2012答案广东省汕头市中考真题
2012年广东中考语文试卷及答案
2012年广东省初中毕业生学业考试(信息卷一)语文卷说明:1.全卷共8页,考试时间为120分钟,总分120+10分。
2.答卷前,考生必须将自己的姓名、学校、班级按要求填写在密封线左边的空格内。
3.答案可用黑色或蓝色字迹的钢笔、签字笔按各题要求答在试卷上,不能用铅笔、圆珠笔和红笔。
4.考试结束时,将试卷交回。
一、基础(25分)1. 根据课文默写或填空。
(10分)(1) 最爱湖东行不足,_______________。
(白居易《钱塘湖春行》)(1分)(2) ______________,童稚携壶浆。
(《观刈麦》白居易)(1分)(3) 王维《使至塞上》中描绘了边陲大漠中壮阔雄奇的景象,境界阔大,气象雄浑,堪称“千古奇观”的名句是“_______________,________________。
”(2分)(4) 凡曝沙之鸟,_____________,_____________,毛羽鳞鬣之间皆有喜气。
(袁宏道《满井游记》)(2分)(5) 把孟浩然《望洞庭湖赠张丞相》默写完整。
(4分)八月湖水平,涵虚混太清。
气蒸云梦泽,波撼岳阳城。
______________,______________。
____________,______________。
2. 根据拼音写出相应的词语。
(4分)(1)今年,蝉鸣得早。
杜鹃花还没有líng luò(),就听见断断续续的蝉声了。
(2) 上帝在这对难念的眼睛中看到了wú yǔ lún bǐ()的美和更大的力量,其中还包含一种新的东西。
(3) 她轻盈地跳跃、旋转,一会儿穿过小树林,一会儿又奔到小溪旁,俯身拾起一块石子丢入溪水中,溪水激起了lián yī()。
(4)如不能辨异,可令读经院哲学,盖此辈皆chuī máo qiú cī()之人。
3. 下面语段中,没有语病的一组句子是( )(3分)①有关医学人士与心理学家认为,一些青少年长期迷恋上网,会患上一种病——“网络成瘾症”。
2012年广东省汕头市中考数学试卷解析版-推荐下载
D. ( a)2=2a2
对全部高中资料试卷电气设备,在安装过程中以及安装结束后进行高中资料试卷调整试验;通电检查所有设备高中资料电试力卷保相护互装作置用调与试相技互术关,系电通,力1根保过据护管生高线0产中不工资仅艺料可高试以中卷解资配决料置吊试技顶卷术层要是配求指置,机不对组规电在范气进高设行中备继资进电料行保试空护卷载高问与中题带资22负料,荷试而下卷且高总可中体保资配障料置各试时类卷,管调需路控要习试在题验最到;大位对限。设度在备内管进来路行确敷调保设整机过使组程其高1在中正资,常料要工试加况卷强下安看2与全22过,22度并22工且22作尽2下可护1都能关可地于以缩管正小路常故高工障中作高资;中料对资试于料卷继试连电卷接保破管护坏口进范处行围理整,高核或中对者资定对料值某试,些卷审异弯核常扁与高度校中固对资定图料盒纸试位,卷置编工.写况保复进护杂行层设自防备动腐与处跨装理接置,地高尤线中其弯资要曲料避半试免径卷错标调误高试高等方中,案资要,料求编5试技写、卷术重电保交要气护底设设装。备备4置管高调、动线中试电作敷资高气,设料中课并3技试资件且、术卷料拒管中试试调绝路包验卷试动敷含方技作设线案术,技槽以来术、及避管系免架统不等启必多动要项方高方案中式;资,对料为整试解套卷决启突高动然中过停语程机文中。电高因气中此课资,件料电中试力管卷高壁电中薄气资、设料接备试口进卷不行保严调护等试装问工置题作调,并试合且技理进术利行,用过要管关求线运电敷行力设高保技中护术资装。料置线试做缆卷到敷技准设术确原指灵则导活:。。在对对分于于线调差盒试动处过保,程护当中装不高置同中高电资中压料资回试料路卷试交技卷叉术调时问试,题技应,术采作是用为指金调发属试电隔人机板员一进,变行需压隔要器开在组处事在理前发;掌生同握内一图部线纸故槽资障内料时,、,强设需电备要回制进路造行须厂外同家部时出电切具源断高高习中中题资资电料料源试试,卷卷线试切缆验除敷报从设告而完与采毕相用,关高要技中进术资行资料检料试查,卷和并主检且要测了保处解护理现装。场置设。备高中资料试卷布置情况与有关高中资料试卷电气系统接线等情况,然后根据规范与规程规定,制定设备调试高中资料试卷方案。
汕头市2012年中考数学试题精析
2012年中考数学精析系列——汕头卷(本试卷满分150分,考试时间100分钟)一、选择题(本大题共8小题,每小题4分,共32分)在每小题列出的四个选项中,只有一个是正确的,请把答题卡上对应题目所选的选项涂黑.3.(2012广东汕头4分)数据8、8、6、5、6、1、6的众数是【】A. 1 B. 5 C. 6 D.8【答案】C。
【考点】众数。
【分析】众数是在一组数据中,出现次数最多的数据,这组数据中,出现次数最多的是6,故这组数据的众数为6。
故选C。
4.(2012广东汕头4分)如图所示几何体的主视图是【】A.B.C.D.【答案】B。
【考点】简单组合体的三视图。
【分析】从正面看,此图形的主视图有3列组成,从左到右小正方形的个数是:1,3,1。
故选B。
5.(2012广东汕头4分)下列平面图形,既是中心对称图形,又是轴对称图形的是【】A.等腰三角形B.正五边形C.平行四边形D.矩形【答案】D。
【考点】中心对称图形,轴对称图形。
【分析】根据轴对称图形与中心对称图形的概念,轴对称图形两部分沿对称轴折叠后可重合;中心对称图形是图形沿对称中心旋转180度后与原图重合。
因此,A、∵等腰三角形不是中心对称图形,是轴对称图形,故此选项错误;B、∵正五边形形不是中心对称图形,是轴对称图形,故此选项错误;C、平行四边形图形是中心对称图形,但不是轴对称图形,故此选项错误;D、∵矩形既是中心对称图形,又是轴对称图形,故此选项正确。
故选D。
6.(2012广东汕头4分)下列运算正确的是【】2a=2aA.a+a=a2 B.(﹣a3)2=a5 C.3a•a2=a3 D.()22【答案】D。
【考点】合并同类项,幂的乘方与积的乘方,同底数幂的乘法。
【分析】根据合并同类项,幂的乘方与积的乘方,同底数幂的乘法运算法则逐一计算作出判断:A、a+a=2a,故此选项错误;B、(﹣a3)2=a6,故此选项错误;C、3a•a2=3a3,故此选项错误;2a=2a,故此选项正确。
2012年广东省汕头市中考数学试题(解析版)
2012年汕头中考数学试卷解析一、选择题(本大题共8小题,每小题4分,共32分)在每小题列出的四个选项中,只有一个是正确的,请把答题卡上对应题目所选的选项涂黑.A.5B.﹣5 C.D.﹣考点:绝对值。
分析:根据绝对值的性质求解.解答:解:根据负数的绝对值等于它的相反数,得|﹣5|=5.故选A.点评:此题主要考查的是绝对值的性质:一个正数的绝对值是它本身;一个负数的绝对值是它的相反数;0的绝对值是0.A.0.64×107B.6.4×106C.64×105D.640×104考点:科学记数法—表示较大的数。
分析:科学记数法的形式为a×10n,其中1≤a<10,n为整数.解答:解:=6.4×106.故选B.点评:此题考查用科学记数法表示较大的数,其规律为1≤|a|<10,n为比原数的整数位数小1的正整数.A.1B.5C.6D.8考点:众数。
分析:众数指一组数据中出现次数最多的数据,根据众数的定义即可求解.解答:解:6出现的次数最多,故众数是6.故选C.点评:本题主要考查了众数的概念,注意众数是指一组数据中出现次数最多的数据,它反映了一组数据的多数水平,一组数据的众数可能不是唯一的,比较简单.4.如图所示几何体的主视图是()A.B.C.D.考点:简单组合体的三视图。
分析:主视图是从立体图形的正面看所得到的图形,找到从正面看所得到的图形即可.注意所有的看到的棱都应表现在主视图中.解答:解:从正面看,此图形的主视图有3列组成,从左到右小正方形的个数是:1,3,1.故选:B.点评:本题主要考查了三视图的知识,主视图是从物体的正面看得到的视图,关键是掌握主视图所看的位置.5.下列平面图形,既是中心对称图形,又是轴对称图形的是()A.等腰三角形B.正五边形C.平行四边形D.矩形考点:中心对称图形;轴对称图形。
分析:根据中心对称图形的定义旋转180°后能够与原图形完全重合即是中心对称图形,以及轴对称图形的定义即可判断出.解答:解:A、∵等腰三角形旋转180°后不能与原图形重合,∴此图形不是中心对称图形,但它是轴对称图形,故此选项错误;B、∵正五边形形旋转180°后不能与原图形重合,∴此图形不是中心对称图形,是轴对称图形,故此选项错误;C、平行四边形旋转180°后能与原图形重合,此图形是中心对称图形,但不是轴对称图形,故此选项错误;D、∵矩形旋转180°后能与原图形重合,∴此图形不是中心对称图形,是轴对称图形,故此选项正确.故选D.点评:此题主要考查了中心对称图形与轴对称的定义,根据定义得出图形形状是解决问题的关键.A.a+a=a2B.(﹣a3)2=a5C.3a•a2=a3D.(a)2=2a2考点:幂的乘方与积的乘方;合并同类项;同底数幂的乘法。
2012年广东省汕头市中考历史试题
2012年广东省汕头市中考历史试题吴涛整理(满分为80分,考试用时为60分钟)一、单项选择题(本大题共28小题,每小题2分,共56分。
在每小题列出的四个选项中,只有一个是正确的,请把答题卡对应题目所选的选项涂黑)(2012·广东汕头)1.西周末年,昏庸的幽王上演了一场“烽火戏诸侯”的闹剧。
诸侯率兵前往护卫周王是遵守了()DA.封建制的法规 B.禅让制的规则 C.世袭制的传统 D.分封制的义务(2012·广东汕头)2.历史小组的同学以“中央集权制度”为主题进行研究性学习。
右图是他们正在编制《秦朝行政机构示意图》,请按图意给空白处选择正确的内容()BA.诸侯 B.丞相 C.殿阁大学士 D.军机大臣(2012·广东汕头)3.北魏孝文帝改革带头纳汉女为妃,让弟弟娶汉女为妻;改姓为元;对30岁以下仍讲胡语者“降爵黜官”。
孝文帝的这些措施()CA.得到了全体贵族的支持 B.有利于北魏统一全国C.促进了民族融合 D.阻碍了汉族文化发展(2012·广东汕头)4.中国银行行徽(下图1)的外观设计灵感源自于我国古代的一种钱币(下图2)。
这种形状的钱币最早在全国统一使用是在()AA.秦朝 B.唐朝 C.宋朝 D.清朝(2012·广东汕头)5.北魏一朝自孝文帝以后,皇帝逝世后的谥号多采用“孝”字,如“孝武帝”和“孝明帝”。
这与孝文帝改革的哪一项内容有关?()DA.迁都洛阳 B.改用汉姓,学习汉语C.该穿汉服,与汉人通婚 D.学习汉族礼法,以孝治国(2012·广东汕头)6.“进士科始于隋大业中,盛于贞观、永徽之际。
缙绅(有官职或做过官的人)虽位极人臣,不由进士者,终不为美”。
对该材料理解正确的是()CA.进士科的兴衰反映了科举制度演变 B.所有人才从进士科选出C.进士科是科举制考试中最重要科目 D.缙绅都要参加进士科考试(2012·广东汕头)7.“春风得意马蹄疾,一日看尽长安花”是诗人金榜题名后在京城写下的诗句。
2012年广东省汕头市中考真题(word版含答案)
2011年广东省汕头市初中毕业生学业考试数 学说明:1.全卷共4页,考试用时100分钟,满分为150分.2.答题前,考生务必用黑色字迹的签字笔或钢笔在答题卡上填写自己的准考证号、姓名、试室号、座位号.用2B 铅笔把对应该号码的标号涂黑.3.选择题每小题选出答案后,用2B 铅笔把答题卡上对应题目选项的答案信息点涂黑,如需改动,用橡皮擦干净后,再选涂其他答案,答案不能答在试卷上.4.非选择题必须用黑色字迹钢笔或签字笔作答,答案必须写在答题卡各题目指定区域内相应的位置上;如需改动,先划掉原来的答案,然后再写上新的答案;不准使用铅笔和涂改液.不按以上要求作答的答案无效.5.考生务必保持答题卡的整洁.考试结束时,将试卷和答题卡一并交回.一、选择题(本大题共8小题,每小题4分,共32分)在每小题列出的四个选项中,只有一个是正确的,请把答题卡上对应题目所选的选项涂黑. 1.5-的绝对值是( ) (A )5 (B )5- (C )15 (D )15- 2.地球半径约为6 400 000米,用科学记数法表示为( )(A )70.6410⨯ (B )66.410⨯ (C )56410⨯ (D )464010⨯ 3.数据8、8、6、5、6、1、6的众数是( )(A )1 (B )5 (C )6 (D )8 4.如左图所示几何体的主视图是( )5.下列平面图形,既是中心对称图形,又是轴对称图形的是( )(A )等腰三角形 (B )正五边形 (C )平行四边形 (D )矩形 6.下列运算正确的是( )(A )2a a a += (B )325()a a -= (C )233a a a ∙= (D )22)2a = 7.已知三角形两边的长分别是4和10,则此三角形第三边的长可能是( ) (A )5 (B )6 (C )11 (D )168.如图,将ABC △绕着点C 顺时针旋转50后得到A B C ''△.若40110A B '==∠,∠,则BCA '∠的度数是( )(A )110 (B )80 (C )40 (D )30二、填空题(本大题共5小题,每小题4分,共20分)请将下列各题的正确答案填写在答题卡相应的位置上.9.分解因式:2210x x -=___________. 10.不等式390x ->的解集是___________.11.如图,A 、B 、C 是O ⊙上的三个点,25ABC =∠,则A O C ∠的度数是___________.12.若x 、y 为实数,且满足|3|0x -=,则2012x y ⎛⎫⎪⎝⎭的值是___________.13.如图,在ABCD Y 中,2430AD AB A ===,,∠.以点A 为圆心,AD 的长为半径画弧交AB 于点E ,连结CE ,则阴影部分的面积是___________(结果保留π).三、解答题(一)(本大题共5小题,每小题7分,共35分)14012sin 45(12--+.15.先化简,再求值:(3)(3)(2)x x x x +---,其中4x =.16.解方程组:4316x y x y -=⎧⎨+=⎩, ①. ②17.如图,在ABC △中,72AB AC ABC ==,∠.(1)用直尺和圆规作ABC ∠的平分线BD 交AC 于点D (保留作图痕迹,不要求写作法); (2)在(1)中作出ABC ∠的平分线BD 后,求BDC ∠的度数.18.据媒体报道,我国2009年公民出境旅游总人数约5 000万人次,2011年公民出境旅游总人数约7 200万人次.若2010年、2011年公民出境旅游总人数逐年递增,请解答下列问题: (1)求这两年我国公民出境旅游总人数的年平均增长率;(2)如果2012年仍保持相同的年平均增长率,请你预测2012年我国公民出境旅游总人数约多少万人次?四、解答题(二)(本大题3小题,每小题9分,共27分)19.如图,直线26y x =-与反比例函数(0)ky x x=>的图象交于点(42)A ,,与x 轴交于点B .(1)求k 的值及点B 的坐标;(2)在x 轴上是否存在点C ,使得AC AB =?若存在,求出点C 的坐标;若不存在,请说明理由.20.如图,小山岗的斜坡AC 的坡度是3tan 4α=,在与山脚C 距离200米的D 处,测得山顶A 的仰角为26.6,求小山岗的高AB .(结果取整数;参考数据:sin 26.60.45cos 26.60.89tan 26.60.50===,,)21.观察下列等式: 第1个等式:111111323a ⎛⎫==⨯- ⎪⨯⎝⎭; 第2个等式:2111135235a ⎛⎫==⨯- ⎪⨯⎝⎭; 第3个等式:3111157257a ⎛⎫==⨯- ⎪⨯⎝⎭; 第4个等式:4111179279a ⎛⎫==⨯- ⎪⨯⎝⎭;……请解答下列问题:(1)按以上规律列出第5个等式:5a =____________=___________;(2)用含n 的代数式表示第n 个等式:n a =____________=___________(n 为正整数); (3)求1234100a a a a a +++++…的值.五、解答题(三)(本大题共3小题,每小题12分,共36分)22.有三张正面分别写有数字211--,,的卡片,它们的背面完全相同,将这三张卡片背面朝上洗匀后随机抽取一张,以其正面的数字作为x 的值,放回卡片洗匀,再从三张卡片中随机抽取一张,以其正面的数字作为y 的值,两次结果记为()x y ,. (1)用树状图或列表法表示()x y ,所有可能出现的结果;(2)求使分式2223x xy yx y x y-+--有意义的()x y ,出现的概率; (3)化简分式2223x xy yx y x y-+--;并求使分式的值为整数的()x y ,出现的概率.23.如图,在矩形纸片ABCD 中,68AB BC ==,.把BCD △沿对角线BD 折叠.使点C 落在C '处,BC '交AD 于点G ;E F 、分别是C D '和BD 上的点,线段EF 交AD 于点H ,把FDE △沿EF 折叠,使点D 落在D '处,点D '恰好与点A 重合. (1)求证:ABC C DG '△≌△; (2)求tan ABG ∠的值; (3)求EF 的长.24. 如图,抛物线213922y x x =--与x 轴交于A B 、两点,与y 轴交于点C ,连接BC AC 、.(1)求AB 和OC 的长;(2)点E 从点A 出发,沿x 轴向点B 运动(点E 与点A B 、不重合),过点E 作直线l 平行BC ,交AC 于点D .设AE 的长为m ,ADE △的面积为S ,求S 关于m 的函数关系式,并写出自变量m 的取值范围;(3)在(2)的条件下,连接CE ,求CDE △面积的最大值;此时,求出以点E 为圆心,与BC 相切的圆的面积(结果保留π).2012年广东省汕头市初中毕业生学业考试参考答案及评分标准数学9.2(5)x x-10.3x>11.5012.1 13.13π3-三、解答题(一)(本大题共5小题,每小题7分,共35分)14.解:原式=12122⨯-+ ················································································4分112+=12-.·········································································································7分15.解:原式=2292x x x--+ ························································································3分=29x-.·····································································································5分当4x=时,原式=2491⨯-=-. ·····················································································7分16.解:①+②,得420x=. ··························································································3分解得5x=. ···························································································································4分将5x=代入①,得54y-=. ···························································································5分解得1y=. ···························································································································6分∴原方程组的解是51xy=⎧⎨=⎩,.·································································································7分17.解:(1)如图所示(作图正确得4分);(2)BD平分ABC∠,72ABC=∠,1362ABD ABC ∴==∠∠. ·························································································· 5分AB AC =,72C ABC ∴==∠∠. ······································································································ 6分 36A ∴=∠,363672BDC A ABD ∴=+=+=∠∠∠. ·································································· 7分18.解:(1)设这两年我国公民出境旅游总人数的年平均增长率为x .依题意,得25000(1)7200x +=. ···················································································· 3分 解得120.2 2.2x x ==-,(不合题意,舍去).答:这两年我国公民出境旅游总人数的年平均增长率为20%. ········································· 5分 (2)若2012年仍保持相同的年平均增长率,则预测2012年我国公民出境旅游总人数约7200(120%)8640⨯+=(万人次).答:预测2012年我国公民出境旅游总人数约8 640万人次. ············································ 7分 四、解答题(二)(本大题共3小题,每小题9分,共27分) 19.解:(1)点(42)A ,在反比例函数(0)ky x x=>的图象上, 24k∴=,解得8k =. ········································································································ 2分 将0y =代入26y x =-,得260x -=,解得3x =,则3OB =.∴点B 的坐标是(3,0). ································································································· 4分 (2)存在. ··························································································································· 5分过点A 作AH x ⊥轴,垂足为H ,则4OH =. ······························································· 6分AB AC =, .BH CH ∴= ······················································································································ 7分 431BH OH OB =-=-=,3115OC OB BH HC ∴=++=++=. ··········································································· 8分∴点C 的坐标是(5,0). ································································································· 9分 20.解:设小山岗的高AB 为x 米. 依题意,得在Rt ABC △中,3tan 4AB x BC BC α===, 43BC x ∴=. ······················································································································· 2分 42003BD DC BC x ∴=+=+. ························································································ 3分在Rt ABD △中,tan ABADB BD=∠,tan 26.60.50=, 0.5042003xx∴=+. ··········································································································· 5分 解得300x =. ······················································································································ 7分 经检验,300x =是原方程的解. ······················································································· 8分 答:小山岗的高AB 为300米. ··························································································· 9分 21.解:(1)311119112911a ⎛⎫==⨯- ⎪⨯⎝⎭. ······································································ 2分 (2)1111(21)(21)22121n a n n n n ⎛⎫==- ⎪-+-+⎝⎭. ·························································· 6分 (3)123100a a a a ++++…=1111133557199201++++⨯⨯⨯⨯… =111111111111232352572199201⎛⎫⎛⎫⎛⎫⎛⎫⨯-+⨯-+⨯-++⨯- ⎪ ⎪ ⎪ ⎪⎝⎭⎝⎭⎝⎭⎝⎭… ························· 7分 =111111111233557199201⎡⎤⎛⎫⎛⎫⎛⎫⎛⎫⨯-+-+-++- ⎪ ⎪ ⎪ ⎪⎢⎥⎝⎭⎝⎭⎝⎭⎝⎭⎣⎦… ········································ 8分 =1112201⎛⎫⨯- ⎪⎝⎭=100201. ·························································································································· 9分 五、解答题(三)(本大题共3小题,每小题12分,共36分)22.解:方法一:树状图如下:············································································································································· 3分所有()x y ,可能的结果共有9种,分别是:(22)--,,(21)--,,(21)-,,(12)--,,(11)--,,(11)-,,(12)-,,(11)-,,(11),.································································ 4分(2)由题意知,要使分式有意义,则220x y -≠且0x y -≠.即x y ≠且x y ≠-. ············································································································· 5分上述9种可能的结果中,共4种能使分式有意义,分别是:(21)-,,(21)--,,(12)-,,(12)--,. ···························································································································· 7分 所以,使分式2223x xy yx y x y-+--有意义的()x y ,出现的概率是49. ································· 8分 (3)原式2223()()()()()x xy xy y x y x yx y x y x y x y x y-++--===+-+-+. ··········································· 10分 由(2)可知,有4种可能的结果能使分式有意义,其中能使分式的计算结果是整数的结果有2种,分别是:(21)-,,(12)-,. 所以,使分式2223x xy yx y x y-+--的值为整数的()x y ,出现的概率是29. ······················· 12分 23.(1)证明:四边形ABCD 为矩形,90C BAD AB CD ∴===∠∠,, ················································································· 1分由图形的折叠性质,得90CD C D C C ''===,∠∠,BAD C AB C D ''∴==∠∠,. ·························································································· 3分 又AGB C GD '=∠∠,ABG C DG '∴△≌△(AAS ). ························································································ 4分(2)解:设AG 为x .8ABG C DG AD AG x '==△≌△,,,8BG DG AD AG x ∴==-=-. ····················································································· 5分 在Rt ABG △中,有222BG AG AB =+, 6AB =,222(8)6x x ∴-=+. 解得74x =. ························································································································· 7分 7tan 24AG ABG AB ∴==∠. ································································································ 8分(3)解法一:由图形的折叠性质,得904EHD DH AH ===∠,, AB EF ∴∥,DHF DAB ∴△∽△,HF DH AB AD ∴=,即162HF =, 3HF ∴=. ··························································································································· 9分 又ABG C DG '△≌△,ABG HDE ∴=∠∠,tan tan EH ABG HDE HD ∴==∠∠,即7244EH =, 76EH ∴=. ······················································································································· 11分 725366EF EH HF ∴=+=+=. ···················································································· 12分 解法二:由图形的折叠性质,得904DHF DH AH AFE DFE ====∠,,∠∠,AF DF BDC BDC EAF '===,∠∠∠, ··································································· 9分 在Rt ABG △中,9086BAD AD AB ===∠,,,。
最新数学中考考试题及答案--广东汕头优秀名师资料
2012年数学中考考试题及答案--广东汕头2012年汕头中考数学试卷解析一选择题本大题共8小题每小题4分共32分在每小题列出的四个选项中只有一个是正确的请把答题卡上对应题目所选的选项涂黑(1(,5的绝对值是A( 5 B( ,5 C( D( ,考点绝对值分析根据绝对值的性质求解( 解答解根据负数的绝对值等于它的相反数得,5 5(故选A( 点评此题主要考查的是绝对值的性质一个正数的绝对值是它本身一个负数的绝对值是它的相反数0的绝对值是0(2(地球半径约为6400000米用科学记数法表示为A( 064×107 B( 64×106 C( 64×105 D( 640×104考点科学记数法表示较大的数分析科学记数法的形式为a×10n其中1?a,10n为整数( 解答解6400000 64×106(故选B( 点评此题考查用科学记数法表示较大的数其规律为1?a,10n为比原数的整数位数小1的正整数(3(数据8865616的众数是A( 1 B( 5 C( 6 D( 8考点众数分析众数指一组数据中出现次数最多的数据根据众数的定义即可求解( 解答解6出现的次数最多故众数是6(故选C( 点评本题主要考查了众数的概念注意众数是指一组数据中出现次数最多的数据它反映了一组数据的多数水平一组数据的众数可能不是唯一的比较简单( 4(如图所示几何体的主视图是A( B( C( D(考点简单组合体的三视图分析主视图是从立体图形的正面看所得到的图形找到从正面看所得到的图形即可(注意所有的看到的棱都应表现在主视图中( 解答解从正面看此图形的主视图有3列组成从左到右小正方形的个数是131( 故选B( 点评本题主要考查了三视图的知识主视图是从物体的正面看得到的视图关键是掌握主视图所看的位置(5(下列平面图形既是中心对称图形又是轴对称图形的是A( 等腰三角形 B( 正五边形 C( 平行四边形 D( 矩形考点中心对称图形轴对称图形分析根据中心对称图形的定义旋转180?后能够与原图形完全重合即是中心对称图形以及轴对称图形的定义即可判断出( 解答解A?等腰三角形旋转180?后不能与原图形重合?此图形不是中心对称图形但它是轴对称图形故此选项错误B?正五边形形旋转180?后不能与原图形重合?此图形不是中心对称图形是轴对称图形故此选项错误C平行四边形旋转180?后能与原图形重合此图形是中心对称图形但不是轴对称图形故此选项错误D?矩形旋转180?后能与原图形重合?此图形不是中心对称图形是轴对称图形故此选项正确(故选D( 点评此题主要考查了中心对称图形与轴对称的定义根据定义得出图形形状是解决问题的关键(6(下列运算正确的是A( aa a2 B( ,a32 a5 C( 3aa2 a3 D( a2 2a2考点幂的乘方与积的乘方合并同类项同底数幂的乘法分析根据合并同类项法则只把系数相加字母部分完全不变积的乘方底数不变指数相乘单项式乘法法则系数与系数相乘同底数幂相乘只在一个单项式里含有的字母连同它的指数作为积的一个因式进行计算即可选出答案( 解答解Aaa 2a故此选项错误B,a32 a6故此选项错误C3aa2 3a3故此选项错误Da2 2a2故此选项正确故选D( 点评此题主要考查了合并同类项积的乘方单项式乘法关键是熟练掌握各个运算的计算法则不要混淆(7(已知三角形两边的长分别是4和10则此三角形第三边的长可能是A( 5 B( 6 C( 11 D( 16考点三角形三边关系专题探究型分析设此三角形第三边的长为x根据三角形的三边关系求出x的取值范围找出符合条件的x的值即可( 解答解设此三角形第三边的长为x则10,4,x,104即6,x,14四个选项中只有11符合条件( 故选C( 点评本题考查的是三角形的三边关系即任意两边之和大于第三边任意两边之差小于第三边(8(如图将?ABC绕着点C顺时针旋转50?后得到?A′B′C′(若?A 40?(?B′ 110?则?BCA′的度数是A( 110? B( 80? C( 40? D( 30?考点旋转的性质分析首先根据旋转的性质可得?A′ ?A?A′CB′ ?ACB即可得到?A′ 40?再有?B′ 110?利用三角形内角和可得?A′CB′的度数进而得到?ACB 的度数再由条件将?ABC绕着点C顺时针旋转50?后得到?A′B′C′可得?ACA′ 50?即可得到?BCA′的度数( 解答解根据旋转的性质可得?A′ ?A?A′CB′ ?ACB ??A 40???A′ 40???B′ 110???A′CB′ 180?,110?,40? 30???ACB 30??将?ABC绕着点C顺时针旋转50?后得到?A′B′C′??ACA′ 50???BCA′ 30?50? 80?故选B( 点评此题主要考查了旋转的性质关键是熟练掌握旋转前后的图形全等进而可得到一些对应角相等(二填空题本大题共5小题每小题4分共20分请将下列各题的正确答案填写在答题卡相应的位置上(9(分解因式2x2,10x 2xx,5 (考点因式分解-提公因式法分析首先确定公因式是2x然后提公因式即可( 解答解原式 2xx,5(故答案是2xx,5( 点评本题考查了提公因式法正确确定公因式是关键(10(不等式3x,9,0的解集是 x,3 (考点解一元一次不等式分析先移项再将x的系数化为1即可(解答解移项得3x,9系数化为1得x,3(故答案为x,3( 点评本题考查的是解一元一次不等式熟知解一元一次不等式的基本步骤是解答此题的关键(11(如图ABC是?O上的三个点?ABC 25?则?AOC的度数是 50 (考点圆周角定理专题计算题分析根据同弧所对的圆心角等于所对圆周角的2倍由已知圆周角的度数即可求出所求圆心角的度数(解答解?圆心角?AOC与圆周角?ABC都对??AOC 2?ABC又?ABC 25?则?AOC 50?(故答案为50 点评此题考查了圆周角定理的运用熟练掌握圆周角定理是解本题的关键(12(若xy为实数且满足x,3 0则2012的值是 1 (考点非负数的性质算术平方根非负数的性质绝对值分析根据非负数的性质列出方程求出xy的值代入所求代数式计算即可解答解根据题意得解得(则2012 2012 1(故答案是1( 点评本题考查了非负数的性质几个非负数的和为0时这几个非负数都为0(13(如图在ABCD中AD 2AB 4?A 30?以点A为圆心AD的长为半径画弧交AB于点E连接CE则阴影部分的面积是 3,π结果保留π(考点扇形面积的计算平行四边形的性质分析过D点作DF?AB于点F(可求ABCD和?BCE的高观察图形可知阴影部分的面积 ABCD的面积,扇形ADE的面积,?BCE的面积计算即可求解( 解答解过D点作DF?AB于点F( ?AD 2AB 4?A 30??DF ADsin30? 1EB AB,AE 2?阴影部分的面积4×1,,2×1?24,π,13,π(故答案为3,π(点评考查了平行四边形的性质扇形面积的计算本题的关键是理解阴影部分的面积 ABCD的面积,扇形ADE的面积,?BCE的面积(三解答题一本大题共4小题每小题7分共35分14(计算,2sin45?,102,1(考点实数的运算零指数幂负整数指数幂特殊角的三角函数值分析本题涉及零指数幂负指数幂特殊角的三角函数值3个考点(在计算时需要针对每个考点分别进行计算然后根据实数的运算法则求得计算结果( 解答解原式,2×,1,( 点评本题考查实数的综合运算能力是各地中考题中常见的计算题型(解决此类题目的关键是熟练掌握负整数指数幂零指数幂特殊角的三角函数值绝对值等考点的运算(15(先化简再求值x3x,3,xx,2其中x 4(考点整式的混合运算化简求值专题探究型分析先把整式进行化简再把x 4代入进行计算即可( 解答解原式 x2,9,x22x2x,9当x 4时原式2×4,9 ,1( 点评本题考查的是整式的混合运算,化简求值在有乘方乘除的混合运算中要按照先乘方后乘除的顺序运算其运算顺序和有理数的混合运算顺序相似(16(解方程组(考点解二元一次方程组分析先用加减消元法求出x的值再用代入法求出y的值即可( 解答解??得4x 20解得x 5把x 5代入?得5,y 4解得y 1故此不等式组的解为( 点评本题考查的是解二元一次方程组熟知解二元一次不等式组的加减消元法和代入消元法是解答此题的关键(17(如图在?ABC中AB AC?ABC 72?(1用直尺和圆规作?ABC的平分线BD交AC于点D保留作图痕迹不要求写作法2在1中作出?ABC的平分线BD后求?BDC的度数(考点作图基本作图等腰三角形的性质专题探究型分析1根据角平分线的作法利用直尺和圆规作出?ABC的平分线即可2先根据等腰三角形的性质及三角形内角和定理求出?A的度数再由角平分线的性质得出?ABD的度数再根据三角形外角的性质得出?BDC的度数即可( 解答解1?一点B为圆心以任意长长为半径画弧分别交ABBC于点EF?分别以点EF为圆心以大于EF为半径画圆两圆相较于点G连接BG角AC于点D 即可(2?在?ABC中AB AC?ABC 72???A 180?,2?ABC 180?,144? 36??AD是?ABC的平分线??ABD ?ABC ×72? 36???BDC是?ABD的外角??BDC ?A?ABD 36?36? 72?(点评本题考查的是基本作图及等腰三角形的性质熟知角平分线的作法是解答此题的关键(四解答题二本大题共4小题每小题7分共27分18(据媒体报道我国2009年公民出境旅游总人数约5000万人次2011年公民出境旅游总人数约7200万人次若2010年2011年公民出境旅游总人数逐年递增请解答下列问题1求这两年我国公民出境旅游总人数的年平均增长率2如果2012年仍保持相同的年平均增长率请你预测2012年我国公民出境旅游总人数约多少万人次考点一元二次方程的应用专题增长率问题分析 1设年平均增长率为x(根据题意2010年公民出境旅游总人数为 50001x万人次2011年公民出境旅游总人数50001x2 万人次(根据题意得方程求解22012年我国公民出境旅游总人数约72001x万人次( 解答解1设这两年我国公民出境旅游总人数的年平均增长率为x(根据题意得50001x2 7200(解得 x1 02 20x2 ,22 不合题意舍去(答这两年我国公民出境旅游总人数的年平均增长率为20(2如果2012年仍保持相同的年平均增长率则2012年我国公民出境旅游总人数为72001x 7200×120 8640万人次(答预测2012年我国公民出境旅游总人数约8640万人次( 点评此题考查一元二次方程的应用根据题意寻找相等关系列方程是关键难度不大(19(如图直线y 2x,6与反比例函数y 的图象交于点A42与x轴交于点B( 1求k的值及点B的坐标2在x轴上是否存在点C使得AC AB若存在求出点C的坐标若不存在请说明理由(考点反比例函数综合题专题数形结合分析 1先把42代入反比例函数解析式易求k再把y 0代入一次函数解析式可求B点坐标2假设存在然后设C点坐标是a0然后利用两点之间的公式可得借此无理方程易得a 3或a 5其中a 3和B点重合舍去故C点坐标可求( 解答解1把42代入反比例函数y 得k 8把y 0代入y 2x,6中可得x 3故k 8B点坐标是302假设存在设C点坐标是a0则?AB AC?即4,a24 5解得a 5或a 3此点与B重合舍去故点C的坐标是50(点评本题考查了反比函数的知识解题的关键是理解点与函数的关系并能灵活使用两点之间的距离公式(20(如图小山岗的斜坡AC的坡度是tanα在与山脚C距离200米的D处测得山顶A的仰角为266?求小山岗的高AB结果取整数参考数据sin266? 045cos266? 089tan266? 050(考点解直角三角形的应用-仰角俯角问题解直角三角形的应用-坡度坡角问题分析首先在直角三角形ABC中根据坡角的正切值用AB表示出BC然后在直角三角形DBA中用BA表示出BD根据BD与BC之间的关系列出方程求解即可( 解答解?在直角三角形ABC中 tanα?BC?在直角三角形ADB中? tan266? 050即BD 2AB?BD,BC CD 200?2AB,AB 200解得AB 300米答小山岗的高度为300米( 点评本题考查了解直角三角形的应用解题的关键是从实际问题中整理出直角三角形并求解( 21(观察下列等式第1个等式a1 ×1,第2个等式a2 ×,第3个等式a3 ×,第4个等式a4 ×,请解答下列问题1按以上规律列出第5个等式a52用含有n的代数式表示第n个等式an n为正整数 3求a1a2a3a4a100的值( 考点规律型数字的变化类分析 12观察知找第一个等号后面的式子规律是关键分子不变为1分母是两个连续奇数的乘积它们与式子序号之间的关系为序号的2倍减1和序号的2倍加1(3运用变化规律计算( 解答解根据观察知答案分别为123a1a2a3a4a100的×1,×,×,×,×1,,,,,1,×( 点评此题考查寻找数字的规律及运用规律计算(寻找规律大致可分为2个步骤不变的和变化的变化的部分与序号的关系(五解答题三本大题共3小题每小题12分共36分22(有三张正面分别写有数字,2,11的卡片它们的背面完全相同将这三张卡片北背面朝上洗匀后随机抽取一张以其正面的数字作为x的值放回卡片洗匀再从三张卡片中随机抽取一张以其正面的数字作为y的值两次结果记为xy( 1用树状图或列表法表示xy所有可能出现的结果2求使分式有意义的xy出现的概率3化简分式并求使分式的值为整数的xy出现的概率(考点列表法与树状图法分式有意义的条件分式的化简求值分析1根据题意列出图表即可表示xy所有可能出现的结果2根据1中的树状图求出使分式有意义的情况再除以所有情况数即可3先化简再找出使分式的值为整数的xy的情况再除以所有情况数即可(解答解1用列表法表示xy所有可能出现的结果如下,2,11,2,2,2,1,21,2,1,2,1,1,11,11,21,1111?使分式有意义的xy出现的概率是 3?使分式的值为整数的xy有1,2,212种情况 ?使分式的值为整数的xy出现的概率是( 点评此题考查了树状图法与列表法求概率(此题难度不大解题的关键是根据题意画出树状图或列出表格注意树状图法与列表法可以不重不漏地表示出所有等可能的结果注意用到的知识点为概率所求情况数与总情况数之比(23(如图在矩形纸片ABCD中AB 6BC 8(把?BCD沿对角线BD折叠使点C落在C′处BC′交AD于点GEF分别是C′D和BD上的点线段EF交AD于点H把?FDE沿EF 折叠使点D落在D′处点D′恰好与点A重合(1求证?ABG??C′DG2求tan?ABG的值3求EF的长(考点翻折变换折叠问题全等三角形的判定与性质矩形的性质解直角三角形专题探究型分析 1根据翻折变换的性质可知?C ?BAG 90?C′D AB CD?AGB ?DGC′故可得出结论2由1可知GD GB故AGGB AD设AG x则GB 8,x在Rt?ABG中利用勾股定理即可求出AG的长进而得出tan?ABG的值3由?AEF是?DEF翻折而成可知EF垂直平分AD故HD AD 4再根据tan?ABG即可得出EH的长同理可得HF是?ABD的中位线故可得出HF的长由EF EHHF即可得出结论( 解答 1证明??BDC′由?BDC翻折而成??C ?BAG 90?C′D AB CD?AGB ?DGC′??ABG ?ADE在?ABG??C′DG中???ABG??C′DG2解?由1可知?ABG??C′DG?GD GB?AGGB AD设AG x则GB 8,x在Rt?ABG中?AB2AG2 BG2即62x2 8,x2解得x?tan?ABG3解??AEF是?DEF翻折而成?EF垂直平分AD?HD AD 4?tan?ABG tan?ADE?EH HD× 4×?EF垂直平分ADAB?AD?HF是?ABD的中位线?HF AB ×6 3?EF EHHF 3 ( 点评本题考查的是翻折变换全等三角形的判定与性质矩形的性质及解直角三角形熟知折叠是一种对称变换它属于轴对称折叠前后图形的形状和大小不变位置变化对应边和对应角相等是解答此题的关键(24(如图抛物线y x2,x,9与x轴交于AB两点与y轴交于点C连接BCAC(1求AB和OC的长2点E从点A出发沿x轴向点B运动点E与点AB不重合过点E作直线l平行BC交AC于点D(设AE的长为m?ADE的面积为s求s关于m的函数关系式并写出自变量m的取值范围3在2的条件下连接CE求?CDE面积的最大值此时求出以点E为圆心与BC相切的圆的面积结果保留π(考点二次函数综合题专题压轴题分析 1已知抛物线的解析式当x 0可确定C点坐标当y 0时可确定AB点的坐标进而确定ABOC的长(2直线l‖BC可得出?AED?ABC相似它们的面积比等于相似比的平方由此得到关于sm的函数关系式根据题干条件点E与点AB不重合可确定m的取值范围( 3?首先用m列出?AEC的面积表达式?AEC?AED的面积差即为?CDE的面积由此可得关于S?CDEm的函数关系式根据函数的性质可得到S?CDE的最大面积以及此时m 的值?过E做BC的垂线EF这个垂线段的长即为与BC相切的?E的半径可根据相似三角形?BEF?BCO得到的相关比例线段求得该半径的值由此得解( 解答解1已知抛物线y x2,x,9当x 0时y ,9则C0,9当y 0时x2,x,9 0得x1 ,3x2 6则A,30B60?AB 9OC 9(2?ED‖BC??AED??ABC? 2即 2得s m20,m,9(3解法一?S?ABC AEOC m×9 m?S?CDE S?ABC,S?ADE m,m2 ,m,2(?0,m,9?当m 时S?CDE取得最大值最大值为(此时BE AB,AE 9, (记?E与BC相切于点M连接EM则EM?BC设?E的半径为r(在Rt?BOC中BC (??BOC ?EBM?COB ?EMB 90?(??BOC??BME???r (?所求?E的面积为π2 π(解法二?S?ABC AEOC m×9 m?S?CDE S?AEC,S?ADE m,m2 ,m,2(?0,m,9?当m 时S?CDE取得最大值最大值为(此时BE AB,AE 9, ( ?S?EBC S?ABC (如图2记?E与BC相切于点M连接EM则EM?BC设?E的半径为r( 在Rt?BOC中BC? (?S?EBC BCEM?×r?r (?所求?E的面积为π2 π(点评该题主要考查了二次函数的性质相似三角形的性质图形面积的求法等综合知识(在解题时要多留意图形之间的关系有些时候将所求问题进行时候转化可以大大的降低解题的难度(。
广东省2012年中考英语试题与答案
2012 年广东省初中毕业生学业考试英语一、听力理解〔每题1分,共25分〕A、听句子〔5分〕根据所听句子的内容和所提的问题,选择符合题意的图画答复下列问题。
1、What did Tom do last Saturday?2.Why didn’t Peter want to have supper?3.Where the students going to have classes?4.Who is Jimmv’s mother?5.Which sige is the speaker talking about?B.听对话〔此题有10小题,每题1分,共10分〕答复每段对话后面的问题,在各题所给的三个选项中选出一个最正确答案,并将答题卡上对应题目所选的选项涂黑。
每段对话听两遍。
听第一段对话,答复第6小题。
6. What time will the woman pick up Peter?A. 7:30.B.7:50.C.8:30.听第二段对话,答复第7小题。
7. Why does the man like country music?A. Because it's popular:B. Because it's exciting.C. Because it's relaxing.听第三段对话,答复第8小题。
8. How will the weather be tomorrow?A. It will be rainy.B.It will be fine.C.It will be snowy.听第四段对话,答复第9小题。
9. Where does the conversation probably take place?A. In the supermarket.B.At the bus stop.C.On the bus.昕第五段对话,答复第10小题。
10. Who might these two speakers be?A. Officer and soldier.B. Teacher and student.C. Boss and secretary.听第六段对话,答复第11~12小题。
2012年广东省汕头市中考思想品德科试题及答案(word)
2012年广东省汕头初中毕业生学业考试思想品德说明:1.全卷共6页,满分为80分,考试用时为60分钟。
2.答卷前,考生务必用黑色字迹的签字笔或钢笔在答题卡上填写自己的准考证号、姓名、试室号、座位号。
用2B铅笔把对应号码的标号涂黑。
3.选择题每小题选出答案后,用2B铅笔把答题卡上对应题目选项的答案信息点涂黑,如需改动,用橡皮擦干净后,再选涂其他答案,答案不能答在试题上。
4.非选择题必须用黑色字迹钢笔或签字笔作答、答案必须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;不准使用铅笔和涂改液。
不按以上要求作答的答案无效。
5.考生务必保持答题卡的整洁。
考试结束时,将试卷和答题卡一并交回。
一、单项选择题(本大题共16小题,每小题2分,共32分。
在各题的四个选项中,只有一项是最符合题意要求的答案。
请把答题卡上对应题目所选的选项涂黑)1.2011年8月12日至23日,第26届世界大学生运动会在广东省市隆重举行,在本届运动会上,中国代表团获得金牌总数位居首位。
A.佛山B、深圳C、珠海D、广州2、2011年11月13日,亚太经合组织第十九次领导人非正式会议在美国州首府檀香山举行,中国国家主席胡锦涛出席会议并发表重要讲话。
A、华盛顿B、亚特兰大C、夏威夷D、加利福尼亚3、2012年3月1日起,《广东省促进条例》正式实施,这标志着广东这一方面的工作进入了法制化的轨道,它也成为我国在这方面的第一部地方性法规。
A、自主创新B、教育创新C、科技创新D、文化创新4、2012年3月5日,温家宝总理在十一届人大会议上所做的《政府工作报告》中提出了今年我国经济社会发展的主要目标:国内生产总值增长、居民消费价格涨幅控制在左右。
A、7.5% 4%B、8% 4.5%C、8.5% 5%D、9% 5.5%5、2012年3月26日是第十七个全国中小学生教育日,主题是“普及安全知识,提高避险能力”。
A、法制B、防震C、科技D、安全6、早读时间,“篮球迷”小高还在谈论昨晚的比赛,这时,大家向他投来异样的目光,小高很不解,就问问同桌,同桌说:“你影响到大家的学习了。
广东省汕头市2012年中考历史试题
2012年广东省汕头市初中毕业生学业考试历史解析说明:1.全卷共6页,满分为80分,考试用时为60分钟2、答卷前,考生务必用黑色字迹的签字笔或钢笔在答题卡上填写自己的准考证号、姓名、试室号、座位号。
用2B 铅笔把对应该号码的标号涂黑。
3、单项选择题每小题选出答案后,用2B 铅笔把答题卡上对应题目选项的答案信息点涂黑,如需改动,用橡皮擦干净后,再选涂其他答案,答案不能答在试卷上。
4、综合题必须用黑色字迹钢笔或签字笔作答,答案必须写在答题卡各题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;不准使用铅笔和涂改液。
不按以上要求作答的答案无效。
5、考生务必保持答题卡的整洁。
考试结束时,将试卷和答题卡一并交回。
一、单项选择题(本大题共28小题,每小题2分,共56分。
在每小题列出的四个选项中,只有一个是正确的,请把答题卡对应题目所选的选项涂黑)1、西周末年,昏庸的幽王上演了一场“烽火戏诸侯”的闹剧。
诸侯率兵前往护卫周王是遵守了A 、封建制的法规B 、禅让制的规则C 、世袭制的传统D 、分封制的义务解析:本题难度适中,考查西周分封制,注意题目时间限制,西周,烽火戏诸侯,诸侯率兵前往护卫指的是分封制,答案选D 。
其它3项时间也对不上。
2、历史小组的同学以“中央集权制度”为主题进行研究性学习。
右图是他们正在编制《秦朝行政机构示意图》,请按图意给空白处选择正确的内容A 、诸侯B 、丞相C 、殿阁大学士D 、军机大臣解析:本题难度适中,注意题中时间限制,是秦朝,C 是明朝的,D答案选B 。
3、北魏孝文帝改革带头纳汉女为妃,让弟弟娶汉女为妻;改姓为元;对30岁以下仍讲胡语者“降爵黜官”。
孝文帝的这些措施A 、得到了全体贵族的支持B 、有利于北魏统一全国C 、促进了民族融合D 、阻碍了汉族文化发展 解析:本题考查北魏孝文帝改革的影响,难度适中,AD B 进名族融合。
选C 。
4、中国银行行徽(下图1)的外观设计灵感源自于我国古代的一种钱币(下图2)。
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2012年广东省汕头市初中毕业生学业考试参考答案及评分标准数学9.2(5)x x-10.3x>11.50 12.1 13.13π3-三、解答题(一)(本大题共5小题,每小题7分,共35分)14.解:原式=12122⨯-+ ················································································4分112+=12-.·········································································································7分15.解:原式=2292x x x--+ ························································································3分=29x-.·····································································································5分当4x=时,原式=2491⨯-=-. ·····················································································7分16.解:①+②,得420x=. ··························································································3分解得5x=. ···························································································································4分将5x=代入①,得54y-=. ···························································································5分解得1y=. ···························································································································6分∴原方程组的解是51xy=⎧⎨=⎩,.·································································································7分17.解:(1)如图所示(作图正确得4分);(2)BD平分ABC∠,72ABC=∠,1362ABD ABC ∴== ∠∠. ·························································································· 5分 AB AC = ,72C ABC ∴== ∠∠. ······································································································ 6分 36A ∴= ∠,363672BDC A ABD ∴=+=+= ∠∠∠. ·································································· 7分 18.解:(1)设这两年我国公民出境旅游总人数的年平均增长率为x .依题意,得25000(1)7200x +=. ···················································································· 3分 解得120.2 2.2x x ==-,(不合题意,舍去).答:这两年我国公民出境旅游总人数的年平均增长率为20%. ········································· 5分(2)若2012年仍保持相同的年平均增长率,则预测2012年我国公民出境旅游总人数约7200(120%)8640⨯+=(万人次).答:预测2012年我国公民出境旅游总人数约8 640万人次. ············································ 7分 四、解答题(二)(本大题共3小题,每小题9分,共27分) 19.解:(1) 点(42)A ,在反比例函数(0)ky x x=>的图象上, 24k∴=,解得8k =. ········································································································ 2分 将0y =代入26y x =-,得260x -=,解得3x =,则3OB =.∴点B 的坐标是(3,0). ································································································· 4分 (2)存在. ··························································································································· 5分过点A 作AH x ⊥轴,垂足为H ,则4OH =. ······························································· 6分AB AC = , .BH CH ∴= ······················································································································ 7分 431BH OH OB =-=-= ,3115OC OB BH HC ∴=++=++=. ··········································································· 8分 ∴点C 的坐标是(5,0). ································································································· 9分 20.解:设小山岗的高AB 为x 米. 依题意,得在Rt ABC △中,3tan 4AB x BC BC α===, 43BC x ∴=. ······················································································································· 2分 42003BD DC BC x ∴=+=+. ························································································ 3分在Rt ABD △中,tan AB ADB BD=∠,tan 26.60.50=, 0.5042003xx∴=+.··········································································································· 5分 解得300x =. ······················································································································ 7分 经检验,300x =是原方程的解. ······················································································· 8分 答:小山岗的高AB 为300米. ··························································································· 9分 21.解:(1)311119112911a ⎛⎫==⨯- ⎪⨯⎝⎭. ······································································ 2分 (2)1111(21)(21)22121n a n n n n ⎛⎫==- ⎪-+-+⎝⎭. ·························································· 6分 (3)123100a a a a ++++…=1111133557199201++++⨯⨯⨯⨯… =111111111111232352572199201⎛⎫⎛⎫⎛⎫⎛⎫⨯-+⨯-+⨯-++⨯- ⎪ ⎪ ⎪ ⎪⎝⎭⎝⎭⎝⎭⎝⎭… ························· 7分 =111111111233557199201⎡⎤⎛⎫⎛⎫⎛⎫⎛⎫⨯-+-+-++- ⎪ ⎪ ⎪ ⎪⎢⎥⎝⎭⎝⎭⎝⎭⎝⎭⎣⎦… ········································ 8分 =1112201⎛⎫⨯- ⎪⎝⎭=100201. ·························································································································· 9分 五、解答题(三)(本大题共3小题,每小题12分,共36分)22.解:方法一:树状图如下:············································································································································· 3分 所有()x y ,可能的结果共有9种,分别是:(22)--,,(21)--,,(21)-,,(12)--,,(11)--,,(11)-,,(12)-,,(11)-,,(11),.································································ 4分 (2)由题意知,要使分式有意义,则220x y -≠且0x y -≠.即x y ≠且x y ≠-. ············································································································· 5分 上述9种可能的结果中,共4种能使分式有意义,分别是:(21)-,,(21)--,,(12)-,,(12)--,. ···························································································································· 7分 所以,使分式2223x xy y x y x y -+--有意义的()x y ,出现的概率是49. ································· 8分 (3)原式2223()()()()()x xy xy y x y x yx y x y x y x y x y-++--===+-+-+. ··········································· 10分由(2)可知,有4种可能的结果能使分式有意义,其中能使分式的计算结果是整数的结果有2种,分别是:(21)-,,(12)-,.所以,使分式2223x xy y x y x y -+--的值为整数的()x y ,出现的概率是29. ······················· 12分 23.(1)证明: 四边形ABCD 为矩形,90C BAD AB CD ∴=== ∠∠,,················································································· 1分由图形的折叠性质,得90CD C D C C ''===,∠∠,BAD C AB C D ''∴==∠∠,. ·························································································· 3分 又AGB C GD '= ∠∠,ABG C DG '∴△≌△(AAS ). ························································································ 4分 (2)解:设AG 为x . 8ABG C DG AD AG x '== △≌△,,,8BG DG AD AG x ∴==-=-. ····················································································· 5分 在Rt ABG △中,有222BG AG AB =+,6AB = , 222(8)6x x ∴-=+.解得74x =. ························································································································· 7分 7tan 24AG ABG AB ∴==∠. ································································································ 8分(3)解法一:由图形的折叠性质,得904EHD DH AH ===∠,,AB EF ∴∥, DHF DAB ∴△∽△, HF DH AB AD ∴=,即162HF =,3HF ∴=.··························································································································· 9分 又ABG C DG ' △≌△, ABG HDE ∴=∠∠,tan tan EH ABG HDE HD ∴==∠∠,即7244EH=, 76EH ∴=. ······················································································································· 11分 725366EF EH HF ∴=+=+=. ···················································································· 12分 解法二:由图形的折叠性质,得904DHF DH AH AFE DFE ==== ∠,,∠∠,AF DF BDC BDC EAF '===,∠∠∠, ··································································· 9分 在Rt ABG △中,9086BAD AD AB === ∠,,,。