping thepay increases modest but adding to holidays and especially pensions that are already generous.Reform has been vigorously opposed, perhaps most egregiously in education, where charter schools, academies and merit pay all faced drawn-out battles. Even though there is plenty of evidence that the quality of the teachers is the most important variable, teachers’ unions have fought against getting rid of bad ones and promoting good ones.As the cost to everyone else has become clearer, politicians have begun to clamp down. In Wisconsin the unions have rallied thousands of supporters against Scott Walker, the hardline Republican governor. But many within the public sector suffer under the current system, too.John Donahue at Harvard’s Kennedy School points out that the norms of culture in Western civil services suit those who want to stay put but is bad for high achievers. The only American public-sector workers who earn well above $250,000 a year are university sports coaches and the president of the United States. Bankers’ fat pay packets have attracted much criticism, but apublic-sector system that does not reward high achievers may be a much bigger problem for America.36. It can be learned from the first paragraph that[A] Teamsters still have a large body of members.[B] Jimmy Hoffa used to work as a civil servant.[C] unions have enlarged their public-sector membership.[D]the government has improved its relationship with unionists.37. Which of the following is true of Paragraph 2?[A] Public-sector unions are prudent in taking actions.[B] Education is required for public-sector union membership.[C] Labor Party has long been fighting against public-sector unions.[D]Public-sector unions seldom get in trouble for their actions.38. It can be learned from Paragraph 4 that the income in the state sector is[A] illegally secured.[B] indirectly augmented.[C] excessively increased.[D]fairly adjusted.39. The example of the unions in Wisconsin shows that unions[A]often run against the current political system.[B]can change people’s political attitudes.[C]may be a barrier to public-sector reforms.[D]are dominant in the government.40. John Donahue’s attitude towards the public-sector system is one of[A]disapproval.[B]appreciation.[C]tolerance.[D]indifference.Part BDirections:In the following text, some sentences have been removed. For Questions 41-45, choose the most suitable one from the list A-G to fit into each of the numbered blanks. There are two extra choices, which do not fit in any of the blanks. Mark your answers on ANSWER SHEET1.（10 points）Think of those fleeting moments when you look out of an aeroplane window and realise that you are flying, higher than a bird. Now think of your laptop, thinner than a brown-paper envelope, or your cellphone in the palm of your hand. Take a moment or two to wonder at those marvels. You are the lucky inheritor of a dream come true.The second half of the 20th century saw a collection of geniuses, warriors, entrepreneurs and visionaries labour to create a fabulous machine that could function as a typewriter and printing press, studio and theatre, paintbrush and gallery, piano and radio, the mail as well as the mail carrier. (41)The networked computer is an amazing device, the first media machine that serves as the mode of production, means of distribution, site of reception, and place of praise and critique. The computer is the 21st century's culture machine.But for all the reasons there are to celebrate the computer, we must also tread with caution. (42)I call it a secret war for two reasons. First, most people do not realise that there are strong commercial agendas at work to keep them in passive consumption mode. Second, the majority of people who use networked computers to upload are not even aware of the significance of what they are doing.All animals download, but only a few upload. Beavers build dams and birds make nests. Yet for the most part, the animal kingdom moves through the world downloading. Humans are unique in their capacity to not only make tools but then turn around and use them to create superfluous material goods - paintings, sculpture and architecture - and superfluous experiences - music, literature, religion and philosophy. (43)For all the possibilities of our new culture machines, most people are still stuck in download mode. Even after the advent of widespread social media, a pyramid of production remains, with a small number of people uploading material, a slightly larger group commenting on or modifying that content, and a huge percentage remaining content to just consume. (44)Television is a one-way tap flowing into our homes. The hardest task that television asks of anyone is to turn the power off after he has turned it on.(45)What counts as meaningful uploading? My definition revolves around the concept of "stickiness" - creations and experiences to which others adhere.[A] Of course, it is precisely these superfluous things that define human culture and ultimately what it is to be human. Downloading and consuming culture requires great skills, but failing to move beyond downloading is to strip oneself of a defining constituent of humanity.[B] Applications like , which allow users to combine pictures, words and other media in creative ways and then share them, have the potential to add stickiness by amusing, entertaining and enlightening others.[C] Not only did they develop such a device but by the turn of the millennium they had also managed to embed it in a worldwide system accessed by billions of people every day.[D] This is because the networked computer has sparked a secret war between downloading and uploading - between passive consumption and active creation - whose outcome will shape our collective future in ways we can only begin to imagine.[E] The challenge the computer mounts to television thus bears little similarity to one format being replaced by another in the manner of record players being replaced by CD players. [F] One reason for the persistence of this pyramid of production is that for the pasthalf-century, much of the world's media culture has been defined by a single medium - television - and television is defined by downloading.[G]The networked computer offers the first chance in 50 years to reverse the flow, to encourage thoughtful downloading and, even more importantly, meaningful uploading.Part CDirections:Read the following text carefully and then translate the underlined segments into Chinese. Your translation should be written clearly on ANSWER SHEET 2. (10 points)Since the days of Aristotle, a search for universal principles has characterized the scientific enterprise. In some ways, this quest for commonalities definesscience. Newton’s laws of motion and Darwinian evolution each bind a host of different phenomena into a single explicatory frame work.(46)In physics, one approach takes this impulse for unification to its extreme, and seeks a theory of everything—a single generative equation for all we see.It is becoming less clear, however, that such a theory would be a simplification, given the dimensions and universes that it might entail, nonetheless, unification of sorts remains a major goal.This tendency in the natural sciences has long been evident in the social sciences too. (47)Here, Darwinism seems to offer justification for it all humans share common origins it seems reasonable to suppose that cultural diversity could also be traced to more constrained beginnings. Just as the bewildering variety of human courtship rituals might all be considered forms of sexual selection, perhaps the world’s languages, music, so cial and religious customs and even history are governed by universal features. (48)To filter out what is unique from what is shared might enable us to understand how complex cultural behavior arose and what guides it in evolutionary or cognitive terms.That, at least, is the hope. But a comparative study of linguistic traits published online today supplies a reality check. Russell Gray at the University of Auckland and his colleagues consider the evolution of grammars in the light of two previous attempts to find universality in language.The most famous of these efforts was initiated by Noam Chomsky, who suggested that humans are born with an innate language—acquisition capacity that dictates a universal grammar. A few generative rules are then sufficient to unfold the entire fundamental structure of a language, which is why children can learn it so quickly.(49)The second, by Joshua Greenberg, takes a more empirical approach to universality identifying traits (particularly in word order) shared by many language which are considered to represent biases that result from cognitive constraintsGray and his colleagues have put them to the test by examining four family trees that between them represent more than 2,000 languages.(50)Chomsky’s grammar should show patterns of language change that are independent of the family tree or the pathway tracked through it. Whereas Greenbergian universality predicts strong co-dependencies between particular types of word-order relations. Neither of these patterns is borne out by the analysis, suggesting that the structures of the languages are lire age-specific and not governed by universalsSection III WritingPart A51. Directions:Some internationals students are coming to your university. Write them an email in the name of the Students’ Union to1)extend your welcome and2)provide some suggestions for their campus life here.You should write about 100 words on ANSWER SHEET2.Do not sign your name at the end of the letter. Use “Li Ming” instead.Do not write the address(10 points)Part B52. Directions: write an essay of 160-200 words based on the following drawing. In youressay you should1) describe the drawing briefly2) explain its intended meaning, and3) give your commentsYou should write neatly on ANSWER SHEET2.（20 points）1.【答案】B【解析】从空后信息可以看出，这句表达的是“_ _法官表现得像政治家”的情况下，法庭就不能保持其作为法律法规的合法卫士的形象，所以应该选C,maintain“维持，保持”，其他显然语义不通。

2012考研数学二真题及答案解析

dy
，所以
=
2x
dx ey +1
（10）计算
lim
x→∞
n
⎛ ⎜⎝
1
1 +n
2
+
22
1 +
n2
+…+
n2
1 +
n2
⎞ ⎟⎠
= ________。
3
π
【答案】：
4
∑ ∫ 【解析】：原式 = lim 1
n→∞ n
n
1
i=1
1
+
⎛ ⎜⎝
i n
⎞2 ⎟⎠
=
1 dx 0 1+ x2
=
arctan x 1 0
三、解答题：15—23 小题，共 94 分.请将解答写在答．题．纸．指定位置上.解答应写出文字说明、证明过程或演算步骤. （15）（本题满分 10 分）
已知函数 f (x) = 1+ x − 1 ，记 a = lim f (x)
sin x x,
x→0
（1）求 a 的值
（2）若当 x → 0 时， f (x) − a 是 xk 的同阶无穷小，求 k
D
∫∫ ∫ ∫ 【解析】：
xydσ = π dθ 1+cosθ r cosθ ⋅ r sin θ ⋅ rdr
0
0
D
∫ = 1 π sin θ ⋅ cosθ ⋅ (1 + cosθ )4 dθ 40
6
∫ = 16
πθ sin
cos θ
(2 cos2
θ
− 1) cos8
θ
dθ
022
2
22
π

2012年考研英语一真题及答案完整解析(1)

2012年全国硕士研究生入学统一考试英语（一）The ethical judgments of the Supreme Court justices have become an important issue recently. The court cannot _1_ its legitimacy as guardian of the rule of law _2_ justices behave like politicians. Yet, in several instances，justices acted in ways that _3_ the court’s reputation for being independent and impartial.Justice Antonin Scalia, for example，appeared at political events。

That kind of activity makes it less likely that the court’s decisions will be _4_ as impartial judgments. Part of the problem is that the justices are not _5_by an ethics code。

At the very least，the court should make itself _6_to the code of conduct that_7_to the rest of the federal judiciary。

This and other similar cases _8_the question of whether there is still a_9_between the court and politics.The framers of the Constitution envisioned law _10_having authority apart from politics. They gave justices permanent positions _11_they would be free to _12_ those in power and have no need to _13_ political support. Our legal system was designed to set law apart from politics precisely because they are so closely _14_。

2012年全国硕士研究生入学统一考试答案及解析

2012年全国硕士研究生入学统一考试管理类专业学位联考综合能力试题参考答案及解析一、问题求解1.【答案】C 。

解析：根据售价=定价*折扣，⨯2002%201）（-=128元。

2.【答案】Ａ。

解析：根据三角形相似性质得=，解得a=b+c 。

3.【答案】C 。

解析：底面面积ππ100102=⨯，顶部面积ππ200104212=⨯⨯，侧面积=π×20×20=400π，所以储物罐的造价=400×300π+300×400π=75.36万元。

4.【答案】B 。

解析：因为排成重复的353后一共有513，135，353，535，531，319，6种情况，所以顾客猜中的概率61=。

5.【答案】B 。

解析：两次陈列的商品各不同数，也就是15种商品中选5种的组合数，即：3003515=C 。

6.【答案】E 。

解析：据表可知甲，乙，丙三地区的人数分别为：40，60，50。

所以其平均分别可求得：甲地区平均分==7.5；乙地区平均分==7.6；丙地区平均分==7.7。

所以由高到低排名为丙、乙、甲。

7.【答案】E 。

解析：因为据表中可知一天中午办理安检不超过15的概率为0.1+0.2+0.2=0.5，所求据对立事件与原事件的概率和为1，可知2天中至少有1天中午办理安检手续的乘客人数超过15的概率是概率为1－0.5×0.5=0.75。

8.【答案】A 。

解析62)31(32)31(32313231⨯-⋅⋅⋅-⨯-⨯-M M M M ⎥⎥⎥⎦⎤⎢⎢⎢⎣⎡---=311))31(1(3132316M M 763))31(1(3131M M M =--= 9.【答案】C 。

解析：根据已知，画出图像⎪⎭⎫ ⎝⎛-=-=⨯-⨯-⨯=439492734133662πππ阴影S 。

10.【答案】D 。

解析：设甲组每天植树x 棵，根据已知，列出方程：2（x-4）+3（x+x-4）=100，解得x=15。

2012考研数学(一二三)真题(含答案)

f x
,
f y
,
f z

.
12、已知曲面 {(x, y, z) | x y z 1, x 0, y 0, z 0}，则 y2dS
。
【答案】 3 12
【解析】由曲面可得 z 1 x y zx ' zy ' 1，
向 xOy 面投影 Dxy {( x, y) | x y 1, x 0, y 0}，
P
为
3
阶可逆矩阵，且
P1
AP

1

，
P

1,
2
,3

，
2
Q 1 2,2,3 则 Q1AQ （）
1

（A）

2

1
【答案】（B）
1

（B）

1

2
2

（C）

1

2
2

（D）

2
ex2
sin
xdx

0

I2

I1 ；
又 I3 I1
3 ex2 sin xdx

2 ex2 sin xdx

3 ex2 sin xdx ，
2
其中
3
ex2
sin
t x
xdx
2 e(t )2 sin(t )d (t ) 2 e(t )2 sin tdt 2 e(x )2 sin xdx
x y ( x, y)(0,0) 2

2012考研真题及答案

2012考研真题及答案2012年的考研真题是许多考生备战考研的重要资料，了解这些真题并熟悉其中的答案对于备考考研的同学来说是至关重要的。

在本文中，将为您介绍2012年的考研真题及其答案。

第一部分：数学一2012年的考研数学一科目主要涵盖了数学分析、高等代数和概率论等内容。

以下是部分考题及其答案的概要。

题一：设函数f(x)在区间[a,b]上连续，且在(a,b)内可导，证明：在(a,b)内至少存在一点ξ，使得f(b)-f(a)=(b-a)f' ( ξ )。

解析：根据罗尔定理，由于f(x)在[a,b]上连续，且在(a,b)内可导，那么在[a,b]上有f(a)=f(b)。

根据拉格朗日中值定理，存在一点ξ∈(a,b)，使得f' ( ξ )=(f(b)-f(a))/(b-a)。

所以，f(b)-f(a)=(b-a)f' ( ξ )。

题二：已知数列{a_n}的通项公式为a_n=2^n-3^n+4^n-5^n，求证数列{a_n}是等差数列。

解析：我们可以通过数学归纳法来证明这个结论。

当n=1时，a_1=2-3+4-5=-2。

当n=k时，假设a_k=2^k-3^k+4^k-5^k成立。

当n=k+1时，我们需要证明a_(k+1) =2^(k+1)-3^(k+1)+4^(k+1)-5^(k+1)也成立。

根据等差数列的性质，我们有a_(k+1)-a_k = (2^(k+1)-3^(k+1)+4^(k+1)-5^(k+1)) - (2^k-3^k+4^k-5^k)。

化简后可得a_(k+1)-a_k= -2 × 3^k + 3^(k+1) -2 × 5^k + 5^(k+1)。

通过整理和变换，我们得到a_(k+1)-a_k = -3^k (2-3) + 5^k (5-2) = 0。

因此，数列{a_n}是等差数列。

通过以上两道题目，我们可以看出2012年考研数学一科目的难度适中，考察了数学分析和代数的基本概念和推导方法。

2012年考研政治真题及参考答案(完整解析版)

2012年研究生考试政治真题(海天版) 2012年全国硕士研究生入学统一考试思想政治理论试题一、单项选择题：1～16小题，每小题1分，共16分。

下列每题给出的四个选项中，只有一个选项是符合题目要求的。

请在答题卡上将所选项的字母涂黑。

1、恩格斯说：“鹰比人看得远得多，但是人的眼睛识别东西远胜于鹰、狗比人具有锐敏得多的嗅觉，但是它连被人当做各种物的特定标志的不同气味的百分之一也辨别不出来、”人的感官的识别能力高于动物，除了人脑及感官发育得更加完善之外，还因为( )A、人不仅有感觉还有思维B、人不仅有理性还有非理性C、人不仅有直觉还有想象D、人不仅有生理机能还有心理活动2、有这样一道数学题：“90%×90%×90%×90%×90%=?”其答案是约59%、90分看似一个非常不错的成绩，然而，在一项环环相扣的连续不断的工作中，如果每个环节都打点折扣，最终得出的成绩就是不及格、这里蕴含的辩证法道理是( )A、肯定中包含否定B、量变引起质变C、必然性通过偶然性开辟道路D、可能和现实是相互转化的3、在资本主义社会里，资本家雇佣工人进行劳动并支付相应的工资、资本主义工资的本质是( )A、工人所获得的资本家的预付资本B、工人劳动力的价值或价格C、工人所创造的剩余价值的一部分D、工人全部劳动的报酬4、2011年9月以来美国爆发的“占领华尔街”海圣教育抗议活动中，示威者打出“我们是99%”的标语，向极富阶层表示不满、漫画所显示的美国社会财富占有的两极分化，是资本主义制度下( )A、劳资冲突的集中表现B、生产社会化的必然产物C、资本积累的必然结果D、虚拟资本泡沫化的恶果5、毛泽东曾在不同场合多次谈到，调查研究有两种方法，一种是走马看花，一种是下马看花、走马看花，不深入，还必须用第二种方法，就是下马看花，过细看花，分析一朵花、毛泽东强调“下马看花”的实际意义在于( )A、解决实际问题必须要有先进理论的指导B、运用多种综合方法分析调查研究的材料C、马克思主义理论必须适合中国革命的具体实际D、只有全面深入地了解中国的实际，才能找出规律6、改革开放以来，我们党对公有制认识上的一个重本突破，就是明确了公有制和公有制的实现形式是两个不同层次的问题、公有制的实现形式是指资产或资本的( )A、占有形式B、分配形式C、所有权归属D、组织形式和经营方式7、2011年进行的全国县乡两级人大换届选举，是2010年3月选举法修改后首次实行城乡按相同人口比例选举人大代表、这是我国政治生活中的一件大事，它( )A、更好地体现了人人平等、地区平等和民族平等B、有利于党在国家政权中发扬民主、贯彻党的群众路线C、集中反映了人民代表大会是人民当家作主的根本途径D、表明我国人大代表的产生与西方议会议员的产生有根本区别8、邓小平指出：“解决民族问题，中国采取的不是民族共和国联邦的制度，而是民族区域自治的制度、我们认为这个制度比较好，适合中国的情况、”我国实行民族区域自治的历史依据是( )A、各民族聚居区发展的不平衡性B、统一的多民族国家的长期存在和发展C、各民族大杂居、小聚居的人口分布格局D、近代以来各民族在共同反抗外来侵略斗争中形成的爱国主义精神9、19世纪40年代以后，资本-帝国主义势力一次又一次地发动对中国的侵略战争，妄图瓜分中国、灭亡中国，但是，帝国主义列强并没有能够海圣教育实现他们的这一图谋，其根本原因是( )A、中西文化存在臣犬差异 B.中国经济政治发展不平衡C、帝国主义列强之间的矛盾和互相制约D、中华民族进行的不屈不挠的反侵略斗争10、毛泽东在《中国革命和中国共产党》中论述了民主革命和社会主义革命的关系、他指出：“民主革命是社会主义革命的必要准备，社会主义革命是民主革命的必然趋势”、这两个革命阶段能够有机连接的原因是( )A、资本主义道路在中国走不通B、俄国十月革命为中国提供了经验C、民主革命中包含了社会主义因素 D.中国国情决定中国革命必须分两步走11、道德修养是一个循序渐进的过程，古火云：“积土成山，风雨兴焉；积水成渊，蛟龙生焉；积善成德，而神明自得，圣心各焉、故不积跬步，无以至千里；不积小流，无以成江海、”下列名言中与这段话在含义上近似的是( )A、仁远乎哉？我欲仁，斯仁至矣B、勿以善小而不为，勿以恶小而为之C、君子求诸己，小人求诸人D、有能一日用其力于仁矣乎？我未见力不足者12、中国特色社会主义法律体系是以我国全部现行法律规范按照一定的标准和原则划分为不同的法律部门，并由这些法律部门所构成的具有内在联系的统一整体、每一法律部门均由一系列调整相同类型社会关系的众多法律、法规所构成、下列选项中属于独立法律部门的是( )A、知识产权法B、商法C、公司法“D、民法商法13、人生目的是人在人生实践中关于自身行为的根本指向和人生追求，它所认识和回答的根本问题是( )A、人为什么活着B、人如何对待生活C、怎样对待人生境遇D、怎样选择人生道路14、社会主义道德建设的核心是( )A、爱国主义B、集体主义C、为人民服务D、社会主义荣辱观15、与“天宫一号"两度完成“太空之吻”的“神舟八号”飞船，于2011年11月17日顺利回“家”，天宫一号与神舟八号一手操作空间交会对接任务获得圆满成功、这标志着我国( )A、载人航天技术已经完全成熟B、实现了由航天大国向航天强国的转变C、实现了载人航天工程“三步走”的发展战略D、为今后建造载人空间站奠定了坚实的技术基础16、2011年5月18日，国际货币基金组织(IMF)总裁多米尼克•斯特劳斯-卡恩因涉案而辞去总裁职务，引发了欧美等发达国家与发展中国家关于海圣教育IMF总裁继任人的争夺、6月28日，国际货币基金组织宣布，该组织新一任总裁是法国经济、财政与工业部长克里斯蒂娜•拉加德、这表明( )A、国际货币基金组织改革进程加快B、新兴国家的话语权和代表性得到提升C、欧美主导国际金融机构的局面仍未改变D、发展中国家作为一支独立力量登上世界舞台二、多项选择题：17～33题，每小题2分，共34分、下列每题给出的四个选项中，至少有两个选项是符合题目要求的、请在答题卡上将所选项的字母涂黑、多选或少选均不得分。

2012年考研政治真题及答案解析

2012年全国硕士研究生入学统一考试思想政治理论试题答案及解析1【答案】A【解析】选项B和选项C说法正确，但是和题干无关，所以不选；选项D是人和动物的共性，所以不选，因此本题的正确答案是选项A。

2【答案】B【解析】本题题干中数学题每一个乘数都是90分即90%，这是个不错的成绩，但是把他们都乘在一起就等于了59分即59%，成绩最后由90分成了59分，成了不及格。

每个环节都打点折扣，得出的成绩就是不及格，通过分析题干可以得出其体现的是量变与质变的关系，即量变引起质变。

其他选项与题干无关。

因此本题的正确答案是选项B。

3【答案】B【解析】本题选项A说法错误，因此不选；选项C说法错误，剩余价值被资本家无偿占有，因此不选；选项D是资本主义工资的表象，不是本质，因此选项D错误，本题的正确答案是选项B。

4【答案】C【解析】本题漫画反映的是资本主义社会的两极分化问题，资本主义两极分化是由于资本积累的规律，即资本积累的必然结果，因此本题的正确答案是选项C。

其他选项与题干无关，因此不选。

5【答案】D【解析】A选项讲的是要有先进理论的指导，观点正确，但在题干中没有体现；B选项“运用多种综合方法分析”不符合题意，因为题干说的是“下马看花”这一种方法；C选项“马克思主义理论必须适合中国革命的具体实际”表述错误，正确表述是马克思主义理论必须同中国革命的具体实际相结合。

故ABC选项不符合题意。

题干中的“下马看花”主要强调了在调查研究中要注重中国的具体实际，D选项符合题意。

因此，本题的正确答案是D选项。

6【答案】D【解析】巩固和发展公有制经济，还要努力寻找能够极大促进生产力发展的公有制实现形式。

公有制经济的性质和实现形式是两个不同层次的问题。

公有制经济的性质体现在所有权的归属上，坚持公有制的性质，根本的是坚持国家和集体对生产资料的所有权。

所有制作为生产关系的基础，有公有制与私有制、社会主义与资本主义的区别。

而所有制的实现形式是采取怎样的经营方式和组织形式问题，它不具有“公”与“私”、“社”与“资”的区分。