2015年二级试题答案解析版

2015年二级建造师考试真题及答案解析《建筑实务》一、单项选择题(共20 题,每题 1 分。

每题的备选项中, 只有 1 个最符合题意)1.某仓库设在建筑物的二层，仓库里面放满水泥，二层楼板承受的是（）。

A．线荷载B．分散荷载C．面荷载D．集中荷载2.临界力的计算公式为P = ，图 A 中杆件的临界力为P，图 B 为在图 A 的杆件中部增加一链杆，临界力为PB，则PA 与PB 的关系如何？（）A．PB=PAB．PB =2PAC．PB= 4PAD．PB=8 PA3.钢筋混凝土梁的跨度L 小于4m 时，架立钢筋的直径应不小于( )mm。

A．6B．8C．10D．124. 砌体结构房屋中，钢筋混凝土梁端下的墙上，有时设置垫块，其目的是（）。

A．解决墙的承载能力B．解决墙体局部压应力过大C．解决高厚比过大D．加强房屋的整体性5. 结构设计中钢材强度的取值依据是（）。

A．比例极限B．弹性极限C．屈服强度D．抗拉强度6.下列材料中，不属于常见的建筑砂浆胶凝材料的是（）。

A．石灰B．水泥C．粉煤灰D．石膏7.浅基坑土方开挖中，基坑边缘堆置土方和建筑材料，最大堆置高度不应超过( )m。

A．1.2B．1.5C．1.8D．2.08.根据相关规范，门窗工程中不需要进行性能复验的项目是（）。

A．人造木板门复验氨的含量B．外墙塑料窗复验抗风压性能C．外墙金属窗复验雨水渗漏性能D．外墙金属窗复验复验空气渗透性能9.某工程地基验槽采用观察法，验槽时应重点观察的是( )。

A．柱基、墙角、承重墙下B．槽壁、槽底的土质情况C．基槽开挖深度D．槽底土质结构是否被人为破坏10.当地质条件和场地条件许可时，开挖深度不大的基坑最可取的开挖方案是( )。

A．放坡挖土B．中心岛式(墩工)挖C．盘式挖土D．逆作法挖土11.水准测量中，设A 点为后视点，B 点为前视点。

A 点的高程是45.382m，后视读数为1.202m，前视读数为1.302m，则B 点的高程是（）m。

2015年全国硕士研究生入学统一考试数学二试题及答案解析一、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)下列反常积分中收敛的是(A) (B)(C) (D)【答案】D。

【解析】题干中给出4个反常积分，分别判断敛散性即可得到正确答案。

；；；，因此(D)是收敛的。

综上所述，本题正确答案是D。

【考点】高等数学—一元函数积分学—反常积分(2)函数在(-∞,+∞)内(A) (B)有可去间断点(C)有跳跃间断点 (D)有无穷间断点【答案】B【解析】这是“”型极限，直接有,在处无定义，且所以是的可去间断点，选B。

综上所述，本题正确答案是B。

【考点】高等数学—函数、极限、连续—两个重要极限(3)设函数().若(A) (B)(C) (D)【答案】A【解析】易求出再有于是，存在此时.当，，=因此，在连续。

选A综上所述，本题正确答案是C。

【考点】高等数学—函数、极限、连续—函数连续的概念，函数的左极限和右极限(4)设函数在(-∞,+∞)内连续，其二阶导函数的图形如右图所示，则曲线的拐点个数为 A O B(A) (B)(C) (D)【答案】C【解析】在(-∞,+∞)内连续，除点外处处二阶可导。

的可疑拐点是的点及不存在的点。

的零点有两个，如上图所示，A点两侧恒正，对应的点不是拐点，B点两侧，对应的点就是的拐点。

虽然不存在，但点两侧异号，因而() 是的拐点。

综上所述，本题正确答案是C。

【考点】高等数学—函数、极限、连续—函数单调性，曲线的凹凸性和拐点(5)设函数满足则与依次是(A)(B)(C)(D)【答案】D【解析】先求出令于是因此综上所述，本题正确答案是D。

【考点】高等数学-多元函数微分学-多元函数的偏导数和全微分(6)设D是第一象限中由曲线与直线围成的平面区域，函数在D上连续，则(A)(B)(C)(D)【答案】B【解析】D是第一象限中由曲线与直线围成的平面区域，作极坐标变换，将化为累次积分。

2015年普通高等学校招生全国统一考试(课标全国卷Ⅱ)一、选择题1.A 因为B={x|(x-1)(x+2)<0}={x|-2<x<1},A={-2,-1,0,1,2},故A∩B={-1,0}.选A.2.B ∵(2+ai)(a -2i)=-4i ⇒4a+(a 2-4)i=-4i, ∴{4a =0,a 2-4=-4,解得a=0. 3.D 由柱形图可知:A 、B 、C 均正确,2006年以来我国二氧化硫年排放量在逐渐减少,所以排放量与年份负相关,∴D 不正确.4.B 设{a n }的公比为q,由a 1=3,a 1+a 3+a 5=21得1+q 2+q 4=7,解得q 2=2(负值舍去).∴a 3+a 5+a 7=a 1q 2+a 3q 2+a 5q 2=(a 1+a 3+a 5)q 2=21×2=42. 5.C ∵-2<1,∴f(-2)=1+log 2[2-(-2)]=3;∵log 212>1, ∴f(log 212)=2log 212-1=2log 26=6.∴f(-2)+f(log 212)=9.6.D 如图,由已知条件可知,截去部分是以△ABC 为底面且三条侧棱两两垂直的正三棱锥D-ABC.设正方体的棱长为a,则截去部分的体积为16a 3,剩余部分的体积为a 3-16a 3=56a 3.它们的体积之比为15.故选D.评析 本题主要考查几何体的三视图和体积的计算,考查空间想象能力. 7.C 设圆心为P(a,b),由点A(1,3),C(1,-7)在圆上,知b=3-72=-2.再由|PA|=|PB|,得a=1.则P(1,-2),|PA|=√(1-1)2+(3+2)2=5,于是圆P 的方程为(x-1)2+(y+2)2=25.令x=0,得y=-2±2√6,则|MN|=|(-2+2√6)-(-2-2√6)|=4√6. 8.B 开始:a=14,b=18, 第一次循环:a=14,b=4; 第二次循环:a=10,b=4; 第三次循环:a=6,b=4; 第四次循环:a=2,b=4;第五次循环:a=2,b=2. 此时,a=b,退出循环,输出a=2.评析 熟悉“更相减损术”对理解框图所确定的算法有帮助. 9.C ∵S △OAB 是定值,且V O-ABC =V C-OAB ,∴当OC⊥平面OAB 时,V C-OAB 最大,即V O-ABC 最大.设球O 的半径为R,则(V O-ABC )max =13×12R 2×R=16R 3=36,∴R=6,∴球O 的表面积S=4πR 2=4π×62=144π.评析 点C 是动点,如果以△ABC 为底面,则底面面积与高都是变量,因此转化成以△OAB 为底面(S △OAB 为定值),这样高越大,体积越大.10.B 当点P 与C 、D 重合时,易求得PA+PB=1+√5;当点P 为DC 的中点时,有OP⊥AB,则x=π2,易求得PA+PB=2PA=2√2.显然1+√5>2√2,故当x=π2时, f(x)没有取到最大值,则C 、D 选项错误.当x∈[0,π4)时, f(x)=tan x+√4+tan 2x ,不是一次函数,排除A,故选B.11.D 设双曲线E 的标准方程为x 2a2-y 2b 2=1(a>0,b>0),则A(-a,0),B(a,0),不妨设点M 在第一象限内,则易得M(2a,√3a),又M 点在双曲线E 上,于是(2a )2a 2-(√3a )2b 2=1,解得b 2=a 2,∴e=√1+b 2a 2=√2. 12.A 令g(x)=f (x )x,则g'(x)=xf '(x )-f (x )x 2,由题意知,当x>0时,g'(x)<0,∴g(x)在(0,+∞)上是减函数.∵f(x)是奇函数, f(-1)=0,∴f(1)=-f(-1)=0, ∴g(1)=f (1)1=0,∴当x∈(0,1)时,g(x)>0,从而f(x)>0; 当x∈(1,+∞)时,g(x)<0,从而f(x)<0. 又∵g(-x)=f (-x )-x=-f (x )-x=f (x )x=g(x),∴g(x)是偶函数,∴当x∈(-∞,-1)时,g(x)<0,从而f(x)>0; 当x∈(-1,0)时,g(x)>0,从而f(x)<0. 综上,所求x 的取值范围是(-∞,-1)∪(0,1).评析 出现xf '(x)+f(x)>0(<0)时,考虑构造函数F(x)=xf(x),出现xf '(x)-f(x)>0(<0)时,考虑构造函数g(x)=f (x )x.二、填空题 13.答案 12解析 由于a,b 不平行,所以可以以a,b 作为一组基底,于是λa+b 与a+2b 平行等价于λ1=12,即λ=12. 14.答案 32解析 作出可行域,如图:由z=x+y 得y=-x+z,当直线y=-x+z 过点A (1,12)时,z 取得最大值,z max =1+12=32. 15.答案 3解析 设f(x)=(a+x)(1+x)4,则其所有项的系数和为f(1)=(a+1)·(1+1)4=(a+1)×16,又奇数次幂项的系数和为12[f(1)-f(-1)],∴12×(a+1)×16=32,∴a=3. 评析 二项展开式问题中,涉及系数和的问题,通常采用赋值法. 16.答案 -1n解析 ∵a n+1=S n+1-S n ,∴S n+1-S n =S n+1S n ,又由a 1=-1,知S n ≠0,∴1S n-1Sn+1=1,∴{1S n}是等差数列,且公差为-1,而1S 1=1a 1=-1,∴1S n=-1+(n-1)×(-1)=-n,∴S n =-1n .三、解答题17.解析 (Ⅰ)S △ABD =12AB·ADsin∠BAD, S △ADC =12AC·ADsin∠CAD.因为S △ABD =2S △ADC ,∠BAD=∠CAD,所以AB=2AC. 由正弦定理可得sin∠B sin∠C =AC AB =12.(Ⅱ)因为S △ABD ∶S △ADC =BD∶DC,所以BD=√2. 在△ABD 和△ADC 中,由余弦定理知AB 2=AD 2+BD 2-2AD·BDcos∠ADB, AC 2=AD 2+DC 2-2AD·DCcos∠ADC. 故AB 2+2AC 2=3AD 2+BD 2+2DC 2=6. 由(Ⅰ)知AB=2AC,所以AC=1.评析 本题考查正弦定理,余弦定理的应用,以及三角形的面积公式.属常规题,中等偏易. 18.解析 (Ⅰ)两地区用户满意度评分的茎叶图如下:A 地区B 地区4 6 8 35 1 36 4 6 4 2 6 2 4 5 5 6 8 8 6 437 3 3 4 6 9 9 2 8 6 518 3 2 1 7 5 5 2 9 1 3通过茎叶图可以看出,A 地区用户满意度评分的平均值高于B 地区用户满意度评分的平均值;A 地区用户满意度评分比较集中,B 地区用户满意度评分比较分散. (Ⅱ)记C A1表示事件:“A 地区用户的满意度等级为满意或非常满意”; C A2表示事件:“A 地区用户的满意度等级为非常满意”; C B1表示事件:“B 地区用户的满意度等级为不满意”; C B2表示事件:“B 地区用户的满意度等级为满意”,则C A1与C B1独立,C A2与C B2独立,C B1与C B2互斥,C=C B1C A1∪C B2C A2. P(C)=P(C B1C A1∪C B2C A2) =P(C B1C A1)+P(C B2C A2) =P(C B1)P(C A1)+P(C B2)P(C A2).由所给数据得C A1,C A2,C B1,C B2发生的频率分别为1620,420,1020,820,故P(C A1)=1620,P(C A2)=420,P(C B1)=1020,P(C B2)=820, P(C)=1020×1620+820×420=0.48.19.解析 (Ⅰ)交线围成的正方形EHGF 如图:(Ⅱ)作EM⊥AB,垂足为M,则AM=A 1E=4,EM=AA 1=8. 因为EHGF 为正方形,所以EH=EF=BC=10. 于是MH=√EH 2-EM 2=6,所以AH=10.以D 为坐标原点,DA ⃗⃗⃗⃗⃗ 的方向为x 轴正方向,建立如图所示的空间直角坐标系D-xyz,则A(10,0,0),H(10,10,0),E(10,4,8),F(0,4,8),FE ⃗⃗⃗⃗⃗ =(10,0,0),HE ⃗⃗⃗⃗⃗⃗ =(0,-6,8). 设n=(x,y,z)是平面EHGF 的法向量, 则{n ·FE ⃗⃗⃗⃗ =0,n ·HE ⃗⃗⃗⃗⃗ =0,即{10x =0,-6y +8z =0,所以可取n=(0,4,3).又AF ⃗⃗⃗⃗⃗ =(-10,4,8),故|cos<n,AF ⃗⃗⃗⃗⃗ >|=|n ·AF ⃗⃗⃗⃗⃗||n ||AF ⃗⃗⃗⃗⃗ |=4√515. 所以AF 与平面EHGF 所成角的正弦值为4√515. 评析 本题背景常规,设问新颖,鼓励动手试验、创新尝试、独立思考.对空间想象力有较高要求.20.解析 (Ⅰ)设直线l:y=kx+b(k≠0,b≠0),A(x 1,y 1),B(x 2,y 2),M(x M ,y M ). 将y=kx+b 代入9x 2+y 2=m 2得(k 2+9)x 2+2kbx+b 2-m 2=0,故 x M =x 1+x 22=-kb k 2+9,y M =kx M +b=9bk 2+9.于是直线OM 的斜率k OM =yM x M=-9k ,即k OM ·k=-9. 所以直线OM 的斜率与l 的斜率的乘积为定值. (Ⅱ)四边形OAPB 能为平行四边形.因为直线l 过点(m3,m),所以l 不过原点且与C 有两个交点的充要条件是k>0,k≠3. 由(Ⅰ)得OM 的方程为y=-9k x. 设点P 的横坐标为x P .由{y =-9k x ,9x 2+y 2=m 2得x P 2=k 2m29k 2+81,即x P =3√k 2+9.将点(m 3,m)的坐标代入l 的方程得b=m (3-k )3,因此x M =k (k -3)m3(k 2+9).四边形OAPB 为平行四边形当且仅当线段AB 与线段OP 互相平分,即x P =2x M . 于是3√k 2+9=2×k (k -3)m 3(k 2+9),解得k 1=4-√7,k 2=4+√7.因为k i >0,k i ≠3,i=1,2,所以当l 的斜率为4-√7或4+√7时,四边形OAPB 为平行四边形. 评析 本题考查直线与圆锥曲线的位置关系,设问常规,但对运算能力要求较高,考查学生的思维能力.21.解析 (Ⅰ)f '(x)=m(e mx-1)+2x.若m≥0,则当x∈(-∞,0)时,e mx -1≤0, f '(x)<0; 当x∈(0,+∞)时,e mx-1≥0, f '(x)>0. 若m<0,则当x∈(-∞,0)时,e mx-1>0, f '(x)<0; 当x∈(0,+∞)时,e mx-1<0, f '(x)>0.所以, f(x)在(-∞,0)单调递减,在(0,+∞)单调递增.(Ⅱ)由(Ⅰ)知,对任意的m, f(x)在[-1,0]单调递减,在[0,1]单调递增,故f(x)在x=0处取得最小值.所以对于任意x 1,x 2∈[-1,1],|f(x 1)-f(x 2)|≤e -1的充要条件是{f (1)-f (0)≤e -1,f (-1)-f (0)≤e -1, 即{e m -m ≤e -1,e -m +m ≤e -1.① 设函数g(t)=e t-t-e+1,则g'(t)=e t-1.当t<0时,g'(t)<0;当t>0时,g'(t)>0.故g(t)在(-∞,0)单调递减,在(0,+∞)单调递增. 又g(1)=0,g(-1)=e -1+2-e<0,故当t∈[-1,1]时,g(t)≤0. 当m∈[-1,1]时,g(m)≤0,g(-m)≤0,即①式成立; 当m>1时,由g(t)的单调性,g(m)>0,即e m-m>e-1; 当m<-1时,g(-m)>0,即e -m+m>e-1. 综上,m 的取值范围是[-1,1].22.解析 (Ⅰ)由于△ABC 是等腰三角形,AD⊥BC,所以AD 是∠CAB 的平分线. 又因为☉O 分别与AB,AC 相切于点E,F,所以AE=AF, 故AD⊥EF. 从而EF∥BC.(Ⅱ)由(Ⅰ)知,AE=AF,AD⊥EF,故AD 是EF 的垂直平分线.又EF 为☉O 的弦,所以O 在AD 上.连结OE,OM,则OE⊥AE.由AG 等于☉O 的半径得AO=2OE,所以∠OAE=30°. 因此△ABC 和△AEF 都是等边三角形. 因为AE=2√3,所以AO=4,OE=2. 因为OM=OE=2,DM=12MN=√3,所以OD=1. 于是AD=5,AB=10√33. 所以四边形EBCF的面积为12×(10√33)2×√32-12×(2√3)2×√32=16√33. 23.解析 (Ⅰ)曲线C 2的直角坐标方程为x 2+y 2-2y=0,曲线C 3的直角坐标方程为x 2+y 2-2√3x=0.联立{x 2+y 2-2y =0,x 2+y 2-2√3x =0,解得{x =0,y =0,或{x =√32,y =32.所以C 2与C 3交点的直角坐标为(0,0)和(√32,32).(Ⅱ)曲线C 1的极坐标方程为θ=α(ρ∈R,ρ≠0),其中0≤α<π. 因此A 的极坐标为(2sin α,α),B 的极坐标为(2√3cos α,α). 所以|AB|=|2sin α-2√3cos α|=4|sin (α-π3)|.当α=5π6时,|AB|取得最大值,最大值为4.24.解析 (Ⅰ)因为(√a +√b )2=a+b+2√ab ,(√c +√d )2=c+d+2√cd , 由题设a+b=c+d,ab>cd 得(√a +√b )2>(√c +√d )2. 因此√a +√b >√c +√d .(Ⅱ)(i)若|a-b|<|c-d|,则(a-b)2<(c-d)2, 即(a+b)2-4ab<(c+d)2-4cd. 因为a+b=c+d,所以ab>cd. 由(Ⅰ)得√a +√b >√c +√d .(ii)若√a +√b >√c +√d ,则(√a +√b )2>(√c +√d )2,即a+b+2√ab>c+d+2√cd.因为a+b=c+d,所以ab>cd.于是(a-b)2=(a+b)2-4ab<(c+d)2-4cd=(c-d)2.因此|a-b|<|c-d|.综上,√a+√b>√c+√d是|a-b|<|c-d|的充要条件.。

2015年全国硕士研究生招生考试英语(二)答案详解SectionⅠUse of English文章分析本文主要就当前社会存在的一个现象进行分析——为什么现在的人不与周围的陌生人交流，而只专注于手机。

第一段提出现象。

第二段指出与陌生人交流其实大有裨益，只是我们不知道。

第三段提出全文要探讨的问题。

第四段给出原因之一——害怕。

第五段承接第四段继续分析，指出我们把手机视为保护毯，避免与陌生人交谈的尴尬。

第六段用一个实验证明其实与陌生人交谈并不是那么尴尬。

第七段对实验结果进行解释，因为人类的的发展源于社会联系。

试题解析In our contemporary culture,the prospect of communicating with—or even looking at—a stranger is virtually unbearable.Everyone around us seems to agree by the way they fiddle with their phones,even without a__1__on a subway.【译文】在当代文化中，与陌生人交流，甚至看一眼陌生人，都几乎难以忍受。

我们周围的每一个人似乎都同意这点，他们玩弄着手机，即使地铁上一点儿信号都没有。

1.[A]ticket车票[B]permit许可证[C]signal信号[D]record记录【答案】C【考点】词义辨析【直击答案】空格所在句意为：陌生人之间没有交流，大家都只关注自己的手机，即使地铁里没有________。

选项中，只有C项符合上下文语义，与phones和subway有关，因此signal正确。

【命题思路】本题四个选项语义不相关，所以只需要根据上下文确定所需填入的语义即可。

【干扰排除】其余三个选项带入原文都与句意不符，故排除。

It's a sad reality—our desire to avoid interacting with other human beings—because there's__2__to be gained from talking to the stranger standing by you.But you wouldn't know it,__3__into your phone.This universal protection sends the___4___:_“Please don't approach me.”【译文】这是个可悲的现实——我们希望避免与其他人交流——因为和身边的陌生人交流会带来诸多益处。

2015年高考新课标全国卷II语文试题(一)文言文阅读(19分)阅读下面的文言文，完成4-7题。

来护儿，字崇善，未识而孤，养于世母关氏。

吴氏提携鞠养，甚有慈训。

幼儿卓荦，初读《诗》日，舍书叹曰："大丈夫在世，或为国灭贼以取功名!”群辈惊其言而壮其志。

及长，雄略秀出，志气英远。

会周师定淮南所住白土村地居疆埸数见军旅护兒常慨然有立功名之志及开皇初宇文忻等镇广陵平陈之役护兒有功焉进位上开府,赏物一千段。

仁寿初,迁瀛州刺史,以善政闻,频见劳勉。

炀帝嗣位,被追入朝,百姓攀恋,累日不能出境,诣阙上书致请者,前后数百人。

帝谓曰:“昔国步未康,卿为名将,今天下无事,又为良二千石,可谓兼美矣。

”大业六年,车驾幸江都,谓护兒曰:“衣锦昼游,古人所重,卿今是也。

”乃赐物二千段,并牛酒,令谒先人墓,宴乡里父老。

仍令三品已上并集其宅,酣饮尽日,朝野荣之。

十二年,驾幸江都,护兒谏曰:“陛下兴军旅,百姓易咨怨,车驾游幸,深恐非宜。

伏愿驻驾洛阳,与时休息。

陛下今幸江都,是臣衣锦之地,臣荷恩深重,不敢专为身谋。

”帝闻之,厉色而起,数日不得见。

后怒解,方被引入,谓曰:“公意乃尔,朕复何望!”护兒因不敢言。

及宇文化及构逆,深忌之。

是日旦将朝,见执。

护兒曰:“陛下今何在?”左右曰:“今被执矣。

”护兒叹曰:“吾备位大臣,荷国重任,不能肃清凶逆,遂令王室至此,抱恨泉壤,知复何言!”乃遇害。

护儿重然诺，敦交契，廉于财利，不事产业。

至于行军用兵，特多谋算，每览兵法，曰："此亦岂异人意也! ”善抚士卒，部分严明，故咸得其死力。

(节选自《北史·来护儿传》)4.下列对文中画波浪线部分的断句,正确的一项是(3分)A.会周师定淮南所/住白土村/地居疆埸/数见军旅护儿/常慨然有立功名之志/ 及开皇初/宇文忻等镇广陵/平陈之役/护儿有功焉/B. 会周师定淮南所/住白土村/地居疆埸/数见军旅/护儿常慨然有立功名之志/ 及开皇初/宇文忻等镇广陵/平陈之役护儿有功焉/C. 会周师定淮南/所住白土村/地居疆埸/数见军旅护儿/常慨然有立功名之志/及开皇初/宇文忻等镇广陵/平陈之役/护儿有功焉/D.会周师定淮南/所住白土村/地居疆埸/数见军旅/护儿常慨然有立功名之志及开皇初/宇文忻等镇广陵/平陈之役/护儿有功焉/【答案】D【解析】此题考查文言断句能力。

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. (10 points)In our contemporary culture, the prospect of communicating with -- or even looking at -- a stranger is virtually unbearable. Everyone around us seems to agree by the way they fiddle with their phones, even without a 1 underground.It's a sad reality -- our desire to avoid interacting with other human beings -- because there's 2 to be gained from talking to the stranger standing by you. But you wouldn't know it, 3 into your phone. This universal armor sends the 4 : "Please don't approach me."What is it that makes us feel we need to hide 5 our screens?One answer is fear, according to Jon Wortmann, executive mental coach. We fear rejection, or that our innocent social advances will be 6 as "creepy,". We fear we'll be 7 . We fear we'll be disruptive. Strangers are inherently 8 to us, so we are more likely to feel 9 when communicating with them compared with our friends and acquaintances. To avoid this anxiety, we 10 to our phones. "Phones become our security blanket," Wortmann says. "They are our happy glasses that protect us from what we perceive is going to be more 11 .”But once we rip off the bandaid, tuck our smartphones in our pockets and look up, it doesn't 12 so bad. In one 2011 experiment, behavioral scientists Nicholas Epley and Juliana Schroeder asked commuters to do the unthinkable: Start a 13 . They had Chicago train commuters talk to their fellow 14 . "When Dr. Epley and Ms. Schroeder asked other people in the same train station to 15 how they would feel after talking to a stranger, the commuters thought their 16 would be more pleasant if they sat on their own," the New York Times summarizes. Though the participants didn't expect a positive experience, after they 17 with the experiment, "not a single person reported having been snubbed."18 , these commutes were reportedly more enjoyable compared with those sans communication, which makes absolute sense, 19 human beings thrive off of social connections. It's that 20 : Talking to strangers can make you feel connected.1. [A] ticket [B] permit [C] signal [D] record2. [A] nothing [B] link [C] another [D] much3. [A] beaten [B] guided [C] plugged [D] brought4. [A] message [B] cede [C] notice [D] sign5. [A] under [B] beyond [C] behind [D] from6. [A] misinterpret [B] misapplied [C] misadjusted [D] mismatched7. [A] fired [B] judged [C] replaced [D] delayed8. [A] unreasonable [B] ungrateful [C] unconventional [D] unfamiliar9. [A] comfortable [B] anxious [C] confident [D] angry10. [A] attend [B] point [C] take [D] turn11. [A] dangerous [B] mysterious [C] violent [D] boring12. [A] hurt [B] resist [C] bend [D] decay13. [A] lecture [B] conversation [C] debate [D] negotiation14. [A] trainees [B] employees [C] researchers [D] passengers15. [A] reveal [B] choose [C] predict [D] design16. [A] voyage [B] flight [C] walk [D] ride17. [A] went through [B] did away [C] caught up [D] put up18. [A] In turn [B] In particular [C] In fact [D] In consequence19. [A] unless [B] since [C] if [D] whereas20. [A] funny [B] simple [C] logical [D] rareSection 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. (40 points)Text 1A new study suggests that contrary to most surveys, people are actually more stressed at home than at work. Researchers measured people’s cortisol, which is a stress marker, while they were at work and while they were at home and found it higher at what is supposed to be a place of refuge.“Further contradicting conventional wisdom, we found that w omen as well as men have lower levels of stress at work than at home, ” writes one of the researchers, Sarah Damske. In fact women even say they feel better at work, she notes.“ It is men, not women, who report being happier at home than at work. ”Another surprise is that findings hold true for both those with children and without, but more so for nonparents. This is why people who work outside the home have better health.What the study doesn’t measure is whether people are still doing work whenthey’re at home, whether it is household work or work brought home from the office. For many men, the end of the workday is a time to kick back. For women who stay home, they never get to leave the office. And for women who work outside the home, they often are playing catch-up-with-household tasks. With the blurring of roles, and the fact that the home front lags well behind the workplace a making adjustments for working women, it’s not surprising that women are more stressed at home.But it’s not just a gender thin g. At work, people pretty much know what they’re supposed to be doing: working, marking money, doing the tasks they have to do in order to draw an income. The bargain is very pure: Employee puts in hours of physical or mental labor and employee draws out life-sustaining moola.On the home front, however, people have no such clarity. Rare is the household in which the division of labor is so clinically and methodically laid out. There are a lot of tasks to be done, there are inadequate rewards for most of them. Your home colleagues-your family-have no clear rewards for their labor; they need to be talked into it, or if they’re teenagers, threatened with complete removal of all electronic devices. Plus, they’re your family. You cannot fire your family. You never really get to go home from home.So it’s not surprising that people are more stressed at home. Not only are the tasks apparently infinite, the co-workers are much harder to motivate.21.According to Paragraph 1,most previous surveys found that home_____[A] offered greater relaxation than the workplace[B] was an ideal place for stress measurement[C] generated more stress than the workplace[D] was an unrealistic place for relaxation22. According to Damaske, who are likely to be the happiest at home?[A] Childless wives[B] Working mothers[C] Childless husbands[D] Working fathers23.The blurring of working women's roles refers to the fact that_____[A] it is difficult for them to leave their office[B] their home is also a place for kicking back[C] there is often much housework left behind[D] they are both bread winners and housewives24.The word“moola”(Line4,Para4)most probably means_____[A] skills[B] energy[C] earnings[D] nutrition25.The home front differs from the workplace in that_____[A] division of labor at home is seldom clear-cut[B] home is hardly a cozier working environment[C] household tasks are generally more motivating[D] family labor is often adequately rewardedText 2For years, studies have found that first-generation college students- those who do not have a parent with a college degree- lag other students on a range of education achievement factors. Their grades are lower and their dropout rates are higher. But since such students are most likely to advance economically if they succeed in higher education, colleges and universities have pushed for decades to recruit more of them. This has created “a paradox” in that recruiting first- generation students, but then watching many of them fail, means that higher education has “continued to reproduce and widen, rather than close” ab achievement gap based on social class, according to the depressing beginning of a paper forthcoming in the journal Psychological Science.But the article is actually quite optimistic, as it outlines a potential solution to this problem, suggesting that an approach (which involves a one-hour, next-to-no-cost program) can close 63 percent of the achievement gap (measured by such factors as grades) between first-generation and other students.The authors of the paper are from different universities, and their findings are based on a study involving 147 students ( who completed the project) at an unnamed private university. First generation was defined as not having a parent with a four-year college degree. Most of the first-generation students(59.1 percent) were recipients of Pell Grants, a federal grant for undergraduates with financial need, while this was true only for 8.6 percent of the students wit at least one parent with a four-year degree.Their thesis- that a relatively modest intervention could have a big impact- was based on the view that first-generation students may be most lacking not in potential but in practical knowledge about how to deal with the issues that face most college students. They cite past research by several authors to show that this is the gap that must be narrowed to close the achievement gap.Many first- generation students “struggle to navigate the middle-class culture of higher education, learn the ‘rules of the game,’ and tak e advantage of college resources,” they write. And this becomes more of a problem when collages don’t talkabout the class advantage and disadvantages of different groups of students. Because US colleges and universities seldom acknowledge how social class can affect students ’educational experience, many first-generation students lack sight about why they are struggling and do not understand how students’ like them can improve.26. Recruiting more first- generation students has_______[A] reduced their dropout rates[B] narrowed the achievement gap[C] missed its original purpose[D] depressed college students27. The author of the research article are optimistic because_______[A] the problem is solvable[B] their approach is costless[C] the recruiting rate has increased[D] their finding appeal to students28. The study suggests that most first- generation students______[A] study at private universities[B] are from single-parent families[C] are in need of financial support[D] have failed their collage29. The author of the paper believe that first-generation students_______[A] are actually indifferent to the achievement gap[B] can have a potential influence on other students[C] may lack opportunities to apply for research projects[D] are inexperienced in handling their issues at college30. We may infer from the last paragraph that_______[A] universities often reject the culture of the middle-class[B] students are usually to blame for their lack of resources[C] social class greatly helps enrich educational experiences[D]colleges are partly responsible for the problem in questionText 3Even in traditional offices, “the lingua franca of corporate America has gotten much more emotional and much more right-brained than it was 20 years ago,” said Harvard Business School professor Nancy Koehn. She started spinning off examples. “If you and I parachuted back to Fortune 500 companies in 1990, we would see much less frequent use of terms like journey, mission, passion. There were goals, there were strate gies, there were objectives, but we didn’t talk about energy; we didn’t talk about passion.”Koehn pointed out that this new era of corporate vocabulary is very “team”-oriented—and not by coincidence. “Let’s not forget sports—in male-dominated corporate America, it’s still a big deal. It’s not explicitly conscious; it’s the idea that I’m a coach, and you’re my team, and we’re in this together. There are lots and lots of CEOs in very different companies, but most think of themselves as coaches and this is their team and they want to win.”These terms are also intended to infuse work with meaning—and, as Khurana points out, increase allegiance to the firm. “You have the importation of terminology that historically used to be associated with non-profit organizations and religious organizations: Terms like vision, values, passion, and purpose,” said Khurana.This new focus on personal fulfillment can help keep employees motivated amid increasingly loud debates over work-life balance. The “mommy wars” of the 1990s are still going on today, prompting arguments about why women still can’t have it all and books like Sheryl Sandberg’s Lean In, whose title has become a buzzword in its own right. Terms like unplug, offline, life-hack, bandwidth, and capacity are all about setting boundaries between the office and the home. But if your work is your “passion,” you’ll be more likely to devote yourself to it, even if that means going home for dinner and then working long after the kids are in bed.But this seems to be the irony of office speak: Everyone makes fun of it, but managers love it, companies depend on it, and regular people willingly absorb it. As Nunberg said, “You can get people to think it’s nonsense at the same time that you buy into it.” In a workplace that’s fundamentally indifferent to your life and its meaning, office speak can help you figure out how you relate to your work—and how your work defines who you are.31. According to Nancy Koehn, office language has become_____[A] more emotional[B] more objective[C] less energetic[D] less strategic32. “T eam”-oriented corporate vocabulary is closely related to_______[A] historical incidents[B] gender difference[C] sports culture[D] athletic executives33.Khurana believes that the importation of terminology aims to______[A] revive historical terms[B] promote company image[C] foster corporate cooperation[D] strengthen employee loyalty34.It can be inferred that Lean In________[A] voices for working women[B] appeals to passionate workaholics[C] triggers debates among mommies[D] praises motivated employees35.Which of the following statements is true about office speak?[A] Managers admire it but avoid it[B] Linguists believe it to be nonsense[C] Companies find it to be fundamental[D] Regular people mock it but accept itText 4Many people talked of the 288,000 new jobs the Labor Department reported for June, along with the drop in the unemployment rate to 6.1 percent, as good news. And they were right. For now it appears the economy is creating jobs at a decent pace. We still have a long way to go to get back to full employment, but at least we are now finally moving forward at a faster pace.However, there is another important part of the jobs picture that was largely overlooked. There was a big jump in the number of people who repot voluntarily working part-time. This figure is now 830,000(4.4 percent)above its year ago level.Before explaining the connection to the Obamacare, it is worth making an important distinction. Many people who work part-time jobs actually want full-time jobs. They take part-time work because this is all they can get. An increase in involuntary part-time work is evidence of weakness in the labor market and it means that many people will be having a very hard time making ends meet.There was an increase in involuntary part-time in June, but the general direction has been down. Involuntary part-time employment is still far higher than before the recession, but it is down by 640,000(7.9percent)from is year ago level.We know the difference between voluntary and involuntary part-time employment because people tell us. The survey used by the Labor Department asks people is they worked less than 35 hours in the reference week. If the answer is “yes”,they are classified as worked less than 35hours in that week because they wanted to work less than full time or because they had no choice .They are only classified as voluntary part-time workers if they tell the survey taker they chose to work less than 35 hours a week.The issue of voluntary part-time relates to Obamacare because one of the main purposes was to allow people to get insurance outside of employment. For many people , especially those with serious health conditions or family members with serious health conditions ,before Obamacare the only way to get insurance was through a job that provided health insurance.However, Obamacare has allowed more than 12 million people to either get insurance through Medicaid or the exchanges. These are people who may previously have felt the need to get a full-time job that provided insurance in order to cover themselves and their families. With Obamacare there is no longer a link between employment and insurance.36. Which part of the jobs picture are neglected?[A] The prospect of a thriving job market.[B] The increase of voluntary part-time market.[C] The possibility of full employment.[D] The acceleration of job creation.37. Many people work part-time because they_____.[A] prefer part-time jobs to full-time jobs.[B] feel that is enough to make ends meet.[C] cannot get their hands on full-time jobs.[D] haven’t seen the weakness of the market.38. Involuntary part-time employment is the US_____.[A] is harder to acquire than one year ago.[B] shows a general tendency of decline.[C] satisfies the real need of the jobless.[D] is lower than before the recession.39. It can be learned that with Obamacare,_____.[A] it is no longer easy for part-timers to get insurance[B] employment is no longer a precondition to get insurance[C] it is still challenging to get insurance for family members[D] full-time employment is still essential for insurance40. The text mainly discusses_______.[A] employment in the US[B] part-timer classification[C] insurance though Medicaid[D] Obamacare’s troublePart 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 blank. There are two extra choices, which do not fit in any of the gaps. Mark your answers on ANSWER SHEET. (10 points)[A] You are not alone[B] Don’t fear responsibility for your life[C] Pave your own unique path[D] Most of your fears are unreal[E] Think about the present moment[F] Experience helps you grow[G] There are many things to be grateful forUnfortunately, life is not a bed of roses. We are going through life facing sad experiences. Moreover, we are grieving various kinds of loss: a friendship, a romantic relationship or a house. Hard times may hold you down at what usually seems like the most inopportune time, but you should remember that they won’t last forever.When our time of mourning is over, we press forward, stronger with a greater understanding and respect for life. Furthermore, these losses make us mature and eventually move us toward future opportunities for growth and happiness. I want to share these ten old truths I’ve learned along the way.41._____________________________Fear is both useful and harmful. This normal human reaction is used to protect us by signaling danger and preparing us to deal with it. Unfortunately, people create inner barriers with a help of exaggerating fears. My favorite actor Will Smith once said, “Fear is no t real. It is a product of thoughts you create. Do not misunderstand me. Danger is very real. But fear is a choice.” I do completely agree that fears are just the product of our luxuriant imagination.42_____________________________If you are surrounded by problems and cannot stop thinking about the past, try to focus on the present moment. Many of us are weighed down by the past or anxious about the future. You may feel guilt over your past, but you are poisoning the present with the things and circumstances you cannot change. Value the present moment and remember how fortunate you are to be alive. Enjoy the beauty of the world around and keep the eyes open to see the possibilities before you. Happiness is not a point of future and not a moment from the past, but a mindset that can be designed into the present.43______________________________Sometimes it is easy to feel bad because you are going through tough times. You can be easily caught up by life problems that you forget to pause and appreciate the things you have. Only strong people prefer to smile and value their life instead of crying and complaining about something.44________________________________No matter how isolated you might feel and how serious the situation is, you should always remember that you are not alone. Try to keep in mind that almost everyone respects and wants to help you if you are trying to make a good change in your life, especially your dearest and nearest people. You may have a circle of friends who provide constant good humor, help and companionship. If you have no friends or relatives, try to participate in several online communities, full of people who are always willing to share advice and encouragement.45________________________________Today many people find it difficult to trust their own opinion and seek balance by gaining objectivity from external sources. This way you devalue your opinion and show that you are incapable of managing your own life. When you are struggling to achieve something important you should believe in yourself and be sure that your decision is the best. You live in your skin,think your own thoughts, have your own values and make your own choices.Section III TranslationDirections:Translate the following text from English into Chinese. Write your translation on ANSWER SHEET 2. (15 points)Think about driving a route that’s very familiar. It could be your commute to work, a trip into town or the way home. Whichever it is, you know every twist and turn like the back of your hand. On these sor ts of trips it’s easy to zone out from the actual driving and pay little attention to the passing scenery. The consequence is that you perceive that the trip has taken less time than it actually has.This is the well-travelled road effect: people tend to underestimate the time it takes to travel a familiar route.The effect is caused by the way we allocate our attention. When we travel down a well-known route, because we don’t have to concentrate much, time seems to flow more quickly. And afterwards, when w e come to think back on it, we can’t remember the journey well because we didn’t pay much attention to it. So we assume it was shorter.Section IV WritingPart A47. Directions:Suppose your university is going to host a summer camp for high school students. Write a notice to1) briefly introduce the camp activities, and2) call for volunteers.You should write about 100 words on the ANSWER SHEET.Do not use your name or the name of your university.Do not write your address. (10 points)Part B48. Directions:Write an essay based on the following chart. In your writing, you should1) interpret the chart, and2) give your comments.You should write about 150 words on the ANSWER SHEET. (15 points)。

1 / 20202015年全国硕士研究生入学统一考试英语二试题及答案解析Section I Use of EnglishDirections ：Read the following text. Choose the best word(s) for each numbered blank and mark A, B, C orD on the ANSWER SHEET. (10 points)In our contemporary culture, the prospect of communicating with — or even looking at — a stranger is virtually unbearable. Everyone around us seems to agree by the way they cling to their phones, even without a 1 on a subway. It’s It’s a a a sad sad sad reality reality reality ——our our desire desire desire to to to avoid avoid avoid interacting interacting interacting with with with other other other human human human beings beings beings ——because there’s there’s 2 2 to be gained from talking to the stranger standing by you. But you wouldn’t know it, 3 into your phone. This universal protection sends the 4 : “Please don’t approach me.”What is it that makes us feel we need to hide 5 our screens? One answer is fear, according to Jon Wortmann, executive mental coach. We fear rejection, or that our innocent social advances will be 6 as “weird weird”. We fear we’ll be ”. We fear we’ll be  7 . We fear we’ll be disruptive. disruptive. Strangers Strangers Strangers are are are inherently inherently 8 to to us, us, us, so so so we we we are are are more more more likely likely likely to to to feel feel 9 when communicating communicating with with with them them them compared compared compared with with with our our our friends friends friends and and and acquaintances. acquaintances. acquaintances. To To To avoid avoid avoid this this this anxiety, anxiety, we 10 to our phones. “Phones become our security blanket,” Wortmann says. “They are our happy glasses that protect us from what we perceive is going to be more 11 .”But But once once once we we we rip rip rip off off off the the the bandaid, bandaid, bandaid, tuck tuck tuck our our our smartphones smartphones smartphones in in in our our our pockets pockets pockets and and and look look look up, up, up, it it doesn’t doesn’t 12 so bad. In one 2011 experiment, behavioral scientists Nicholas Epley and Juliana 12 so bad. In one 2011 experiment, behavioral scientists Nicholas Epley and Juliana Schroeder Schroeder asked asked asked commuters commuters commuters to to to do do do the the the unthinkable: unthinkable: unthinkable: Start Start Start a a 13 . They They had had had Chicago Chicago Chicago train train commuters talk to their fellow 14 . “When Dr. Epley and Ms. Schroeder asked other people in the the same same same train train train station station station to to 15 how how they they they would would would feel feel feel after after after talking talking talking to to to a a a stranger, stranger, stranger, the the the commuters commuters thought thought their their 16 would would be be be more more more pleasant pleasant pleasant if if if they they they sat sat sat on on on their their their own,” own,” own,” the the the New New New Y ork Y ork Times Times summarizes. Though the participants didn’t expect a positive experience, after they 17 with the experiment, “not a single person reported havi ng been embarrassed .”.”18 , these these commutes commutes commutes were were were reportedly reportedly reportedly more more more enjoyable enjoyable enjoyable compared compared compared with with with those those those without without communication, which makes absolute sense, 19 human beings thrive off of social connections. 20 : Talking to strangers can make you feel connected. It’s that 20 : Talking to strangers can make you feel connected. 1. [A] ticket [B] permit [C] signal [D] record 2. [A] nothing [B] link [C] another [D] much 3. [A] beaten [B] guided [C] plugged [D] brought 4. [A] message [B] cede [C] notice [D] sign 5. [A] under [B] beyond [C] behind [D] from 6. [A] misinterpreted [B] misapplied [C] misadjusted [D] mismatched 7. [A] fired [B] judged [C] replaced [D] delayed 8. [A] unreasonable [B] ungrateful [C] unconventional [D] unfamiliar 9. [A] comfortable [B] anxious [C] confident [D] angry 10. [A] attend [B] point [C] take [D] turn 11. [A] dangerous [B] mysterious [C] violent [D] boring 12. [A] hurt [B] resist [C] bend [D] decay 13. [A] lecture [B]conversation [C] debate [D] negotiation 14. [A] trainees [B] employees [C] researchers [D] passengers 15. [A] reveal [B] choose [C] predict [D] design 16. [A] voyage [B] flight [C] walk [D] ride 17. [A] went through [B] did away [C] caught up [D] put up 18. [A] In turn [B]In particular [C] In fact [D] In consequence 19. [A] unless [B] since [C] if [D] whereas 20. [A] funny [B] simple [C] logical [D] rare Section 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.(40 points)Text 1 A new study suggests that contrary to most surveys, people are actually more stressed at home than at work. Researchers measured people’s cortisol, which is a stress marker, while they were at work and while they were at home and found it higher at what is supposed to be a place of refuge. “Further contradicting conventional wisdom, we found that women as well as men have lower levels of stress at work than at home,” writes one of the researchers, Sarah Damske. In fact women t work, she notes. “It is men, not women, who report being happier at even say they feel better ahold true for both those with true for both those with children and that findings hold home than at work.” Another surprise is without, but more so for nonparents. This is why people who work outside the home have better health. What the study doesn’t measure is whether people are still doing work when they’re at home, whether it is household work or work brought home from the office. For many men, the end of the workday is a time to kick back. For women who stay home, they never get to leave the office. And for women who work outside the home, they often are playing catch-up-with-household tasks. With the the blurring blurring blurring of of of roles, roles, roles, and and and the the the fact fact fact that that that the the the home home home front front front lags lags lags well well well behind behind behind the the the workplace workplace workplace in in in making making adjustments for worki ng women, it’s not surprising that women are more stressed at home.But it’s not just a gender thing. At work, people pretty much know what they’re supposed to be doing: working, marking money, doing the tasks they have to do in order to draw an income. The bargain is very pure: Employee puts in hours of physical or mental labor and employee draws out life-sustaining moola.  On the home front, however, people have no such clarity. Rare is the household in which the division of labor is so clinically and methodically laid out. There are a lot of tasks to be done, there are inadequate rewards for most of them. Your home colleagues — your family — have no clear rewards rewards for for for their their their labor; labor; labor; they they they need need need to to to be be be talked talked talked into into into it, it, it, or or or if if if they’re they’re they’re teenagers, teenagers, teenagers, threatened threatened threatened with with co complete removal of all electronic devices. Plus, they’re your family. You cannot fire your family. mplete removal of all electronic devices. Plus, they’re your family. You cannot fire your family. You never really get to go home from home. So it’s not surprising that people are more stressed at home. Not only are the tasks apparently infinite, the co-workers are much harder to motivate. 21. According to Paragraph 1, most previous surveys found that home ______. [A] was an unrealistic place for relaxation [B] generated more stress than the workplace [C] was an ideal place for stress measurement [D] offered greater relaxation than the workplace 22. According to Damaske, who are likely to be the happiest at home? [A] Working mothers [B] Childless husbands [C] Childless wives [D] Working fathers 23. The blurring of working women’s roles refers to the fact that ______. [A] they are both bread winners and housewives [B] their home is also a place for kicking back [C] there is often much housework left behind [D] it is difficult for them to leave their office 24. The word moola (Paragraph 4) most probably means ______. [A] energy [B] skills [C] earnings [D] nutrition 25. The home front differs from the workplace in that ______. [A] home is hardly a cozier working environment [B] division of labor at home is seldom clear-cut [C] household tasks are generally more motivating [D] family labor is often adequately rewarded Text 2For years, studies have found that first-generation college students — those who do not have a parent parent with with with a a a college college college degree degree degree —— lag lag other other other students students students on on on a a a range range range of of of education education education achievement achievement achievement factors. factors. Their grades are lower and their dropout rates are higher. But since such students are most likely to advance economically if they succeed in higher education, colleges and universities have pushed for decades decades to to to recruit recruit recruit more more more of of of them. them. them. This This This has has has creat creat created ed ed “a “a “a paradox” paradox” paradox” in in in that that that recruiting recruiting recruiting first first first-generation -generation students, students, but but but then then then watching watching watching many many many of of of them them them fail, fail, fail, means means means that that that higher higher higher education education education has has has “continued “continued “continued to to reproduce and widen, rather than close” an achievement gap based on social class, according to the depressing beginning of a paper forthcoming in the journal Psychological Science . But But the article is the article is a ctually actually actually quite optimistic, as quite optimistic, as i t it it outlines a potential solution outlines a potential solution to to this problem, this problem, suggesting suggesting that that that an an an approach approach approach (which (which (which involves involves involves a a a one-hour, one-hour, one-hour, next-to-no-cost next-to-no-cost next-to-no-cost program) program) program) can can can close close close 63 63 percent of the achievement gap (measured by such factors as grades) between first-generation and other students. The authors of the paper are from different universities, and their findings are based on a study involving involving 147 147 147 students students students (who (who (who completed completed completed the the the project) project) project) at at at an an an unnamed unnamed unnamed private private private university. university. First generation was defined as not having a parent with a four-year college degree. Most of the first-generation students (59.1 percent) were recipients of Pell Grants, a federal grant for undergraduates with financial need, while this was true only for 8.6 percent of the students with at least one parent with a four-year degree. Their thesis — that a relatively modest intervention could have a big impact — was based on the the view view view that that that first-generation first-generation first-generation students students students may may may be be be most most most lacking lacking lacking not not not in in in potential potential potential but but but in in in practical practical knowledge about how to deal with the issues that face most college students. They cite past research by several authors to show that this is the gap that must be narrowed to close the achievement gap. Many first-first-generation generation students “struggle to navigate the middle middle-class -class culture of higher education, learn the ‘rules of the game,’ and take advantage of college resources,” they write. And this becomes more of a problem when collages don’t talk about the clas class s advantage and disadvantages disadvantages of of of different different different groups groups groups of of of students. students. students. Because Because Because US US US colleges colleges colleges and and and universities universities universities seldom seldom acknowledge acknowledge how how how social social social class class class can can can affect affect affect students’ students’ students’ educational educational educational experience, experience, experience, many many many first first first-generation -generation students lack sight about why they are struggling and do not understand how students like them can improve. 26. Recruiting more first-generation students has ______. [A] reduced their dropout rates [B] narrowed the achievement gap [C] missed its original purpose [D] depressed college students 27. The author of the research article are optimistic because ______. [A] the problem is solvable [B] their approach is costless [C] the recruiting rate has increased [D] their findings appeal to students 28. The study suggests that most first-generation students ______. [A] study at private universities [B] are from single-parent families [C] are in need of financial support [D] have failed their college 29. The author of the paper believe that first-generation students ______. [A] are actually indifferent to the achievement gap [B] can have a potential influence on other students [C] may lack opportunities to apply for research projects [D] are inexperienced in handling their issues at college 30. We may infer from the last paragraph that ______. [A] universities often reject the culture of the middle-class [B] students are usually to blame for their lack of resources [C] social class greatly helps enrich educational experiences [D] colleges are partly responsible for the problem in question Text 3 Even in in traditional traditional traditional offices, offices, offices, “the “the “the lingua lingua lingua franca franca franca of of of corporate corporate corporate America America America has has has gotten gotten gotten much much much more more emotional and much more right-brained than it was 20 years ago,” said Harvard Business School professor professor Nancy Nancy Nancy Koehn. Koehn. Koehn. She She She started started started spinning spinning spinning off off off examples. examples. examples. “If “If “If you you you and and and I I I parachu parachu parachuted ted ted back back back to to Fortune 500 companies in 1990, we would see much less frequent use of terms like journey, mission, passion. passion. There There There were were were goals, goals, goals, there there there were were were strategies, strategies, strategies, there there there were were were objectives, objectives, objectives, but but but we we we didn’t didn’t didn’t talk talk talk about about energy; we didn’t talk about passion.” Koehn p o inted out that this new era of corporate vocabulary is very “team”ointed out that this new era of corporate vocabulary is very “team”-oriented -oriented —— and not by coincidence. “Let’s not forget sports — in male-dominated corporate America, it’s still a big deal. It’s not explicitly conscious; it’s the idea that I’m a coach, and you’re my team, and we’re in this this together. together. together. There There There are are are lots lots lots and and and lots lots lots of of of CEOs CEOs CEOs in in in very very very different different different companies, companies, companies, but but but most most most think think think of of themselves as coaches and this is their team and they want to win.” These terms terms are are are also also also intended intended intended to to to infuse infuse infuse work work work with with with meaning meaning meaning —— and, and, as as as Khurana Khurana Khurana points points points out, out, increase allegiance to the firm. “You have the importation of terminology that historically used to be associated with non-profit organizations and religious organizations: Terms like vision, values, passion, and purpose,” said Khu rana.  This new focus on personal fulfillment can help keep employees motivated amid increasingly loud loud debates debates debates over over over work-work-work-life life life balance. balance. balance. The The The “mommy “mommy “mommy wars” wars” wars” of of of the the the 1990s 1990s 1990s are are are still still still going going going on on on today, today, prompting prompting arguments arguments arguments about about about why why why women women women still still still can’t can’t can’t have have have it it it all all all and and and books books books like like like Sheryl Sheryl Sheryl Sandberg’s Sandberg’s Lean In, whose title has become a buzzword in its own right. Terms like unplug, offline, life-hack, bandwidth, and capacity are all about setting boundaries between the office and the home. But if your work is your “passion,” you’ll be more likely to devote yourself to it, even if that means going home for dinner and then working long after the kids are in bed.  But this seems to be the irony of office speak: Everyone makes fun of it, but managers love it, companies companies depend depend depend on on on it, it, it, and and and regular regular regular people people people willingly willingly willingly absorb absorb absorb it. it. it. As As As Nunberg Nunberg Nunberg said, said, said, “Y ou “Y ou can can can get get people people to to to think think think it’s it’s it’s nonsense nonsense nonsense at at at the the the same same same time time time that that that you you you buy buy buy into into into it.” it.” it.” In In In a a a workplace workplace workplace that’s that’s fundamentally indifferent to your life and its meaning, office speak can help you figure out how you relate to your work — and how your work defines who you are. 31. According to Nancy Koehn, office language has become ______. [A] more emotional [B] more objective [C] less energetic [D] less strategic 32. “Team”-oriented corporate vocabulary is closely related to ______. [A] historical incidents [B] gender difference [C] sports culture [D] athletic executive 33. Khurana believes that the importation of terminology aims to ______. [A] revive historical terms [B] promote company image [C] foster corporate cooperation [D] strengthen employee loyalty 34. It can be inferred that Lean In ______. [A] voices for working women [B] appeals to passionate workaholics [C] triggers debates among mommies [D] praises motivated employees 35. Which of the following statements is true about office speak? [A] Managers admire it but avoid it [B] Linguists believe it to be nonsense [C] Companies find it to be fundamental [D] Regular people mock it but accept it Text 4 Many people talked of the 288,000 new jobs the Labor Department reported for June, along with the drop in the unemployment rate to 6.1 percent, as good news. And they were right. For now it appears the economy is creating jobs at a decent pace. We still have a long way to go to get back to full employment, but at least we are now finally moving forward at a faster pace.  However, there is another important part of the jobs picture that was largely overlooked. There was a big jump in the number of people who repot voluntarily working part-time. This figure is now 830,000 (4.4 percent) above its year ago level.  Before Before explaining explaining the connection to the Obamacare, it is worth making an important distinction. Many people who work part-time jobs actually want full-time jobs. They take part-time work work because because because this this this is is is all all all they they they can can can get. get. get. An An An increase increase increase in in in involuntary involuntary involuntary part-time part-time part-time work work work is is is evidence evidence evidence of of weakness in the labor market and it means that many people will be having a very hard time making ends meet.  There was was an an an increase increase increase in in in involuntary involuntary involuntary part-time part-time part-time in in in June, June, June, but but but the the the general general general direction direction direction has has has been been down. Involuntary part-time employment is still far higher than before the recession, but it is down by 640,000 (7.9 percent) from is year ago level.  We know know the the the difference difference difference between between between voluntary voluntary voluntary and and and involuntary involuntary involuntary part-time part-time part-time employment employment employment because because people tell us. The survey used by the Labor Department asks people if they worked less than 35 hours in the reference week. If the answer is “yes”, they are classified as worked less than 35 hours in that week because they wanted to work less than full time or because they had no choice. They are only classified as voluntary part-time workers if they tell the survey taker they chose to work less than 35 hours a week.  The issue of voluntary part-time relates to Obamacare because one of the main purposes was to allow allow people people people to to to get get get insurance insurance insurance outside outside outside of of of employment. employment. employment. For For For many many many people, people, people, especially especially especially those those those with with serious health conditions or family members with serious health conditions, before Obamacare the only way to get insurance was through a job that provided health insurance.  However, Obamacare has allowed more than 12 million people to either get insurance through Medicaid or the exchanges. These are people who may previously have felt the need to get a full-time job that provided insurance in order to cover themselves and their families. With Obamacare there is no longer a link between employment and insurance. 36. Which part of the jobs picture are neglected? [A] The prospect of a thriving job market. [B] The increase of voluntary part-time market. [C] The possibility of full employment. [D] The acceleration of job creation. 37. Many people work part-time because they ______. [A] prefer part-time jobs to full-time jobs. [B] feel that is enough to make ends meet. [C] cannot get their hands on full-time jobs. [D] haven’t seen the weakness of the market. 38. Involuntary part-time employment in the US ______. [A] is harder to acquire than one year ago. [B] shows a general tendency of decline. [C] satisfies the real need of the jobless. [D] is lower than before the recession. 39. It can be learned that with Obamacare, ______. [A] it is no longer easy for part-timers to get insurance [B] employment is no longer a precondition to get insurance [C] it is still challenging to get insurance for family members [D] full-time employment is still essential for insurance 40. The text mainly discusses ______. [A] employment in the US [B] part-timer classification [C] insurance through Medicaid [D] Obamacare’s troubl e Part BDirections:Read the following text and answer the questions by choosing the most suitable subheading from the list A-G for each numbered paragraph (41-45).There are two extra subheadings which you do not need to use. Mark your answers on the ANS WER SHEET. (10 (10 points)[A] You are not alone [B] Don’t fear responsibility for your life[C] Pave your own unique path [D] Most of your fears are unreal [E] Think about the present moment [F] Experience helps you grow [G] There are many things to be grateful for Unfortunately, Unfortunately, life life life is is is not not not a a a bed bed bed of of of roses. roses. roses. We We We are are are going going going through through through life life life facing facing facing sad sad sad experiences. experiences. Moreover, we are grieving various kinds of loss: a friendship, a romantic relationship or a house. Hard Hard times times times may may may hold hold hold you you you down down down at at at what what what usually usually usually seems seems seems like like like the the the most most most inopportune inopportune inopportune time, time, time, but but but you you should remember that they won’t last forever.When our time of mourning is over, we press forward, stronger with a greater understanding and and respect respect respect for for for life. life. life. Furthermore, Furthermore, Furthermore, these these these losses losses losses make make make us us us mature mature mature and and and eventually eventually eventually move move move us us us toward toward future opportunities for growth and happiness. I want to share these ten old truths I’ve learned along the way. 41. ___________________ Fear is both useful and harmful. This normal human reaction is used to protect us by signaling danger and preparing us to deal with it. Unfortunately, people create inner barriers with a help of exaggerating exaggerating fears. fears. fears. My My My favorite favorite favorite actor actor actor Will Will Will Smith Smith Smith once once once said, said, said, “Fear “Fear “Fear is is is not not not real. real. real. It It It is is is a a a product product product of of thoughts thoughts you you you create. create. create. Do Do Do not not not misunderstand misunderstand misunderstand me. me. me. Danger Danger Danger is is is very very very real. real. real. But But But fear fear fear is is is a a a choice.” choice.” choice.” I I I do do completely agree that fears are just the product of our luxuriant imagination. 42. ___________________ If you are surrounded by problems and cannot stop thinking about the past, try to focus on the present moment. Many of us are weighed down by the past or anxious about the future. You may feel guilt over your past, but you are poisoning the present with the things and circumstances you cannot change. Value the present moment and remember how fortunate you are to be alive. Enjoy the beauty of the world around and keep the eyes open to see the possibilities before you. Happiness is not a point of future and not a moment from the past, but a mindset that can be designed into the present. 43. ___________________ Sometimes it is easy to feel bad because you are going through tough times. You can be easily caught up by life problems that you forget to pause and appreciate the things you have. Only strong people prefer to smile and value their life instead of crying and complaining about something. 44. ___________________ No No matter matter matter how how how isolated isolated isolated you you you might might might feel feel feel and and and how how how serious serious serious the the the situation situation situation is, is, is, you you you should should should always always remember that you are not alone. Try to keep in mind that almost everyone respects and wants to help you if you are trying to make a good change in your life, especially your dearest and nearest people. Y ou may have a circle of friends who provide constant good humor, help and companionship. If you have no friends or relatives, try to participate in several online communities, full of people who are always willing to share advice and encouragement. 45. ___________________ Today Today many many many people people people find find find it it it difficult difficult difficult to to to trust trust trust their their their own own own opinion opinion opinion and and and seek seek seek balance balance balance by by by gaining gaining objectivity objectivity from from from external external external sources. sources. sources. This This This way way way you you you devalue devalue devalue your your your opinion opinion opinion and and and show show show that that that you you you are are incapable of managing your own life. When you are struggling to achieve something important you should believe in yourself and be sure that your decision is the best. You live in your skin, think your own thoughts, have your own values and make your own choices. 。

2015年高考全国卷2英语试题第I卷第一部分听力（共两节，满分30分）略第二部分阅读理解（共两节，满分40分）AMy color televisi on has give n me nothing but a headache. I was able to buy ita little over a year ago because I had my relatives give me money for my birthdayin stead of clothes that would n 't fit. I let a salesclerk fool me into buying adiscontinued model. I realized this a day later, when I saw newspaper advertisementsfor the set at seventy-five dollars less than I had paid. The set worked so beautiful when I first got it home that I would keep it on until stations signed off for the ________________________night. Fortunately, I didn ' t get any channels showing all -night movies or I wouldn ever have gotte n to bed.Then I started developing a problem with the set that involved static（静电）noise.For some reas on, whe n certa in shows switched in to a commercial, a loud no ise would sound for a few sec on ds. Gradually, this no ise bega n to appear duri ng a show, and to get rid of it, I had to change to another channel and then change it back. Sometimes this tech nique would not work, and I had to pick up the set and shake it to removethe sound. I actually began to build up my arm muscles（肌肉）shaking my set.Whenneither of these methods removed the static noise, I would sit helplessly and wait for the noise to go away. At last I ended up hitting the set with my first,and it stopped working altogether. My trip to the repair shop cost me $62, and the sit is work ing well now, but I keep expect ing more trouble.21. Why did the author say he was fooled into buying the TV set?A. He got an older model tha n he had expected.B. He couldn ' t return it when it was broken.C. He could have bought it at a lower price.D. He failed to find any movie shows on it.【参考答案】C【考查内容】细节理解题【解析思路】根据第一段第四行" when I saw newspaper advertisements for the set at seventy-five dollars less than I had paid . ”当我看到报纸上75美元比我买的价格低的时候，我感觉我上当了。

2015·全国卷Ⅱ(英语）本试卷分第Ⅰ卷（选择题)和第Ⅱ卷(非选择题)两部分。

第Ⅰ卷第一部分听力(共两节，满分30分)第一节(共5小题:每小题1。

5分，满分7.5分）听下面5段对话。

每段对话后有一个小题，从题中所给的A、B、C三个选项中选出最佳选项,并标在试卷的相应位置.听完每段对话后，你都有10秒钟的时间来回答有关小题和阅读下一小题.每段对话仅读一遍。

例:How much is the shirt?A．￡19。

15. B．￡9。

18。

C．￡9.15.答案是C。

1．[2015·全国卷Ⅱ］What time is it now?A．9：10. B．9：50.C．10：00.2．[2015·全国卷Ⅱ] What does the woman think of the weather?A．It’s nice. B．It's warm.C．It’s cold。

3．［2015·全国卷Ⅱ］What will the man do?A．Attend a meeting. B．Give a lecture.C．Leave his office。

4．[2015·全国卷Ⅱ］What is the woman's opinion about the course？A．Too hard. B．Worth taking.C．Very easy。

5．[2015·全国卷Ⅱ] What does the woman want the man to do？A．Speak louder. B．Apologize to her。

C．Turn off the radio。

第二节(共15小题:每小题1.5分，满分22。

5分）听下面5段对话或独白.每段对话或独白后有几个小题，从题中所给的A、B、C三个选项中选出最佳选项，并标在试卷的相应位置。

听每段对话或独白前，你将有时间阅读各个小题，每小题5秒钟；听完后，各小题将给出5秒钟的作答时间。

2015年高考全国卷2数学试题解析1．已知集合{}|12A x x =-<<,{}|03B x x =<<,则A B =（ ）A ．()1,3-B ．()1,0-C ．()0,2D ．()2,3【答案】A考点：集合运算.2. 若为a 实数,且2i 3i 1ia +=++,则a =( ) A ．4- B ．3- C ．3 D ．4【答案】D【解析】试题分析：由题意可得()()2i 1i 3i 24i 4a a +=++=+⇒= ,故选D.考点：复数运算.3. 根据下面给出的2004年至2013年我国二氧化碳年排放量（单位：万吨）柱形图,以下结论中不正确的是（ ）A ．逐年比较,2008年减少二氧化碳排放量的效果最显著B ．2007年我国治理二氧化碳排放显现成效C ．2006年以来我国二氧化碳年排放量呈减少趋势D ．2006年以来我国二氧化碳年排放量与年份正相关【答案】 D考点：柱形图4. 已知()1,1=-a ,()1,2=-b ,则(2)+⋅=a b a （ ）A ．1-B ．0C ．1D ．2【答案】C【解析】2004年 2005年 2006年 2007年 2008年 2009年 2010年 2011年 2012年 2013年 190020002100220023002400250026002700试题分析：由题意可得22=a ,3,⋅=-a b 所以()222431+⋅=+⋅=-=a b a a a b .故选C. 考点：向量数量积.5. 设n S 是等差数列{}n a 的前n 项和,若1353a a a ++=,则5S =（ ）A ．5B ．7C ．9D ．11【答案】A【解析】试题解析：13533331a a a a a ++==⇒=,()15535552a a S a +===.故选A. 考点：等差数列6. 一个正方体被一个平面截去一部分后,剩余部分的三视图如下图,则截去部分体积与剩余部分体积的比值为（ ）1A.8 1B.7 1C.6 1D.5【答案】D 【解析】试题分析：截去部分是正方体的一个角,其体积是正方体体积的16,所以截去部分体积与剩余部分体积的比值为15,故选D.考点：三视图7. 已知三点(1,0),(0,3),(2,3)A B C,则△ABC外接圆的圆心到原点的距离为（）5 A. 321B.325C.34D.3【答案】B考点：直线与圆的方程.8. 右边程序框图的算法思路来源于我国古代数学名著《九章算术》中的“更相减损术”,执行该程序框图,若输入的,a b分别为14,18,则输出的a为（）A.0B.2C.4D.14【答案】B【解析】试题分析：由题意输出的a 是18,14的最大公约数2,故选B.考点：1. 更相减损术；2.程序框图.9．已知等比数列{}n a 满足114a =,()35441a a a =-,则2a =（ ） A.2 B.1 1C.2 1D.8【答案】C【解析】试题分析：由题意可得()235444412a a a a a ==-⇒=,所以34182a q q a ==⇒= ,故2112a a q == ,选C.考点：等比数列.10. 已知B A ,是球O 的球面上两点,︒=∠90AOB ,C 为该球面上的动点.若三棱锥ABC O -体积的最大值为36,则球O 的表面积为（ ）A.π36B. π64C.π144D. π256【答案】C考点：球与几何体的切接.11. 如图,长方形的边AB =2,BC =1,O 是AB 的中点,点P 沿着边BC ,CD 与DA 运动,记BOP x ∠= ,将动点P 到A ,B 两点距离之和表示为x 的函数()f x ,则的图像大致为（ ）A ．B ．C ．D ．【答案】B考点：函数图像12. 设函数21()ln(1||)1f x x x =+-+,则使得()(21)f x f x >-成立的x 的取值范围是（ ）A ．1,13⎛⎫ ⎪⎝⎭B ．()1,1,3⎛⎫-∞+∞ ⎪⎝⎭C ．11,33⎛⎫- ⎪⎝⎭D ．11,,33⎛⎫⎛⎫-∞-+∞ ⎪ ⎪⎝⎭⎝⎭ 【答案】A【解析】试题分析：由21()ln(1||)1f x x x =+-+可知()f x 是偶函数,且在[)0,+∞是增函数,所以()()()()121212113f x f x f x f x x x x >-⇔>-⇔>-⇔<< .故选A. 考点：函数性质二、填空题：本大题共4小题,每小题5分,共20分13. 已知函数()32f x ax x =-的图像过点（-1,4）,则a = ．【答案】-2【解析】试题分析：由()32f x ax x =-可得()1242f a a -=-+=⇒=- .考点：函数解析式14. 若x ,y 满足约束条件50210210x y x y x y +-≤⎧⎪--≥⎨⎪-+≤⎩,则z =2x +y 的最大值为 ．【答案】8考点：线性规划15. 已知双曲线过点()4,3,且渐近线方程为12y x =±,则该双曲线的标准方程为 ． 【答案】2214x y -=考点：双曲线几何性质16. 已知曲线ln y x x =+在点()1,1 处的切线与曲线()221y ax a x =+++ 相切,则a = ．【答案】8【解析】 试题分析：由11y x'=+可得曲线ln y x x =+在点()1,1处的切线斜率为2,故切线方程为21y x =-,与()221y ax a x =+++ 联立得220ax ax ++=,显然0a ≠,所以由 2808a a a ∆=-=⇒=. 考点：导数的几何意义.三、解答题17（本小题满分12分）△ABC 中D 是BC 上的点,AD 平分∠BAC ,BD =2DC .（I ）求sin sin B C∠∠ ； （II ）若60BAC∠=,求B ∠. 【答案】（I ）12；30.考点：解三角形试题解析：（I ）由正弦定理得,,sin sin sin sin AD BD AD DC B BAD C CAD ==∠∠∠∠ 因为AD 平分∠BAC ,BD =2DC ,所以sin 1.sin 2B DC C BD ∠==∠. （II ）因为()180,60,C BAC B BAC ∠=-∠+∠∠=所以()31sin sin cos sin .22C BAC B B B ∠=∠+∠=∠+∠ 由（I ）知2sin sin B C ∠=∠, 所以3tan 30.B B ∠=∠= 考点：解三角形18. （本小题满分12分）某公司为了了解用户对其产品的满意度,从A ,B 两地区分别随机调查了40个用户,根据用户对其产品的满意度的评分,得到A 地区用户满意度评分的频率分布直方图和B 地区用户满意度评分的频率分布表.A地区用户满意度评分的频率分布直方图（I）在答题卡上作出B地区用户满意度评分的频率分布直方图,并通过此图比较两地区满意度评分的平均值及分散程度.（不要求计算出具体值,给出结论即可）B地区用户满意度评分的频率分布直方图（II）根据用户满意度评分,将用户的满意度评分分为三个等级：估计那个地区的用户的满意度等级为不满意的概率大,说明理由.【答案】（I）见试题解析（II）A地区的用户的满意度等级为不满意的概率大.考点：1.频率分布直方图；2.概率估计.19. （本小题满分12分）如图,长方体1111ABCD A B C D -中AB =16,BC =10,18AA =,点E ,F 分别在1111,A B D C 上,11 4.A E D F ==过点E ,F 的平面α与此长方体的面相交,交线围成一个正方形.（I ）在图中画出这个正方形（不必说明画法与理由）；（II ）求平面α把该长方体分成的两部分体积的比值.【答案】（I ）见试题解析（II ）97 或79考点：1.几何体中的截面问题；2.几何体的体积20. （本小题满分12分）已知椭圆()2222:10x y C a b a b +=>> 2,点(2在C 上.（I ）求C 的方程；（II ）直线l 不经过原点O ,且不平行于坐标轴,l 与C 有两个交点A ,B ,线段AB 中点为M ,证明：直线OM 的斜率与直线l 的斜率乘积为定值.【答案】（I ）2222184x y +=（II ）见试题解析 考点：直线与椭圆21. （本小题满分12分）已知()()ln 1f x x a x =+-.（I ）讨论()f x 的单调性；（II ）当()f x 有最大值,且最大值大于22a -时,求a 的取值范围.【答案】（I ）0a ≤,()f x 在()0,+∞是单调递增；0a >,()f x 在10,a ⎛⎫ ⎪⎝⎭单调递增,在1,a ⎛⎫+∞ ⎪⎝⎭单调递减；（II ）()0,1.【解析】考点：导数的应用.请考生在22、23、24题中任选一题作答,如果多做,则按所做的第一题计分,作答时请写清题号22. （本小题满分10分）选修4-1：几何证明选讲如图O是等腰三角形AB C内一点,圆O与△ABC的底边BC交于M,N两点,与底边上的高交于点G,且与AB,AC分别相切于E,F两点.（I ）证明EF BC ；（II ）若AG 等于圆O 半径,且23AE MN == ,求四边形EBCF 的面积.【答案】（I ）见试题解析；（II ）1633考点：1.几何证明；2.四边形面积的计算.23. （本小题满分10分）选修4-4：坐标系与参数方程在直角坐标系xOy 中,曲线1cos ,:sin ,x t C y t αα=⎧⎨=⎩ （t 为参数,且0t ≠ ）,其中0απ≤<,在以O 为极点,x轴正半轴为极轴的极坐标系中,曲线23:2sin ,:23cos .C C ρθρθ==（I ）求2C 与3C 交点的直角坐标；（II ）若1C 与 2C 相交于点A ,1C 与3C 相交于点B ,求AB 最大值.【答案】（I ）()330,0,,22⎛⎫ ⎪ ⎪⎝⎭；（II ）4. 【解析】试题分析：（I ）把2C 与3C 的方程化为直角坐标方程分别为2220x y y +-=,22230x y x +-=,联立解考点：参数方程、直角坐标及极坐标方程的互化.24. （本小题满分10分）选修4-5：不等式证明选讲设,,,a b c d 均为正数,且a b c d +=+.证明：（I ）若ab cd > ,>（II ）>a b c d -<-的充要条件.【答案】【解析】试题分析：（I ）由a b c d +=+及ab cd >,可证明22>,开方即得>（II ）本小题可借助第一问的结论来证明,但要分必要性与充分性来证明. 试题解析：解：（I ）因为22a b c d =++=++。