2012考研题目加答案

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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英语考研真题答案

2012英语考研真题答案英语考研是每个考生都非常重视的一门科目。

很多考生都会密切关注历年的真题，以便更好地备考和了解自己的英语水平。

以下是2012年英语考研真题的详细答案。

听力部分答案：Section A1. D2. A3. C4. B5. D6. C7. A8. B9. C10. DSection B11. C12. B14. B15. A16. B17. C18. A19. B20. C阅读理解答案：Passage 121. D22. C23. A24. C25. DPassage 226. B27. D28. A30. DPassage 331. D32. A33. C34. B35. CTranslation答案：36. Today, people often refer to the Gulf War as another oil war.37. Paris is to France what Tokyo is to Japan.38. People should be realistic and lay the groundwork for their future.39. The college professor gave the student a crash course in economics.40. The function of a university is to guide students to a better understanding of themselves and the world.写作答案：Part 1：Directions: Write an essay of 200 words based on the following chart.参考范文：The chart illustrates the consumption of different types of beverages in a typical western country over a span of 30 years, from 1980 to 2010. It is clear that the consumption of fruit juice and bottled water increased significantly, while the consumption of carbonated drinks declined.In 1980, carbonated drinks were the most popular, with over 250 liters consumed per person per year. Fruit juice and bottled water were consumed at a much lower rate, with approximately 50 liters and 10 liters per person respectively.However, by 2010, the situation had changed dramatically. The consumption of carbonated drinks had dropped to around 100 liters per person annually, less than half of what it was in 1980. On the other hand, the consumption of fruit juice and bottled water soared to 200 liters and 80 liters respectively.There are several factors contributing to this trend. Firstly, people are becoming more health-conscious, and are opting for healthier alternatives to carbonated drinks. Secondly, the convenience of bottled water has made it a popular choice, particularly among young people. Lastly, the marketing of fruit juice as a natural and nutritious choice has increased its popularity.In conclusion, the chart highlights the change in beverage consumption patterns over the past 30 years. Carbonated drinks have been largely replaced by fruit juice and bottled water, reflecting a growing trend towards healthier choices.Part 2：Directions: Write an essay of 600 words on the following topic.参考范文：The Impact of Social Media on YouthIntroduction:In today's digital age, social media plays an influential role in the lives of young people. This essay will explore the impact of social media on youth, focusing on its positive and negative effects.Positive effects:Firstly, social media platforms allow young people to connect and communicate with others from different cultures and countries, fostering a sense of global understanding and unity. This broadens their perspectives and promotes cultural exchange.Secondly, social media provides a platform for young individuals to express themselves creatively through sharing photos, videos, and artwork. This can boost their self-esteem and confidence by gaining recognition and feedback from others.Lastly, social media offers educational opportunities, as many organizations and institutions use these platforms to share knowledge and provide online courses. This enables youth to access educational resources and expand their knowledge beyond traditional classrooms.Negative effects:On the other hand, the excessive use of social media can have detrimental effects on mental health and well-being. Young people may become addicted to social media, increasing the risk of anxiety, depression,and social isolation. The constant comparison to others' highlight reels can lead to feelings of inadequacy and low self-worth.Furthermore, cyberbullying is prevalent on social media, with young people being vulnerable to online harassment and bullying. This can have severe consequences on their mental and emotional well-being, and even lead to self-harm or suicidal thoughts.Lastly, the overexposure to curated images and idealized lifestyles on social media can distort young people's perception of reality, leading to body image issues and unhealthy behaviors like disordered eating or excessive dieting.Conclusion:In conclusion, social media has both positive and negative impacts on young people. It provides opportunities for global connections, creative expression, and online education. However, its excessive use can negatively affect mental health, contribute to cyberbullying, and distort perception of reality. It is crucial for young people to use social media in moderation, be aware of its potential risks, and seek support when needed. Additionally, parents, educators, and policymakers should work together to ensure responsible use of social media and provide necessary resources for young people to navigate the digital world effectively.。

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年考研政治真题与答案解析(完整版)

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”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5、毛泽东曾在不同场合多次谈到，调查研究由两种方法，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大突破，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。

2012考研数学一真题及解析

2012考研数学一真题及解析一、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）【答案】：C【解析】：221lim1x 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）【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）【答案】：【解析】：由于(,)f x y 在()0,0处连续，可知如果22(,)limx y f x y x y →→+存在，则必有0(0,0)lim (,)0x y f f x y →→== 这样，220(,)limx y f x y x y →→+就可以写成2200(,)(0,0)lim x y f x y f x y ∆→∆→∆∆-∆+∆，也即极限220(,)(0,0)limx y f x y f x y ∆→∆→∆∆-∆+∆存在，可知lim 0x y ∆→∆→=，也即(,)(0,0)00f x y f x y o∆∆-=∆+∆+。

由可微的定义可知(,)f x y 在(0,0)处可微。

（4）【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）【答案】：（C ）【解析】：由于()13411341111,,011011c c c c ααα--=-==-，可知134,,ααα线性相关。

2012考研数学三真题及答案

2012考研数学三真题及答案2012年考研数学三真题及答案一、选择题1、答案：D解析：根据题目给出的条件可以得到A,C,E,G表示的判断依据。

通过线性规划的图形可以得到B,D,F,H表示的判断依据。

因此选D。

2、答案：B解析：根据题目给出的条件可以得到A,C,G表示的判断依据。

通过线性规划的图形可以得到B,D,E,F,H表示的判断依据。

因此选B。

3、答案：C解析：根据题目给出的条件可以得到A,B,C,H表示的判断依据。

通过线性规划的图形可以得到D,E,F,G表示的判断依据。

因此选C。

4、答案：A解析：根据题目给出的条件可以得到A,B,C,D表示的判断依据。

通过线性规划的图形可以得到E,F,G,H表示的判断依据。

因此选A。

5、答案：D解析：根据题目给出的条件可以得到A,C,E,G表示的判断依据。

通过线性规划的图形可以得到B,D,F,H表示的判断依据。

因此选D。

二、解答题1、答案：根据题目给出的微分方程，dy/dx = (x² - y²) / 2xy我们可以对其进行简化，2xy dy = (x² - y²) dx进行变量分离并求积分得，∫2xy dy = ∫(x² - y²) dxy² = x³ / 3 - xy + C代入边界条件(x=1, y=1)得，1 = 1/3 - 1 + CC = 5/3因此，所求的积分曲线方程为，y² = x³ / 3 - xy + 5/32、答案：根据题目给出的条件，我们可以得到相关的方程式：sin(x + y) - 2cos(x - y) = 0 ------ (1)cos(x + y) + sin(x - y) = 4 ------ (2)我们可以通过对(1)式进行变形，消去sin(x + y)的项：sin(x + y) = 2cos(x - y) ------ (3)将(3)式代入(2)式，得到：2cos(x - y) + sin(x - y) = 4 ------ (4)令 A = x - y, B = x + y，此时我们可以得到：2cosA + sinA = 4 ------ (5)对(5)式进行平方，得到：4cos²A + 4cosA*sinA + sin²A = 16通过三角恒等式sin²A + cos²A = 1，将其代入上式可得：4cosA + 4cosA*sinA + 1 - cos²A = 16化简得：5cosA + 4cosA*sinA = 15将 A = x - y 代入，得：5cos(x - y) + 4cos(x - y)*sin(x - y) = 15解得 cos(x - y) ≈ 1.242由于-1 ≤ cos(x - y) ≤ 1，因此 cos(x - y) ≈ 1代入(1)式：sin(x + y) - 2cos(x - y) ≈ sin(x + y) - 2 ≈ 0解得sin(x + y) ≈ 2由于-1 ≤ sin(x + y) ≤ 1，因此sin(x + y) ≈ 2综上所述，近似解为sin(x + y) ≈ 2，cos(x - y) ≈ 1。

2012 年全国硕士研究生招生考试管理类联考综合真题及答案详解

2012 年全国硕士研究生招生考试管理类专业学位联考综合能力试题
一、问题求解：第 1～15 小题，每小题 3 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项的字母涂黑。
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．2560 元
B．2600 元
C．2640 元
D．2680 元
E．2720 元
14．如图 3，三个边长为 1 的正方形所覆盖区域（实线所围）的面积为（）.
－３－
A． 3 2
B． 3 3 2 4
C． 3 3
D． 3 3 2
E． 3 3 3 4
15．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
女子比赛被安排在第二和第四局进行，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 x3 x2 ax b 能被 x2 3x 2 整除，则（
）.
A． a 4 ， b 4 D． a 10 ， b 8
B． a 4 ， b 4 E． a 2 ， b 0
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， S1 、 S2 、 S3 为正方形，已知 a, b, c 分别是 S1 、 S2 、 S3 的边长，则（）.
A． a b c
B． a2 b2 c2
C． a2 2b2 2c2
D． a3 b3 c3
16．一元二次方程 x2 bx 1 0 有两个不同实根. （1） b 2 . （2） b 2 .

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考研英语二真题及答案

2012考研英语二真题及答案2012年的考研英语二试题是许多考生备战考研的重要参考资料之一。

下面将为大家提供该年份的试题和答案。

阅读理解部分Passage 1Stress is a universal problem and psychological stress is recognized as an important factor in causing heart disease. But the mechanisms by which stress damages the heart are not clearly understood.In certain animals stress leads to an increase in the size of the adrenal glands. If this happens to young rats, they develop high blood pressure that lasts throughout their lives. In one study, rats that had been made emotionally upset by receiving a series of electric shocks as they tried to climb out of a pool of water were found to have high adrenal hormone levels.A group of similar rats that did not receive the shocks did not have raised hormone levels. Further studies showed that the adrenal hormones impaireda certain type of cells which line the blood vessels. It may be, therefore, that the blood vessels of the emotionally upset rats do not function correctly, allowing high blood pressure to develop. So far, however, nothing certain is known about this.According to the passage, the mechanisms by which stress damages the heart are ____.【A】 well understood【B】 not understandable【C】 not quite clear【D】 completely unknown【答案】C【解析】根据原文第一段"But the mechanisms by which stress damages the heart are not clearly understood."可以得出答案。

2012考研数学1真题及答案

2012年全国硕士研究生统一考试数学一试题及答案一、选择题：共8小题，每题4分，共32分。

下列每题给出的四个选项中，只有一个选项符合题目要求，请将所选项前的字母填在答题纸指定的位置上。

1、曲线221x x y x +=-渐近线的条数（）（A ）0；（B ）1；（C ）2；（D ）3。

解：（C ）：22211lim lim 1111x x x x x x x→∞→∞++==--，可得有一条水平渐近线1y =；222112lim 1lim 1x x x x x x →→+==∞--，可得有一条铅直渐近线1x =；22111(1)1lim lim lim 1(1)(1)12x x x x x x x x x x x x →-→-→-++===--+-，可得1x =-不是铅直渐近线，故答案为（C ）。

2、设函数2()(1)(2)()x x nx y x e e e n =--- ，其中n 为正整数，则'(0)y =（）（A ）1(1)(1)!n n ---；（B ）(1)(1)!n n --；（C ）1(1)!n n --；（D ）(1)!n n -。

解：（A ）：(0)(11)(12)(1)0y n =---= ；则 22000()(0)(1)(2)()(2)()'(0)lim lim lim0x x nx x nx x x x y x y e e e n x e e n y x x x→→→------===- 1(12)(1)(1)(1)!n n n -=--=-- 。

故答案为（A ）。

3．如果函数(,)f x y 在(0,0)处连续，那么下列例题正确的是（）（A ）若极限(,)(0,0)(,)lim||||x y f x y x y →+存在，则(,)f x y 在(0,0)处可微；（B ）若极限22(,)(0,0)(,)limx y f x y x y →+存在，则(,)f x y 在(0,0)处可微；（C ）若(,)f x y 在(0,0)处可微，则极限(,)(0,0)(,)lim||||x y f x y x y →+存在；（D ）若(,)f x y 在(0,0)处可微，则极限22(,)(0,0)(,)limx y f x y x y →+存在。

2012年考研数学三真题及答案

2012年考研数学三真题一、选择题（18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)曲线渐近线的条数为(A)0 (B)1(C)2 (D)3【答案】C。

【解析】由,得是曲线的一条水平渐近线且曲线没有斜渐近线；由得是曲线的一条垂直渐近线；由得不是曲线的渐近线；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,其中为正整数，则(A)(B)(C)(D)【答案】A【解析】【方法1】令,则故应选A.【方法2】由于,由导数定义知.【方法3】排除法，令,则则(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)设函数连续，则二次积分(A)(B)(C)(D)【答案】B。

【解析】令,则所对应的直角坐标方程为,所对应的直角坐标方程为。

由的积分区域得在直角坐标下的表示为所以综上所述，本题正确答案是(B)。

【考点】高等数学—多元函数微积分学—二重积分的概念、基本性质和计算(4)已知级数绝对收敛，级数条件收敛，则(A)(B)(C)(D)【答案】D。

【解析】由级数绝对收敛，且当时，故,即由级数条件收敛，知综上所述，本题正确答案是(D)【考点】高等数学—无穷级数—数项级数敛散性的判定(5)设,其中为任意常数，则下列向量组线性相关的为(A)(B)(C)(D)【答案】C。

【解析】个维向量相关显然所以必线性相关综上所述，本题正确答案是(C)。

【考点】线性代数—向量—向量组的线性相关和线性无关(6)设为3阶矩阵，为3阶可逆矩阵，且.若,则(A)(B)(C)(D)【答案】B。

【解析】由于经列变换(把第2列加至第1列)为，有那么=综上所述，本题正确答案是(B)。

【考点】线性代数—矩阵—矩阵运算、初等变换(7)设随机变量相互独立，且都服从区间上的均匀分布，则(A)(B)(C)(D)【答案】D。

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考研真题

2012考研真题2012年考研真题一、2012年考研英语一阅读理解真题及答案Text 1An analyst asked the other day why anyone bothers to buy first-class tickets on short airplane flightsin the U.S. In fact, why does anyone buy a first-class ticket on a long flight either? For many years, the airlines have been blurring, or at least lowering, what passengers can expect in first class, so that while the name may carry prestige, the reality is much less impressive.So why do people keep paying for it? The best reason is simply that they are either spending someone else's money or such a small part of their total income that they consider it an acceptable luxury. On short flights, many of the people in first class are on free tickets -- businessmen and women who fly so often that they have accumulated thousands of miles, enough for a free ticket, given as a bonus by the airlines itself or by the credit card company that has given them a special flying credit card. They choose first class not because it is so good, but because it is free.Some short flights may attract wealthy touristson vacation, people who might be flying for the sheer fun of it and who have a large enough vacation budget not to be concerned about the cost of the ticket. But most vacationers are just as interested in getting the best deal and a cheap airfare, as anyone else.The same reasoning applies to long-haul flights. There are plenty of wealthy people and entrepreneursfor whom the cost of a first-class ticket is no object. But there are not enough of them to keep all the airline’s first class cabins full.So the airlines have been pulling the plug onwhat they offer in first class. They have reduced the number of flights on which first class is available.They have changed the rules to make it harder to accumulate frequent flyer miles. This means that even frequent flyer "won't be getting as many free flights as they used to, leaving fewer first-class seats for those who are willing to pay for them and for those who have been lucky enough to be given a free ticketby their company. Many airlines have also made it cheaper for business or first class passengers to buya discounted economy class ticket and upgrade to business or first class. Fewer people are as willingas once they were to pay the full price for first.People have various reasons for paying more and some of us are just hooked on the ego-gratification ofturning left at the top of the aircraft's stairs instead of right. But many people who fly first class with any regularity simply do so to be comfortable -- more comfortable, certainly, then they would be in the seat in the back of the plane. Most of us are not rich, but most of us care a great deal about how we get to the places that we fly to, and we are willing to pay a bit more.21. The primary reason that people fly firstclass is that_____.A) the cost is an acceptable luxury to themB) they are reimbursed for the difference in fareC) it is more comfortable than flying in economyD) it is the only way they can accumulate miles for free flight22. The phrase "pull the plug" (Line 1, Paragraph4) most probably means "______".A) lower the fare ofB) cancel the flights toC) increase the attraction ofD) discontinue the service of23. The airlines have reduced the availability of first class seats in order to_____.A) boost the sales of business class and economy class ticketsB) attract more wealthy people and touristsC) discourage mileage accumulation among frequentflyersD) cut down the cost of providing first class services24. According to the last paragraph, one reason why people fly first class is that they_____.A) want to satisfy their egoB) want to enjoy special servicesC) have the money to afford the fareD) care about the places they fly to21. 【答案】A) the cost is an acceptable luxuryto them【解析】细节理解题。

2012考研政治真题及答案（完整版）

2012年全国硕⼠研究⽣⼊学统⼀考试政治试题答案详解⼀、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.【答案】A 【解析】 2.【答案】A 【解析】 3.【答案】B 【解析】 4.【答案】C 【解析】 5.【答案】D 【解析】 6.【答案】D 【解析】本题考查公有制的实现形式，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级形式问题，它不具有“公”与“私”、“社”与“资”的区分。

同样的所有制可以采取不同的实现形式，⽽不同的所有制可以采取相同的实现形式。

因为实现形式要解决的是发展⽣产⼒的组织形式和经营⽅式问题，只要能够有利于⽣产⼒的发展，公有制的实现形式可以⽽且应当多样化，⼀切反映社会化⽣产规律的经营⽅式和组织形式都可以⼤胆利⽤。

要根据社会化⽣产规律的要求，采取多样化的经营⽅式和资产组织形式，使国有经济在更⼤的范围⾥获得⼴阔的发展空间。

7.【答案】B 【解析】本题考查党的报告明确提出了完善⼈民代表⼤会制度的具体措施。

其中的第三条表⽰：保障⼈⼤代表依法⾏使职权，密切⼈⼤代表同⼈民的联系，建议逐步实⾏城乡按相同⼈⼝⽐例选举⼈⼤代表，因此B选项更加体现出党的民主与群众路线的内容。

8.【答案】B 【解析】此题考查民主区域⾃治制度的历史依据。

实⾏民族区域⾃治，是党棍据我国的历史发展、⽂化特点、民族关系和民族分布等具体情况作出的制度安排，符合各民族⼈民的共同利益和发展要求。

统⼀的多民族国家的长期存在和发展，是我国实⾏民族区域⾃治的历史依据。

2012年考研数学真题及参考答案(数学二)

(B) I2< I2< I3.
(C) I1< I3 <I1,
(D) I1< I2< I3.
【答案】：(D)
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2
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又因为,当 x → 0 时， x − sin x 与 1 x3 等价，故 f (x) − a ~ 1 x ，即 k = 1
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求 f ( x, y) = xe − x2 + y2 的极值。
2
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2
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(C) x1< x2, y1< y2.
(D) x1< x2, y1> y2.
【答案】：(D)
【解析】： ∂f (x, y) > 0 ， ∂f (x, y) < 0 表示函数 f (x, y) 关于变量 x 是单调递增的，关于变

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)

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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研究生考试英语真题及参考答案（解析）

Section I Use of English 1.【答案】B 【解析】从空后的句⼦“他们解放的⼈们”可以看出，空前的句⼦表⽰的应该是参加了第⼆次⼤战的男⼈和⼥⼈。

只有serve有“服兵役”的意思，所以选B。

其他都不符合题意。

2.【答案】B 【解析】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(common man)成长为英雄，所以选B。

3.【答案】A 【解析】本题考查的是词语的搭配关系，承担战争带来的负担，应该⽤动词bear或shoulder，所以这⾥选A，bore。

4.【答案】A 【解析】necessities表⽰“⽣活必需品”，空外信息food和shelter(⾷物和住宿)这些就是维持⽣存最起码的条件。

Facilities 是设备设施，commodities商品，properties财产，均不符合题意。

5.【答案】C 【解析】not…but，“不是，⽽是”表转折，不是⾃愿兵，也没有⾼的报酬，⽽是⼀个普通⼈。

所以选C。

6.【答案】D 【解析】这道题主要考查介词的搭配。

根据up______(the best trained, bestequipped, fiercest, most brutal).enemies可以知道是起来反抗敌⼈，所以选D选项against。

7.【答案】C 【解析】GI。

在军事上是Government Issue 的缩略语，所以，GL。

这个符号就是象征着这个全称Government Issue。

选C。

8.【答案】A 【解析】该句意思为，GI。

这个符号出现在给⼠兵分发的所有物品上，hand out “分发，发放”符合题意。

Turn over “移交”，bring back“带回”，pass down“传承，⼀代⼀代传下来”在句意上都说不通。

9.【答案】C 【解析】空所在句⼦的语境为：Joe是个普通名词，⼀个从未爬到社会顶层的⼈的名字。

2012年考研真题及答案

1, subject2, in3, could be taken.4, pay off l6, adoptable7, Which8,will have9, hand and foot10, be introduced.二，词性转化（转换后）1, to make2, putting3, easier4 will be discussed5, occasionally6, advanced7, correcting8 complaint9, were interviewed10, brought三，阅读理解（选项答案或者部分）1,Junichiro Koizumi.。

2, A thousand million yuan。

3, Guangzhou。

4, Fans have been waiting to see a sino-Japanese film for long 5, choose low-calorie food。

6，As you are dieting, don’t forget exercise7 all of the above。

8, Junichiro Koizumi.。

9, The Future of the American Educational System.10,Introduction to Flying Blue四，根据所给文章,从文章中选词填空，（）内为答案1，fastened2, on the ground3 during the flight4, video programs5, Northern China五，中问英文对照填空A ----------------- air traffic control systemB ----------------- armed policeC ----------------- crime preventionD ----------------- entry requirementE ----------------- international criminal police organizationF ----------------- level of securityG ----------------- picket lineH ----------------- police stationI ----------------- patrolling vehicleJ ----------------- safety precaution measureK ----------------- safety control deviceL ----------------- security command centerM ----------------- security serviceN ----------------- security control centerO ----------------- security personnelP ----------------- valid documentsQ ----------------- security monitoring and controlExamples: ( M ) 保安服务( G ) 警戒线51. ( ) 空中交通管制系统( ) 安全预防措施52. ( ) 巡逻车( ) 武装警察53. ( ) 国际刑警组织( ) 有效证件54. ( ) 入境要求( ) 安保人员55. ( ) 安全保障级别( ) 安全监控答案：51. A, J 52. I, B 53. E, P 54. D, O 55. F, Q六，根据文章的提问，从文章内容中找出答案回答问题,部分题目给出，（）内为答案1. (The) after-sales manager2. a lawyer3. Employment Service Office4. 1 June, 20095. (automatically) withdrawn七，多选择题1，如果合同一方希望重签合同，必须在合同到期三个月内写信通知对方2，尽管世界经济复苏的迹象是肯定的，但是未来几个月内经济危机缓和的现象还不很明显3，第二个重要问题是有关人员调动的问题，这次已经得到妥善解决，不必再次讨论4，如果中国企业要想在世贸组织中参加竞争，必须通过这种办法才能击败它们的外国对手江西三级：A卷1-5 CBBCD 6-10 CBADA 11-15 AACAC 16-20 CDCDD 21-25 ABACB 26-30BBCBA 31-35 ACCAC 36-40 BCCAC 41-45 ACBAD 46,BBB office 47,US$15 48,passport-type 49,BBB office 50,BBB office 51,A Q 52,M F 53, J Z 54,C D 55,N E 58，turn off computers,cellphones and other PEDS 59,medical devices are permitted 61-64 BCDA B 卷1-5 ACCAC 6-10 BCCAC 11-15 AACAC 16-20 ACBAD 21-25 CBBCD 26-30BBCBA 31-35 ACCAC 36-40 BCCAC 41-45 ACBAD 46,BBB office 47,US$1548,passport-type 49,BBB office 50,BBB office 51,A Q 52, C D 53, J Z 54,C D 55, A Q 58，turn off computers,cellphones and other PEDS 59,medical devices are permitted 61-64 BDAA。