A磨操I试题2013 (2)
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3COLLISION complex interactionMomentum and Newton’s 2nd Law8910v B v P ExampleCalculate the recoil speed of a pistol (mass 0.90given that the bullet has mass 8.0$g and emerges from the pistol with a speed of 352$ms –1the momentum of the exhaust gas is negligible.ImpulseJ of a force is defined as the change in momentum !p caused by that force.From Newton’s Second Law, if F is constantF = !p /!t F !t = !p = J: 1.0 kg object falls under gravity. Calculate the impulse the object experiences due to its weight after s.[98 kg m s downwards]1112Impulse (2)is not constantor J = & F i.e. impulse = area under F vs t curveis constant F av = FConsider a ball hitting a wall:F wall on ball(a) What is themaximum force the bat exerts on the ball?(b) What is the average force the bat exerts on the ball?Example: Hitting a cricket ballA 150g cricket ball is bowled with a speed of 20 ms –1. The batsman hits it straight back to the bowler at 40 ms –1, and the impulsive force of bat on ball has the shape as shown.[30 kN, 15 kN]15What is Energy?Energy can move things, heat things up, cool them down, join things, break things, cut things, make noise, make light, (no direction, not a vector — easy maths!)Stored energy - "potential energy": gravitational, elastic, chemical。
2013年广州市普通高中毕业班综合测试(二)语文2013.4本试卷共8页,24小题,满分为150分。
考试用时150分钟。
注意事项:1 .答卷前,考生务必用2B铅笔在“考生号”处填涂考生号。
用黑色字迹的钢笔或签字笔将自己所在的市、县/区、学校以及自己的姓名和考生号、试室号、座位号填写在答题卡上。
用2B铅笔将试卷类型(A)填涂在答题卡相应位置上。
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漏涂、错涂、多涂的,答案无效。
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考试结束后,将试卷和答题卡一并交回。
一、本大题4小题,每小题3分,共12分。
1.下列词语中加点的字,读音全都正确的一组是A.谒.见(yâ)抚恤.(xù)造福桑梓.(xīn)审时度.势(duó)B.修葺.(qì)拂.晓(fó)瞠.目结舌(chēnɡ)潸.然泪下(shān)C.契.机(qiâ)莅.临(lì)矫.枉过正(jiǎo)一曝.十寒(pù)D.混淆.(xiáo)喟.叹(kuì)拐弯抹.角(mò)数.见不鲜(shuò)2.下列句子中加点的词语,使用恰当的一项是A.有人大代表提出,政府应加强对幼儿教育的管理,使义务教育涵盖..学前阶段,保证每一位儿童都能平等接受优质的学前教育。
B.一些编剧在改编名著的时候,没有很好地理解原著的精髓,胡编乱造了许多情节,这样反而..大大地削弱了作品原有的思想性。
Unit 4 My Favourite SubjectSection A(Pronunciation-2f)第2课时(分层作业)【夯实基础】一、选词填空仔细阅读下面五个句子,然后用下面方框中所给的单词或短语填空,使每个句子在结构、句义和逻辑上正1.I like P. E. , and it is my favorite .2.The yellow sweater very nice and I like it.3.I often sports after school with my friends.4.Tom says history is , but I think it is useful.5.John’s birthday dinner is next week. Let’s the food.二、完成句子6.越来越多的外国人开始学中文。
More and more foreigners begin to learn .7.放学后打篮球怎么样?playing basketball after school?8.你为什么喜欢历史?you like history?9.你们什么时候上地理课?When do you ?10.紫色和蓝色是我最喜欢的颜色。
(完成译句)Purple and blue are my .【提升能力】三、单项选择11.—________.—He is very kind and friendly.A.What does your father do?B.What is your father like?C.What’s your father’s job?D.What does your father like?12.My schoolbag is red. _________ yours, Bob?A.What’s B.What about C.What color13.—________ is the art festival?—I think it’s in March, but I’m not sure.A.What B.Where C.When D.How14.It’s easy for students to buy things ________ there are many stores near the school.A.but B.or C.because D.so15.—What’s your favorite ________, Tom?—P.E. You know, I like playing sports very much.A.color B.subject C.food D.vegetable16.Geography is Carl’s favorite subject, ________ it’s useful.A.because B.or C.but D.so17.— ______? —Ms. Li.A.How is your math teacher B.Who is your math teacherC.Where is your math teacher D.What’s your math teacher like18.—In the morning, Tina plays sports for one hour.—That's a good ________.A.habit B.question C.music D.sport19.— ________? — Yes, please. I need a pair of white shorts.A.What do you want B.What’s your favorite colorC.Can I help you D.How much is this one20.I’m good ________ old people and I’m good ________ playing the guitar.A.for; with B.for; at C.at; for D.with; at四、短文填空阅读下面短文,在空白处填入一个适当的单词或括号内单词的正确形式。
2022初三物理二模试卷有答案点击查看更多初中三年级数学语文英语物理化学单元月考期末下册复习备考同步辅导教案一、单项选择题(以下各小题均有四个选项,其中只有一个选项符合题意。
共24分,每题2分)1.在国际单位制中,功的单位是A.千克(kg)B.牛顿(N)C.焦耳(J)D.瓦特(W)2.四冲程汽油机正常工作时,把机械能转化为内能的冲程是3.在图1所示的四种现象中,属于光的折射现象的是4. 在以下四种情境中,人对物体做功的是5.人们能分辨出分别由小提琴和二胡演奏的同一首乐曲,是因为这两种乐器发出的声音6.以下物态变化现象中,属于液化的是A.春天,河里的冰逐渐变成水B.夏天,剥开冰棒的包装纸,会看到“白气〞7.在图2所示的电路中,闭合开关S,三盏灯都能发光。
假设其中任意一盏灯的灯丝烧断,其它两盏灯仍然发光的电路是8.如图3所示,在光滑水平地面上,一物体在拉力F 的作用下作匀速直线运动,那么这个拉力可能的方向是9.质量相同的两个实心正方体A和B,如图4甲所示,将它们放在水平地面上时,它们对地面产生的压强为 ;当将它们放入水中后分别静止漂浮和悬浮在如图乙所示的位置时,它们受到水的浮力为,那么:A. B.C. D.10.以下有关力、运动、能的说法中,正确的选项是的合力为零时,运动速度一定为零B.当物体运动速度为零时,物体所受到的合力一定为零C.当物体运动速度为零时,物体的动能一定为零D.当物体所受的合力为零时,物体的动能一定为零11. 如图5所示,R1、R2是阻值相同的两个定值电阻,当闭合开关S1后,两电流表示数相同;当再闭合开关S2后B.电流表A1的示数为零,A2的示数变大C.电流表A1的示数不变,A2的示数变大12.在图6所示装置中,杠杆和滑轮的重力及滑轮的摩擦均可忽略不计,杠杆AB 可以绕O点在竖直平面内自由转动,A端通过竖直方向的轻绳与滑轮组相连,在B端用一轻绳沿竖直方向将杠杆拉住,使其始终保持水平平衡。
2013 年全国硕士研究生入学统一考试英语(二)试题答案与解析Section I Use of English一、文章题材结构分析本文主要分析了无现金社会为何迟迟不来的原因。
第一段是文章的中心段落,指出真正的无现金社会很可能不会马上到来。
第二、三段从电子支付设备昂贵、纸质支票提供收据、使用纸质支票能获得浮存利息以及电子支付方式存在的安全隐私问题四个方面分析纸币系统得以继续存在的理由。
二、试题解析1.【答案】A (However)【解析】空前作者讲到“鉴于电子货币的优势,你也许会认为,我们将快速步入无现金社会,实现完全电子支付。
”而空后说“真正的无现金社会很可能不会马上到来”,两者之前出现了明显的转折关系,因此答案A。
B. moreover 表递进C.therefore 表结果D. Otherwise 表对比2.【答案】D (around)【解析】由空格所在句的“but”得知,句子前后是转折关系。
事实上,这样的预测已经二十年了,但迄今还没有实现。
A. off 停止; B. back 返回; C. over 结束,与后文均不构成转折,故答案选D. around 出现。
3.【答案】B (concept)【解析】空格所在的句子意思为例如, 1975 年《商业周刊》预测电子支付手段不久将“彻底改变货币本身的____”将四个选项带入,能够彻底改变的对象只能是金钱的概念(定义),而A“力量”,C“历史”,D “角色”,语义都不恰当,并且如果选择role 的话,应该是复数roles, 因为是金钱的作用不止一个,故答案选B。
4.【答案】D (reverse)【解析】空格填入的动词跟前面的动词revolutionize (变革)意思上应该是同义替换的,要选择含有变革,彻底改变意思的词汇,四个选项中A. reward 奖励B. 抵抗C. resume 重新开始,继续,都不合适,只有D 选项reverse“颠覆”最为贴切,本句译为“电子支付方式不久将改变货币的定义,并将在数年后颠覆货币本身。
2013·新课标全国Ⅱ(理综物理)14.C1 [2013·新课标全国卷Ⅱ] 一物块静止在粗糙的水平桌面上.从某时刻开始,物块受到一方向不变的水平拉力作用.假设物块与桌面间的最大静摩擦力等于滑动摩擦力.以a 表示物块的加速度大小,F 表示水平拉力的大小.能正确描述F 与a 之间关系的图像是( )14.C [解析] 方法一:由于静摩擦力的作用,当F =0时并不会产生加速度,A 、B 、D 错误,C 正确;方法二:由牛顿第二定律有:F -μmg =ma ,可得:F =ma +μm g ,即F 是a 的一次函数,且截距为正,C 正确.15.B7 [2013·新课标全国卷Ⅱ] 如图,在固定斜面上的一物块受到一外力F 的作用,F 平行于斜面向上.若要物块在斜面上保持静止,F 的取值应有一定范围,已知其最大值和最小值分别为F 1和F 2(F 2>0).由此可求出( )A .物块的质量B .斜面的倾角C .物块与斜面间的最大静摩擦力D .物块对斜面的正压力15.C [解析] 考查静摩擦力的临界平衡问题.当F 为最大值时,此时F 1=mg sin θ+F f ①;当F 为最小值时,此时F 2=mg sin θ-F f ②;由①②可知能求出最大静摩擦力,但不能求出物块的质量、斜面的倾角,C 正确.16.L2 [2013·新课标全国卷Ⅱ] 如图,在光滑水平桌面上有一边长为L 、电阻为R 的正方形导线框;在导线框右侧有一宽度为d (d >L )的条形匀强磁场区域,磁场的边界与导线框的一边平行,磁场方向竖直向下.导线框以某一初速度向右行动.t =0时导线框的右边恰与磁场的左边界重合,随后导线框进入并通过磁场区域.下列v -t 图像中,可能正确描述上述过程的是( )16.D [解析] 由于线框在进入磁场过程要切割磁感线而产生感应电流,故线框受到安培力的作用做减速运动,A 错误;安培力F 安=B 2L 2v R,因v 在减小,故F 安在减小,加速度a =F 安m在减小,即线框进入磁场过程做加速度减小的变减速运动,B 错误;由于d >L ,若线框完全进入磁场中仍有速度,则线框将会在磁场中做匀速运动直至右边滑出磁场,线框出磁场过程仍做加速度减小的减速运动,C 错误,D 正确.17.K2 [2013·新课标全国卷Ⅱ] 空间有一圆柱形匀强磁场区域,该区域的横截面的半径为R ,磁场方向垂直于横截面.一质量为m 、电荷量为q (q >0)的粒子以速率v 0沿横截面的某直径射入磁场,离开磁场时速度方向偏离入射方向60°.不计重力,该磁场的磁感应强度大小为( ) A.3m v 03qR B.m v 0qR C.3m v 0qR D.3 m v 0qR17.A [解析] 由Bq v 0=m v 20r 可得:B =m v 0qr,粒子沿半径射入磁场必沿半径射出磁场,可作出运动轨迹图如图所示,由几何知识可得:r =3R ,即B =3m v 03qR,A 正确.18.K1 [2013·新课标全国卷Ⅱ] 如图,在光滑绝缘水平面上,三个带电小球a 、b 和c 分别位于边长为l 的正三角形的三个顶点上;a 、b 带正电,电荷量均为q ,c 带负电.整个系统置于方向水平的匀强电场中.已知静电力常量为k .若三个小球均处于静止状态,则匀强电场场强的大小为( ) A.3kq 3l 2 B.3kq l 2C.3kq l 2D.2 3kq l 218.B [解析] 由题意,三个小球均处于静止状态,对c 球而言,a 、b 两球在c 球所在位置处产生的合场强与匀强电场的场强等大反向,故匀强电电场的场强大小E =2kq l2cos30°=3kq l 2,B 正确. 19.L1[2013·新课标全国卷Ⅱ] 在物理学发展过程中,观测、实验、假说和逻辑推理等方法都起到了重要作用.下列叙述符合史实的是( )A .奥斯特在实验中观察到电流的磁效应,该效应揭示了电和磁之间存在联系B .安培根据通电螺线管的磁场和条形磁铁的磁场的相似性,提出了分子环流假说C .法拉第在实验中观察到,在通有恒定电流的静止导线附近的固定导线圈中,会出现感应电流D .楞次在分析了许多实验事实后提出,感应电流应具有这样的方向,即感应电流的磁场总要阻碍引起感应电流的磁通量的变化19.ABD [解析] 奥斯特观察到电流的磁效应,表明电流可以产生磁场,揭示了电与磁的联系,A 正确;安培根据通电螺线管和条形磁铁磁场的相似性,提出了分子环流假说,符合物理史实,B 正确;法拉第发现处于变化的磁场中的闭合线圈中会产生感应电流,C 错误;D 项的叙述符合楞次定律的发现过程,D 正确.20.E6[2013·新课标全国卷Ⅱ] 目前,在地球周围有许多人造地球卫星绕着它运转,其中一些卫星的轨道可近似为圆,且轨道半径逐渐变小.若卫星在轨道半径逐渐变小的过程中,只受到地球引力和稀薄气体阻力的作用,则下列判断正确的是( )A .卫星的动能逐渐减小B .由于地球引力做正功,引力势能一定减小C .由于气体阻力做负功,地球引力做正功,机械能保持不变D .卫星克服气体阻力做的功小于引力势能的减小20.BD [解析] 由G Mm r 2=m v 2r 可得v =GM r,轨道半径变小,则运行的速度变大,卫星的动能增大,A 错误;轨道半径变小,地球引力做正功,引力势能减小,B 正确;由于气体阻力做负功,产生热量,故机械能减小,C 错误;由动能定理,动能增大,则克服气体阻力做的功小于引力做的功,而引力做功等于引力势能的减小,故克服气体阻力做的功小于引力势能的减小,D 正确.21.D4[2013·新课标全国卷Ⅱ] 公路急转弯处通常是交通事故多发地带.如图,某公路急转弯处是一圆弧,当汽车行驶的速率为v c 时,汽车恰好没有向公路内外两侧滑动的趋势.则在该弯道处,( )A .路面外侧高内侧低B .车速只要低于v c ,车辆便会向内侧滑动C .车速虽然高于v c ,但只要不超出某一最高限度,车辆便不会向外侧滑动D .当路面结冰时,与未结冰时相比,v c 的值变小21.AC [解析] 由题意,当汽车的速率为v c 时无滑动趋势,说明此时汽车与路面没有横向摩擦力,路面应不是平的,而应是外侧高内侧低,由重力的分力充当向心力,A 正确;当车速低于v c 时,车和地面之间会产生横向静摩擦力,阻碍汽车向内侧滑动,B 错误;当车速高于v c 时,车和地面之间仍会有摩擦力,此力与重力的分力一起提供向心力,只要车速不超过某一最高速度,车辆便不会向外侧滑动,C 正确;因为v c 是车和地面无摩擦时的临界值,所以与路况无关,D 错误.22.E6[2013·新课标全国卷Ⅱ] 某同学利用下述装置对轻质弹簧的弹性势能进行探究:一轻质弹簧放置在光滑水平桌面上,弹簧左端固定,右端与一小球接触而不固连;弹簧处于原长时,小球恰好在桌面边缘,如图(a)所示.向左推小球,使弹簧压缩一段距离后由静止释放;小球离开桌面后落到水平地面.通过测量和计算,可求得弹簧被压缩后的弹性势能.图(a)回答下列问题:(1)本实验中可认为,弹簧被压缩后的弹性势能E p 与小球抛出时的动能E k 相等.已知重力加速度大小为g .为求得E k ,至少需要测量下列物理量中的________(填正确答案标号).A .小球的质量mB .小球抛出点到落地点的水平距离sC .桌面到地面的高度hD .弹簧的压缩量ΔxE .弹簧原长l 0(2)用所选取的测量量和已知量表示E k ,得E k =________.(3)图(b)中的直线是实验测量得到的s -Δx 图线.从理论上可推出,如果h 不变,m 增加,s -Δx 图线的斜率会________(填“增大”“减小”或“不变”);如果m 不变,h 增加,s -Δx 图线的斜率会________(填“增大”“减小”或“不变”).由图(b)中给出的直线关系和E k 的表达式可知,E p 与Δx 的________次方成正比.图(b)22.(1)ABC(2)mgs 24h(3)减小 增大 2[解析] (1)根据平抛运动规律求小球抛出时的动能.动能E k =12m v 20,根据平抛运动规律有:h =12gt 2,s =v 0t , 可得:E k =mgs 24h,故需要测量小球的质量m 、小球抛出点到落地点的水平距离s 和桌面到地面的高度h ,选项A 、B 、C 正确.(3)由图像可知,s 与Δx 成正比,设图像斜率为k ,则s =k Δx ,弹性势能E p 与动能E k的关系为E p =E k =mgs 24h ,故E p =mgk 24h·Δx 2,即弹簧的弹性势能与Δx 的二次方成正比.当h 不变时,m 增大,k 就减小;当m 不变时,h 增大,k 就增大.23.J6[2013·新课标全国卷Ⅱ] 某同学用量程为1 mA 、内阻为120 Ω的表头按图(a)所示电路改装成量程分别为1 V 和1 A 的多用电表.图中R 1和R 2为定值电阻,S 为开关.回答下列问题:(1)根据图(a)所示的电路,在图(b)所示的实物图上连线.(2)开关S 闭合时,多用电表用于测量________(填“电流”“电压”或“电阻”);开关S 断开时,多用电表用于测量________(填“电流”“电压”或“电阻”).(3)表笔A 应为________色(填“红”或“黑”).(4)定值电阻的阻值R 1=________Ω,R 2=________Ω.(结果取3位有效数字)图(a) 图(b)23.(1)连线如图所示(2)电流 电压(3)黑(4)1.00 880[解析] (1)根据电路图连接实物图,注意两表笔与表头的正负接线柱.(2)根据“串联分压,并联分流”可知,当S 断开时,多用电表测量电压;当S 闭合时,多用电表测量电流.(3)电流从红表笔流进多用电表,从黑表笔流出.从电路图中表头和表笔的接法可知电流从表笔A 流出,所以A 为黑表笔.(4)当S 断开时为电压表,此时R 2= 1 V 10-3 A-120 Ω=880 Ω ;当S 闭合时为电流表,此时R 1=10-3 A ×()120 Ω+880 Ω1 A -10-3 A ≈1.00 Ω. 24.I7[2013·新课标全国卷Ⅱ] 如图,匀强电场中有一半径为r 的光滑绝缘圆轨道,轨道平面与电场方向平行.a 、b 为轨道直径的两端,该直径与电场方向平行.一电荷量为q (q >0)的质点沿轨道内侧运动,经过a 点和b 点时对轨道压力的大小分别为N a 和N b .不计重力,求电场强度的大小E 、质点经过a 点和b 点时的动能.24.[解析]质点所受电场力的大小为f =qE ①设质点质量为m ,经过a 点和b 点时的速度大小分别为v a 和v b ,由牛顿第二定律有f +N a =m v 2a r② N b -f =m v 2b r③ 设质点经过a 点和b 点时的动能分别为E k a 和E k b ,有E k a =12m v 2a④ E k b =12m v 2b⑤根据动能定理有E k b -E k a =2rf ⑥联立①②③④⑤⑥式得E =16q(N b -N a ) ⑦ E k a =r 12(N b +5N a ) ⑧ E k b =r 12(5N b +N a ) ⑨ 25.C5[2013·新课标全国卷Ⅱ]一长木板在水平地面上运动,在t =0时刻将一相对于地面静止的物块轻放到木板上,以后木板运动的速度-时间图像如图所示.已知物块与木板的质量相等,物块与木板间及木板与地面间均有摩擦,物块与木板间的最大静摩擦力等于滑动摩擦力,且物块始终在木板上.取重力加速度的大小g =10 m/s 2,求:(1)物块与木板间、木板与地面间的动摩擦因数;(2)从t =0时刻到物块与木板均停止运动时,物块相对于木板的位移的大小.25.[解析] (1)从t =0时开始,木板与物块之间的摩擦力使物块加速,使木板减速,此过程一直持续到物块和木板具有共同速度为止.由图可知,在t 1=0.5 s 时,物块和木板的速度相同.设t =0到t =t 1时间间隔内,物块和木板的加速度大小分别为a 1和a 2,则a 1=v 1t 1① a 2=v 0-v 1t 1② 式中v 0=5 m/s 、v 1=1 m/s 分别为木板在t =0、t =t 1时速度的大小.设物块和木板的质量为m ,物块和木板间、木板与地面间的动摩擦因数分别为μ1、μ2,由牛顿第二定律得μ1mg =ma 1 ③(μ1+2μ2)mg =ma 2 ④联立①②③④式得μ1=0.20 ⑤μ2=0.30 ⑥(2)在t 1时刻后,地面对木板的摩擦力阻碍木板运动,物块与木板之间的摩擦力改变方向.设物块与木板之间的摩擦力大小为f ,物块和木板的加速度大小分别a ′1和a ′2,则由牛顿第二定律得f =ma ′1 ⑦2μ2mg -f =ma ′2 ⑧假设f <μ1mg ,则a ′1=a ′2;由⑤⑥⑦⑧式得f =μ2mg >μ1mg ,与假设矛盾.故 f =μ1mg ⑨由⑦⑨式知,物块加速度的大小a ′1等于a 1;物块的v -t 图像如图中点划线所示. 由运动学公式可推知,物块和木板相对于地面的运动距离分别为s 1=2×v 212a 1⑩ s 2=v 0+v 12t 1+v 212a ′2⑪ 物块相对于木板的位移的大小为s =s 2-s 1 ⑫联立①⑤⑥⑧⑨⑩⑪⑫式得s =1.125 m ⑬33.[物理——选修3-3](15分)H3[2013·新课标全国卷Ⅱ](1)(5分)关于一定量的气体,下列说法正确的是________(填正确答案标号.选对1个得2分,选对2个得4分,选对3个得5分;每选错1个扣3分,最低得分为0分).A .气体的体积指的是该气体的分子所能到达的空间的体积,而不是该气体所有分子体积之和B .只要能减弱气体分子热运动的剧烈程度,气体的温度就可以降低C .在完全失重的情况下,气体对容器壁的压强为零D .气体从外界吸收热量,其内能一定增加E .气体在等压膨胀过程中温度一定升高33.(1)ABE [解析] 气体分子间隙很大,气体体积是指气体的分子能够到达的空间的体积,A 正确;根据分子动理论,温度越高,分子热运动越剧烈,相反,温度越低,分子热运动剧烈程度越弱,B 正确;气体压强是微观止大量分子对容器壁频繁碰撞的结果,与宏观上物体的运动状态无关,C 错误;改变内能的方式有两种——做功和热传递,气体吸收热量,若同时对外做功,则内能不一定增加,D 错误;在等压膨胀过程中,气体的体积V 增大,压强p 不变,由pV T=C (常量)可知,温度T 一定升高,E 正确. 33.[2013·新课标全国卷Ⅱ] (2)(10分)如图,一上端开口、下端封闭的细长玻璃管竖直放置.玻璃管的下部封有长l 1=25.0 cm 的空气柱,中间有一段长l 2=25.0 cm 的水银柱,上部空气柱的长度l 3=40.0 cm.已知大气压强为p 0=75.0 cmHg.现将一活塞(图中未画出)从玻璃管开口处缓慢往下推,使管下部空气柱长度变为l ′1=20.0 cm.假设活塞下推过程中没有漏气,求活塞下推的距离.33.(2)[解析] 以cmHg为压强单位.在活塞下推前,玻璃管下部空气柱的压强为p1=p0+l2①设活塞下推后,下部空气柱的压强为p′1,由玻意耳定律得p1l1=p′1l′1②设活塞下推距离为Δl,则此时玻璃管上部空气柱的长度为l′3=l3+l1-l′1-Δl③设此时玻璃管上部空气柱的压强为p′3,则p′3=p′1-l2④由玻意耳定律得p0l3=p′3l′3⑤由①至⑤式及题给数据解得Δl=15.0 cm⑥34.[物理——选修3-4](15分)C1[2013·新课标全国卷Ⅱ](1)(5分)如图,一轻弹簧一端固定,另一端连接一物块构成弹簧振子,该物块是由a、b 两个小物块粘在一起组成的.物块在光滑水平面上左右振动,振幅为A0,周期为T0.当物块向右通过平衡位置时,a、b之间的粘胶脱开;以后小物块a振动的振幅和周期分别为A和T,则A________A0(填“>”“<”或“=”),T________T0(填“>”“<”或“=”).33.(1)<<34.(2)[2013·新课标全国卷Ⅱ] (10分)如图,三棱镜的横截面为直角三角形ABC,∠A=30°,∠B=60°.一束平行于AC边的光线自AB边的P点射入三棱镜,在AC边发生反射后从BC边的M点射出.若光线在P点的入射角和在M点的折射角相等,(ⅰ)求三棱镜的折射率;(ⅱ)在三棱镜的AC边是否有光线透出?写出分析过程.(不考虑多次反射)34.(2)[解析] (ⅰ)光路图如图所示,图中N点为光线在AC边发生反射的入射点,设光线在P点的入射角为i、折射角为r,在M点的入射角为r′、折射角依题意也为i,有i=60°①由折射定律有sin i=n sin r②n sin r′=sin i③由②③式得r=r′④OO′为过M点的法线,∠C为直角,OO′∥AC.由几何关系有∠MNC=r′⑤由反射定律可知∠PNA=∠MNC⑥联立④⑤⑥式得∠PNA =r ⑦由几何关系得r =30° ⑧联立①②⑧式得n =3 ⑨(ⅱ)设在N 点的入射角为i ″,由几何关系得i ″=60° ⑩此三棱镜的全反射临界角满足n sin θc =1 ⑪由⑨⑩⑪式得i ″>θc ⑫此光线在N 点发生全反射,三棱镜的AC 边没有光线透出.35.[物理——选修3-5](15分)O2[2013·新课标全国卷Ⅱ](1)(5分)关于原子核的结合能,下列说法正确的是________(填正确答案标号.选对1个得2分,选对2个得4分,选对3个得5分;每选错1个扣3分,最低得分为0分).A .原子核的结合能等于使其完全分解成自由核子所需的最小能量B .一重原子核衰变成α粒子和另一原子核,衰变产物的结合能之和一定大于原来重核的结合能C .铯原子核 (133 55Cs)的结合能小于铅原子核(208 82Pb)的结合能D .比结合能越大,原子核越不稳定E .自由核子组成原子核时,其质量亏损所对应的能量大于该原子核的结合能35.(1)ABC [解析] 根据结合能的概念,将原子核分解成自由核子所需要的最小能量等于结合能,A 正确;结合能越大,原子核越稳定,重核衰变放出能量,转化为结合能更大的衰变产物,B 正确;组成原子核的核子越多,它的结合能越高,故铯原子核的结合能小于铅原子核的结合能,C 正确;比结合能是指原子核结合能对其中所有核子的平均值,亦即若把原子核全部拆成自由核子,平均对每个核子所要添加的能量,所以比结合能越大,原子核越牢固,D 错误;自由核子组成原子核时,放出的能量与组成的原子核的结合能相等,E 错误.35.O2[2013·新课标全国卷Ⅱ] 如图,光滑水平直轨道上有三个质量均为m 的物块A 、B 、C .B 的左侧固定一轻弹簧(弹簧左侧的挡板质量不计).设A 以速度v 0朝B 运动,压缩弹簧;当A 、B 速度相等时,B 与C 恰好相碰并粘接在一起,然后继续运动.假设B 和C 碰撞过程时间极短.求从A 开始压缩弹簧直至与弹簧分离的过程中,(ⅰ)整个系统损失的机械能;(ⅱ)弹簧被压缩到最短时的弹性势能.35.(2)[解析] (ⅰ)从A 压缩弹簧到A 与B 具有相同速度v 1时,对A 、B 与弹簧组成的系统,由动量守恒定律得m v 0=2m v 1 ①此时B 与C 发生完全非弹性碰撞,设碰撞后的瞬时速度为v 2,损失的机械能为ΔE .对B 、C 组成的系统,由动量守恒和能量守恒定律得m v 1=2m v 2 ②12m v 21=ΔE +12(2m )v 22 ③ 联立①②③式得ΔE =116m v 20④ (ⅱ)由②式可知v 2<v 1,A 将继续压缩弹簧,直至A 、B 、C 三者速度相同,设此速度为v 3,此时弹簧被压缩至最短,其弹性势能为E p .由动量守恒和能量守恒定律得m v 0=3m v 3 ⑤12m v 20-ΔE =12(3m )v 23+E p ⑥ 联立④⑤⑥式得E p =1348m v 20 ⑦。
2013年12月英语四级考试真题及答案(第二套)Part I Writing (30 minutes)Directions: For this part, you are allowed 30 minutes to write a short essay. You should start your essay with a brief account of the increasing use of the mobile phone in people's life and then explain the consequences of overusing it. You should write at least 120 words but no more than 180 words.注意:此部分试题在答题卡1上。
______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________PartⅡListening Comprehension(30 minutes)Section ADirections:In this section, you will hear 8 short conversations and 2 long conversations. At the end of each conversation, one or more questions will be asked about what was said. Both the conversation and the questions will be spoken only once. After each question there will be a pause.During the pause, you must read the four choices marked A), B), C) and D), and decide which is the best answer. Then mark the corresponding letter on Answer Sheet 1with a single line through the centre.注意:此部分试题请在答题卡1上作答。
2013年全国硕士研究生入学统一考试英语二试题(答案解析版)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)Given the advantages of electronic money, you might think that we would move quickly to the cashless society in which all payments are made electronically. ___1___, a true cashless society is probably not around the corner. Indeed, predictions of such a society have been ___2___ for two decades but have not yet come to fruition. For example, Business Week predicted in 1975 that electronic means of payment “would soon revolutionize the very ___3___ of money itself,” only to ___4___ itself several years later. Why has the movement to a cashless society been so ___5___ in coming?Although e-money might be more convenient and may be more efficient than a payments system based on paper, several factors work __6___ the disappearance of the paper system. First, it is very ___7___ to set up the computer, card reader, and telecommunications networks necessary to make electronic money the ___8___ form of payment. Second, paper checks have the advantage that they ___9___ receipts, something that many consumers are unwilling to ___10___. Third, the use of paper checks gives consumers several days of "float"-it takes several days ___11___ a check is cashed and funds are ___12___ from the issuer's account, which means that the writer of the check can earn interest on the funds in the meantime. ___13___ electronic payments are immediate, they eliminate the float for the consumer. Fourth, electronic means of payment ___14___ security and privacy concerns. We often hear media reports that an unauthorized hacker has been able to access a computer database and to alter information ___15___ there.Because this is not an ___16___ occurrence, unscrupulous persons might be able to access bank accounts in electronic payments systems and ___17___ funds by moving them from someone else’s accounts into their own. The ___18___ of this type of fra ud is no easy task, and a whole new field of computer science has developed to ___19___ security issues. A further concern is that the use of electronic means of payment leaves an electronic___20___ that contains a large amount of personal data on buying habits. There are worries that government, employers, and marketers might be able to access these data, thereby encroaching on our privacy.1. [A] However [B] Moreover [C] Therefore [D] Otherwise2. [A] off [B] back [C] over [D] around3. [A] power [B] concept [C] history [D] role4. [A] reward [B] resist [C] resume [D] reverse5. [A] silent [B] sudden [C] slow [D] steady6. [A] for [B] against [C]with [D] on7. [A] imaginative [B] expensive [C] sensitive [D] productive8. [A] similar [B] original [C] temporary [D] dominant9. [A] collect [B] provide [C] copy [D] print10. [A] give up [B] take over [C] bring back [D] pass down11. [A] before [B] after [C] since [D] when12. [A] kept [B] borrowed [C] released [D] withdrawn13. [A] Unless [B] Until [C] Because [D] Though14. [A] hide [B] express [C] raise [D]ease15. [A] analyzed [B] shared [C] stored [D] displayed16. [A] unsafe [B] unnatural [C] uncommon [D] unclear17. [A] steal [B] choose [C] benefit [D] return18. [A] consideration [B] prevention [C] manipulation [D] justification19. [A] cope with [B] fight against [C] adapt to [D] call for20. [A] chunk [B] chip [C] path [D] trail答案:1-5: ADBDC6-10: BBDBA11-15: ADCCC16-20: CABAD【答案详解】1. [标准答案] [A][考点分析] 本题考察逻辑关系[选项分析] 因为考察逻辑关系,所以需要我们先对填空前后的原文信息做定位分析:填空之后的信息为”a true cashless society is probably not around the corner .”(一个无现金社会不太可能马上出现),而文章之前的信息都是在说我们可能马上就进入一个无现金社会,两者之间出现了明显的转折关系,因此只有however符合题意。
小学上册英语第2单元测验试卷(含答案)英语试题一、综合题(本题有100小题,每小题1分,共100分.每小题不选、错误,均不给分)1.What do we call the tool we use to write on paper?A. BrushB. PenC. RulerD. Scissors答案:B2.My sister is learning to _______ (动词). 她想要 _______ (动词).3.My toys teach me lessons about ________ (名词) and friendship.4.The country known for its lush greenery is ________ (以郁郁葱葱闻名的国家是________).5. A solute is the substance that is ________ in a solution.6.The __________ is a large desert located in the Middle East. (阿拉伯沙漠)7.What do we call a group of fish?A. FlockB. SchoolC. PackD. Swarm答案:B8.I like _____ (ice cream).9. A _____ (狮子) is known as the king of the jungle.10.What do you call a place where you can see stars and planets?A. MuseumB. ObservatoryC. AquariumD. Library答案: B11.I see a _____ (小鸟) in the tree.12.The __________ (历史的交汇) creates understanding.13.My dad enjoys going to the ____ (movies).14.What shape has three sides?A. SquareB. TriangleC. CircleD. Rectangle答案: B15.The __________ is beautiful when the leaves turn color. (秋天)16. A saturated solution can exist in equilibrium with its ______.17.The ______ can live a long time.18.The chemical symbol for neon is ______.19.My sister has a ________ (毛绒玩具), and she takes it everywhere, even to ________ (学校).20.The _______ (The American Revolutionary War) established a new nation.21.What do you call a person who travels to space?A. AstronautB. PilotC. CosmonautD. Engineer答案: A22.The _______ (小鹦鹉) can mimic human speech.anic chemistry is the study of ______ compounds.24.The _______ changes its colors in the fall.25.为下列图片选择相符的句子。
2013高考英语新课标卷II试题答案详解第一部分英语知识运用(共两节,满分45分)第一节单项填空(共15小题;每小题1分,满分15分)1. — I'm sorry I made a mistake!— ______ 。
Nobody is perfect. 答案:D。
Take it easyA。
Take your time B。
Y ou’re right C。
Whatever you say D。
Take it easy 解析:本题考查日常用语.Take your time. 别着急,慢慢来. You're right. 你说的对。
Whatever you say。
无论你说什么;你说了算;随便你。
Take it easy. 别紧张;别着急;不要放在心上。
译文:“对不起我错了。
” “别太在意。
人无完人。
”2。
Would you like to _______ with us to the film tonight?A。
come along B。
come off C. come across D. come through答案:A. come along解析:本题考查动词短语。
come along 一起来;出现;进展;come off 离开;实现;举行;come across 走过来;出现于;偶然碰到;come through 经历;传出;脱险;译文:今晚你想要和我们一起去看电影吗?3。
I was glad to meet Jenny again,_______ I didn’t want to spend all day with her. A. but B. and C。
so D. or答案:A。
but解析:本题考查连词.but conj. 但是,表示转折关系;and conj。
并且,表示并列关系;so conj. 所以,表示因果关系;or conj。
或者,否则,表示选择关系;译文:我很高兴再次见到Jenny,但是我不想整天都和她呆在一起。
小学下册英语第2单元真题(含答案)英语试题一、综合题(本题有100小题,每小题1分,共100分.每小题不选、错误,均不给分)1.What do you call a written work that tells a story?A. PoemB. BookC. ArticleD. Essay答案:B2.What do we call a young male goat?A. KidB. CalfC. LambD. Foal3. A _____ is a large area of stars, gas, and dust.4.We have a ______ (大) library in town.5.The kangaroo keeps its baby in its _________ (育儿袋).6.My friend has a very __________ (丰富的) imagination.7.What do you call a person who studies the weather?A. MeteorologistB. ClimatologistC. CartographerD. Ecologist8. A _______ reaction produces heat and light.9.The reaction between an acid and a metal produces ______.10.__________ (材料科学) examines the properties and applications of substances.11.My uncle is a talented ____ (painter).12.The __________ (土壤的质量) impacts plant growth significantly.13.What do we call a small, furry animal that loves to dig?A. BadgerB. FoxC. RabbitD. Squirrel14.He likes to draw ___. (pictures)15.An ionic bond is formed when electrons are _____ between atoms.16.I enjoy ________ (晨跑) in the park.17.The first successful heart-lung transplant was performed in _______. (1981年)18.He is very ___. (strong)19.Which of these is a vegetable?A. AppleB. CarrotC. BananaD. Orange20., I watch ________ (名词) about toys and learn new ways to play. This gives me many ________ (名词) ideas. Sometime21.The __________ (历史的传承价值) is vital for growth.22.The athlete won a _____ (奖牌) in the competition.23. A molecule is formed when two or more atoms bond ______.24.The alligator swims in the ____.25.My friend loves to share __________ (故事) with others.26.The capital of Ukraine is __________.27. A flamingo stands on one ________________ (脚).28.My favorite subject is ________ (数学).29.Which country is known as the Land of the Rising Sun?A. ChinaB. JapanC. ThailandD. India答案:B30.I enjoy _______ (听故事) before bed.31.What do we call the act of taking care of someone?A. CaringB. NurturingC. SupportingD. Assisting32.What is the opposite of "happy"?A. JoyfulB. SadC. AngryD. Excited33.Which animal says "woof"?A. CatB. DogC. BirdD. Fish答案:B34.The ancient Egyptians used ________ for their architectural designs.ing pesticides can help control ______ in your garden. (使用农药可以帮助控制花园中的害虫。
2013年全国硕士研究生入学统一考试英语(二)试题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)Given the advantages of electronic money, you might think that we would move quickly to the cashless society in which all payments are made electronically. __1__, a true cashless society is probably not around the corner. Indeed, predictions have been __2__ for two decades but have not yet come to fruition. For example, Business Week predicted in 1975 that electronic means of payment would soon “revolutionize the very __3__ of money itself,” only to __4__ itself several years later. Why has the movement to a cashless society been so __5__ in coming?Although electronic means of payment might be more efficient than a payments system based on paper, several factors work __6__ the disappearance of the paper system. First, it is very __7__ to set up the computer, card reader, and telecommunications networks necessary to make electronic money the __8__ form of payment. Second, paper checks have the advantage that they __9__ receipts, something that many consumers are unwilling to __10__. Third, the use of paper checks gives consumers several days of “float”—it takes several days __11__ a check is cashed and funds are __12__ from the issuer’s account, which means that the writer of the check can cam interest on the funds in the meantime. __13__ electronic payments are immediate, they eliminate the float for the consumers.Forth, electronic means of payment may __14__ security and privacy concerns. We often hear media reports that an unauthorized hacker has been able to access a computer database and to alter information __15__ there. The fact that this is not an __16__ occurrence means that dishonest persons might be able to access bank accounts in electronic payments systems and __17__ from someone else’s accounts. The __18__ of this type of fraud is no easy task, and a new field of computer science is developing to __19__ security issues. A further concern is that the use of electronic means of payment leaves an electronic __20__ that contains a large amount of personal data. There are concerns that government, employers, and marketers might be able to access these data, thereby violating our privacy.1. [A] However [B] Moreover [C] Therefore [D] Otherwise2. [A] off [B] back [C] over [D] around3. [A] power [B] concept [C] history [D] role4. [A] reward [B] resist [C] resume [D] reverse5. [A] silent [B] sudden [C] slow [D] steady6. [A] for [B] against [C]with [D] on7. [A] imaginative [B] expensive [C] sensitive [D] productive8. [A] similar [B] original [C] temporary [D] dominant9. [A] collect [B] provide [C] copy [D] print10. [A] give up [B] take over [C] bring back [D] pass down11. [A] before [B] after [C] since [D] when12. [A] kept [B] borrowed [C] released [D] withdrawn13. [A] Unless [B] Until [C] Because [D] Though14. [A] hide [B] express [C] raise [D]ease15. [A] analyzed [B] shared [C] stored [D] displayed16. [A] unsafe [B] unnatural [C] uncommon [D] unclear17. [A] steal [B] choose [C] benefit [D] return18. [A] consideration [B] prevention [C] manipulation [D] justification19. [A] cope with [B] fight against [C] adapt to [D] call for20. [A] chunk [B] chip [C] path [D] trailSection II Reading ComprehensionPart ADirections: Read the following four texts. Answer the questions after each text by choosing A, B, C or D. Mark your answers on ANSWER SHEET 1. (40 points)Text 1In an essay entitled “Making It in America,”, the author Adam Davidson relates a joke from cotton country about just how much a modern textile mill has been automated: The average mill has only two employees today, “a man and a dog. The man is there to feed the dog, and the dog is there to keep the man aw ay from the machines.”Davidson’s article is one of a number of pieces that have recently appeared making the point that the reason we have such stubbornly high unemployment and declining middle-class incomes today is largely because of the big drop in demand because of the Great Recession, but it is also because of the advances in both globalization and the information technology revolution, which are more rapidly than ever replacing labor with machines or foreign workers.In the past, workers with average skills, doing an average job, could earn an average lifestyle. But, today, average is officially over. Being average just won’t earn you what it used to. It can’t when so many more employers have so much more access to so much more above average cheap foreign labor, cheap robotics, cheap software, cheap automation and cheap genius. Therefore, everyone needs to find their extra — their unique value contribution that makes them stand out in whatever is their field of employment.Yes, new technology has been eating jobs forever, and always will. But there’s been an acceleration. As Davidson notes, “In the 10 years ending in 2009, U.S. factories shed workers so fast that they erased almost all the gains of the previous 70 years; roughly one out of every three manufacturing jobs — about 6 million in total —disappeared.”There will always be change — new jobs, new products, new services. But the one thing we know for sure is that with each advance in globalization and the I.T. revolution, the best jobs will require workers to have more and better education to make themselves above average.In a world where average is officially over, there are many things we need to do to support employment, but nothing would be more important than passing some kind of G. I. Bill for the 21st century that ensures that every American has access to post-high school education.21. The joke in Paragraph 1 is used to illustrate_______.[A] the impact of technological advances[B] the alleviation of job pressure[C] the shrinkage of textile mills[D] the decline of middle-class incomes22. According to Paragraph 3, to be a successful employee, one has to______.[A] work on cheap software[B] ask for a moderate salary[C] adopt an average lifestyle[D] contribute something unique23. The quotation in Paragraph 4 explains that ______.[A] gains of technology have been erased[B] job opportunities are disappearing at a high speed[C] factories are making much less money than before[D] new jobs and services have been offered24. According to the author, to reduce unemployment, the most important is_____.[A] to accelerate the I.T. revolution[B] to ensure more education for people[C] to advance economic globalization[D] to pass more bills in the 21st century25. Which of the following would be the most appropriate title for the text?[A] New Law Takes Effect[B] Technology Goes Cheap[C] Average Is Over[D] Recession Is BadText 2A century ago, the immigrants from across the Atlantic included settlers and sojourners. Along with the many folks looking to make a permanent home in the United States came those who had no intention to stay, and 7 million people arrived while about 2 million departed. About a quarter of all Italian immigrants, for example, eventually returned to Italy for good. They even had an affectionate nickname, "uccelli di passaggio," birds of passage.Today, we are much more rigid about immigrants. We divide newcomers into two categories: legal or illegal, good or bad. We hail them as Americans in the making, or our broken immigration system and the long political paralysis over how to fix it. We don't need more categories, but we need to change the way we think about categories. We need to look beyond strict definitions of legal and illegal. To start, we can recognize the new birds of passage, those living and thriving in the gray areas. We might then begin to solve our immigration challenges.Crop pickers, violinists, construction workers, entrepreneurs, engineers, home health-care aides and physicists are among today's birds of passage. They are energetic participants in a global economy driven by the flow of work, money and ideas. They prefer to come and go as opportunity calls them. They can manage to have a job in one place and a family in another.With or without permission, they straddle laws, jurisdictions and identities with ease. Weneed them to imagine the United States as a place where they can be productive for a while without committing themselves to staying forever. We need them to feel that home can be both here and there and that they can belong to two nations honorably.Accommodating this new world of people in motion will require new attitudes on both sides of the immigration battle. Looking beyond the culture war logic of right or wrong means opening up the middle ground and understanding that managing immigration today requires multiple paths and multiple outcomes. Including some that are not easy to accomplish legally in the existing system.26. “Birds of passage” refers to those who____.[A] immigrate across the Atlantic[B] leave their home countries for good[C] stay in a foreign temporarily[D]find permanent jobs overseas27. It is implied in paragraph 2 that the current immigration system in the US____.[A] needs new immigrant categories[B] has loosened control over immigrants[C] should be adopted to meet challenges[D]has been fixed via political means28. According to the author, today’s birds of passage want___.[A] financial incentives[B] a global recognition[C] opportunities to get regular jobs[D]the freedom to stay and leave29. The author suggests that the birds of passage today should be treated __.[A] as faithful partners[B] with economic favors[C] with legal tolerance[D]as mighty rivals30 which of the following would be the most appropriate title for the text?[A] Come and Go: Big Mistake[B] Living and Thriving: Great Risk[C] With or Without: Great Risk[D]Legal or Illegal: Big MistakeText 3Scientists have found that although we are prone to snap overreactions, if we take a moment and think about how we are likely to react, we can reduce or even eliminate the negative effects of our quick, hard-wired responses.Snap decisions can be important defense mechanisms; if we are judging whether someone is dangerous, our brains and bodies are hard-wired to react very quickly, within milliseconds. But weneed more time to assess other factors. To accurately tell whether someone is sociable, studies show, we need at least a minute, preferably five. It takes a while to judge complex aspects of perso nality, like neuroticism or open-mindedness.But snap decisions in reaction to rapid stimuli aren’t exclusive to the interpersonal realm. Psychologists at the University of Toronto found that viewing a fast-food logo for just a few milliseconds primes us to read 20 percent faster, even though reading has little to do with eating. We unconsciously associate fast food with speed and impatience and carry those impulses into whatever else we’re doing. Subjects exposed t o fast-food flashes also tend to think a musical piece lasts too long.Yet we can reverse such influences. If we know we will overreact to consumer products or housing options when we see a happy face (one reason good sales representatives and real estate agents are always smiling), we can take a moment before buying. If we know female job screeners are more likely to reject attractive female applicants, we can help screeners understand their biases — or hire outside screeners.John Gottman, the marriage expert, explains that we quickly “thin slice” information reliably only after we ground such snap reactions in “thick sliced” long-term study. When Dr. Gottman really wants to assess whether a couple will stay together, he invites them to his island retreat for a much longer evaluation: two days, not two seconds.Our ability to mute our hard-wired reactions by pausing is what differentiates us from animals: dogs can think about the future only intermittently or for a few minutes. But historically we have spent about 12 percent of our days contemplating the longer term. Although technology might change the way we react, it hasn’t changed our nature. We still have the imaginative capacity to rise above temptation and reverse the high-speed trend.31. The time needed in making decisions may____.[A] vary according to the urgency of the situation[B] prove the complexity of our brain reaction[C] depend on the importance of the assessment[D] predetermine the accuracy of our judgment32. Our reaction to a fast-food logo shows that snap decisions____.[A] can be associative[B] are not unconscious[C] can be dangerous[D] are not impulsive33. To reverse the negative influences of snap decisions, we should____.[A] trust our first impression[B] do as people usually do[C] think before we act[D] ask for expert advice34. John Gottman says that reliable snap reactions are based on____.[A] critical assessment[B] ‘‘thin sliced’’ study[C] sensible explanation[D] adequate information35. The author’s attitu de toward reversing the high-speed trend is____.[A] tolerant[B] uncertain[C] optimistic[D] doubtfulText 4Europe is not a gender-equality heaven. In particular, the corporate workplace will never be completely family—friendly until women are part of senior management decisions, and Europe’s top corporate-governance positions remain overwhelmingly male. Indeed, women hold only 14 percent of positions on Europe corporate boards.The Europe Union is now considering legislation to compel corporate boards to maintain a certain proportion of women—up to 60 percent. This proposed mandate was born of frustration. Last year, Europe Commission Vice President Viviane Reding issued a call to voluntary action. Reding invited corporations to sign up for gender balance goal of 40 percent female board membership. But her appeal was considered a failure: only 24 companies took it up.Do we need quotas to ensure that women can continue to climb the corporate Ladder fairy as they balance work and family?“Personally, I don’t like quotas,” Reding said recently. “But I like what the quotas do.” Quotas get action: they “open the way to equality and they break through the glass ceiling,” according to Reding, a result seen in France and other countries with legally binding provisions on placing women in top business positions.I understand Reding’s reluctance and her frustration. I don’t like quotas either; they run counter to my belief in meritocracy, government by the capable. But, when one considers the obstacles to achieving the meritocratic ideal, it does look as if a fairer world must be temporarily ordered.After all, four decades of evidence has now shown that corporations in Europe as the US are evading the meritocratic hiring and promotion of women to top position— no matter how much “soft pressure” is put upon them. When women do break through to the summit of corporate power--as, for example, Sheryl Sandberg recently did at Facebook—they attract massive attention precisely because they remain the exception to the rule.If appropriate pubic policies were in place to help all women---whether CEOs or their children’s caregivers--and all families, Sandberg would be no more newsworthy than any other highly capable person living in a more just society.36. In the European corporate workplace, generally_____.[A] women take the lead[B] men have the final say[C] corporate governance is overwhelmed[D] senior management is family-friendly37. The European Union’s intended legislation is ________.[A] a reflection of gender balance[B] a reluctant choice[C] a response to Reding’s call[D] a voluntary action38. According to Reding, quotas may help women ______.[A] get top business positions[B] see through the glass ceiling[C] balance work and family[D] anticipate legal results39. The author’s attitude toward Reding’s appeal is one of _________.[A] skepticism[B] objectiveness[C] indifference[D] approval40. Women entering top management become headlines due to the lack of ______.[A] more social justice[B] massive media attention[C] suitable public policies[D] greater “soft pressure”Part BDirections:You are going to read a list of headings and a text. Choose the most suitable heading from the list A-F for each numbered paragraph (41-45).Mark your answers on ANSWER SHEET1. (10 points)[A] Live like a peasant[B] Balance your diet[C] Shopkeepers are your friends[D] Remember to treat yourself[E] Stick to what you need[F] Planning is everything[G] Waste not, want notThe hugely popular blog the Skint Foodie chronicles how Tony balances his love of good food with living on benefits. After bills, Tony has £60 a week to spend, £40 of which goes on food, but 10 years ago he was earning £130,000 a year working in corporate communications and eating at London's best restaurants at least twice a week. Then his marriage failed, his career burned out and his drinking became serious. "The community mental health team saved my life. And I feltlike that again, to a certain degree, when people responded to the blog so well. It gave me the validation and confidence that I'd lost. But it's still a day-by-day thing." Now he's living in a council flat and fielding offers from literary agents. He's feeling positive, but he'll carry on blogging - not about eating as cheaply as you can - "there are so many people in a much worse state, with barely any money to spend on food" - but eating well on a budget. Here's his advice for economical foodies.41._____________________Impulsive spending isn't an option, so plan your week's menu in advance, making shopping lists for your ingredients in their exact quantities. I have an Excel template for a week of breakfast, lunch and dinner. Stop laughing: it's not just cost effective but helps you balance your diet. It's also a good idea to shop daily instead of weekly, because, being human, you'll sometimes change your mind about what you fancy.42________________________This is where supermarkets and their anonymity come in handy. With them, there's not the same embarrassment as when buying one carrot in a little greengrocer. And if you plan properly, you'll know that you only need, say, 350g of shin of beef and six rashers of bacon, not whatever weight is pre-packed in the supermarket chiller.43____________________________You may proudly claim to only have frozen peas in the freezer - that's not good enough. Mine is filled with leftovers, bread, stock, meat and fish. Planning ahead should eliminate wastage, but if you have surplus vegetables you'll do a vegetable soup, and all fruits threa tening to “go off” will be cooked or juiced.44_______________________Everyone says this, but it really is a top tip for frugal eaters. Shop at butchers, delis and fish-sellers regularly, even for small things, and be super friendly. Soon you'll feel comfortable asking if they've any knuckles of ham for soups and stews, or beef bones, chicken carcasses and fish heads for stock which, more often than not, they’ll let you have for free.45______________________You won't be eating out a lot, but save your pennies and once every few months treat yourself to a set lunch at a good restaurant —£1.75 a week for three months gives you £21 - more than enough for a three-course lunch at Michelin-starred Arbutus. It's £16.95 there - or £12.99 for a large pizza from Domino's: I know which I'd rather eat.Section III Translation46. Directions:Translate the following text from English to Chinese. Write your translation on ANSWER SHEET2. (15 points)I can pick a date from the past 53 years and know instantly where I was, what happened in the news and even the day of the week. I’ve been able to do this since I was 4.I never feel overwhelmed with the amount of information my brain absorbs. My mind seems to be able to cope and the information is stored away neatly. When I think of a sad memory, I do what everybody does – try to put it to one side. I don't think it's harder for me just because mymemory is clearer. Powerful memory doesn't make my emotions any more acute or vivid. I can recall the day my grandfather died and the sadness I felt when we went to the hospital the day before. I also remember that the musical play Hair opened on Broadway on the same day – they both just pop into my mind in the same way.Section IV WritingPart A47. Directions:Suppose your class is to hold a charity sale for kids in need of help. Write your classmates an e-mail to1) inform them about the details, and2) encourage them to participate.You should write about 100 words.Don’t use your own name. U se “Li Ming” instead. Don't write your address. (10 points)Part B48. Write an essay based on the following chart. In your writing, you should(1) interpret the chart, and(2) give your commentsYou should write about 150 words.Write your essay on ANSWER SHEET 2. (15 points)2013年全国硕士研究生入学统一考试英语(二)试题Section I: Use of English (10 points)1 - 5: ADBDC6 - 10: BBDBA11-15: ADCCC16-20: CABADSection II: Reading Comprehension (50 points)21-25: ADBBC26-30: CCDCD31-35: DACDC36-40: BAADC41-45: FEGCDSection III :Translation (15 Points)从过去的53年中任选一天,我都能立刻知道当时自己在哪里,新闻中发生了什么事情,甚至那天是周几。
本试卷分第I卷(客观题)和第II卷(主观题)两部分。
共四大题,34小题。
考试形式为开卷书面必达。
可查阅所带教材等书面资料,但不得相互讨论和互借资料。
考试时间为60分钟。
试卷满分为100分。
注意事项:1.作答前,考生务必用0.5毫米黑色墨水签字笔将学校、班级、姓名、准考证号码填(涂)在答题卡的相应位置上。
2.答客观题时必须用2B铅笔将答题卡上对应题号的正确选项涂黑。
如需改动,用橡皮擦干净后,再途选其他答案,答案不能答在试卷上。
3.答主观题时必须用0.5毫米黑色墨水签字笔作答,答案写在答题卡各题目指定区域内相应位置上。
如需改动,先划掉原来的答案,然后再写上新的答案。
不准使用铅笔盒涂改液。
不按以上要求作答的答案无效。
4.考生必须保持答题卡的整洁。
考试结束后,请将答题卡交回。
第I卷(客观题共60分)一、单项选择题:在下列各题的四个选项中,只有一项最符合题意。
每小题选出答案后,用2B铅笔将答题卡上对应题号的选项涂黑。
(本答题共20小题,每小题2分,共40分)1.2012年11月4日,中国共产党第十八次全国代表大会通过关于《中国共产党章程(修正案)》的决议。
党章把同马克思列宁主义、毛泽东思想、邓小平理论、“三个代表”重要思想一道确立为党的行动指南。
A.科学发展观B.中华民族传统文化C.各族人民的共同理想D.中国特色社会主义2.2012年9月25日,国务院新闻办公室发表《钓鱼岛是中国的固有领土》白皮书。
白皮书系统阐明和论证了钓鱼岛自古以来就是中国固有领土的事实,表明了中国政府和人民维护钓鱼岛主权的决心。
对钓鱼岛问题,我们应有的正确态度是。
①钓鱼岛及其附属岛屿自古以来就是中国的神圣领土②坚决维护国家主权,绝不会屈服于任何外来压力③可以采取任何手段表达爱国诉求④要合法、理性、文明爱国A.①②③B.①②④C.①③④D.②③④3.2012年7月24日,我国成立的下辖西沙、中沙、南沙诸群岛及其海域,我国领土最南端,陆地面积最小、总面积最大、人口最少的地级市是。
2013年普通高等学校招生全国统一考试(Ⅱ)一.选择题(共12小题)1.已知集合M={x|(x﹣1)2<4,x∈R},N={﹣1,0,1,2,3},则M∩N=()A.{0,1,2}B.{﹣1,0,1,2}C.{﹣1,0,2,3}D.{0,1,2,3}2.设复数z满足(1﹣i)z=2i,则z=()A.﹣1+i B.﹣1﹣i C.1+i D.1﹣i3.等比数列{a n}的前n项和为S n,已知S3=a2+10a1,a5=9,则a1=()A.B.C.D.4.已知m,n为异面直线,m⊥平面α,n⊥平面β.直线l满足l⊥m,l⊥n,l⊄α,l⊄β,则()A.α∥β且l∥αB.α⊥β且l⊥βC.α与β相交,且交线垂直于l D.α与β相交,且交线平行于l5.已知(1+ax)(1+x)5的展开式中x2的系数为5,则a=()A.﹣4 B.﹣3 C.﹣2 D.﹣16.执行右面的程序框图,如果输入的N=10,那么输出的S=()A.B.C.D.7.一个四面体的顶点在空间直角坐标系O﹣xyz中的坐标分别是(1,0,1),(1,1,0),(0,1,1),(0,0,0),画该四面体三视图中的正视图时,以zOx平面为投影面,则得到正视图可以为()A.B.C.D.8.设a=log36,b=log510,c=log714,则()A.c>b>a B.b>c>a C.a>c>b D.a>b>c9.已知a>0,实数x,y满足:,若z=2x+y的最小值为1,则a=()A.2 B.1 C.D.10.已知函数f(x)=x3+ax2+bx+c,下列结论中错误的是()A.∃x0∈R,f(x0)=0B.函数y=f(x)的图象是中心对称图形C.若x0是f(x)的极小值点,则f(x)在区间(﹣∞,x0)单调递减D.若x0是f(x)的极值点,则f′(x0)=011.设抛物线C:y2=2px(p>0)的焦点为F,点M在C上,|MF|=5,若以MF为直径的圆过点(0,2),则C的方程为()A.y2=4x或y2=8x B.y2=2x或y2=8xC.y2=4x或y2=16x D.y2=2x或y2=16x12.已知点A(﹣1,0),B(1,0),C(0,1),直线y=ax+b(a>0)将△ABC分割为面积相等的两部分,则b的取值范围是()A.(0,1)B.C.D.二.填空题(共4小题)13.已知正方形ABCD的边长为2,E为CD的中点,则•=.14.从n个正整数1,2,…,n中任意取出两个不同的数,若取出的两数之和等于5的概率为,则n=.15.设θ为第二象限角,若tan(θ+)=,则sinθ+cosθ=.16.等差数列{a n}的前n项和为S n,已知S10=0,S15=25,则nS n的最小值为.三.解答题(共7小题)17.△ABC在内角A、B、C的对边分别为a,b,c,已知a=bcosC+csinB.(Ⅰ)求B;(Ⅱ)若b=2,求△ABC面积的最大值.18.如图,直棱柱ABC﹣A1B1C1中,D,E分别是AB,BB1的中点,AA1=AC=CB=AB.(Ⅰ)证明:BC1∥平面A1CD(Ⅱ)求二面角D﹣A1C﹣E的正弦值.19.经销商经销某种农产品,在一个销售季度内,每售出1t该产品获利润500元,未售出的产品,每1t亏损300元.根据历史资料,得到销售季度内市场需求量的频率分布直方图,如图所示.经销商为下一个销售季度购进了130t该农产品.以x(单位:t,100≤x≤150)表示下一个销售季度内的市场需求量,T(单位:元)表示下一个销售季度内经销该农产品的利润.(Ⅰ)将T表示为x的函数;(Ⅱ)根据直方图估计利润T不少于57000元的概率;(Ⅲ)在直方图的需求量分组中,以各组的区间中点值代表该组的各个值,并以需求量落入该区间的频率作为需求量取该区间中点值的概率(例如:若x∈[100,110))则取x=105,且x=105的概率等于需求量落入[100,110)的频率,求T的数学期望.20.平面直角坐标系xOy中,过椭圆M:(a>b>0)右焦点的直线x+y﹣=0交M于A,B两点,P为AB的中点,且OP的斜率为.(Ⅰ)求M的方程(Ⅱ)C,D为M上的两点,若四边形ACBD的对角线CD⊥AB,求四边形ACBD面积的最大值.21.已知函数f(x)=e x﹣ln(x+m)(Ι)设x=0是f(x)的极值点,求m,并讨论f(x)的单调性;(Ⅱ)当m≤2时,证明f(x)>0.22.已知动点P、Q都在曲线(β为参数)上,对应参数分别为β=α与β=2α(0<α<2π),M为PQ的中点.(1)求M的轨迹的参数方程;(2)将M到坐标原点的距离d表示为α的函数,并判断M的轨迹是否过坐标原点.2018年04月22日fago的高中数学组卷参考答案与试题解析一.选择题(共12小题)1.已知集合M={x|(x﹣1)2<4,x∈R},N={﹣1,0,1,2,3},则M∩N=()A.{0,1,2}B.{﹣1,0,1,2}C.{﹣1,0,2,3}D.{0,1,2,3}【分析】求出集合M中不等式的解集,确定出M,找出M与N的公共元素,即可确定出两集合的交集.【解答】解:由(x﹣1)2<4,解得:﹣1<x<3,即M={x|﹣1<x<3},∵N={﹣1,0,1,2,3},∴M∩N={0,1,2}.故选:A.【点评】此题考查了交集及其运算,熟练掌握交集的定义是解本题的关键.2.设复数z满足(1﹣i)z=2i,则z=()A.﹣1+i B.﹣1﹣i C.1+i D.1﹣i【分析】根据所给的等式两边同时除以1﹣i,得到z的表示式,进行复数的除法运算,分子和分母同乘以分母的共轭复数,整理成最简形式,得到结果.【解答】解:∵复数z满足z(1﹣i)=2i,∴z==﹣1+i故选:A.【点评】本题考查代数形式的除法运算,是一个基础题,这种题目若出现一定是一个送分题目,注意数字的运算.3.等比数列{a n}的前n项和为S n,已知S3=a2+10a1,a5=9,则a1=()A.B.C.D.【分析】设等比数列{a n}的公比为q,利用已知和等比数列的通项公式即可得到,解出即可.【解答】解:设等比数列{a n}的公比为q,∵S3=a2+10a1,a5=9,∴,解得.∴.故选:C.【点评】熟练掌握等比数列的通项公式是解题的关键.4.已知m,n为异面直线,m⊥平面α,n⊥平面β.直线l满足l⊥m,l⊥n,l⊄α,l⊄β,则()A.α∥β且l∥αB.α⊥β且l⊥βC.α与β相交,且交线垂直于l D.α与β相交,且交线平行于l【分析】由题目给出的已知条件,结合线面平行,线面垂直的判定与性质,可以直接得到正确的结论.【解答】解:由m⊥平面α,直线l满足l⊥m,且l⊄α,所以l∥α,又n⊥平面β,l⊥n,l⊄β,所以l∥β.由直线m,n为异面直线,且m⊥平面α,n⊥平面β,则α与β相交,否则,若α∥β则推出m∥n,与m,n异面矛盾.故α与β相交,且交线平行于l.故选:D.【点评】本题考查了平面与平面之间的位置关系,考查了平面的基本性质及推论,考查了线面平行、线面垂直的判定与性质,考查了学生的空间想象和思维能力,是中档题.5.已知(1+ax)(1+x)5的展开式中x2的系数为5,则a=()A.﹣4 B.﹣3 C.﹣2 D.﹣1【分析】由题意利用二项展开式的通项公式求得展开式中x2的系数为+a•=5,由此解得a的值.【解答】解:已知(1+ax)(1+x)5=(1+ax)(1+x+x2+x3+x4+x5)展开式中x2的系数为+a•=5,解得a=﹣1,故选:D.【点评】本题主要考查二项式定理的应用,二项式展开式的通项公式,求展开式中某项的系数,属于中档题.6.执行右面的程序框图,如果输入的N=10,那么输出的S=()A. B.C. D.【分析】从赋值框给出的两个变量的值开始,逐渐分析写出程序运行的每一步,便可得到程序框图表示的算法的功能.【解答】解:框图首先给累加变量S和循环变量i赋值,S=0+1=1,k=1+1=2;判断k>10不成立,执行S=1+,k=2+1=3;判断k>10不成立,执行S=1++,k=3+1=4;判断k>10不成立,执行S=1+++,k=4+1=5;…判断i>10不成立,执行S=,k=10+1=11;判断i>10成立,输出S=.算法结束.故选:B.【点评】本题考查解决程序框图中的循环结构时,常采用写出前几次循环的结果,找规律.7.一个四面体的顶点在空间直角坐标系O﹣xyz中的坐标分别是(1,0,1),(1,1,0),(0,1,1),(0,0,0),画该四面体三视图中的正视图时,以zOx平面为投影面,则得到正视图可以为()A.B.C.D.【分析】由题意画出几何体的直观图,然后判断以zOx平面为投影面,则得到正视图即可.【解答】解:因为一个四面体的顶点在空间直角坐标系O﹣xyz中的坐标分别是(1,0,1),(1,1,0),(0,1,1),(0,0,0),几何体的直观图如图,是正方体的顶点为顶点的一个正四面体,所以以zOx平面为投影面,则得到正视图为:故选:A.【点评】本题考查几何体的三视图的判断,根据题意画出几何体的直观图是解题的关键,考查空间想象能力.8.设a=log36,b=log510,c=log714,则()A.c>b>a B.b>c>a C.a>c>b D.a>b>c【分析】利用log a(xy)=log a x+log a y(x、y>0),化简a,b,c然后比较log32,log52,log72大小即可.【解答】解:因为a=log36=1+log32,b=log510=1+log52,c=log714=1+log72,因为y=log2x是增函数,所以log27>log25>log23,∵,,所以log32>log52>log72,所以a>b>c,故选:D.【点评】本题主要考查不等式与不等关系,对数函数的单调性的应用,不等式的基本性质的应用,属于基础题.9.已知a>0,实数x,y满足:,若z=2x+y的最小值为1,则a=()A.2 B.1 C.D.【分析】作出不等式对应的平面区域,利用线性规划的知识,通过平移即先确定z的最优解,然后确定a的值即可.【解答】解:作出不等式对应的平面区域,(阴影部分)由z=2x+y,得y=﹣2x+z,平移直线y=﹣2x+z,由图象可知当直线y=﹣2x+z经过点C时,直线y=﹣2x+z的截距最小,此时z最小.即2x+y=1,由,解得,即C(1,﹣1),∵点C也在直线y=a(x﹣3)上,∴﹣1=﹣2a,解得a=.故选:C.【点评】本题主要考查线性规划的应用,利用数形结合是解决线性规划题目的常用方法.10.已知函数f(x)=x3+ax2+bx+c,下列结论中错误的是()A.∃x0∈R,f(x0)=0B.函数y=f(x)的图象是中心对称图形C.若x0是f(x)的极小值点,则f(x)在区间(﹣∞,x0)单调递减D.若x0是f(x)的极值点,则f′(x0)=0【分析】利用导数的运算法则得出f′(x),分△>0与△≤0讨论,列出表格,即可得出.【解答】解:f′(x)=3x2+2ax+b.(1)当△=4a2﹣12b>0时,f′(x)=0有两解,不妨设为x1<x2,列表如下x(﹣∞,x1)x1(x1,x2)x2(x2,+∞)f′(x)+0﹣0+f(x)单调递增极大值单调递减极小值单调递增由表格可知:①x2是函数f(x)的极小值点,但是f(x)在区间(﹣∞,x2)不具有单调性,故C不正确.②∵+f(x)=+x3+ax2+bx+c=﹣+2c,=,∵+f(x)=,∴点P为对称中心,故B正确.③由表格可知x1,x2分别为极值点,则,故D正确.④∵x→﹣∞时,f(x)→﹣∞;x→+∞,f(x)→+∞,函数f(x)必然穿过x轴,即∃xα∈R,f(xα)=0,故A正确.(2)当△≤0时,,故f(x)在R上单调递增,①此时不存在极值点,故D正确,C不正确;②B同(1)中②正确;③∵x→﹣∞时,f(x)→﹣∞;x→+∞,f(x)→+∞,函数f(x)必然穿过x轴,即∃x0∈R,f(x0)=0,故A正确.综上可知:错误的结论是C.由于该题选择错误的,故选:C.【点评】熟练掌握导数的运算法则、中心得出的定义、单调性与极值的关系等基础知识与方法,考查了分类讨论的思想方法等基本方法.11.设抛物线C:y2=2px(p>0)的焦点为F,点M在C上,|MF|=5,若以MF为直径的圆过点(0,2),则C的方程为()A.y2=4x或y2=8x B.y2=2x或y2=8xC.y2=4x或y2=16x D.y2=2x或y2=16x【分析】根据抛物线方程算出|OF|=,设以MF为直径的圆过点A(0,2),在Rt△AOF 中利用勾股定理算出|AF|=.再由直线AO与以MF为直径的圆相切得到∠OAF=∠AMF,Rt△AMF中利用∠AMF的正弦建立关系式,从而得到关于p的方程,解之得到实数p的值,进而得到抛物线C的方程.【解答】解:∵抛物线C方程为y2=2px(p>0),∴焦点F坐标为(,0),可得|OF|=,∵以MF为直径的圆过点(0,2),∴设A(0,2),可得AF⊥AM,Rt△AOF中,|AF|==,∴sin∠OAF==,∵根据抛物线的定义,得直线AO切以MF为直径的圆于A点,∴∠OAF=∠AMF,可得Rt△AMF中,sin∠AMF==,∵|MF|=5,|AF|=∴=,整理得4+=,解之可得p=2或p=8因此,抛物线C的方程为y2=4x或y2=16x.故选:C.方法二:∵抛物线C方程为y2=2px(p>0),∴焦点F(,0),设M(x,y),由抛物线性质|MF|=x+=5,可得x=5﹣,因为圆心是MF的中点,所以根据中点坐标公式可得,圆心横坐标为=,由已知圆半径也为,据此可知该圆与y轴相切于点(0,2),故圆心纵坐标为2,则M点纵坐标为4,即M(5﹣,4),代入抛物线方程得p2﹣10p+16=0,所以p=2或p=8.所以抛物线C的方程为y2=4x或y2=16x.故选:C.【点评】本题给出抛物线一条长度为5的焦半径MF,以MF为直径的圆交抛物线于点(0,2),求抛物线的方程,着重考查了抛物线的定义与简单几何性质、圆的性质和解直角三角形等知识,属于中档题.12.已知点A(﹣1,0),B(1,0),C(0,1),直线y=ax+b(a>0)将△ABC分割为面积相等的两部分,则b的取值范围是()A.(0,1)B.C.D.【分析】解法一:先求得直线y=ax+b(a>0)与x轴的交点为M(﹣,0),由﹣≤0可得点M在射线OA上.求出直线和BC的交点N的坐标,①若点M和点A重合,求得b=;②若点M在点O和点A之间,求得<b<;③若点M在点A的左侧,求得>b>1﹣.再把以上得到的三个b的范围取并集,可得结果.解法二:考查临界位置时对应的b值,综合可得结论.【解答】解:解法一:由题意可得,三角形ABC的面积为=1,由于直线y=ax+b(a>0)与x轴的交点为M(﹣,0),由直线y=ax+b(a>0)将△ABC分割为面积相等的两部分,可得b>0,故﹣≤0,故点M在射线OA上.设直线y=ax+b和BC的交点为N,则由可得点N的坐标为(,).①若点M和点A重合,则点N为线段BC的中点,故N(,),把A、N两点的坐标代入直线y=ax+b,求得a=b=.②若点M在点O和点A之间,此时b>,点N在点B和点C之间,由题意可得三角形NMB的面积等于,即=,即=,可得a=>0,求得b<,故有<b<.③若点M在点A的左侧,则b<,由点M的横坐标﹣<﹣1,求得b>a.设直线y=ax+b和AC的交点为P,则由求得点P的坐标为(,),此时,由题意可得,三角形CPN的面积等于,即•(1﹣b)•|x N﹣x P|=,即(1﹣b)•|﹣|=,化简可得2(1﹣b)2=|a2﹣1|.由于此时b>a>0,0<a<1,∴2(1﹣b)2=|a2﹣1|=1﹣a2 .两边开方可得(1﹣b)=<1,∴1﹣b<,化简可得b>1﹣,故有1﹣<b<.再把以上得到的三个b的范围取并集,可得b的取值范围应是,故选:B.解法二:当a=0时,直线y=ax+b(a>0)平行于AB边,由题意根据三角形相似且面积比等于相似比的平方可得=,b=1﹣,趋于最小.由于a>0,∴b>1﹣.当a逐渐变大时,b也逐渐变大,当b=时,直线经过点(0,),再根据直线平分△ABC的面积,故a不存在,故b<.综上可得,1﹣<b<,故选:B.【点评】本题主要考查确定直线的要素,点到直线的距离公式以及三角形的面积公式的应用,还考察运算能力以及综合分析能力,分类讨论思想,属于难题.二.填空题(共4小题)13.已知正方形ABCD的边长为2,E为CD的中点,则•=2.【分析】根据两个向量的加减法的法则,以及其几何意义,可得要求的式子为()•(),再根据两个向量垂直的性质,运算求得结果.【解答】解:∵已知正方形ABCD的边长为2,E为CD的中点,则=0,故=()•()=()•()=﹣+﹣=4+0﹣0﹣=2,故答案为2.【点评】本题主要考查两个向量的加减法的法则,以及其几何意义,两个向量垂直的性质,属于中档题.14.从n个正整数1,2,…,n中任意取出两个不同的数,若取出的两数之和等于5的概率为,则n=8.【分析】列出从n个正整数1,2,…,n中任意取出两个不同的数的所有取法种数,求出和等于5的种数,根据取出的两数之和等于5的概率为列式计算n的值.【解答】解:从n个正整数1,2,…,n中任意取出两个不同的数,取出的两数之和等于5的情况有:(1,4),(2,3)共2种情况;从n个正整数1,2,…,n中任意取出两个不同的数的所有不同取法种数为,由古典概型概率计算公式得:从n个正整数1,2,…,n中任意取出两个不同的数,取出的两数之和等于5的概率为p=.所以,即,解得n=8.故答案为8.【点评】本题考查了古典概型及其概率计算公式,考查了组合数公式,解答此题时既可以按有序取,也可以按无序取,问题的实质是一样的.此题是基础题.15.设θ为第二象限角,若tan(θ+)=,则sinθ+cosθ=﹣.【分析】已知等式利用两角和与差的正切函数公式及特殊角的三角函数值化简,求出tanθ的值,再根据θ为第二象限角,利用同角三角函数间的基本关系求出sinθ与cosθ的值,即可求出sinθ+cosθ的值.【解答】解:∵tan(θ+)==,∴tanθ=﹣,而cos2θ==,∵θ为第二象限角,∴cosθ=﹣=﹣,sinθ==,则sinθ+cosθ=﹣=﹣.故答案为:﹣【点评】此题考查了两角和与差的正切函数公式,以及同角三角函数间的基本关系,熟练掌握公式是解本题的关键.16.等差数列{a n}的前n项和为S n,已知S10=0,S15=25,则nS n的最小值为﹣49.【分析】由等差数列的前n项和公式化简已知两等式,联立求出首项a1与公差d的值,结合导数求出nS n的最小值.【解答】解:设等差数列{a n}的首项为a1,公差为d,∵S10=10a1+45d=0,S15=15a1+105d=25,∴a1=﹣3,d=,∴S n=na1+d=n2﹣n,∴nS n=n3﹣n2,令nS n=f(n),∴f′(n)=n2﹣n,∴当n=时,f(n)取得极值,当n<时,f(n)递减;当n>时,f(n)递增;因此只需比较f(6)和f(7)的大小即可.f(6)=﹣48,f(7)=﹣49,故nS n的最小值为﹣49.故答案为:﹣49.【点评】此题考查了等差数列的性质,以及等差数列的前n项和公式,熟练掌握性质及公式是解本题的关键.三.解答题(共7小题)17.△ABC在内角A、B、C的对边分别为a,b,c,已知a=bcosC+csinB.(Ⅰ)求B;(Ⅱ)若b=2,求△ABC面积的最大值.【分析】(Ⅰ)已知等式利用正弦定理化简,再利用两角和与差的正弦函数公式及诱导公式变形,求出tanB的值,由B为三角形的内角,利用特殊角的三角函数值即可求出B的度数;(Ⅱ)利用三角形的面积公式表示出三角形ABC的面积,把sinB的值代入,得到三角形面积最大即为ac最大,利用余弦定理列出关系式,再利用基本不等式求出ac的最大值,即可得到面积的最大值.【解答】解:(Ⅰ)由已知及正弦定理得:sinA=sinBcosC+sinBsinC①,∵sinA=sin(B+C)=sinBcosC+cosBsinC②,∴sinB=cosB,即tanB=1,∵B为三角形的内角,∴B=;(Ⅱ)S=acsinB=ac,△ABC由已知及余弦定理得:4=a2+c2﹣2accos≥2ac﹣2ac×,整理得:ac≤,当且仅当a=c时,等号成立,则△ABC面积的最大值为××=××(2+)=+1.【点评】此题考查了正弦、余弦定理,三角形的面积公式,两角和与差的正弦函数公式,以及基本不等式的运用,熟练掌握定理及公式是解本题的关键.18.如图,直棱柱ABC﹣A1B1C1中,D,E分别是AB,BB1的中点,AA1=AC=CB=AB.(Ⅰ)证明:BC1∥平面A1CD(Ⅱ)求二面角D﹣A1C﹣E的正弦值.【分析】(Ⅰ)通过证明BC1平行平面A1CD内的直线DF,利用直线与平面平行的判定定理证明BC1∥平面A1CD(Ⅱ)证明DE⊥平面A1DC,作出二面角D﹣A1C﹣E的平面角,然后求解二面角平面角的正弦值即可.【解答】解:(Ⅰ)证明:连结AC1交A1C于点F,则F为AC1的中点,又D是AB中点,连结DF,则BC1∥DF,因为DF⊂平面A1CD,BC1⊄平面A1CD,所以BC1∥平面A1CD.(Ⅱ)因为直棱柱ABC﹣A1B1C1,所以AA1⊥CD,由已知AC=CB,D为AB的中点,所以CD⊥AB,又AA1∩AB=A,于是,CD⊥平面ABB1A1,设AB=2,则AA1=AC=CB=2,得∠ACB=90°,CD=,A1D=,DE=,A1E=3故A1D2+DE2=A1E2,即DE⊥A1D,所以DE⊥平面A1DC,又A1C=2,过D作DF⊥A1C于F,∠DFE为二面角D﹣A1C﹣E的平面角,在△A1DC中,DF==,EF==,所以二面角D﹣A1C﹣E的正弦值.sin∠DFE=.【点评】本题考查直线与平面平行的判定定理的应用,二面角的平面角的求法,考查空间想象能力与计算能力.19.经销商经销某种农产品,在一个销售季度内,每售出1t该产品获利润500元,未售出的产品,每1t亏损300元.根据历史资料,得到销售季度内市场需求量的频率分布直方图,如图所示.经销商为下一个销售季度购进了130t该农产品.以x(单位:t,100≤x≤150)表示下一个销售季度内的市场需求量,T(单位:元)表示下一个销售季度内经销该农产品的利润.(Ⅰ)将T表示为x的函数;(Ⅱ)根据直方图估计利润T不少于57000元的概率;(Ⅲ)在直方图的需求量分组中,以各组的区间中点值代表该组的各个值,并以需求量落入该区间的频率作为需求量取该区间中点值的概率(例如:若x∈[100,110))则取x=105,且x=105的概率等于需求量落入[100,110)的频率,求T的数学期望.【分析】(Ⅰ)由题意先分段写出,当x∈[100,130)时,当x∈[130,150)时,和利润值,最后利用分段函数的形式进行综合即可.(Ⅱ)由(I)知,利润T不少于57000元,当且仅当120≤x≤150.再由直方图知需求量X ∈[120,150]的频率为0.7,利用样本估计总体的方法得出下一个销售季度的利润T不少于57000元的概率的估计值.(Ⅲ)利用利润T的数学期望=各组的区间中点值×该区间的频率之和即得.【解答】解:(Ⅰ)由题意得,当x∈[100,130)时,T=500x﹣300(130﹣x)=800x﹣39000,当x∈[130,150)时,T=500×130=65000,∴T=.(Ⅱ)由(Ⅰ)知,利润T不少于57000元,当且仅当120≤x≤150.由直方图知需求量X∈[120,150]的频率为0.7,所以下一个销售季度的利润T不少于57000元的概率的估计值为0.7.(Ⅲ)依题意可得T的分布列如图,T4500053006100065000p0.10.20.30.4所以ET=45000×0.1+53000×0.2+61000×0.3+65000×0.4=59400.【点评】本题考查用样本的频率分布估计总体分布及识图的能力,求解的重点是对题设条件及直方图的理解,了解直方图中每个小矩形的面积的意义,是中档题.20.平面直角坐标系xOy中,过椭圆M :(a>b>0)右焦点的直线x+y ﹣=0交M于A,B两点,P为AB的中点,且OP 的斜率为.(Ⅰ)求M的方程(Ⅱ)C,D为M上的两点,若四边形ACBD的对角线CD⊥AB,求四边形ACBD面积的最大值.【分析】(Ⅰ)把右焦点(c,0)代入直线可解得c.设A(x1,y1),B(x2,y2),线段AB的中点P(x0,y0),利用“点差法”即可得到a,b的关系式,再与a2=b2+c2联立即可得到a,b,c.(Ⅱ)由CD⊥AB,可设直线CD的方程为y=x+t,与椭圆的方程联立得到根与系数的关系,即可得到弦长|CD|.把直线x+y﹣=0与椭圆的方程联立得到根与系数的关系,即可得到=即可得到关于t的表达式,利用二次函数的单调性弦长|AB|,利用S四边形ACBD即可得到其最大值.【解答】解:(Ⅰ)把右焦点(c,0)代入直线x+y﹣=0得c+0﹣=0,解得c=.设A(x1,y1),B(x2,y2),线段AB的中点P(x0,y0),则,,相减得,∴,∴,又=,∴,即a2=2b2.联立得,解得,∴M的方程为.(Ⅱ)∵CD⊥AB,∴可设直线CD的方程为y=x+t,联立,消去y得到3x2+4tx+2t2﹣6=0,∵直线CD与椭圆有两个不同的交点,∴△=16t2﹣12(2t2﹣6)=72﹣8t2>0,解﹣3<t<3(*).设C(x3,y3),D(x4,y4),∴,.∴|CD|===.联立得到3x2﹣4x=0,解得x=0或,∴交点为A(0,),B,∴|AB|==.===,∴S四边形ACBD∴当且仅当t=0时,四边形ACBD面积的最大值为,满足(*).∴四边形ACBD面积的最大值为.【点评】本题综合考查了椭圆的定义、标准方程及其性质、“点差法”、中点坐标公式、直线与椭圆相交问题转化为方程联立得到一元二次方程根与系数的关系、弦长公式、四边形的面积计算、二次函数的单调性等基础知识,考查了推理能力、数形结合的思想方法、计算能力、分析问题和解决问题的能力.21.已知函数f(x)=e x﹣ln(x+m)(Ι)设x=0是f(x)的极值点,求m,并讨论f(x)的单调性;(Ⅱ)当m≤2时,证明f(x)>0.【分析】(Ⅰ)求出原函数的导函数,因为x=0是函数f(x)的极值点,由极值点处的导数等于0求出m的值,代入函数解析式后再由导函数大于0和小于0求出原函数的单调区间;(Ⅱ)证明当m≤2时,f(x)>0,转化为证明当m=2时f(x)>0.求出当m=2时函数的导函数,可知导函数在(﹣2,+∞)上为增函数,并进一步得到导函数在(﹣1,0)上有唯一零点x0,则当x=x0时函数取得最小值,借助于x0是导函数的零点证出f(x0)>0,从而结论得证.【解答】(Ⅰ)解:∵,x=0是f(x)的极值点,∴,解得m=1.所以函数f(x)=e x﹣ln(x+1),其定义域为(﹣1,+∞).∵.设g(x)=e x(x+1)﹣1,则g′(x)=e x(x+1)+e x>0,所以g(x)在(﹣1,+∞)上为增函数,又∵g(0)=0,所以当x>0时,g(x)>0,即f′(x)>0;当﹣1<x<0时,g(x)<0,f′(x)<0.所以f(x)在(﹣1,0)上为减函数;在(0,+∞)上为增函数;(Ⅱ)证明:当m≤2,x∈(﹣m,+∞)时,ln(x+m)≤ln(x+2),故只需证明当m=2时f(x)>0.当m=2时,函数在(﹣2,+∞)上为增函数,且f′(﹣1)<0,f′(0)>0.故f′(x)=0在(﹣2,+∞)上有唯一实数根x0,且x0∈(﹣1,0).当x∈(﹣2,x0)时,f′(x)<0,当x∈(x0,+∞)时,f′(x)>0,从而当x=x0时,f(x)取得最小值.由f′(x0)=0,得,ln(x0+2)=﹣x0.故f(x)≥=>0.综上,当m≤2时,f(x)>0.【点评】本题考查了利用导数研究函数的单调性,利用导数求函数在闭区间上的最值,考查了不等式的证明,考查了函数与方程思想,分类讨论的数学思想,综合考查了学生分析问题和解决问题的能力.熟练函数与导数的基础知识是解决该题的关键,是难题.22.已知动点P、Q都在曲线(β为参数)上,对应参数分别为β=α与β=2α(0<α<2π),M为PQ的中点.(1)求M的轨迹的参数方程;(2)将M到坐标原点的距离d表示为α的函数,并判断M的轨迹是否过坐标原点.【分析】(1)利用参数方程与中点坐标公式即可得出;(2)利用两点之间的距离公式、三角函数的单调性即可得出.【解答】解:(1)依题意有P(2cosα,2sinα),Q(2cos2α,2sin2α),因此M(cosα+cos2α,sinα+sin2α).M的轨迹的参数方程为为参数,0<α<2π).(2)M点到坐标原点的距离d=(0<α<2π).当α=π时,d=0,故M的轨迹过坐标原点.【点评】本题考查了参数方程与中点坐标公式、两点之间的距离公式、三角函数的单调性,考查了推理能力与计算能力,属于中档题.23.【选修4﹣﹣5;不等式选讲】设a,b,c均为正数,且a+b+c=1,证明:(Ⅰ)(Ⅱ).【分析】(Ⅰ)依题意,由a+b+c=1⇒(a+b+c)2=1⇒a2+b2+c2+2ab+2bc+2ca=1,利用基本不等式可得3(ab+bc+ca)≤1,从而得证;(Ⅱ)利用基本不等式可证得:+b≥2a,+c≥2b,+a≥2c,三式累加即可证得结论.【解答】证明:(Ⅰ)由a2+b2≥2ab,b2+c2≥2bc,c2+a2≥2ca得:a2+b2+c2≥ab+bc+ca,由题设得(a+b+c)2=1,即a2+b2+c2+2ab+2bc+2ca=1,所以3(ab+bc+ca)≤1,即ab+bc+ca≤.(Ⅱ)因为+b≥2a,+c≥2b,+a≥2c,故+++(a+b+c)≥2(a+b+c),即++≥a+b+c.所以++≥1.【点评】本题考查不等式的证明,突出考查基本不等式与综合法的应用,考查推理论证能力,属于中档题.。
襄阳公司2013年磨操专业技能考试试卷(共100分)姓名:部门:岗位:得分:一、填空题(共20 分,每空 1 分)1、选粉细度的提高会使选粉机的选粉效率逐步(下降),产品细度越来越(小)。
2、磨制硅酸盐水泥时,入水泥磨的组分材料主要有(硅酸盐水泥孰料)、(石膏)和(混合材料)。
3、按水泥的性能和用途进行划分,水泥可以分为三类,即(通用水泥)、(专用水泥)和(特性水泥)。
4 、影响水泥安定性的因素主要有(f-CaO)、(氧化镁)、(三氧化硫)。
5 、表示水泥细度,常用的方法有(筛余百分数)、(比表面积)。
6 、硅酸盐水泥系列中共有六大品种,分别是(硅酸盐水泥)、(普通硅酸盐水泥)、(矿渣硅酸盐水泥)、(粉煤灰质硅酸盐水泥)、(火山灰质硅酸盐水泥)、(复合硅酸盐水泥)。
7、设备开机前应与相关部门联系确认后,具备开机条件,并确认(现场设备无人)后才允许开机。
二、判断题(共10 分,每题 1 分)1、挥发分高、灰分低的煤,其细度可以放粗些。
(√)2、安定性不合格的水泥为不合格品。
(√ )3、出磨水泥产生假凝现象一般是由于石膏配比过多。
(×)4、水泥制备过程中一般地必不可少的两种物料为硅酸盐熟料和石膏。
()5、通过调节煤磨循环风机进口阀门开度大小可调节煤粉细度。
(√)6、水泥细度越细早期强度越高,所以成品细度越细越好。
( × )7、煤粉越细,则燃烧的速度越快。
(√)8、生料立磨开磨时,未形成稳定料层就压辊,易造成振动(√)9、立磨振动的根本原因与料层稳定性和厚度、与液压系统压力稳定性有关(√)10、立磨循环负荷越小越好。
(×)三、选择题(共20 分,每题 2 分)1、水泥磨隔仓板堵塞,水泥磨系统负压( C )。
A、无变化B、会提高C、会下降2、目前用预分解窑生产水泥时,如果没有原料的预均化设施,则生料的均化多采用( B )。
A.连续式气力均化库B.间歇式气力均化库C.预均化堆场3、如果生料输送系统突然发生故障,造成生料喂料突然中断,上述故障处理方法错误的是:( A )A.分解炉喷煤量逐渐减少,直至全停B.窑头喷煤量逐渐减少,直至全停C.窑速逐渐降低,直至停窑D.通知相关岗位迅速检查生料输送系统4、启动立磨风机时或增大其进口风门的开度,预热器系统的出口负压将会( A )。
小学下册英语第2单元寒假试卷英语试题一、综合题(本题有100小题,每小题1分,共100分.每小题不选、错误,均不给分)1.I enjoy _______ (和家人一起)在公园散步。
2.Mr. Smith is a ______. He repairs cars.3.How many planets are in our solar system?A. 7B. 8C. 9D. 104.The capital of Chile is __________.5.What is the name of the famous scientist known for his laws of motion?A. GalileoB. Isaac NewtonC. Albert EinsteinD. Nikola TeslaB6.Sedimentary rocks can contain ______ from ancient organisms.7. A catalyst can speed up a _______ without being consumed. (反应)8.What do you call a written account of someone’s life?A. BiographyB. AutobiographyC. MemoirD. Journal9.The fish swims in _______ (清澈的) water.10.Which country is known for pyramids?A. GreeceB. EgyptC. MexicoD. China11. A _______ is a reaction that produces an explosion.12.The chemical symbol for tantalum is ______.13.The cake has ______ (berries) on top.14.The ______ of a plant can tell you about its environment. (植物的特征可以告诉你它的环境。
绝密★启用前2013年普通高等学校招生全国统一考(新课标Ⅱ卷)数学(文理合卷)注意事项:1. 本试卷分第Ⅰ卷(选择题)和第Ⅱ卷(非选择题)两部分。
答卷前考生将自己的姓名\准考证号填写在本试卷和答题卡相应位置。
2. 回答第Ⅰ卷时,选出每小题答案后,用铅笔把答题卡上对应题目的答案标号标黑,如需改动,用橡皮擦干净后,再选涂其他答案标号。
写在本试卷上无效。
3. 答第Ⅱ卷时,将答案写在答题卡上,写在本试卷上无效。
4. 考试结束,将试题卷和答题卡一并交回。
第Ⅰ卷(选择题 共50分)一、选择题:本大题共10小题。
每小题5分,共50分。
在每个小题给出的四个选项中,只有一项是符合题目要求的。
(1)(理数)已知集合}3,2,1,0,1{},,4)1({2-=∈<-=N R x x x M ,则=⋂N M ( )(A)}2,1,0{ (B)}2,1,0,1{- (C)}3,2,0,1{- (D)}3,2,1,0{ (文数)已知集合}3,2,1,0,1{},13{-=<<-=N x x M ,则=⋂N M ( )(A)}1,0,1,2{-- (B) }0,1,2,3{--- (C) }0,1,2{-- (D) }1,2,3{---(2)(理数)设复数z 满足i z i 2)1(=-,则z =( )(A)i +-1(B)i --1 (C)i +1 (D)i -1 (文数)=+i12( ) (A)22 (B)2 (C)2 (D)1(3)(理数)等比数列}{n a 的前n 项和为n S ,已知12310a a s +=,95=a ,则=1a ( ) (A)31 (B)31- (C)91 (D)91- (文数)设y x ,满足约束条件⎪⎩⎪⎨⎧≤≥-+≥+-30101x y x y x ,则y x z 32-=的最小值是( )(A)7- (B)6- (C)5- (D)3-(4)(理数)已知n m ,为异面直线,α⊥m ,β⊥n 。
小学下册英语第二单元真题(含答案)英语试题一、综合题(本题有100小题,每小题1分,共100分.每小题不选、错误,均不给分)1.The __________ is a large area of wetlands in the United States. (大沼泽地)2. A ________ (乌龟) moves slowly and lives both on land and in water.3.The _____ (小鸟) is building a nest in the tree.4.We see _____ (fish) in the aquarium.5.My dad loves __________. (烹饪)6.The _____ (小羊) is very fluffy.7.There are many ________ (树木) in the forest.8.The ________ (technology) is advancing quickly.9.The ______ is responsible for carrying oxygen in the blood.10.What is the opposite of hot?A. WarmB. CoolC. ColdD. Mild11.What do we call a young horse?A. CalfB. FoalC. KidD. Lamb12.My aunt works as a __________ (护士) in the clinic.13.Which shape has four equal sides?A. RectangleB. CircleC. SquareD. Triangle答案:C14.You can grow _______ in pots on your balcony.15.The sun is shining ________ today.16. A chemical reaction involves the rearranging of ______.17.The garden has many _______ that blossom beautifully all year long.18.I see a deer in the ___. (forest)19.My favorite sport is ______ (羽毛球).20.What is the value of 10 3 + 5?A. 10B. 11C. 12D. 13答案:B21.The peacock has beautiful _______ (羽毛).22.What do we call the study of the universe?A. AstronomyB. AstrologyC. CosmologyD. Astrophysics答案:A23.What is the term for a baby rabbit?A. KittenB. BunnyC. CubD. Pup答案:B24.I enjoy exploring with my toy ________ (玩具名称).25.The ________ has a sweet fragrance.26.He is _______ (playing) chess with his dad.27.I can have endless fun with my ________ (玩具类型).28.Which animal is known for its ability to change color?A. ChameleonB. FrogC. PenguinD. Snake答案:A29.The chemical formula for iron(III) oxide is _______.30.I enjoy ______ (与家人一起) playing games.31.Which of these is NOT a type of fruit?A. AppleB. OrangeC. CarrotD. Banana答案:C32.The _______ is home to various creatures.33.The ______ is where we live on Earth.34.What is the name of the famous cat in "Puss in Boots"?A. FelixB. TomC. PussD. Garfield答案:C35.I have a ___ (pen/pencil) in my bag.36.My best friend's family has a _______ (动物). 它的性格很 _______ (形容词).37._____ (oak) trees are strong and sturdy.38.What is the opposite of ‘full’?A. EmptyB. PackedC. CompleteD. Whole39. A solution that contains a high concentration of solute is called ______.40.The _______ is the center of our solar system.41.I see a ___ in the water. (fish)42.The stars are shining ________.43.What do you call a story with magical elements?A. BiographyB. FictionC. Non-fictionD. History44.What is the term for the outer layer of the atmosphere?A. TroposphereB. StratosphereC. MesosphereD. Exosphere答案:D Exosphere45.What instrument is used to measure angles?A. RulerB. CompassC. ProtractorD. Caliper答案:C46.What type of animal is a salmon?A. MammalB. ReptileC. BirdD. Fish答案:D47.What is the name of the first successful Mars rover mission?A. SpiritB. OpportunityC. CuriosityD. Perseverance48.The _______ (蜥蜴) can be found on warm rocks.49.The chemical formula for lithium hydroxide is ______.50. A tarantula can defend itself with its ______ (毒螯).51.What do you call a baby elephant?A. CalfB. FoalC. PupD. Lamb52.My cat loves to nap in the ______ (阳光).53.The country known for its biodiversity is ________ (以生物多样性闻名的国家是________).54.What is the name of the popular board game where you try to guess words?A. PictionaryB. CharadesC. TabooD. Scattergories答案:A55.The ________ was a significant conflict in American history.56. A __________ is a substance that helps speed up a reaction.57.I can ______ (count) to .58.The chemical symbol for rhenium is ______.59.Do you know how to __________ (动词) a __________ (玩具名)?60.For lunch, I usually have a ________ (三明治) and some ________ (水果).61.What is the name of the famous volcano in Hawaii?A. KilaueaB. Mauna LoaC. Mauna KeaD. All of the above答案:D All of the above62. A reaction that occurs rapidly is called a ______ reaction.63.I hope to one day become a ______ (科学家) and contribute to important discoveries.64.What do we call the traditional game played with a ball and net?A. CricketB. BaseballC. TennisD. Soccer65.The ______ (颜色) of leaves changes with the seasons.66.The ________ was a significant moment in the history of labor rights.67.__________ is what happens when ice absorbs heat and melts.68.The Ptolemaic model placed Earth at the center of the ______.69.When water boils, it turns into _______.70.What do you call a baby deer?A. CalfB. FawnC. KidD. Foal答案:B71.The study of plants can reveal much about our planet's ______ systems. (植物学的研究可以揭示我们星球生态系统的许多内容。