东北三省三校(哈尔滨师大附中、东北师大附中、 辽宁省实验中学)2021年高考复习数学二模试卷(文科)
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压轴解答题第二关 以解析几何中与椭圆相关的综合问题【名师综述】纵观近三年的高考题,解析几何题目是每年必考题型,主要体现在解析几何知识内的综合及与其它知识之间的综合,且椭圆考查的最多,,同时可能与平面向量、导数相交汇,每个题一般设置了两个问,第(1)问一般考查曲线方程的求法,主要利用定义法与待定系数法求解,而第(2)问主要涉及最值问题、定值问题、对称问题、轨迹问题、探索性问题、参数范围问题等.这类问题综合性大,解题时需根据具体问题,灵活运用解析几何、平面几何、函数、不等式、三角知识,正确构造不等式,体现了解析几何与其他数学知识的密切联系.类型一 中点问题典例1已知椭圆()2222:10x y C a b a b+=>>的离心率13e =,焦距为2.(1)求椭圆C 的方程;(2)过点()0,2Q 作斜率为()0k k ≠的直线l 与椭圆C 交于A 、B 两点,若x 轴上的一点E 满足AE BE =,试求出点E 的横坐标的取值范围.【来源】河南省温县第一高级中学2021-2022学年高三上学期1月月考文科数学试题【举一反三】已知椭圆C :()222210y x a b a b+=>>的焦距与椭圆2213x y +=的焦距相等,且C 经过抛物线()212y x =- (1)求C 的方程;(2)若直线y kx m =+与C 相交于A ,B 两点,且A ,B 关于直线l :10x ty ++=对称,O 为C 的对称中心,且AOB 的面积为103,求k 的值. 类型二 垂直问题典例2 已知椭圆1C :22221x y a b +=(0a b >>)的离心率为22,1C 的长轴是圆2C :222x y +=的直径.(1)求椭圆的标准方程;(2)过椭圆1C 的左焦点F 作两条相互垂直的直线1l ,2l ,其中1l 交椭圆1C 于P ,Q 两点,2l 交圆2C 于M ,N 两点,求四边形PMQN 面积的最小值.【来源】广东省肇庆市2021届高三二模数学试题【举一反三】已知椭圆222:1(1)x C y a a+=>,离心率63e =.直线:1l x my =+与x 轴交于点A ,与椭圆C 相交于,E F 两点.自点,E F 分别向直线3x =作垂线,垂足分别为11,E F .(Ⅰ)求椭圆C 的方程及焦点坐标;(Ⅱ)记1AEE ,11AE F ,1AFF 的面积分别为1S ,2S ,3S ,试证明1322S S S 为定值. 类型三 面积问题典例3如图,已知椭圆221:12x y Γ+=和抛物线22:3x y Γ=,斜率为正的直线l 与y 轴及椭圆1Γ依次交于P 、A 、B 三点,且线段AB 的中点C 在抛物线2Γ上.(1)求点P 的纵坐标的取值范围;(2)设D 是抛物线2Γ上一点,且位于椭圆1Γ的左上方,求点D 的横坐标的取值范围,使得PCD 的面积存在最大值.【来源】浙江省2022届高三水球高考命题研究组方向性测试Ⅴ数学试题【举一反三】已知椭圆C :22221(x y a b a b+=>>0)的右焦点F 与右准线l :x =4的距离为2.(1)求椭圆C 的方程;(2)若直线():0m y kx t t =+≠与椭圆C 相交于A ,B 两点,线段AB 的垂直平分线与直线m 及x 轴和y 轴分别相交于点D ,E ,G ,直线GF 与右准线l 相交于点H .记AEGF ,ADGH 的面积分别为S 1,S 2,求12S S 的值.【来源】江苏省苏州中学等四校2021-2022学年高三下学期期初联合检测数学试题类型四 范围与定值问题典例4已知椭圆C :()2222 1x y a b c a b +=>>2()2,1P .(1)求C 的方程;(2)若A ,B 是C 上两点,直线AB 与曲线222x y +=相切,求AB 的取值范围. 【来源】重庆市2022届高三下学期开学考试数学试题【举一反三】已知椭圆2222:1(0)x y C a b a b+=>>的右焦点为(2,0)F ,过点F 且垂直于x 轴的直线与椭圆相交所得的弦长为2. (1)求椭圆C 的方程;(2)过椭圆内一点P (0,t ),斜率为k 的直线l 交椭圆C 于M ,N 两点,设直线OM ,ON (O 为坐标原点)的斜率分别为k 1,k 2,若对任意k ,存在实数λ,使得12k k k λ+=,求实数λ的取值范围. 【来源】江苏省扬州大学附中2021届高三下学期2月检测数学试题典例5 已知椭圆2222:1(0)x y C a b a b+=>>的一个焦点与短轴的两个端点组成的三角形是等腰直角三角形,点(10,1)P 是椭圆C 上一点. (1)求椭圆C 的标准方程;(2)设(,)R s t 是椭圆C 上的一动点,由原点O 向22()()4x s y t -+-=引两条切线,分别交椭圆C 于点P ,Q ,若直线,OP OQ 的斜率均存在,并分别记为12,k k ,求证:12k k ⋅为定值. 【来源】云南省昭通市2022届高三期末数学(理)试题【举一反三】已知椭圆2222:1(0)x y C a b a b +=>>经过两点33,2M ⎭,242N ⎝⎭. (1)求椭圆C 的方程:(2)A 、B 分别为椭圆C 的左、右顶点,点P 为圆224x y +=上的动点(P 不在坐标轴上),P A 与PB 分别与椭圆C 交E 、F 两点,直线EF 交x 轴于H 点,请问点P 的横坐标与点H 的横坐标之积是否为定值?若是,求出这个定值;若不是,说明理由.【来源】江西省景德镇市2022届高三第二次质检数学(理)试题【精选名校模拟】1.已知椭圆2222C :1(0)x y a b a b+=>>的离心率为12,直线1:22l y x =-+与椭圆C 有且仅有一个公共点A .(Ⅰ)求椭圆C 的方程及A 点坐标;(Ⅱ)设直线l 与x 轴交于点B .过点B 的直线与C 交于E ,F 两点,记点A 在x 轴上的投影为G ,T 为BG 的中点,直线AE ,AF 与x 轴分别交于M ,N 两点.试探究||||TM TN ⋅是否为定值?若为定值,求出此定值;否则,请说明理由.【来源】湖南省长沙市第一中学、广东省深圳实验学校2021届高三下学期联考数学试题2.如图,已知椭圆2222:1(0)x y C a b a b+=>>上一点(0,2)A ,右焦点为(c,0)F ,直线AF 交椭圆于B点,且满足||2||AF FB =, 33||2AB =.(1)求椭圆C 的方程;(2)若直线(0)y kx k =>与椭圆相交于,C D 两点,求四边形ACBD 面积的最大值. 【来源】黑龙江省漠河市高级中学2020-2021学年高三上学期第三次摸底考试文科数学试题3.已知椭圆22221(0)x y a b a b +=>>的左焦点为F ,离心率3e = 4.(Ⅰ)求椭圆的方程;(Ⅱ)过点F 的直线l 与椭圆交于M ,N 两点(非长轴端点),MO 的延长线与椭圆交于P 点,求PMN 面积的最大值,并求此时直线l 的方程.【来源】天津市十二区县重点学校2021届高三下学期毕业班联考(一)数学试题4.已知椭圆C :22221x y a b +=(0a b >>)的左、右焦点分别为1F ,2F 3G 是椭圆上一点,12GF F △的周长为643+.(1)求椭圆C 的方程;(2)直线l :y kx m =+与椭圆C 交于A ,B 两点,且四边形OAGB 为平行四边形,求证:OAGB 的面积为定值.【来源】陕西省宝鸡市2021届高三下学期高考模拟检测(二)文科数学试题5.已知椭圆()2222:10x y C a b a b +=>>的离心率22e =,过右焦点(),0F c 的直线y x c =-与椭圆交于A ,B 两点,A 在第一象限,且2AF =.(1)求椭圆C 的方程;(2)在x 轴上是否存在点M ,满足对于过点F 的任一直线l 与椭圆C 的两个交点P ,Q ,都有MP MQ ⋅为定值?若存在,求出点M 的坐标;若不存在,说明理由.【来源】河南省济源(平顶山许昌市)2021届高三第二次质量检测理科数学试题6.已知椭圆2222:1(0,0)x y C a b a b+=>>的离心率为12,并且经过()03P ,点.(1)求椭圆C 的方程;(2)设过点P 的直线与x 轴交于N 点,与椭圆的另一个交点为B ,点B 关于x 轴的对称点为B ',直线PB '交x 轴于点M ,求证:OM ON ⋅为定值. 【来源】北京平谷区2021届高三数学一模试题7.已知经过原点O 的直线与离心率为22的椭圆()2222:10x y C a b a b +=>>交于A ,B 两点,1F 、2F 是椭圆C 的左、右焦点,且12AF F △面积的最大值为1.(1)求椭圆C 的标准方程;(2)如图所示,设点P 是椭圆C 上异于左右顶点的任意一点,过点Р的椭圆C 的切线与2x =-交于点M .记直线1PF 的斜率为1k ,直线2MF 的斜率为2k ,证明:12k k ⋅为定值,并求出该定值. 【来源】广西南宁市2021届高三一模数学(文)试题8.设O 是坐标原点,以1F 、2F 为焦点的椭圆()2222:10x y C a b a b+=>>的长轴长为2,以12F F 为直径的圆和C 恰好有两个交点. (1)求C 的方程;(2)P 是C 外的一点,过P 的直线1l 、2l 均与C 相切,且1l 、2l 的斜率之积为112m m ⎛⎫-≤≤-⎪⎝⎭,记u 为PO 的最小值,求u 的取值范围.【来源】广东省深圳市2021届高三一模数学试题9.已知点(1,0)A ,点B 是圆221:(1)16O x y ++=上的动点,线段AB 的垂直平分线与1BO 相交于点C ,点C 的轨迹为曲线E . (1)求E 的方程(2)过点1O 作倾斜角互补的两条直线12,l l ,若直线1l 与曲线E 交于,M N 两点,直线2l 与圆1O 交于,P Q 两点,当,,,M N P Q 四点构成四边形,且四边形 MPNQ 的面积为831l 的方程. 【来源】广东省广州市2021届高三一模数学试题10.已知椭圆2222:1(0)x y C a b a b+=>>的离心率是12,椭圆C 过点31,2⎛⎫ ⎪⎝⎭.(1)求椭圆C 的方程;(2)已知12,F F 是椭圆C 的左、右焦点,过点2F 的直线l (不过坐标原点)与椭圆C 交于,A B 两点,求11F A F B ⋅ 的取值范围.【来源】东北三省三校(哈师大附中 东北师大附中 辽宁省实验中学 )2020-2021学年高三下学期第一次联合模拟考试文科数学试题11.已知椭圆2222:1x y C a b+=7,离心率为12,过椭圆左焦点1F 作不与x 轴重合的直线与椭圆C 相交于M ,N 两点,直线m 的方程为:2x a =-,过点M 作ME 垂直于直线m 交直线m 于点E .(1)求椭圆C 的标准方程;(2)①求证线段EN 必过定点P ,并求定点P 的坐标; ②点O 为坐标原点,求OEN 面积的最大值.【来源】广东省广州市执信中学2022届高三下学期二月月考数学试题12.已知()12,0A -,()22,0A 分别为椭圆C :()222210x y a b a b +=>>的左、右顶点,点31,2H ⎛⎫ ⎪⎝⎭在椭圆上.过点1,02D ⎛⎫⎪⎝⎭的直线交椭圆于两点P ,Q (P ,Q 与顶点1A ,2A 不重合),且直线1A P 与2A Q ,1A Q 与2A P 分别交于点M ,N . (1)求椭圆C 的方程(2)设直线1A P 的斜率为1k ,直线1A Q 的斜率为2k . ①证明:12k k ⋅为定值; ②求DMN 面积的最小值.【来源】山东省潍坊市2021-2022学年高三上学期期末数学试题13.已知椭圆()2222:10x y E a b a b+=>>的右焦点为F ,点A ,B 分别为右顶点和上顶点,点O 为坐标原点,11e OF OA FA+=,OAB 2,其中e 为E 的离心率. (1)求椭圆E 的方程;(2)过点O 异于坐标轴的直线与E 交于M ,N 两点,射线AM ,AN 分别与圆22:4C x y +=交于P ,Q 两点,记直线MN 和直线PQ 的斜率分别为1k ,2k ,问12k k 是否为定值?若是,求出该定值;若不是,请说明理由.【来源】四川省绵阳市2021-2022学年高三上学期第二次诊断性考试理科数学试题14.已知点M 是椭圆C :()222210y x a b a b +=>>上一点,1F ,2F 分别为椭圆C 的上、下焦点,124F F =,当1290F MF ∠=︒,12F MF △的面积为5.(1)求椭圆C 的方程:(2)设过点2F 的直线l 和椭圆C 交于两点A ,B ,是否存在直线l ,使得2OAF 与1OBF △(O 是坐标原点)的面积比值为5:7.若存在,求出直线l 的方程:若不存在,说明理由.【来源】江西省赣州市2022届高三上学期期末数学(文)试题15.已知椭圆2222:1(0)x yC a ba b+=>>过点3P⎛⎝⎭3(1)求椭圆C的方程;(2)在y轴上是否存在点M,过点M的直线l交椭圆C于A,B两点,O为坐标原点,使得三角形AOB的面积1tan2=-∠S AOB若存在,求出点M的坐标;若不存在,说明理由.【来源】江西省赣州市2022届高三上学期期末数学(理)试题。
2024年高考语文临考押题卷01(新课标卷专用)(考试时间:150分钟试卷满分:150分)注意事项:1.答卷前,考生务必将自己的姓名、考生号等填写在答题卡和试卷指定位置。
2.回答选择题时,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涂黑。
如需改动,用橡皮擦干净后,再选涂其他答案标号。
回答非选择题时,将答案写在答题卡上。
写在本试卷上无效。
3.考试结束后,将本试卷和答题卡一并交回。
一、现代文阅读(35分)(一)(2024届东北三省三校(哈师大附中、辽宁省实验中学、东北师大附中)高三第二次联合模拟考试语文试题)现代文阅读Ⅰ(本题共5小题,17分)材料一:《红楼梦》后四十回续书作者问题不是“新闻”,实实在在是“旧闻”。
张庆善指出,早在2008年《红楼梦》新校本第三次修订出版时,就已经由“曹雪芹、高鹗著”改为“曹雪芹著,无名氏续,程伟元、高鹗整理”了。
张庆善认为曹雪芹其实把《红楼梦》写完了,理由是:从创作规律而言,曹雪芹创作《红楼梦》批阅十载,增删五次,纂成目录,分出章回,历时十年之久,不可能只写出前八十回就不再往下写了,翻来覆去只修改前八十回,这不符合创作规律;现有的大量脂砚斋批语,已经透露出八十回以后的情节,曹雪芹的亲友脂砚斋、畸笏叟都已经看到了这些稿子,如庚辰本第四十二回回前批:“钗玉名虽二个,人却一身,此幻笔也。
今书至三十八回时已过三分之一有余,故写是回,使二人合而为一。
请看黛玉逝世后宝钗之文字,便知余言不谬矣。
”曹雪芹《红楼梦》写完了,原稿八十回后为什么没有传下来?张庆善认为是《红楼梦》传阅时弄丢了。
曹雪芹逝世后,畸笏叟保存残稿,更不敢轻易拿去给别人看,怕再弄丢,最终八十回后的稿子也随着畸笏叟的去世而成了永远的谜案。
在曹雪芹逝世后的二三十年里,《红楼梦》都是以八十回本在社会上流传,直到1791年,程伟元、高鹗整理出版了一百二十回本《红楼梦》,才结束了《红楼梦》以八十回本流传的时代。
那么,《红楼梦》后四十回是从哪里来的?张庆善认为,后四十回是程伟元多年搜寻得来的,程伟元邀请高鹗帮助修订整理,高鹗欣然答应,“细加厘剔,截长补短”,依据就是程伟元、高鹗为程甲本、程乙本出版所写的序和引言。
2024年东北三省三校(哈师大附中、东北师大附中、辽宁省实验中学)高考数学四模试卷一、单选题:本题共8小题,每小题5分,共40分。
在每小题给出的选项中,只有一项是符合题目要求的。
1.已知,x,,则()A.2B.3C.4D.52.若,是夹角为的两个单位向量,与垂直,则()A.0B.2C.D.3.某种酸奶每罐净重单位:服从正态分布随机抽取1罐,其净重在179g与之间的概率为()注:若,,,A. B. C. D.4.等差数列的前n项和记为,若,,则()A.51B.102C.119D.2385.过点作圆的切线PA,A为切点,,则的最大值是()A. B. C. D.6.已知双曲线的左,右焦点分别为,,点P在双曲线的右支上,I为的内心,记,,的面积分别为,,,且满足,则双曲线的离心率是()A. B. C.2 D.37.某高中2023年的高考考生人数是2022年高考考生人数的倍.为了更好地对比该校考生的升学情况,统计了该校2022年和2023年高考分数达线情况,得到如图所示扇形统计图:下列结论正确的是()A.该校2023年与2022年的本科达线人数比为6:5B.该校2023年与2022年的专科达线人数比为6:7C.2023年该校本科达线人数比2022年该校本科达线人数增加了D.2023年该校不上线的人数有所减少8.如图,在棱长为2的正方体中,已知M,N,P分别是棱,,BC的中点,Q为平面PMN上的动点,且直线与直线的夹角为,则点Q的轨迹长度为()A.B.C.D.二、多选题:本题共3小题,共18分。
在每小题给出的选项中,有多项符合题目要求。
全部选对的得6分,部分选对的得2分,有选错的得0分。
9.已知,内角A,B,C分别对应边a,b,c则下列命题中正确的是()A.若,则为钝角三角形B.若,,,则的面积为C.在锐角中,不等式恒成立D.若,,且有两解,则b的取值范围是10.已知函数,则下列说法正确的是()A.的极值点为B.的极值点为1C.直线是曲线的一条切线D.有两个零点11.已知和分别是定义在R上的偶函数和奇函数,且,则下列说法中正确的是()A.4为的一个周期B.8为的一个周期C. D.三、填空题:本题共3小题,每小题5分,共15分。
本试卷分第Ⅰ卷(阅读题)和第Ⅱ卷(表达题)两部分,其中第Ⅰ卷第三、四题为选考题,其它题为必考题。
考生作答时,将答案答在答题卡上,在本试卷上答题无效。
考试结束后,将本试卷和答题卡一并交回。
注意事项:1.答题前,务必先将自己的姓名、准考证号填写在答题卡上,认真核对条形码上的姓名、准考证号,并将条形码粘贴在卡的指定位置上。
2.答题时0.5毫米黑色签字笔或碳素笔书写,字体工整,笔迹清楚。
3.请按照题号在各题的答题区域(黑色线框)内作答,走出答题区域书写的答案无效。
4.保持卡面清洁,不折叠,不破损。
5.做选考题时,考生按照题目要求作答,在答题卡上把所选题目对应的题号标明。
第Ⅰ卷阅读题甲必考题一、现代文阅读(9分,每小题3分)阅读下面的文字,完成1-3题。
经典的定义也无须再做论证,套用库切《何谓经典》中说的话,那些“历经最糟糕的野蛮攻击而得以劫后余生的作品就是经典”。
当然,撇开其讲演的特殊语境,那些历经后人最诚挚的颂扬而光景常新的作品,无疑也在其列。
越是越出惯常的理解,不能仅将经典局限在古今中外的文学名著上,许多人文社科类著作,包括一部分自然科学著作,因对人的处境有真切的关心,对人生在这个世界上的命运有深刻周彻的肯认,对人内心经验有感同身受的体谅,并精鹜八极,鞭辟入里,也都是经典,都应成为我们阅读的重点。
传统人文社科类经典大多着力于揭示人与世界的终极奥旨,字里行间,洋溢着个人与人类及宇宙深切的同体感。
那种既重视个体世间安顿,又时时仰望精神天空,不懈追索两者相携相成的执着与热忱,还有让一己放心落下的同时,努力让人类全体身心和谐的高尚追求,是人自身全部尊严的最好注释。
其中,作为“知识之王”的哲学经典,尤其具有范式意义,尤应认真阅读和了解。
一方面,它强调主体的自由出场和自我证明,故在根本处与文学艺术相近。
好的艺术经典以形象诠释人生,好的哲学经典(有时包括宗教经典)则以抽象演绎人生。
它们探讨的虽是“宇宙秩序”,但归结在“生活秩序”,面对同一个世界,回答同一个问题,所以可相资相益,相互参证。
英 语 试 卷 参 考 答 案【听力理解】 1-5 ABCAB 6-10 CBABC 11-15 BACBA 16-20 ACCBA 【阅读理解】 21-23 BDA 24-27 BDCA 28-31 BCDB 32-35 CBCD 36-40 GEAFC 【完形填空】 41-45 BCACD 46-50 ABDBA 51-55 DCCAA 56-60 BDBCD 【语法填空】 61. the 62. which 63. making 64. to 65. unskilled 66. lost 67. What 68. goes 69. him 70. players 【短文改错】 Dear Lucy,I’m sorry to learn that your mom read your journal and you felt annoyed. After all,it is up to you if towhethershare what you write.You’d better have a open discussion about how all of you feel. You should calmly tellher that youan bothexpect to have a certain amount ∧privacy. If she feels the best of all way to know aboutyou is to read yourof waysjournal, and it means there is a lack of communication.As we get old, we start to want more privacy, but this can lead to parents feel likethey are left out of ourolder feelingworld. You may as well understand what your mom does. I believe there must be a win-winsolution todidmaking your mom feel she is still strongly connecting to you.connectedYours, Li Hua 【书面表达】 In response to the national call against food waste, our school launched the Clean Plate Campaign last week. Food loss and waste exist and millions of people are still hungry. The food wasted globally every year could feed these hungry people. Various school activities were carried out for this reason. Young volunteers put up posters and signs promoting food saving on campus to increase awareness of respecting food labor and valuing food among students. Also,class meetings were held to make a change in the students ’ attitude and encourage them to become eco-pioneers. Through the campaign, we have become more aware that there is no excuse for wasting food. To save food is a traditional virtue in China, which we should never forget. 【听力原文】 (Text 1) W: What was that? Could you say that again, please? This bus is really noisy. The man next to me is listening to loud music. M: Hi! I said my battery is about to die! I’ll call you back using Ben’s phone! (Text 2)W: Since you only have a couple of items, you can go ahead of me in line. M: Thanks! I’m late for work and don’t have time to wait for you to pay for all of your food. (Text 3) W: So, we have to interview someone about the war? What’s the point of that? M: Reading textbooks and surfing the Internet are not the only ways to get information. Sometimes people are just as good, if not better. (Text 4) M: Mrs. Jenkins is such a nice teacher. She always has good advice, and has such a good sense of humor. W: I wish Mrs. Dunkirk was lik e that. She’s strict, and her assignments are hard. (Text 5) M: I have book club at 7:00 tonight. I’m wondering if I should even show up. I didn’t read the book. W: Just call and tell them. They’ll understand. You haven’t missed one all year. (Text 6) W: Congratulations on getting your first car! Who taught you how to drive? M: My father. He used to collect old cars, but now he just has a couple sports cars that he drives on the weekends. W: Do you think he’ll let you drive any of them? M: Wow, I sure hop e so! But I don’t think I’m quite ready for that, so I’m not getting worked up about it. W: Driving should be as easy as possible, in my opinion. M: Yeah, but it should also be fun. Speaking of that, are you ready? Let’s drive to the beach!W: OK, I just need to get my sunglasses from your living room. I must have left them in thereduring breakfast.(Text 7) W: My sink is leaking and has poor water pressure. Could you send someone to fix it?M: OK. They will be there by the end of the day. W: I am going to be at work until 6:00 p.m., so I won’t be able to let them inside. M: Don’t worry. They have a master key that will let them in.W: Couldn’t they just come tomorrow? I don’t like anyone being in my apartment when I’m not there.M: I’m sorry, but they don’t work on Saturdays.W: OK, how about Monday then? I don’t work on Mondays.M: Sure, they should be there by 10:00 a.m. on Monday.W: I guess I’ll just have to put a basin under the sink for now.(Text 8)W: What do you feel like doing this weekend? Want to go to the movies?M: Not really. I went to the movies last weekend.W: Well, want to go ice-skating? All the lakes are frozen.M: I’m so bad at ice-skating. Every time I go, I lose balance and fall.W: Yeah, I’m not very good either, but it’s fun.Want to go to watch my brother’s hockey game?M: Sure! I love hockey. I want to learn how to play hockey better so I can play someday. W: My brother is really good. My dad was a professional hockey player. He is retired now. M: Really? That’s so cool!W: Thanks! My brother is playing hockey for a college team and he hopes he’ll be able to go professional.M: I hope so, too. Then I can say I learned hockey from a professional!W: Well, you’re going to need to learn how to ice-skate first!(Text 9)W: I h ave some good news for you. We’ve decided we’d like to send you to Shanghai ona business trip this weekend.M: Oh?W: I thought you’d be a bit more excited about it. Everything will be paid for, and I’ll send my assistant with you to take care of everything for you. All you have to do is get on the train tonight at 7:00 p.m.M: The train? Will I be flying back?W: Oh, no. We’ve bought your return ticket for you. I think you’ll find it quite comfortable.M: Will the train be very crowded?W: Oh, no. The train hasn’t been crowded at all recently. Besides, you’re in first class, so you’ll be fine.M: When is the first meeting then?W: They’ve scheduled the meeting for 9:00 tomorrow morning.M: Where will I be staying?W: We’ve booked you a room in the same hotel as your meetings, so you won’t need to deal much with public transportation.M: That’s smart. Would it be all right if I left early today to prepare for the trip? W: No problem. Get some rest if you can. You do n’t know how tight the schedule is for this business trip. (Text 10)The class of 2012 is reunited again! The class officers have been busy meeting and planning since January 2018. We have decided to hold our class reunion on June 1, 2018. Each member of the class should be receiving an invitation in March of 2018. You can park in the main parking lot for free. Each member of the class of 2012 is invited to attend and can bring one guest. The cost for each person will be $20, which will include dinner and drinks. The entry to the event will be at the front office. The reunion will be held at Redhawk High School in the cafeteria at 7:00 p.m. We will need volunteers to help with decorations, planning, and other details, so if you are interested, please contact Rob Jones before May 1, 2018 by calling 455-555-6789. If you intend to attend the event, please contact Molly Jones at 455-555-4567 before May 1, 2018. Additional information can be found at . We look forward to seeing familiar faces!。
第二次模拟考试答案_物理(2)A D (2分,各1分) 23.(1)R 2(3分) (2)3A (0~3A )(3分) (3)(3分)限流供电,r2与电压表串联测电压,电流表内接 (4)12.0(2分) 24. 解分)(分)(分)分)(分)分))(分)分)分)分)(2242BC 11(222tan /H 1(1(21H 21(2P 2(P 1(2)2(21122h x vt x ght x vt x gt gh m g m gv gh v m v m gh m m ===========θ25. 解(1)由于带电粒子偏转,PQ 极板上将带上电荷,设电压为U ,则极板MN 间的电压也为U ,当带电粒子在PQ 极板间做匀速运动时,有q dU B qv =10,(2分) 若在荧光屏Y 上只有一个亮点,则负电荷不能通过极板MN 。
2021mv Uq ≥,(2分) 解得mqdB v 102≤(2分) (2)荧光屏上有两个亮点,则mqdB v 102>(2分),在此条件下, q dUB qv =10,得01v dB U =对正电荷,设到达B 2中后速度为1v ,则20212121mv mv Uq -=(2分) 设做圆周运动的半径为R 1,则12121R mv B qv =,(2分)得mqv dB mv qB mR 0120212+=对负电荷,设到达B 2中后速度为2v ,则20222121mv mv Uq -=-(2分) 设做圆周运动的半径为R 2,则22222R mv B qv =,(2分)得mqv dB mv qB mR 0120222-=所以,正、负两种电荷形成的亮点到荧光屏上小孔的距离之比为qv dB m v qv dB m v R R d d 0120012021212222-+==(2分) 33.(1)BD(2) (1)活塞刚离开卡口时,对活塞mg +P 0S =P 1S 得P 1 =P 0+mgS(2分)两侧气体体积不变,右管气体 P 0T 0=P 1T 1得T 1=T 0(1+mgP 0S ) (3分)(2)左管内气体,长度为L 23,压强为:P 2= P 0+mg S +ρgL (2分)应用理想气体状态方程2023T SL P T LSP = 得T 2=3T 02P 0(P 0+mg S +ρgL )(3分)34.(1)B (2)解分)(分2/103/)3(8s m v nc v v cn ⨯===S=362L π (5分)35. (1)BCD(2)解:(1)当弹簧再次恢复原长时a 滑块的速度达到最大, 设a 滑块的最大速度为1v ,a 滑块能达最大速度时b 滑块的速度为2v 由题意得:02v m I = ①112202v m v m v m += ②211222202212121v m v m v m += ③ 解得:210212122m m Iv m m m v +=+=④ (2)两滑块间有最大距离时,两滑块的速度相等。
2019年东北三省三校第一次模拟考试文综地理详解答案1.D2.C3.B4.C5.D6.A7.C8.A9.C 10.B 11.D1.D 【解析】A选项电子商务取代传统商业叙述过于绝对,电子商务只是部分取代了传统商业;B选项物流业先于电子商务产生,目前两者关系是相辅相成的。
C选项区域经济联系目前正在逐渐增强。
D选项商业布局区位因素,如市场、交通等因素对商业的影响正在减弱,所以影响商业布局的区位因素发生了变化。
2.C 【解析】电子商务发展依赖于信息、流通等部门,导致商业网络组织形式发生变化的主要因素是科技信息的发展。
3.B 【解析】 A选项云南全年的蔬菜总产量据图计算应为1880万吨左右,而广西为2780万吨左右,故云南产量小于广西。
B选项经计算海南省总蔬菜产量为600万吨左右,是三省区最低的省(区)。
C选项广西冬春菜产量占比高主要是北方消费市场的季节差的需求。
D选项海南与云南种植蔬菜的热量差异不大。
4.C 【解析】“南菜北运”可以促进生产地区与市场的融合,丰富农产品的种类,促进市场供应,提高人民生活水平,被称为“菜篮子”工程,但不可能促进全国各地均衡发展,故不属于选项为C选项。
5.D 【解析】从题干可知,河口地区是径流和潮流相互作用的区域,在径流势力比潮流势力强的河口,会导致泥沙大量堆积,则形成三角洲式河口;在河流势力比潮流势力弱时,会导致海水强烈冲刷河口地区,形成三角港式河口。
甲乙两河口都有可能出现咸潮现象,但乙河口为三角港式河口,则乙河口地区潮流势力更强,更易出现海水倒灌,形成咸潮,故A选项错误;甲河口径流势力比潮流势力强,更容易泥沙堆积,形成三角洲,B选项错误;试题中能反映出河口地区径流与潮流的相互作用关系,但无法判断河流输沙量的大小,C错误;乙河口为三角港式河口,受海水的侵蚀更严重,D选项正确。
6.A 【解析】近几年甲河口区“前缘急坡”后退明显,说明河口地区泥沙沉积减少,海水侵蚀速度大于河流沉积速度,中上游修水库会导致河流携带的泥沙在库区沉积,而入海泥沙减少,A选择正确;流域植被破坏会导致河流含沙量增加,河口地区泥沙沉积量增加,会使“前缘急坡”向海洋扩展,C选项错误;地壳运动和全球变暖导致的海平面上升,都是极其缓慢的过程,不会出现近几年“前缘急坡”的明显后退,B、D选项错误。
一、单选题1. 甲、乙两物体做直线运动的v-t 图象如图所示,下列说法正确的是()A .甲、乙两物体都做匀速直线运动B .甲、乙两物体都做匀加速直线运动C .甲物体都做匀速直线运动,乙物体静止D .甲物体做匀加速直线运动,乙物体做匀速直线运动2. 物理学是一门以实验为基础的科学,以下说法正确的是A .光电效应实验表明光具有波动性B .电子的发现说明电子是构成物质的最小微粒C .居里夫人首先发现了天然放射现象D .α粒子散射实验是原子核式结构理论的实验基础3. 某同学用图甲的装置探究摩擦力的变化情况。
水平桌面上固定的力传感器,通过水平棉线拉住物块,物块放置在粗糙的长木板上,长木板左端固定的细绳跨过光滑滑轮悬挂一小桶。
从开始,断断续续往小桶中缓慢加水,传感器记录的图像如图乙所示。
不考虑水平桌面与木板间的摩擦,下列判断正确的是( )A .t 1~t 2内,物块受到的是滑动摩擦力B .0~t 3内,小桶中的水量时刻在增加C .t 3~t 4内,木板的加速度逐渐增大D .t 4~t 5内,木板一定做匀速运动4. 某一物体做直线运动,其速度随时间变化的v-t 图像如图所示.下列说法正确的是( )A .在t =36s 时,物体速度的方向发生了变化B .在0-44s 内,bc 段对应的加速度最大C .在36s-44s 内,物体的加速度为-6m/s 2D .在36s-44s 内,物体的位移为192m5. 排球是我们三中的体育特色。
某同学在体育课上进行排球训练,一次垫球时,他用双臂将排球以原速率斜向上垫回,球在空中运动一段时间后落地。
不计空气阻力,下列说法正确的是( )2024届东北三省三校(哈师大附中、东北师大附中、辽宁省实验中学)高三下学期二、多选题A .垫球过程该同学对球做功不为零B .垫球过程该同学对球做功为零C .球在上升过程中处于超重状态D .球在下落过程中处于超重状态6. 已知如图所示为穿过匝数n =100的线圈的磁通量F 随时间t 按正弦规律变化的图像,其产生的电压为交变电压(π=3.14)。
2021年东北三省三校(哈师大附中、东北师大附中、辽宁省高考英语一模试卷学校:__________ 班级:__________ 姓名:__________ 考号:__________1. (3分) Once again, Ke Jie has shown the world that he is certainly a Go grandmaster (围棋大师).On Nov.3,(1)________23﹣year﹣old Chinese Go player won another championship. He defeated Shin Jinseo of South Korea, 2﹣0 in the 25th Samsung World Go Masters final,(2)________was held online this year,(3)________ (make) him the youngest Chinese Go player to hold eight world titles.His road(4)________success was paved with pain and difficulties. Ke was(5)________(skilled)and often ranked bottom of many competitions until he stepped up his professional career at age 11. In 2015,he became the youngest three﹣time champion in the history of the game.Despite being the world's top player, Ke met a challenge in 2017 when he(6)________ (lose), 0﹣3 to the AI program AlphaGo. Ke cried after the game. "(7)________doesn't kill you makes you stronger," as the saying(8)________(go). Ke has learned about from AlphaGo and put it into practice,which helped(9)________(he)secure 22 wins in a row against human(10)________(player)after failing to AlphaGo. "AI is quite strong, and people are studying this technology all the time. I can feel my opponents(对手)attacking me well, but all I can do is fight back," Ke told CGTN.2. (10分)假设英语课上老师要求同桌之间交换修改作文,请你修改你同桌写的以下信件内容。
一、单选题1. 某同学想自己设计并改装一个欧姆表。
他手上有如下器材:量程300μA 、内阻900Ω的电流计;电动势1.5V 的一节干电池;滑动变阻器、电阻箱和若干定值电阻。
他设计的电路如图甲所示,实验时他将两表笔短接,电流计指针满偏时,他计算出电路中的总电阻为5kΩ。
然后他将一个50Ω和10Ω的电阻分别接到两表笔之间时,发现电流计指针指示的位置几乎一样,很难区分。
经过研究后他认为,要想比较准确地测量几十欧姆的电阻,用图甲所示电路并不合适,为此他设计了如图乙所示的电路。
并联合适电阻 R ₂后,使干路电流是流经电流计电流的100倍。
则( )A .将图乙电路中的两表笔短接,此时电路中的总电阻是5ΩB .分别将一个50Ω和10Ω的电阻先后接到图乙电路的两表笔之间,通过干电池的电流几乎没有区别C .分别将一个50Ω和10Ω的电阻先后接到图乙电路的两表笔之间,电流计指针指示的位置明显不同D .在图甲电路和图乙电路的两表笔之间分别接入5kΩ和50Ω的电阻,通过两电流计的电流明显不同2.如图甲所示,正方形硬质金属框放置在磁场中,金属框平面与磁场方向垂直。
磁感应强度B 随时间t 变化规律如图乙所示。
在0~0.2s 的时间内与0.2s~0.6s的时间内( )A .通过金属框的电荷量之比为2∶1B .金属框中电流的电功率之比为4∶1C .金属框中产生的焦耳热之比为4∶1D .金属框两边受到安培力方向相反,大小之比为3∶13. 通过实验研究通电长直导线间的相互作用规律。
如图所示,为两根平行的长直导线,通过外接直流电源分别给两导线通以相应的恒定电流。
为导线所在平面内的两点。
下列说法中正确的是( )A.两导线中的电流大小相等、方向相反时,点的磁感应强度为零B .导线电流向上、导线电流向下时,导线所受安培力向右C .点的磁感应强度一定不为零D .两导线所受安培力的大小一定相等4. 加速度传感器是一些智能手机上配备的较为实用的软件,能显示物体运动过程中的加速度变化情况。
东北三省三校2021届高三第二学期第一次联合高考模拟考试英语试卷哈尔滨师大附中东北师大附中辽宁省实验中学本试卷分第I卷(选择题)和第I卷(非选择题)两部分。
考试结束,将本试卷和答题卡--并交回满分150分,考试时间120分钟。
注意事项;1.答第I卷前,考生务必将自己的姓名、准考证号填写在本试卷和答题十相应位置上。
2.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涂黑,如需改动,用橡皮擦干净后,再选涂其他答案标号,不能答在本试卷上,否则无效。
第I卷选择题(满分100分)第一部分昕力(共两节,满分30分)第一节(共5小题;每小题1.5分,满分7.5分)听下面5段对话。
每段对话后有-个小题,从题中所给的A、B、C三个选项中选出最佳选项, 并标在试卷的相应位置。
听完每段对话后,你都有10秒钟的时间来回答有关小题和阅读下一小题。
每段对话仅读-遍。
例:How much is the shirt?A.₤19.15.B. ₤ 9. 18.C. ₤ 9. 15.答案是C。
1. What does the woman ask the man to do?A. Repeat what he said.B. Call her back soon,C. Stop listening to music.2. Where are the speakers?A. At an office.B. At a grocery store.C. Ata restaurant.3. What kind of homework does the man give his students?A. Reading.B. Using the Internet.C. Interviewing someone.4. What does the woman think of Mrs. Dunkirk?A. She is strict.B. She is humorous.C. She gives good advice.5. Why doesn't the man want to go to book club tonight?A. He is running late.B. He didn't read the book.C. He usually misses it.第二节(共15小题;每小题1.5分,满分22.5分)听下面5段对话或独白。
东北三省三校(哈师大附中、东北师大附中、辽宁省实验中学)2021届高三英语二模联考试题(含解析)一、阅读理解(本大题共15小题,共30.0分)AMoringa Farm Internship ProgramDATE: 5 May〜30 November 2021LOCATION: Jaipur IndiaEVENT TYPE:TwiningEVENT INDUSTRY/TOPIC: Clean Energy, Climate & Environment, Food & Agriculture andQuality/Process Moringa(辣木),a kind of miracle tree, has come a long way today to become a symbol of the fight against growing nutrition deficiency[营养不足)across the globe. It is also a crop suited to the climatic conditions of the region, which is unusually rich in its nutrition contentliterally from top to bottom.Supporting learning:The Moringa Farm Internship Program is sort of like a live, interactive slideshow of agriculture making of Moringa from "Soil to Super food" that touches all the participant's senses.The Program's Objectives:The Moringa Farm Internship Program is devoted to enriching the knowledge and lives of young people by providing them with a unique f educational experience on an organic Moringa Farm in rural Jaipur,India. Program participants can learn about conservation, maintenance (维护),care, and management of Moringa Farming by means of hands-on work experience with local Moringa Farm staff.Participants will be able to interact with Moringa specialists and educators? on all issues that may affect their operations. Experts will let you know management strategies and equipment operation up close on hand to answer your specific questions.The Moringa Farm Internship will provide an excellent opportunity to learn about sustainable tools, techniques, and approaches that can be used in Moringa Production and value-added production systems, righting(突出)pest and disease management, leaf/seed production, and tools and equipment for commercial production.If you're trying to learn about Moringa, there's nothing like going to a farm and getting your hands dirty. So click here to register now!1.Why is Moringa specifically described in the text? ______A. To stress the importance of the crop.B. To encourage people to plant Moringa.C. To show the significance of the program.D. To draw attention to nutrition deficiency.2.What can we know about the Moringa Farm Internship Program? ______A. It is intended for farmers,B. It lasts more than half a year.C. It provides vocational training.D. It is available on the Internet.3.How do the program's participants learn about Moringa? ______A. By attending various courses about it,B. By involving themselves in farming it.C. By observing specialists and educators.D. By watching slideshows about the crop.【答案】【小题1】C 【小题2】D 【小题3】B【解析】1. C 推理判断题.根据第一段"Moringa (辣木), a kind of mirade te..ecome a symbol of the fight against growingnutrition deficiency (营养不足)across the globe.It is also a crop suited to the dlimatic conditions of the region,which isunusually rich in its nutrition content lterally from top to bottom.(辣木是一种神奇的树,成为对抗全球营养缺乏的象征.它也是一种适合该地区气候条件的作物,其营养成分从叶到根都非常丰富)可知,这部分对辣木的非凡作用进行了专门的介绍,而!该计划又是针对辣木的.由此可推断,此处介绍的目的是为了体现计划的意义和重要性,故选C.2. D 细节理解题.根据最后一段最后一句So click here to register now! (点击这里注册吧! )可知,在网上可以找到该计划,故选D.3. B 推理判断题.根据第九段"Program participants can learn about conservation ,maintenance (维护),care ,and managementof Moringa Farming by means of hands-on work expe rience with local Moringa Farm staff.(参与者可以与当地辣木农场员I-.起实际体验工作,了解辣木种植的养护、维护、护理和管理)可知,参与人员通过亲自参加辣木种植来了解辣木,故选B.本文为说明文.文章主要介绍辣木农场实习计划的主题、目的、实习内容等相关事项.1.直接信息题:直接信息题是指能够直接从原文中找到信息,选项在语言表达上与原文基本一致的题目.2.间接信息题:间接信息题是能够从原文中找到信息,但在语言表达上与原文有差异,做题时需要对原文信息进行转换.3.综合信息题:综合信息题是指这类题目所涉及的信息不是原文的某一句话,可能是原文的几句话,或者是散落在文章不同的地方,要求学生把原文所提供的信息综合起来分析,而不能断章取义.BWe had two dogs, Lucky and Lil' Bit. Lucky loved to find ways to leave the confines(束缚)of her indoor living routine, which made her a masterful escape artist. Lil Bit, on the other hand, did exactly as she was told, never straying, always staying close to home…except when she came under the influence of Lucky.Whenever the two got out together, they could be seen out of sights often staying away for hours. More often than not, they'd arrive home near suppertime, covered in mud and leaves and smelling to high heaven from their afternoon outing in the woods.I remember one such occasion when they'd once again mysteriously escaped, except this time,they returned clean and no worse for wear. It wasn't until a few days later that we learned why. My wife ran into our neighbor Carl who lived a few houses down from us."I saw your two dogs the other day," Carl said with a smile."Oh, yes? I'm so sorry. They'd been so good lately, so it was such a surprise when they got out. I sure hope they didn't cause any trouble." my wife replied."Oh, no, no trouble at all. Did you have any idea where they went?""No," my wife answered."They attended my dog's funeral(葬礼)Carl said sadly."What?" Ann exclaimed, "Oh, no. I didn't know Toby had died."Yep, it died a couple days ago. I was burying him in the back lot when your two dogs came running up. They sat down not far from me while. I finished burying him, then they left. " "Wow that's amazing!" my wife replied. "Toby was Lil' Bitt father, you know.""No, I didn't know that," Carl replied, "but I guess that explains why she felt like she needed to be there. She had to say her final goodbye. "4.What words can best explain the meaning of the word "straying" underlined in Para. 1? ______A. Wandering away.B. Staying still.C. Shouting loudly.D. Disobeying impolitely.5.What difference between Lucky and Lily Bit ls suggested in the first paragraph? ______A. Their abilities were different.B. Their hobbies were different.C. Their personalities were different.D. Their physical features were different.6.What would generally happen to the two dogs after they got home from outside? ______A. They got more united.B. They looked in a mess.C. They smelled nice as usual.D. They got willing to do as told to.7.What is the author's purpose of writing the text? ______A. To show his respect for dogs.B. To be in memory of his dogs.C. To suggest learning from dogs.D. To think highly of his two dogs.【答案】【小题1】A 【小题2】C 【小题3】B 【小题4】D【解析】1.A.词义猜测题.根据文章第一段Lil Bit,on the other hand,did exactly as she was told,never straying,always staying close to home…except when she came under the influence of Lucky .另一方面,就像她被告知的那样,从不迷路,总是呆在家附近…除非她受到幸运的影响.可知意为走失;故选A.2.C.细节理解题.根据文章第一段Lucky loved to find ways to leave the confines(束缚)of her indoor living routine,which made her a masterful escape artist.Lil B it,on the other hand,did exactly as she was told,never straying,always staying close to home…except when she came under the influence of Lucky幸运的是,她喜欢设法摆脱室内生活的束缚束缚,这使她成为一个出色的逃避现实的艺术家;可知Lucky和Lily Bit ls的区别是他们的性格不同;故选C.3.A.细节理解题.根据文章第二段More often than not, they'd arrive home near suppertime, covered in mud and leaves and smelling to high heaven from their afternoon outing in the woods.更多的时候,他们会在晚饭时间到家,浑身是泥,树叶,下午在树林里郊游时闻到天堂的味道.可知这两只狗从外面回家后通常会看起来一团糟;故选A.4.D.细节理解题.根据文章最后一段"No,I didn't know that," Carl replied,"but I guess that explains why she felt like she needed to b e there.She had to say her final goodbye."不,我不知道,卡尔回答说,但我想这解释了为什么她觉得她需要去那儿.可知作者写文是为表示对自己两条狗的高度评价;故选D本文属于说明文阅读,作者通过这篇文章主要向我们描述了作者养的两条狗 Lucky and Lil' Bit,他们有情有义为隔壁死去的狗祭奠.考察学生的推理判断能力和联系上下文的的能力,在做推理判断题不要以个人的主观想象代替文章的事实,要根据文章事实进行合乎逻辑的推理判断.此类的填空题一定要联系上下文,根据上下文的内容加上自己的理解,再作出正确的判断CTwo years ago, Kiirsat Ceylan was in New York to give a talk about disability rights at the U. N. Blind since birth, the Turkish man was struggling to find his hotel, holding a cane in one hand and pulling his luggage with the other."Not surprisingly, suddenly I bumped into a pole/*he says*"It was a bit bloody."The problem with a cane is that, while it can tell you what's on the grounds it doesn't help with objects at the body or head level. It wasn't the first time Ceylan had run into something,injuring himself."" I have no problem with my scars, which make me more handsome I guess," Ceylan says,laughing. "But I don't need hew ones."With WeWalk, a new smart cane, Ceylan hopes to help other blind people navigate their environments more easily*The cane uses an ultrasonic(超声波)sensor which detects objects at body or head level and gives a warning vibration. WeWalk users pair the cane with their smartphones and then use the cane's touchpad to access features like voice assistant or navigation*Before leaving home,they can plug their destination into Google Maps and get spoken directions as they walk In the future, Ceylan hopes to connect WeWalk with public transportation and ridesharing services.Assistive technology is often expensive for blind people, says Eelke Folmer, a computer science professor at the University of Nevada! Reno. "But developers fail to realize their devices are out of reach for many blind people, To Folmer, the price point-﹩ 500-- sets the WeWalk cane apart from other technologies.Ceylan sees WeWalk as part of an attempt to help blind people achieve greater freedom of movement,which he believes will give them greater access to education and jobs. The canes are already having an impact on users, Ceylan says. He recently received an email from a teacher in Ireland who had become blind as an adult. He'd been depressed and housebound. But since getting a WeWalk cane, your device forced me to go out. It became my anti- depressant. " he wrote.8.Why is a story about Kursat Ceylan given at the beginning of the text? ______A. To stress the difficulty caused by blindness.B. To show his reason for developing his cane.C. To indicate the problems with present canes.D. To show his positive and humorous character.9.What can WeWalk do at present according to the text? ______A. Provide fast Internet access.B. Start conversations with users.C. Tell users what is around them.D. Connect with ridesharing services.10.What does Folmer think is the advantage of WeWalk over other assistive technologies? ______A. It is easily affordable,B. It is easily controllable.C. It works better for users,D. It looks more attractive.11.What is the text mainly about? ______A. The increasing demand for smart canes.B. A blind man s devotion to smart canes.C. A smart cane's effects on blind people,D. An assistive technology for the blind.【答案】【小题1】B 【小题2】C 【小题3】A 【小题4】B【解析】1.B.细节理解题.根据第五段的With WeWalk, a new smart cane,Ceylan hopes to help other blind people naviga te their environments more easily.有了新的智能拐杖WeWalk,Ceylan希望能帮助其他盲人更容易地驾驭他们的环境.可知,文章提到Kursat Ceylan 的故事是想说明他研发这种拐杖的原因.故选B.2.C.细节理解题.根据第五段的With WeWalk, a new smart cane,Ceylan hopes to help other blind people naviga te their environments more easily.有了新的智能拐杖WeWalk,Ceylan希望能帮助其他盲人更容易地驾驭他们的环境.可知,WeWalk可以告诉使用者周围的情况.故选C.3.A.细节理解题,根据文章倒数第二段的句子To Folmer,the price point-﹩500-- sets the WeWalk cane apart from other technologies.对Folmer来说,500英镑的价格使WeWalk手杖有别于其他技术.可知,Folmer 认为这种拐杖和其他的拐杖比起来是使用者能负担得起.故选A.4.B.主旨大意题,根据文章的内容可知,文章介绍盲人Kursat Ceylan 一直致力于研发一直智能拐杖,帮助盲人到处自由行走.故选B.文章介绍盲人Kursat Ceylan 一直致力于研发一直智能拐杖,帮助盲人到处自由行走.阅读理解题测试考生在阅读基础上的逻辑推理能力,要求考生根据文章所述事件的逻辑关系,对未说明的趋势或结局作出合理的推断;或根据作者所阐述的观点理论,对文章未涉及的现象、事例给以解释.考生首先要仔细阅读短文,完整了解信息,准确把握作者观点.DWhen you think of a national park, you generally picture fresh air and wild animals, right?Well, now you're going to have to add tea shops and something called "the Tube" to your definition,because London, England has signed up to be the first "National Park City."London was established by the Romans around 2,000 years ago and has been continually inhabited (居住于)since then*In all that time, however, nobody had the idea to replace all the parks with big box stores or high buildings^ which means London already has a much lower urban density (密度)than most of the worlds cities. Nowadays about a third of the city is green space,In July 2021, London announced its willingness to become the world's first National Park City,Now the city is moving toward the goal of achieving 50% green space by the year 2050 by connecting and expanding public parks, greening up unused parking lots and the private yards of existing and new houses, fixing some green roofs on existing buildings and even cutting holes in fences for wildlife to pass through."Inspired by the aims and values of our precious rural national parks, the London National Park City is basically about making life better in the capital through both small everyday things and long-term strategic thinking," Daniel Raven-Ellison, who began the campaign to make London a National Park City six years ago said in a press release. "We've been doing that in London for centuries, which is why London is so green and diverse,>fLondon will have a much easier job achieving this type of green transformation than more densely-urbanized cities like Paris and New York, which have 10% and 27% greenspace,respectively. But that doesn't mean it's not possible--the National Park City Foundation hopes to employ 25 more cities in addition to London by the year 2025. Glasgow, Scotland and Newcastle upon Tyne in northeast England are both currently considering becoming National Park Cities.12.What makes London more likely to become a national park city than other cities? ______A. Its smaller population.B. The government's efforts.C. Its less dense urbanization,D. Its citizens' great support.13.Where can we find the data on London's measures to achieve its goal? ______A. In Paragraph 1.B. In Paragraph 2.C. In Paragraph 3.D. In Paragraph 4.14.What is Daniel Raven-Ellison trying to talk about in the fourth paragraph? ______A. London's long-term strategic thinking.B. The significance of London's campaign.C. The effects of national parks on London.D. The resources of London s green space.15.What can we infer from the last paragraph? ______A. Trying to be a national park city is turning new trend.B. National park cities are springing up around the world.C. It is so easy for London to become a national park city.D. National park cities are making improvements to our life.【答案】【小题1】C 【小题2】C 【小题3】B 【小题4】A【解析】1.C.细节理解题.根据文章第二段which means London already has a much lower urban density (密度)than most of the worlds cities.这意味着伦敦的城市密度已经远远低于世界上大多数城市.可知,伦敦与世界上的其他城市相比较是一个城市化密度比较低的地区;故选C.2.C.推理判断题.根据文章第三段Now the city is moving toward the goal of achieving 50% green space by the year 2050 by connecting and expanding public parks现在,该市正朝着到2050年通过连接和扩展公共公园实现50%绿地率的目标迈进.可知,在第三段提到了伦敦为了实现到2050年达到50%是绿色空间这一目标而努力,后面是具体的措施;故选C.3.B.细节理解题.根据文章第四段the London National Park City is basically about making life better in the capital ,伦敦国家公园城市基本上是为了改善首都的生活.以及最后一句中的which is why London is so green and diverse可知,伦敦行动正在把城市变得更美丽、更多样化,环境更清新,由此推知这是伦敦行动产生的影响;故选B.4.A.推理判断题.根据文章最后一段that doesn't mean it's not possible--the National Park City Foundation hopes to employ 25 more cities in addition to London by the year 2025这并不意味着这是不可能的--国家公园城市基金会希望到2025年,除了伦敦之外,还能再雇佣25个城市.可知,许多城市都在努力争取成为国家公园城市,这已经变成了一种流行的趋势;故选A.本文属于新闻报道类的短文阅读.主要介绍了伦敦致力于建成国家级的公园城市,努力创造更加湛蓝、清澈的天空.国家公园城市的创建已经成为了一种趋势.做题时要在理解好文意的基础上,与题目有机的结合,从文章中找到相关细节性的句子与选项细细比对,进行选择或推理判断,找出符合文章内容的正确答案.做题注意灵活,有时可采用排除法或直选法确定出最终答案.二、阅读七选五(本大题共5小题,共10.0分)Continuous learning benefits us in many ways. First of all, it allows the increase in knowledge and ability in our career. For example, watching someone work can make us a better worker. (1) For example, we can learn about the general workforce and how the application process works to better prepare us for job searching. This can help if for some reason you lose your job and need to find other work.What's more, continuous learning can open our mind. Having an open mind and willingness to takeon new ideas can do wonders. First of all it builds your attitude towards change. (2) Second,when you take continuous learning into account, you can begin to understand how others feel abouta particular issue.(3) They are always looking for new experiences and do different things. Moreover,they not only have knowledge on various topics that aren't always related to present roles but also know about the latest trends and technologies in the industry.To develop continuous learning, you have to begin with setting a clear and specific goal. (4) Once your goal is set, build a system to help support your strategy. You want to be looking for different sources of information, but also to be picky about it, In other words, try to learn within your specific field but ensure the information is coming from a trustworthy source- At the same time, do use tools to help improve your learning system. (5) Seminars (研讨会),workshops , and live classes are the tools that modern learners need as they make learning effective-A.Learning can improve other areas in our lives.B.Besides, learning can prepare us for the unexpected.C.If always learning, you are always improving.D.Excellent continuous learners behave in a specific manner.E.Being excited about change can affect others around you positively.F.There're various tools to help you present information and learning.G.Knowing what you want to achieve can encourage you to keep learnings16. A. A B. B C. C D. D E. E F. FG. G17. A. A B. B C. C D. D E. E F. FG. G18. A. A B. B C. C D. D E. E F. FG. G19. A. A B. B C. C D. D E. E F. FG. G20. A. A B. B C. C D. D E. E F. FG. G【答案】【小题1】B 【小题2】E 【小题3】D 【小题4】G 【小题5】F【解析】BEDGF1. B.考查细节理解和上下文之间的衔接.根据第一段中的First of all可推知,接下来描述的是第二个方面,结合后面的句子This can help if for some reason you lose your job and need to find other wo rk.可知,这是描述的当你失去工作或者需要找另一份工作时的帮助,所有B项Besides,learning can prepare us for the unexpected.具有承上启下的作用,能给你带来意料之外的结果;故选B.2. E.考查细节理解和上下文之间的衔接.根据前面一句First of all it builds your attitude towards change可知,第一点主要介绍的是建立你应对变化的态度,Being excited about change can affect others around you positively.正是介绍的积极应对变化会对周围的人产生好的影响;故选E.3. D.考查细节理解和上下文之间的衔接.后面的句子They are always looking for new experiences and do different things.说的是他们总是在寻找新的经历,做着不同的事情,与之相对应的就是D.Excellent continuous learners behave in a specific manner(优秀的持续的学习者总是行事特殊),后面的句子就是举例说明这一点.故选D.4. G.考查细节理解和上下文之间的衔接.该空的前面you have to begin with setting a clear and specific goal是说要从设定一个清晰明确的目标开始,后面又说一旦设定了目标就要怎么做,那么Knowing what you want to achieve can encourage you to keep learnings(知道自己想要实现的目标能够鼓舞你继续学习)能够和上下文相衔接.故选G.5. F.考查细节理解和上下文之间的衔接.前面do use tools to help improve your learning system是说要一定使用不同的工具来提高你的学习系统,后面又列举了几个不工具的名称,所以F项There're various tools to help you present information and learning(有各种各样的工具可以帮助你们展现信息和学习进程)符合;故选F.本文属于议论文的短文阅读.主要介绍的是不断的学习给我们在很多方面带来益处.并从几个方面进行了详细的分析和解读.七选五阅读是完成性阅读,和完形填空很类似,不同的是一个选词,一个选句子.解题时,要注意上下文语境,充分考虑信息词(选项中和空格前后句子中相同或相近七的词),选出最符合语境的句子三、完形填空(本大题共20小题,共30.0分)When I was growing up, there was a pizza shop right down the street from me, The pizza shop was(21) by a Chinese woman who opened the place around 11 :00 a. m. and closed it around midnight every day. The food was good, and its(22)were a right size. As far as I knew, the menu never(23). The woman would take a(n)(24) and then return to the kitchen and make it while the customer stood(25) at the counter.One day the woman(26) the pizza shop to a man. The man(27)on running thepizza shop with his wife. I was around fifteen and one day I went inside the pizza shop and began talking with the new owners. Within minutes of my starting the(28), the man and his wife offered me a(n)(29). They'd printed many paper menus and they wanted me to hang them on the doors in the area.I enjoyed the work as it was fun. As I did this with them one Sunday afternoon, they told me about how(30)the Chinese woman had been. They told me she used too expensive cheese. They were planning to stop(31)chicken because chicken was expensive and pizza was really(32)to make. They were(33)the business was going to be a cash cow for them.As I listened to all this, I decided these people must be very smart. (34), within several months, they were out of(35) completely, and the pizza place sat there vacant for over a year(36) it was turned into flooring store. The new owners thought only about how the business could(37) them, and how they could reduce(38)to fatten their own wallets. This is why they endedup(39). After all, everyone loves people and businesses that are more(40) with serving others than themselves.21. A. purchased B. expanded C. operated D. frequented22. A. populations B. portions C. measures D. surroundings23. A. improved B. extended C. worsened D. altered24. A. order B. chance C. walk D. dish25. A. resting B. admiring C. waiting D. observing26. A. transferred B. sold C. referred D. donated27. A. focused B. went C. insisted D. planned28. A. trade B. argument C. discussion D. deal29. A. recommendation B. jobC. assignmentD. reward30. A. stupid B. intelligent C. awkward D. hardworking31. A. preparing B. buying C. serving D. consuming32. A. swift B. cheap C. interesting D. convenient33. A. worried B. lucky C. hopeful D. sure34. A. Instead B. Additionally C. However D. Consequently35. A. business B. sight C. place D. control36. A. Unfortunately B. Instantly C. Suddenly D. Eventually37. A. influence B. benefit C. promote D. involve38. A. costs B. bills C. prices D. ingredients39. A. declining B. quitting C. failing D. compromising40. A. satisfied B. concerned C. patient D. familiar【答案】【小题1】C 【小题2】C 【小题3】D 【小题4】A 【小题5】C【小题6】A 【小题7】B 【小题8】C 【小题9】B 【小题10】A【小题11】C 【小题12】B 【小题13】C 【小题14】C 【小题15】B【小题16】D 【小题17】B 【小题18】A 【小题19】C 【小题20】B【解析】1---5 CCDAC 6--10 ABCBA 11--15 CBCCB 16--20 DBACB(1)C.考查动词及语境理解.A.purchased购买; B. expanded扩展; C. operated操作,使运行;D.frequented常去.根据后文who opened the place around 11 :00 a.m.and closed it around midnight every day.可见是一个中国妇女经营这件披萨店,所以选C.(2)C.考查名词及语境理解.A.populations人口; B. portions 部分;C. measures尺寸;D.surroundings环境.根据a right size是合适的尺寸,所以说的应该是measures尺度,所以选C.(3)D.考查及语境理解.A.improved提高; B. extended 扩展;C. worsened变得更糟; D.altered 改变,更改.据我所知,菜单从来没有改变过,所以选D.(4)A.考查名词及语境理解.A.order 订单;B. chance 机会;C. walk 走路;D.dish盘子.根据后文句子return to the kitchen and make it while the customer stood(5)at the counter.可见是拿到订单后去厨房做出来,客人在外边等着,所以选A.(5)C.考查动词及语境理解.A.resting 休息;B. admiring崇拜; C. waiting等待; D.observing 观察.可见老板是拿到订单后去厨房做出来,客人在外边等着,所以选C.(6)A.考查及语境理解.A.transferred转移,转让; B. sold 卖;C. referred谈及; D.donated 捐赠.根据后文句子 began talking with the new owners.可见这个女的把披萨店转给了一个男人,所以选A.(7)B.考查短语及语境理解.A.focused on集中注意力于;B. went on继续;C. insisted on坚持;D.planned on做计划.这个男的和他的妻子继续经营披萨店,所以选B.(8)C.考查名词及语境理解.A.trade 买卖;B. argument 争论;C. discussion 讨论;D.deal 交易.根据前文句子I went inside the pizza shop andbegan talking with the new owners,我和他们谈话,讨论了几分钟,这对夫妇提供给我一份工作,所以选C.(9)B.考查名词及语境理解.A.recommendation 推荐;B. job 工作;C. assignment任务; D.reward 回报.根据后文句子They'd printed many paper menus and they wanted me to hang them on the doorsin the area,他们印了很多纸菜单,想让我把它们挂在那个地方的门上,I enjoyed the work as it was fun.可见这应该是他们提供给我的一个工作,所以选B.(10)A.考查形容词及语境理解.A.stupid 愚蠢的;B. intelligent 聪明的;C. awkward可怕的;D.hardworking努力工作的.根据后文They told me she used too expensive cheese.这对夫妇告诉我原来的老板用太贵的奶酪,在他们的眼中应该是愚蠢的,所以选A.(11)C.考查动词及语境理解.A.preparing准备; B. buying买; C. serving 提供;D.consuming 消费.根据后文句子chicken was expensive and pizza was really(12)to make.鸡肉太贵了,可见他们不再提供鸡肉.所以选C.(12)B.考查形容词及语境理解.A.swift 迅速的;B. cheap 便宜的;C. interesting有趣的;D.convenient方便的.根据前文句子They were planning to stop(11)chicken because chicken was expensive ,可见披萨的制作降低了成本,很便宜.所以选B.(13)C.考查形容词及语境理解.A.worried 焦急的;B. lucky 幸运的;C. hopeful有希望的; D.sure 确定的.他们希望这家店铺能成为他们的摇钱树.所以选C.(14)C.考查副词及语境理解.A.Instead代替; B. Additionally 此外;C. However然而;D.Consequently因此.根据前文句子As I listened to all this,I decided these people must be very smart,我以为他们很聪明,然而几个月之后,披萨店就不见了,所以选C.(15)B.考查名词及语境理解.A.business 商业;B. sight看,景观; C. place 地方;D.control 控制.根据后文句子and the pizza place sat there vacant for over a year(16)it was turned into flooring store,可见几个月之后,披萨店就不见了.所以选B.(16)D.考查副词及语境理解.A.Unfortunately不幸地; B. Instantly 立刻;C. Suddenly 突然;D.Eventually最终.根据前文句子the pizza place sat there vacant for over a year,最终转成了一个地板店,所以选D.(17)B.考查动词及语境理解.A.influence影响; B. benefit 好处;C. promote晋升; D.involve 参与,牵扯.根据前文对披萨店老板的描述可知老板只考虑披萨店给他们带来好处,所以选B.(18)A.考查名词及语境理解.A.costs 外套;B. bills 账单;C. prices价格; D.ingredients 原料,成分.根据前文句子The new owners thought only about how the business could(17)them,老板只考虑披萨店给他们带来好处,他们能够降低成本来填满自己的钱包.所以选A.(19)C.考查动词及语境理解.A.declining 宣布;B. quitting 停止;C. failing 失败;D.compromising 比较.老板只考虑披萨店给他们带来好处,他们能够降低成本来填满自己的钱包.这就是他们为什么以失败告终的原因,所以选C.(20)B.考查及语境理解.A.satisfied 满意的;B. concerned 关心的;C. patient 有耐心的;D.familiar 熟悉的.毕竟,每个人都爱那些更关心为他人服务的人和企业.所以选B.本文记述了一家披萨店不同老板经营的披萨店的景象,也告诉我们第二个老板只考虑披萨店给他们带来好处,他们能够降低成本来填满自己的钱包.这就是为什么以失败告终的原因.做完型填空首先要通读全文,了解大意.一篇完形填空的文章有许多空格,所以,必须先通读一至两遍,才能大概了解文章的内容.千万不要看一句,做一句.其次要逐句分析,前后一致.选择答案时,要考虑整个句子的内容,包括搭配、时态、语法等.答案全部填完后,再通读一遍文章,检查是否通顺流畅了,用词得当,意思正确.四、语法填空(本大题共1小题,共15.0分)41.Plastic is a huge problem for our planet. It is really (1) ( challenge) to get rid of anda lot of it ends up in nature or in the ocean in particular. There, it is a threat (2) ouranimals and plants.Now a company from the Netherlands, a small country in western Europe, says that it will use plastic (3) ( find) in the ocean to build roads. Volker Wessels (4) (turn) the plastic into building blocks for the roads. They will be like puzzle pieces (5) fit into each other.Not only will this be good for the environment, but also it will be good for the people who look after roads. If a part of the road (6) (damage),it will be easy to remove it andreplace it with another piece. The company says that nearly any type of plastic can be used(7) (make) the road pieces.Scientists (8) (work) on the project say that they are in the final stages of testing the materials for (9) (safe). They say that the first road built will be (10) bicycle path somewhere in the Netherlands.【答案】【小题1】challenging【小题2】to【小题3】found【小题4】will turn【小题5】which【小题6】is damaged【小题7】to make【小题8】working【小题9】safety【小题10】a【解析】(1)challenging.考查派生词.做It is 的表语,表示"具有挑战性的",用形容词challenging.(2)to.考查介词.和名词a threat连用,表示"是…的威胁",修饰名词our animals and plants,用介词to.(3)found.考查非谓语动词.做定语,和名词plastic是被动关系,用过去分词found.(find) in the ocean to build roads. Volker Wessels(4)will turn.考查谓语动词.根据后文可知不玩你就用一般将来时态,所以谓语动词用will turn.(5)which.考查定语从句.代指先行词 puzzle pieces,做非限制性定语从句fit into each other的主语,用关系词which.(6)is damaged.考查谓语动词.根据主将从现可知从句用一般现在时态,后文主语a part of the road 一致,表示"被损坏",谓语动词用is damaged.(7)to make.考查动词不定式.表示"被用了做某事",用be used to do sth,所以用动词不定式to make.(8)working.考查非谓语动词.做定语,和名词Scientists构成主动关系,用现在分词working.(9)safety.考查派生词.做 testing the materials for的宾语,表示"安全",用名词safety.(10)a.考查冠词.修饰名词bicycle path,表示"一条自行车道",用不定冠词a.塑料对我们的星球来说是一个巨大的问题.要摆脱塑料确实是一个挑战,很多塑料最终会进入大自然,特别是海洋.在那里,塑料对我们的动植物是一个威胁.现在,一家来自西欧小国荷兰的公司说,他们将使用在海洋中发现的塑料来建造道路,他们正在对材料进行安全性测试的最后阶段.他们说,在荷兰某处修建的第一条道路将是一条自行车道.语法填空是通过语篇在语境中考查语法知识的运用能力.我们在解题前应快速浏览短文掌握大意,有把握的空格可以进行填写.在读懂的基础上,再结合短文提供的特定的语言环境去逐句分析逐题解答.按题型设计分三种情况:1.纯空格试题的解题技巧首先分析句子结构,根据所缺成分确定哪类词.然后,根据句子意思,确定具体填什么词,或根据两句间的逻辑关系确定具体用哪个连词.比如第65小题,考查连词.根据前后文的关系可得出,此处为转折关系,故填however.2.给出了动词的试题解题技巧首先,判断要填的动词是谓语动词还是非谓语动词.若句子没有别的谓语动词或者虽然已有谓语动词,五、书面表达(本大题共1小题,共25.0分)42.假定你叫李华,在你校就读的来自美国的交换生杰克很想学习中国书法(Chinese calligraphy),想找一位中国书法教师.请给他写封邮件,内容包括:1.已为他找了一名教师李先生;。
考点48 圆的方程1.(广东省2025届高考适应性考试理)若向量a ,b ,c 满意a b ≠,0c ≠,且()()0c a c b -⋅-=,则a b a bc++-的最小值是( )A .3B .22C .2D .32【答案】C 【解析】设向量a OA =,b OB =,c OC =,则由()()0c a c b -⋅-=得0AC BC ⋅=,即C 的轨迹为以AB 为直径的圆,圆心为AB 中点M ,半径为1||2AB , 因此11||||||(||)||22c OC OM r OA OB AB =≤+=++ 1111(||)(||)(||)(||)2222OA OB OA OB a b a b =++-=++- 从而2a b a bc++-≥,选C.2.(河南省重点中学2025届高三4月联合质量检测数学理)设是圆 上的点,直线与双曲线:的一条斜率为负的渐近线平行,若点到直线距离的最大值为8,则( )A .9B .C .9或D .9或【答案】C 【解析】 因为双曲线的一条斜率为负的渐近线的斜率为,所以,解得. 圆的圆心坐标是,半径为,因为圆心到直线距离为, 所以点到直线距离的最大值为,解得或.当时,;当时,.综上,或.故选.3.(广西桂林市、崇左市2025届高三下学期二模联考数学理)过双曲线的右支上一点分别向圆:和圆:作切线,切点分别为,则的最小值为()A.5 B.4 C.3 D.2【答案】A【解析】圆的圆心为,半径为;圆的圆心为,半径为,设双曲线的左右焦点为,,连接,,,,可得.当且仅当为右顶点时,取得等号,即最小值5.故选:.4.(福建省龙岩市2025届高三5月月考数学理)已知点A 在圆22(2)1x y -+=上,点B 在抛物线28y x =上,则||AB 的最小值为( ) A .1 B .2 C .3 D .4【答案】A 【解析】由题得圆()2221x y -+=的圆心为(2,0),半径为1. 设抛物线的焦点为F(2,0),刚好是圆()2221x y -+=的圆心, 由题得|AB|≥|BF|-|AF|=|BF|-1, 设点B 的坐标为(x,y),所以|AB|≥x -(-2)-1=x+1,因为x≥0, 所以|AB|≥1,所以|AB|的最小值为1. 故选:A5.(新疆2025届高三第三次诊断性测试数学理)若直线1ax by +=与圆221x y +=有两个公共点,则点(),P a b 与圆221x y +=的位置关系是( )A .在圆上B .在圆外C .在圆内D .以上都有可能【答案】B 【解析】解:因为直线1ax by +=与圆221x y +=有两个公共点,221a b<+,即1<因为点P 1, 所以点P 在圆外,故选B .6.(河南省焦作市2024-2025学年高三年级第三次模拟考试数学理)已知抛物线E :y 2=2px (p >0)的准线为l ,圆C :(x ﹣2p )2+y 2=4,l 与圆C 交于A ,B ,圆C 与E 交于M ,N .若A ,B ,M ,N 为同一个矩形的四个顶点,则E 的方程为( )A .y 2=xB .y 2C .y 2=2xD .y 2=x【答案】C 【解析】 【分析】 如图,圆C :(x ﹣2p )2+y 2=4的圆心C (2p,0)是抛物线E :y 2=2px (p >0)的焦点, ∵圆C :(x ﹣2p )2+y 2=4的半径为2, ∴|NC|=2,依据抛物线定义可得:|NA|=|NC|=2. ∵A ,B ,M ,N 为同一个矩形的四个顶点, ∴点A ,N 关于直线x =2p 对称,即22N A P x x P +=⨯=,∴32N x p =, ∴|NA|=322p p ⎛⎫-- ⎪⎝⎭=2,∴2p =2,则E 的方程为y 2=2x . 故选:C .7.(闽粤赣三省十校2025届高三下学期联考数学理)过抛物线24y x =的焦点F 的直线交抛物线于A B 、两点,分别过A B 、作准线的垂线,垂足分别为A B ''、两点,以线段A B ''为直径的圆C 过点(2,3)-,则圆C 的方程为( )A .22(1)(1)5x y ++-= B .22(1)(1)17x y +++=C .22(1)(2)26x y +++= D .22(1)(2)2x y ++-=【答案】A 【解析】由抛物线方程可知:()1,0F ,准线方程为:1x =-设直线AB 方程为:1x my =+,代入抛物线方程得:2440y my --= 设()11,A x y ,()22,B x y ,则124y y m +=,124y y = 又()11,A y '-,()21,B y '-,C 在圆上 0A C B C ''∴⋅=即()()()()1211330y y -⨯-+--= ()12121030y y y y ⇒-++= 即101240m -+= 12m ⇒=∴圆心坐标为:()1,2m -,即()1,1-()()2212135-++-=∴圆的方程为:()()22115x y ++-=本题正确选项:A .8.(东北三省三校(哈尔滨师大附中、东北师大附中、辽宁省试验中学)2025届高三第一次模拟数学理)Rt ABC ∆中,090ABC ∠=,23AB =,4BC =,ABD ∆中,0120ADB ∠=,则CD 的取值范围是( ) A .[272,272]-+ B .(4,232]+ C .[272,232]-+ D .[232,232]-+【答案】C 【解析】由题,以点B 为坐标原点,AB 所在直线为x 轴,BC 所在直线为y 轴建立直角坐标系;(0,0);(23,0);(0,4)B A C 设点(,)D x y ,因为0120ADB ∠=,所以由题易知点D 可能在直线AB 的上方,也可能在AB 的下方; 当点D 可能在直线AB 的上方; 直线BD 的斜率1yk x=;直线AD 的斜率223y k x =-由两直线的夹角公式可得:212123tan12031123y yk k xx y y k k xx ---=⇒-=+⋅+⋅-化简整理的22(3)(1)4x y -++=可得点D 的轨迹是以点(3,1)M -为圆心,半径2r 的圆,且点D 在AB 的上方,所以是圆在AB 上方的劣弧部分;此时CD 的最短距离为:22(3)(41)2272CM r -=++-=- 当当点D 可能在直线AB 的下方;同理可得点D 的轨迹方程:22(3)(1)4x y -+-= 此时点D 的轨迹是以点(3,1)N 为圆心,半径2r 的圆,且点D 在AB 的下方,所以是圆在AB 下方的劣弧部分;此时CD 的最大距离为:22(3)(41)2232CN r +=+-+=+所以CD 的取值范围为272,232⎡⎤-+⎣⎦.9.(湖北省黄冈市2025届高三上学期元月调研理)已知圆关于对称,则的值为A.B.1 C.D.0【答案】A【解析】化圆为.则圆心坐标为,圆关于对称,所以直线经过圆心,,得.当时,,不合题意,.故选A.10.(北京市朝阳区2024-2025学年度高三期末)在平面直角坐标系xOy中,过A(4,4),B(4,0),C(0,4)三点的圆被x轴截得的弦长为()A.2 B.C.4 D.【答案】C【解析】依据题意,设过三点的圆为圆,其方程为,又由,则由,解得,即圆,令,得,解得,即圆M与轴的交点坐标分别为,所以圆M被轴截得的弦长为4,故选C.11.(江西省名校学术联盟2025届高三年级教学质量检测考试12月联考)数学理)已知点,,则以线段为直径的圆的方程为A. B.C .D .【答案】D 【解析】 圆心为的中点,半径为,则以线段为直径的圆的方程为.故选D.12.(四川省南充市2024-2025学年上学期高2025届高三年级第一次高考适应性考试)点,是圆上的不同两点,且点,关于直线对称,则该圆的半径等于A .B .C .1D .3【答案】D 【解析】圆x 2+y 2+kx+2y-4=0的圆心坐标为(,因为点M ,N 在圆x 2+y 2+kx+2y-4=0上,且点M ,N 关于直线l :x-y+1=0对称, 所以直线l :x-y+1=0经过圆心, 所以.所以圆的方程为:x 2+y 2+4x+2y-4=0,圆的半径为:故选:C .13.(2025届四川省成都市石室中学高三二诊模拟考试数学理)在直角坐标系xOy 中,点(0,3)A ,直线:24l y x =-,设圆C 的半径为1,圆心在l 上,若圆C 上存在唯一一点M ,使2MA MO =,则圆心C 的非零横坐标是__________. 【答案】125【解析】圆心在l 上,设(),24C a a -,点(),M x y ,因为2MA MO =()222232x y x y +-=+化简得:()2214x y ++=,所以点(),M x y 在以()0,1D -为圆心,以2为半径的圆上,又点(),M x y 在圆C 上,所以圆C 与圆D 有唯一公共点,即两圆相切,211CD =-=,或者213CD =+=,即251280a a -+=或25120a a -=,解得0a =(舍)或125,故填125. 14.(广东省肇庆市2025届中学毕业班第三次统一检测数学理)已知椭圆C :2212x y +=,直线l :1y x =-与椭圆C 交于A ,B 两点,则过点A ,B 且与直线m :43x =相切的圆的方程为______. 【答案】2211639x y ⎛⎫+-= ⎪⎝⎭. 【解析】解:椭圆C :2212x y +=,直线l :1y x =-与椭圆C 交于A ,B 两点,联立可得:22121x y y x ⎧+=⎪⎨⎪=-⎩,消去y 可得,2225848y xy x xy x +--+,解得0x =或43x =,可得(0,1)A -,41(,)33B , 过点A ,B 且与直线m :43x =相切的圆切点为B ,圆的圆心1(0,)3,半径为:43.所求圆的方程为:2211639x y ⎛⎫+-= ⎪⎝⎭.故答案为:2211639x y ⎛⎫+-= ⎪⎝⎭. 15.(宁夏石嘴山市第三中学2025届高三四模考试数学理)点(),M x y 在曲线C :224210x x y -+-=上运动,22+1212150t x y x y a =+---,且t 的最大值为b ,若,a b R +∈,则111a b++的最小值为_____. 【答案】1 【解析】曲线C 可整理为:()22225x y -+= 则曲线C 表示圆心为2,0,半径为5的圆()()2222+121215066222t x y x y a x y a =+---=++---设d =d 表示圆上的点到()6,6-的距离则max 515d ==2max 15222t a b ∴=--=,整理得:14a b ++=()111111*********b a a b a b a b a b +⎛⎫⎛⎫∴+=+++=⨯+++ ⎪ ⎪+++⎝⎭⎝⎭又112211b a b a a b a b+++≥⋅=++(当且仅当11b a a b +=+,即1a =,2b =时取等号) 1114114a b ∴+≥⨯=+,即111a b ++的最小值为1 本题正确结果:116.(贵州省贵阳市2024年高三5月适应性考试二理)圆与曲线相交于,,,四点,为坐标原点,则__________.【答案】.【解析】 ∵圆的圆心为M (-3,2), ∴圆关于M (-3,2)中心对称,又曲线,关于(-3,2)中心对称, ∴圆与曲线的交点关于(-3,2)中心对称,不妨设与,与关于(-3,2)中心对称,则,,∴,故答案为.17.(北京市房山区2024年高考第一次模拟测试数学理)已知点A (-2,0),B (0,2),若点P 在圆(x-3)2+(y+1)2=2上运动,则面积的最小值为______.【答案】4 【解析】∵点A (-2,0),B (0,2),∴AB 的直线方程为=1,即x-y+2=0.圆心C (3,-1)到直线AB 的距离为d=,因为点P 在圆(x-3)2+(y+1)2=2上运动,所以点P 到直线AB 距离的最小值为:=,且.则ABP面积的最小值为.故答案为:4.(湖南省长沙市第一中学2025届高三下学期高考模拟卷三数学理)已知直线18.过定点,线段是圆的直径,则________.【答案】7.【解析】直线可化为,联立,解得点,∵线段是圆的直径,∴19.(广西桂林市、崇左市2025届高三下学期二模联考数学理)以抛物线:的顶点为圆心的圆交于两点,交的准线于两点.已知,,则等于__________.【答案】.【解析】如图:,,,,,,,,解得:,故答案为:.20.(北京市大兴区2025届高三4月一模数学理)在极坐标系下,点π(1,)2P 与曲线2cos ρθ=上的动点Q距离的最小值为_________. 21 【解析】由题得点P 的直角坐标为(0,1),222222cos 2cos +201)1x y x x y ρθρρθ=∴=∴-=∴-+=,,,(,所以曲线是以点(1,0)为圆心,以1为半径的圆, 所以点P 221+1121=.21.21.(江苏省南京市、盐城市2025届高三其次次模拟考试)在平面直角坐标系xOy 中,已知点()1,0A -,()5,0B .若圆()()22:44M x y m -+-=上存在唯一点P ,使得直线PA ,PB 在y 轴上的截距之积为5,则实数m 的值为______. 【答案】21【解析】依据题意,设P 的坐标为(,)a b ,直线PA 的方程为(1)1by x a =++,其在y 轴上的截距为1b a +, 直线PB 的方程为(5)5b y x a =--,其在y 轴上的截距为55b a --,若点P 满意使得直线PA ,PB 在y 轴上的截距之积为5,则有5()()515b b a a ⨯-=+-, 变形可得22(2)9b a +-=,则点P 在圆22(2)9x y -+=上,若圆22:(4)()4M x y m -+-=上存在唯一点P ,则圆M 与22(2)9x y -+=有且只有一个公共点,即两圆内切或外切,又由圆心距为22(42)2m -+,则两圆只能外切, 则有2425m +=, 解可得:21m =±, 故答案为:21±.22.(湖北省十堰市2025届高三年级元月调研考试理)已知圆22:(6)(6)16M x y -+-=,点(8,4)A ,过点A 的动直线与圆M 交于P ,Q 两点,线段PQ 的中点为N ,O 为坐标原点,则OMN ∆面积的最大值为______. 【答案】12 【解析】由题可知MN PQ ⊥,所以点N 在以线段AM 为直径的圆上,OMN ∆的边62OM =,故当N 到直线OM 的距离最大时,OMN ∆的面积最大,以线段AM 为直径的圆的圆心为()7,5,半径为2,直线OM的方程为0x y -=,点()7,5到直线OM 的距离为222=,所以N 到直线OM 的距离的最大值为22,故OMN ∆的面积的最大值为16222122⨯⨯=. 故答案为:1223.(江西省名校学术联盟2025届高三年级教学质量检测考试12月联考数学理)已知圆与轴相切于点,与轴正半轴交于点,,且,设点是圆上的动点,则的取值范围是__________. 【答案】【解析】由题意,可设圆C 的方程为,则,,所以, 则圆C 的方程为,即,可得,设,则===,由题意可知,,所以.故答案为:.24.(江苏省苏州市2025届高三调研测试理)在平面直角坐标系中,已知过点的圆和直线相切,且圆心在直线上,则圆的标准方程为__________.【答案】【解析】依据题意,设圆C 的圆心为(m ,n ),半径为r , 则圆C 的标准方程为(x ﹣m )2+(y ﹣n )2=r 2,则有, 解可得:m =1,n =﹣2,r,则圆C 的方程为:(x ﹣1)2+(y +2)2=2, 故答案为:(x ﹣1)2+(y +2)2=225.(东北三省三校(哈尔滨师大附中、东北师大附中、辽宁省试验中学)2025届高三第一次模拟数学理)已知椭圆1C :2214xy +=的左、右两个顶点分别为,A B ,点P 为椭圆1C 上异于,A B 的一个动点,设直线,PA PB 的斜率分别为12,k k ,若动点Q 与,A B 的连线斜率分别为34,k k ,且3412(0)k k k k λλ=≠,记动点Q的轨迹为曲线2C .(1)当4λ=时,求曲线2C 的方程;(2)已知点1(1,)2M ,直线AM 与BM 分别与曲线2C 交于,E F 两点,设AMF ∆的面积为1S ,BME ∆的面积为2S ,若[1,3]λ∈,求12S S 的取值范围. 【答案】(1) 224(2)x y x +=≠± (2) []5,7 【解析】(1)设()00,P x y ()02x ≠±,则220014x y +=,因为()()2,0,2,0A B -,则2020001222000011422444x y y y k k x x x x -=⋅===-+---(),Q x y 设 ()2x ≠±所以2341222244y y y k k k k x x x λλ=⋅===-+--,整理得 2214x y λ+= ()2x ≠±.所以,当4λ=时,曲线2C 的方程为 ()2242x y x +=≠±.(2)设()()1122,,,E x y F x y . 由题意知,直线AM 的方程为:62x y =-,直线BM 的方程为:22x y =-+.由(Ⅰ)知,曲线2C 的方程为2214x y λ+= ()2x ≠±,联立 ()2262244x y x x y λλ=-⎧≠±⎨+=⎩,消去x ,得()29160y y λλ+-=,得 1691y λλ=+ 联立()2222244x y x x y λλ=-+⎧≠±⎨+=⎩,消去x ,得()2120y y λλ+-=,得 221y λλ=+2212111111sin 91222211111sin 2222MA MF AMF y y MA MF S S MB ME MB ME BME y y λλ∠--+=====+∠-- 设()918911g ,λλλλ+==-++ 则()g λ在[]1,3上递增 又()()15,37g g ==,12S S ∴的取值范围为[]5,7 26.(四川省成都市高新区2025届高三上学期“一诊”模拟考试数学理)已知抛物线,过点的直线与抛物线相切,设第一象限的切点为. (Ⅰ)证明:点在轴上的射影为焦点; (Ⅱ)若过点的直线与抛物线相交于两点,圆是以线段为直径的圆且过点,求直线与圆的方程.【答案】(I )详见解析;(II )详见解析. 【解析】(Ⅰ)由题意知可设过点的直线方程为,由消去整理得,又因为直线与抛物线相切, 所以,解得.当时,直线方程为,可得点坐标为,又因为焦点,所以点在轴上的射影为焦点. (Ⅱ)设直线的方程为,由,其中恒成立. 设,,则,所以,.由于圆是以线段为直径的圆过点,则,所以所以,解得或.当时,直线的方程为,圆的方程为;当时,直线的方程为,圆的方程为.27.(江西省抚州市七校2025届高三10月联考数学理)已知圆与直线相切于点,圆心在轴上.(1)求圆的方程;(2)过点且不与轴重合的直线与圆相交于两点,为坐标原点,直线分别与直线相交于两点,记的面积分别是.求的取值范围.【答案】(1);(2).【解析】(1)由题可知,设圆的方程为,,解得,,所以圆的方程为.(2)由题意知,,设直线的斜率为,则直线的方程为,由,得,解得或,则点的坐标为.又直线的斜率为,同理可得点的坐标为.由题可知,,.因此,又,同理,所以,当且仅当时取等号.又,所以的取值范围是.。
东北三省三校东北三省三校(哈尔滨师⼤附中、东北师⼤附中、辽宁省实验中学)⾼考数学试题模拟⼀、选择题1.已知集合A={x|-2<x <1},B={x|x 2-2x≤0},则A∩B=()A .{x|0<x <1}B .{x|0≤x <1}C .{x|-1<x≤1}D .{x|-2<x≤1}2.复数ii 212-+=()A .2(2+i) B .1+i C .I D .-i3.点M(1,1)到抛物线y=ax 2准线的距离为2,则a 的值为()A .41B .-121C .41或-121D .-41或1214.设S n 是公差不为零的等差数列{a n }的前n 项和,且a 1>0,若S 5=S 9,则当S n 最⼤时,n=() A .6B .7C .10D .95.执⾏如图所⽰的程序框图,要使输出的S 值⼩于1,则输⼊的t 值不能是下⾯的()A .2012B .2016C .2014D .20156.下列命题中①对于命题p :?x ∈R ,使得x 2+x-1<0,则¬p :?x ∈R ,均有x 2+x-1>0;②p 是q 的必要不充分条件,则¬p 是¬q 的充分不必要条件;③命题“若x=y ,则sinx=siny”的逆否命题为真命题;④“m=-1”是“直线 l 1:mx+(2m-1)y+1=0与直线l 2:3x+my+3=0垂直”的充要条件.正确命题的个数是()A .1个B .2个C .3个D .4个7.如图,⽹格纸上⼩正⽅形的边长为1,若粗线画出的是某⼏何体的三视图,则此⼏何体的体积为()A .6B .8C .10D .128.设双曲线的⼀个焦点为F ,虚轴的⼀个端点为B ,焦点F 到⼀条渐近线的距离为d ,若|FB|≥3d ,则双曲线离⼼率的取值范围是()A .(1,2)B .[2,+∞)C .(1,3]D .[3,+∞)9.不等式组≤≤≤≤-4022y x 表⽰的点集记为A ,不等式组≥≥+-202xy y x 表⽰的点集记为B ,在A 中任取⼀点P ,则P ∈B 的概率为()A .329B .327C .169D .16710.设⼆项式(x-21)n (n ∈N *)展开式的⼆项式系数和与各项系数和分别为a n ,b n ,则nn b b b a a a ++++++.....2121=()A .2n-1+3B .2(2n-1+1)C .2n+1D .111.数列{a n }满⾜a n =31n 3-45n 2+3+m ,若数列的最⼩项为1,则m 值为()A .41B .31C .-41D .-3112.已知函数f(x)=<--≥+)0(),1ln()0(,1212x x x x ,若函数F(x)=f(x)-kx 有且只有两个零点,则k 的取值范围为() A .(0,1)B .(0,0.5) C .(0.5,1)D .(1,+∞)⼆、填空题13.向量a ,b 满⾜|a |=1,|b |=2,(a +b )⊥(2a -b ),则向量a 与b 的夹⾓为_______14.三棱柱ABC-A 1B 1C 1各顶点都在⼀个球⾯上,侧棱与底⾯垂直,∠ACB=120°,CA=CB=23,AA 1=4,则这个球的表⾯积为 ________15.⾼⼀开设4门选修课,有4名同学,每⼈只选⼀门,恰有2门课程没有同学选修,共有____ 种不同选课⽅案16.已知函数y=sin (πx+φ)-2cos (πx+φ)(0<φ<π)的图象关于直线x=1对称,则sin2φ=_________5题图7题图三、解答题17.已知△ABC的⾯积为2,且满⾜0<AB?AC≤4,设AB和AC的夹⾓为θ.(1)求θ的取值范围;(2)求函数f(θ)=2sin2(2π+θ)-3cos2θ的取值范围.18.为调查市民对汽车品牌的认可度,在秋季车展上,从有意购车的500名市民中,随机抽样100名市民,按年龄情况进⾏统计的频率分布表Ⅰ和频率分布直⽅图2 频率分布表Ⅰ(1)频率分布表中的①②位置应填什么数?并补全频率分布直⽅图,再根据频率分布直⽅图统计这500名志愿者得平均年龄;(2)在抽出的100名志愿者中按年龄采⽤分层抽样的⽅法抽取20名参加的宣传活动,再从这20名中选取2名志愿者担任主要发⾔⼈.记这2名志愿者中“年龄低于30岁”的⼈数为X,求X的分布列及数学期望.19.如图,四棱锥P-ABCD的底⾯是边长为1的正⽅形,PA⊥底⾯ABCD,E、F分别为AB、PC的中点.(Ⅰ)求证:EF∥平⾯PAD;(Ⅱ)若PA=2,试问在线段EF上是否存在点Q,使得⼆⾯⾓Q-AP-D的余弦值为55?若存在,确定点Q的位置;若不存在,请说明理由.20.椭圆22ax+22by=1(a>b>0)的左、右焦点为F1、F2,点A(2,2)在椭圆上,且AF2与x轴垂直.(1)求椭圆的⽅程;(2)过A作直线与椭圆交于另外⼀点B,求△AOB⾯积的最⼤值.21.已知a是实常数,函数f(x)=xlnx+ax2.(1)若曲线y=f(x)在x=1处切线过点A(0,-2),求实数a的值;(2)若f(x)有两个极值点x1,x2(x1<x2),①求证:-0.5<a<0;②求证:f(x2)>f(x1)>-0.5.22.曲线C的极坐标⽅程是ρ=2cosθ,以极点为平⾯直⾓坐标系的原点,极轴为x轴的正半轴,建⽴平⾯直⾓坐标系,直线L的参数⽅程是=+=tymtx5.05.1(t为参数)(1)求曲线C的直⾓坐标⽅程和直线L的普通⽅程;(2)设点P(m,0),若直线L与曲线C交于A,B两点,且|PA|?|PB|=1,求实数m的值.23.设函数f(x)=|2x-1|-|x+2|.(Ⅰ)解不等式f(x)>0;(Ⅱ)若?x0∈R,使得f(x0)+2m2<4m,求实数m的取值范围.分组(单位:岁)频数频率[20,25] 5 0.05[25,30] 20 0.20[30,35] ①0.350[35,40] 30 ②[40,45] 10 0.10合计100 1.000答案1解:∵集合A={x|-2<x <1},B={x|x 2-2x≤0}={x|0≤x≤2},∴A∩B={x|0≤x <1},故选:B .2解:原式=i ,故选:C .3解:抛物线准线⽅程为y=-a41,点M(1,1)到抛物线y=ax 2准线的距离为2,可得|1+a41|=2,解得a=41或-121.故选:C .4解:由题意可得S 9-S 5=a 6+a 7+a 8+a 9=0,∴2(a 7+a 8)=0,∴a 7+a 8=0,⼜a 1>0,∴该等差数列的前7项为正数,从第8项开始为负数,∴当S n 最⼤时,n=7故选:B5解:模拟执⾏程序框图,可得程序框图的功能是求S=sin 3π+sin 32π+…sin 3πt 的值,因为sin 3πt 的取值以6为周期,且sin 3πk +sin 3)1(π+k +…sin 3)6(π+k =0,由2012=335*6+2,所以输⼊的t 值是2012时,S=sin 3π+sin 32π=3>1 2014=335*6+4,所以输⼊的t 值是2014时,S=sin 3π+sin 32π+sin 33π+sin 34π=23<12015=335*6+5,所以输⼊的t值是2015时,S=sin 3π+sin 32π+sin 33π+sin 34π+sin 35π=0<12016=335*6+6,所以输⼊的t 值是2016时,S=sin 3π+sin 32π+sin 33π+sin 34π+sin 35π+sin2π=0<1,故选:A . 6解:①对于命题p :?x ∈R ,使得x 2+x-1<0,则¬p :?x ∈R ,均有x 2+x-1≥0,因此不正确;②p 是q 的必要不充分条件,则¬p 是¬q 的充分不必要条件,正确;③由于命题“若x=y ,则sinx=siny”是真命题,因此其逆否命题也为真命题,正确;④当m=0时,直线l 1:mx+(2m-1)y+1=0与直线l 2:3x+my+3=0垂直;m≠0时,若两条直线垂直,则?12-m m ×(?m3)=-1,解得m=-1,可知:“m=-1”是“直线l 1:mx+(2m-1)y+1=0与直线l 2:3x+my+3=0垂直”的充分不必要条件,因此不正确.综上可得:正确命题的个数为:2.故选:B .7解:由三视图可知该⼏何体的直观图是三棱锥,其中⾯VAB ⊥⾯ABC ,VE ⊥AB ,CD ⊥AB ,且AB=5,VE=3, CD=4,则该三棱锥的体积V=1/3×1/2AB?CD?VE=1/3×1/2×5×4×3=10,故选:C(7)(8)8解:设F (c ,0),B (0,b ),⼀条渐近线的⽅程为bx+ay=0,则d=bc/22c b +=b ,|FB|=22c b +,因为|FB|≥3d ,所以3≥3b ,所以c 2≥2c 2-2a 2,所以2a 2≥c 2,所以1<e≤2.故选:A .9解:分别画出点集A ,B 如图,A 对应的区域⾯积为4×4=16,B 对应的区域⾯积,如图阴影部分⾯积为dx x x )2(212?--+=(21x 2+2x ?31x 3|21-=29,由⼏何概型公式得,在A 中任取⼀点P ,则P ∈B 的概率为29/16=329;故选A . 10解:由于⼆项式(x-21)n (n ∈N *)展开式的⼆项式系数和与各项系数和分别为a n 、b n ,则a n =2n ,b n =2-n ,所以nn b b b a a a ++++++.....2121=nn---++++++2...222...222121=2n+1 故选:C .11解:数列a n =31n 3-45n 2+3+m ,令f (x )=31x 3-45x 2+3+m ,(x≥1).f′(x )=x 2-25x ,由f′(x )>0,解得x >25,此时函数f (x )单调递增;由f′(x )<0,解得1≤x <25,此时函数f (x )单调递减.∴对于f (n )来说,最⼩值只能是f (2)或f (3)中的最⼩值. f (3)-f (2)=9-25、445-(38-5)>0,∴f (2)最⼩,∴31×8-5+3+m=1,解得m=31.故选:B .12解:由题意,x≥0,f (x )=0.512+x 为双曲线4y 2-x 2=1在第⼀象限的部分,渐近线⽅程为y=±0.5x ;当k=1时,由y=-ln (1-x ),可得y′=11-x =1可得x=0,即y=-ln (1-x )在x=0处的切线⽅程为y=x ,此时函数F (x )=f (x )-kx 有且只有1个零点,∴若函数F (x )=f (x )-kx 有且只有两个零点,则k 的取值范围为(0.5,1),故选:C .13解:因为|a |=1,|b |=2,(a +b )⊥(2a -b ),所以2a 2+a ?b -b 2=0,则2+a ?b -2=0,即a ?b =0,所以a ⊥b ,则向量a 与b 的夹⾓为90°,故答案为:90°.14解:在△ABC 中∠ACB=120°,CA=CB=23,由余弦定理可得AB=6,由正弦定理可,得△ABC 外接圆半径r=23,设此圆圆⼼为O′,球⼼为O ,在RT △OAO′中,得球半径R=4,故此球的表⾯积为4πR 2=64π.故答案为:64π. 15解:恰有2门选修课没有被这4名学⽣选择,先从4门课中任选2门,为24C =6种,四个学⽣选这两种课共有24=16中, 排除四个⼈全选其中⼀门课程为16-2=14种,故有1424C =84种.故答案为:84.16解:y=sin (πx+φ)-2cos (πx+φ)=5sin (πx+φ-α),其中sinα=2/5,cosα=1/5.∵函数的图象关于直线x=1对称,∴π+φ-α=2π+kπ,即φ=α-2π+kπ,则sin2φ=sin2(α-2π+kπ)=sin(2α-π+2kπ)=sin(2α-π)=-sin2α=-2sinαcosα=-2×2/5×1/5=?4/5,故答案为:?4/517解:(1)由题意可得AB ?AC =cbcosθ,∵△ABC 的⾯积为2,∴0,5bcsinθ=2,变形可得cb=4/sinθ,∴AB ?AC =cbcosθ=4cosθ/sinθ=4/tanθ,由0<AB ?AC ≤4,可得0<4/tanθ≤4,解得tanθ≥1,⼜∵0<θ<π,∴向量夹⾓θ的范围为[4π,2(2)化简可得f (θ)=2sin 2(4π+θ)-3cos2θ=1+sin2θ-3cos2θ=1+2sin (2θ-3π)∵由(1)知θ∈[4π,2π),∴2θ-3π∈[6π,32π),∴sin (2θ-3π)∈[0,5,1],∴1+2sin (2θ-3π)∈[2,3],∴f (θ)的取值范围为:[2,3]18解:解:(1)由题意知频率分布表中的①位置应填数字为:100-5-20-30-10=35,②位置应填数字为:30/100=0.30.补全频率分布直⽅图,如右图所⽰.平均年龄估值为:0,5(45×0.05+55×0.2+65×0.35+75×0.3+85×0.1)=33.5(岁).(2)由表知,抽取的20⼈中,年龄低于30岁的有5⼈,故X 的可能取值为0,1,2,P (X=0)=220215/c c =21/38, P (X=1)=22011515/c c c =15/38,P (X=2)=22025/c c =1/19,∴X 的分布列为:EX=0×21/38+1×15/38+2×1/19=1/2. X 0 1 2P 21/38 15/38 1/1919解:证明:(Ⅰ)取PD 中点M ,连接MF 、MA ,在△PCD 中,F 为PC 的中点,∴MF//0.5DC ,正⽅形ABCD 中E 为AB 中点,∴AE//0.5DC ,∴AE//MF ,故四边形EFMA 为平⾏四边形,∴EF ∥AM ,⼜∵EF ?平⾯PAD ,AM ?平⾯PAD ,∴EF ∥平⾯PAD ;(Ⅱ)结论满⾜条件的Q 存在,是EF 中点.理由如下如图以点A 为坐标原点建⽴空间直⾓坐标系,则P(0,0,2),B (0,1,0),C (1,1,0),E (0,0.5,0),F (0.5,0.5,1),由题易知平⾯PAD 的法向量为n =(0,1,0),假设存在Q 满⾜条件:设EQ =λEF ,∵EF =(0.5,0,1),∴Q(0.5λ,0.5,λ),AQ =(0.5λ,0.5,λ),λ∈[0,1],设平⾯PAQ 的法向量为m =(x ,y ,z ),由0.5λx+0.5y+λz=0,z =0,可得m =(1,-λ,0),∴cos <m ,n >=m n /|m ||n |=-λ/21λ+,由已知:-λ/21λ+=5/5,解得λ=0.5,所以满⾜条件的Q 存在,是EF 中点.20解::(1)有已知:c=2,b 2/a =2, ∴a=22,b 2=4,故椭圆⽅程为4822y(2)当AB 斜率不存在时S △AOB =0.5×22×2=22,当AB 斜率存在时设其⽅程为:y ?2=k (x ?2)(k ≠2/2),由y =kx +(2?2k ). x 2+2y 2=8得(2k 2+1)x 2+4(2?2k )kx +2(2?2k )2?8=0,由已知:△=16(2?2k )2k 2-8(2k 2+1)[(2?2k )2?4]=8(2k +2)2>0,即:k ≠?2/2,|AB|=21λ+?22?|2k+2|/(2k 2+1),O 到直线AB 的距离:d=|2-2k|/21λ+,∴S △AOB =0.5|AB |d =2|2?4/(2k2+1)|,∴2k 2+1∈[1,2)∪(2,+∞),∴2?4/(2k 2+1)∈[?2,0)∪(0,2),∴此时 S △AOB ∈(0,22],综上所求:当AB 斜率不存在或斜率存在时:△AOB ⾯积取最⼤值为22.21解:(1)解:由已知可得,f′(x )=lnx+1+2ax (x >0),切点P (1,a ),f (x )在x=1处的切线斜率为k=1+2a ,切线⽅程:y-a=(2a+1)(x-1),把(0,-2)代⼊得:a=1;(2)证明:①依题意:f′(x )=0 有两个不等实根x 1,x 2(x 1<x 2),设g (x )=lnx+2ax+1 则:g′(x )=1/x+2a (x >0)当a≥0时,有g′(x )>0,所以g (x )是增函数,不符合题意;当a <0时:由g′(x )=0得:x=-1/2a >0,列表如下:x (0,-0.5a )-0.5a (-0.5a ,+∞)g′(x ) + 0 - g (x )↗极⼤值↘依题意:g(-1/2a)=ln(-1/2a)>0,解得:-0.5<a <0,综上可得,-0.5<a <0得证;②由①知:f(x),f′(x)变化如下: X (0,x 1)x 1(x 1,x 2)x 2(x 2,+∞) f′(x )-0+0- f (x )↘↗↘由表可知:f (x )在[x 1,x 2]上为增函数,所以:f (x 2)>f (x 1)⼜f′(1)=g (1)=1+2a >0,故x 1∈(0,1),由(1)知:ax 1=(-1-lnx)/2,f (x 1)=x 1lnx 1+ax 12=0.5(x 1lnx 1-x 1)(0<x 1<1)设h (x )=0.5(xlnx-x )(0<x <1),则h′(x )=0.5lnx <0成⽴,所以h (x )单调递减,故:h (x )>h (1)=-0.5,也就是f (x 1)>-0.5综上所证:f (x 2)>f (x 1)>-0.5成⽴.22解::(1)曲线C 的极坐标⽅程是ρ=2cosθ,化为ρ2=2ρcosθ,可得直⾓坐标⽅程:x 2+y 2=2x .直线L 的参数⽅程是??=+=ty m t x 5.05.1(t 为参数),消去参数t 可得x =3y +m .(2)把??=+=ty m t x 5.05.1(t 为参数),代⼊⽅程:x 2+y 2=2x 化为:t 2+(3m ?3)t +m 2-2m=0,由△>0,解得-1<m <3.∴t 1t 2=m 2-2m .∵|PA|?|PB|=1=|t 1t2|,∴m 2-2m=±1,解得m =1±2,1.⼜满⾜△>0.∴实数m=1±2,1.23解::(Ⅰ)不等式f (x )>0,即|2x-1|>|x+2|,即 4x 2-4x+1>x 2+4x+4,即 3x 2-8x+3>0,求得它的解集为{x|x <-31,或x >3}.(Ⅱ)f(x)=|2x-1|-|x+2|=??<≤----<+-5.02,132,3x x x x ,故f(x)最⼩值为f (0.5)=-2.5,根据?x 0∈R ,使得f (x 0)+2m 2<4m ,可得4m-2m 2>-2.5,即4m 2-8m-5<0,求得-0.5<m <2.5.。
2023年东北三省三校黑龙江省哈师大附中、东北师大附中、辽宁省实验中学高考数学二模试卷1. 已知集合,,若,则( )A. B. C. D.2. 已知复数z满足,则( )A. B. C. D.3. 已知向量,,则( )A. 3B.C. 1D.4. 有7名运动员男2女参加A,B,C三个集训营集训,其中A集训营安排5人,B集训营与C集训营各安排1人,且两名女运动员不在同一个集训营,则不同的安排方案种数为( )A. 18B. 22C. 30D. 365.两条直线和分别与抛物线交于异于原点的A、B两点,且直线AB过点,则( )A. B. 1 C. D. 26. 如图,直角梯形ABCD中,,,,梯形ABCD绕AD所在直线旋转一周,所得几何体的外接球的表面积为( )A. B. C. D.7. 定义在R上的奇函数满足,且在上单调递减,若方程在有实数根,则方程在区间上所有实数根之和是( )A. 6B. 12C. 30D. 568. 已知三个互异的正数a,b,c满足,,则关于a,b,c下列判断正确的是( )A. B. C. D.9. 函数,则下列说法正确的是( )A. 为偶函数B. 的最小正周期是C. 在单调递增D. 的最小值为10. 金枪鱼因为肉质柔嫩鲜美、营养丰富深受现代人喜爱,常被制作成罐头食用.但当这种鱼罐头中的汞含量超过时,食用它就会对人体产生危害.某工厂现有甲、乙两条金枪鱼罐头生产线,现从甲、乙两条生产线中各随机选出10盒罐头并检验其汞含量单位为,其中甲生产线数据统计如下:,,,,,,,,,,其方差为乙生产线统计数据的均值为,方差为,下列说法正确的是( )A. 甲生产线的金枪鱼罐头汞含量数值样本的上四分位数是B. 甲生产线的金枪鱼罐头汞含量数值样本的上四分位数是C. 由样本估计总体,甲生产线生产的金枪鱼罐头汞含量平均值高于两条生产线生产的金枪鱼罐头汞含量平均值D. 由样本估计总体,甲生产线生产的金枪鱼罐头汞含量数值较两条生产线生产的金枪鱼罐头汞含量数值更稳定11. 已知正方体的棱长为,点E,F是棱,的中点,点M 是侧面内运动包含边界,且AM与面所成角的正切值为,下列说法正确的是( )A. 的最小值为B. 存在点M,使得C. 存在点M,使得平面BDFD. 所有满足条件的动线段AM形成的曲面面积为12. 已知函数,下列结论正确的是( )A. 对任意m,,函数有且只有两个极值点B. 存在m,,曲线有经过原点的切线C.对于任意,且,均满足D. 当时,恒成立13. 大气压强,它的单位是“帕斯卡”,已知大气压强随高度的变化规律是,其中是海平面大气压强,当地高山上一处大气压强是海平面处大气压强的,则高山上该处的海拔为______ 米答案保留整数,参考数据14. 曲线围成的图形的面积是______ .15. 已知双曲线的右焦点为,过点F且斜率为2的直线与双曲线C的两条渐近线分别交于M、N两点,若P是线段MN的中点,且,则双曲线的离心率为______ .16. A、B、C、D、E五个队进行单循环赛单循环赛制是指所有参赛队在竞赛中均能相遇一次,胜一场得3分,负一场得0分,平局各得1分.若A队2胜2负,B队得8分,C 队得9分,E队胜了D队,则D队得分为______ .17. 记的内角A、B、C的对边分别为a、b、c,已知证明:;若,,角B的内角平分线与边AC交于点D,求BD的长.18. 调查问卷中常常涉及到个人隐私或本人不愿正面回答的问题,被访人可能拒绝回答,即使回答,也不能期望答案是真实的.某小区要调查业主对物业工作是否满意的真实情况,现利用“随机化选答抽样”方法制作了具体调查方案,其操作流程如下:在一个箱子里放3个红球和2个白球,被调查者在摸到球后记住颜色并立即将球放回,如果抽到的是红球,则回答“你的性别是否为男性?”如果抽到的是白球,则回答“你对物业工作现状是否满意?”两个问题均用“是”或“否”回答.共收取调查问卷100份,其中答案为“是”的问卷为60份,求一个业主对物业工作表示满意的概率,已知该小区共有业主500人,估计该小区业主对物业工作满意的人数;现为了提高对物业工作满意的业主比例,对小区业主进行随机访谈,请表示不满意的业主在访谈中提出两个有待改进的问题.若物业对每一个待改进的问题均提出一个相应的解决方案,该方案需要由5名业主委员会代表投票决定是否可行.每位代表投赞同票的概率均为,方案需至少3人投赞成票,方能予以通过,并最终解决该问题,求某个问题能够被解决的概率;假设业主所提问题各不相同,每一个问题能够被解决的概率都为,并且都相互独立.物业每解决一个问题,业主满意的比例将提高一个百分点.为了让业主满意的比例提高到,试估计至少要访谈多少位业主?19.如图,已知斜四棱柱,底面ABCD为等腰梯形,,点在底面ABCD的射影为O,且,,,求证:平面平面;若M为线段上一点,且平面MBC与平面ABCD夹角的余弦值为,求直线与平面MBC所成角的正弦值.20. 已知数列,设,若满足性质:存在常数c,使得对于任意两两不等的正整数i、j、k,都有,则称数列为“梦想数列”.若,判断数列是否为“梦想数列”,并说明理由;若,判断数列是否为“梦想数列”,并说明理由;判断“梦想数列”是否为等差数列,并说明理由.21. 已知椭圆:的离心率为,x轴被抛物线:截得的线段长与长轴长的比为2:求、的方程;设与y轴的交点为M,过坐标原点O的直线l与相交于点A、B,直线MA、MB分别与相交于D、设直线MD、ME的斜率分别为、,求的值;记、的面积分别是、,求的最小值.22. 已知函数当时,求过原点且与相切的直线方程;若有两个不同的零点,,不等式恒成立,求实数m的取值范围.答案和解析1.【答案】D【解析】解:由题意可知,,即,解得,故故选:由已知可推得,代入即可解得,代入即可得出答案.本题主要考查交集及其运算,属于基础题.2.【答案】C【解析】解:设,a,,因为,所以,所以,解得,,所以故选:首先设复数,再根据复数模的公式,以及复数相等,即可求解.本题主要考查复数模公式,属于基础题.3.【答案】B【解析】解:因为,,所以,所以故选:根据向量的坐标运算求解即可.本题主要考查平面向量的坐标运算,以及向量模公式,属于基础题.4.【答案】B【解析】解:由题意可知,完成这件事情分3类,第1类:2个女生分别去A,B,5个男生有1人去了C,有种;第2类:2个女生分别去A,C,5个男生有1人去了B,有种;第3类:2个女生分别去B,C,5个男生有去了A,有种;根据分类加法计数原理,不同的安排方案种数为种.故选:利用特殊元素优先考虑及分类加法计数原理即可求解.本题主要考查排列、组合及简单计数问题,属于基础题.5.【答案】C【解析】解:联立,由于,可得,,即,同理可得,由直线AB经过,所以,化简得,由于,所以,故选:联立直线的方程与抛物线的方程,可得A,B的坐标,由两点斜率可得k的值.本题考查直线与抛物线的位置关系,方程思想,化归转化思想,属基础题.6.【答案】D【解析】解:由题意可知,旋转一周得到的几何体为圆台.取圆台的轴截面,由题意知,球心O一定在线段AD或AD的延长线上,如图1,当球心O在线段AD上时.过点C作于E点,则,,所以,设球的半径为R,,,则由勾股定理可得,,整理可得,解得舍去;如图2,当球心O在DA的延长线上时.过点C作于E点,则,,所以,设球的半径为R,,则,则由勾股定理可得,,整理可得,解得所以,所以圆台外接球的表面积为故选:由题意可知,旋转一周得到的几何体为圆台,可知外接球的球心一定在线段AD或AD的延长线上.取圆台的轴截面,分情况讨论,作图,分别根据几何关系求出球的半径,即可得出答案.本题考查圆台外接球的表面积计算,考查分类讨论思想以及运算求解能力,属于中档题.7.【答案】C【解析】解:因为函数满足,所以函数的图像关于直线对称,故,又是R上奇函数,所以,所以,故函数的周期为4,考虑一个周期,由函数在区间上单调递减,又由是R上奇函数,且关于直线对称,知在区间上单调递增,在区间上单调递减,在区间上单调递增,因为,,故当时,,当当时,,当时,,因为方程在区间有实数根,则这实根是唯一的,又因为函数的图像关于直线对称,则方程在区间有唯一实数根,方程在区间和区间上没有实根,所以方程在一个周期内有且只有2个实数根,根据对称性,知这两根之和为2,因为函数在区间上恰好3个周期,所以根据函数周期性和对称性知,方程在区间上所有实数根之和为故答案为:利用函数是R上奇函数且满足,得出函数是周期为4的周期函数,且关于直线对称,利用周期性和对称性,讨论出函数在一个周期内的单调性,从而判断出方程在一个周期内的根的个数,并利用对称性求出两根之和,从而求出方程在区间上所有实数根之和.本题主要考查函数的零点与方程根的关系,考查运算求解能力,属于中档题.8.【答案】D【解析】解:因为,所以,设,则,令得,令得,所以函数在递减,函数在递增,所以,当,时,,设,易知在上单调递减,且,所以,所以,所以,又,所以,所以,所以;当,时,,设,易知在上单调递减,且,所以,所以,即,又,所以,所以,所以;综上可得:成立.故选:把变形为,构造函数,求导,得,或,,然后构造,利用函数单调性比较即可.本题主要考查了利用导数研究函数的单调性和最值,属于中档题.9.【答案】AD【解析】解:对于A,,因为,所以是偶函数,故选项A正确;对于B,因为,所以的最小正周期不是,故B错误;对于C,当时,,且,所以函数在上单调递增,在上单调递减,故C错误;对于D,当时,,且,所以,;当时,,且所以所以在上值域为,又,所以是的周期,所以在R上值域为,故函数的最小值为,故D正确.故选:利用奇偶性和周期性的定义可判断选项AB;求出在的单调性即可判断C;讨论去绝对值再利用三角函数的性质可得函数的最小值可判断选项本题主要考查了函数的奇偶性和周期性的定义,考查了三角函数的图象和性质,属于中档题.10.【答案】ACD【解析】解:AB选项,,则从小到大排列,第8个数为上四分位数,即,A正确,B错误;C选项,甲生产线数据平均数为,故两条生产线生产的金枪鱼罐头汞含量为,因为,所以C正确;D选项,甲、乙生产线生产的金枪鱼罐头汞含量方差分别为,,因为,所以甲生产线生产的金枪鱼罐头汞含量数值较两条生产线生产的金枪鱼罐头汞含量数值更稳定,D正确.故选:AB选项,根据百分位数定义求解出上四分位数;C计算出甲生产线数据平均数,从而得到结论;D 选项,由两条生产线生产的金枪鱼罐头汞含量方差大小得到结论.本题主要考查平均数的求解,以及方差和百分数的定义,属于基础题.11.【答案】ACD【解析】解:根据题意可知平面,所以为AM与面所成角,且,因为正方体的棱长为,AM与面所成角的正切值为,所以,解得,所以点M的轨迹为以D点为圆心,2为半径的圆在侧面内的弧,如图,此时,对于A选项,有,当且仅当M,,D三点共线时等号成立,故的最小值为,正确;对于B选项,因为平面,平面,所以,假设存在点M,使得,则,平面ADM,由于平面ADM,故有,另一方面,在侧面中,取棱的中点N,由点E是棱的中点,进而结合平面几何知识易得,故要使,则点N与点M重合,由于,,显然不重合,故错误;对于C选项,如图,设,则易知O为AC中点,连接OF,,,因为点E,F是棱,的中点,所以,在中,,,,所以,四边形为平行四边形,即,因为,平面BDF,OF,平面BDF,所以平面BDF,平面BDF,因为,所以平面平面BDF,所以当M为与弧的交点时,平面,故平面BDF,正确;对于D选项,由题知,所有满足条件的动线段AM形成的曲面是:以A为顶点,D点为底面圆心,底面半径为2的圆锥的部分侧面,所以其所在的圆锥的母线长为,因为,,所以,所以弧的长为,所以结合扇形面积公式可得:所有满足条件的动线段AM形成的曲面面积为,故正确.故选:由正方体的性质得为AM与面所成角,且,进而得点M的轨迹为以D 点为圆心,2为半径的圆在侧面内的弧,再依次讨论各选项,即可得答案.本题考查正方体中轨迹的问题,线面平行的判定定理与面面平行的判定定理,解三角形,扇形面积公式,化归转化思想,属中档题.12.【答案】BCD【解析】解:对于A,当,时,,,解得,故当时,,单调递减,当时,,单调递减,当时,,单调递增,所以函数只有一个极小值点,故A错误;对于B,由A选项知,当,时,,,假设其存在过原点知切线,则可设切点为,斜率为所以,其切线方程为:又因为其过坐标原点,则,整理解方程得,故该曲线存在过原点的切线,故B正确;对于C,对于m,,,故当时,有解,即为,所以当时,,单调递减,当时,,单调递增,因为在上恒成立,所以在上单调递增,所以当时,函数为凹函数,所以对于任意,且,均满足,故C正确;对于D,当时,,当m,n同为奇数时,函数为奇函数,,则,故,即成立;当m,n同为偶数时,函数为偶函数,,则,故,即成立;当m为奇数,n为偶数时,时,,当时,,即;当时,,即;故m为奇数,n为偶数时,成立;当m为偶数,n为奇数时,时,,当时,,即;当时,,即;故m为偶数,n为奇数时,成立;综上,当时,恒成立,故D正确.故选:根据当,时,,研究函数的极值点与过原点的切线问题判断AB;证明当时,函数为凹函数即可判断C;分m,n同奇数或同偶数时和m,n是一奇,一偶数时讨论判断本题主要考查利用导数研究函数的极值,利用导数研究曲线上某点的切线方程,考查逻辑推理能力,属于难题.13.【答案】8730【解析】解:由题意可知:,解得,所以故答案为:根据题意解方程即可得解.本题主要考查函数在实际问题中的应用,考查运算求解能力,属于基础题.14.【答案】【解析】解:将或代入曲线方程中,曲线方程不变,曲线关于x轴,y轴对称,只需求出第一象限的面积即可,当,时,曲线方程可化为,其表示的图形占整个图形的,又表示的图形为一个腰长为1的等腰直角三角形和半径为的一个半圆,,围成的图形的面积为:故答案为:由于曲线围成的图形关于x轴,y轴对称,故只需要求出第一象限的面积即可.本题考查利用代数方法研究曲线方程问题,属中档题.15.【答案】【解析】解:设直线MN为,双曲线的渐近线方程为,联立可得,,,不妨令,同理可得,设,则,,故,故,解得,方程两边同时除以得,,令,可得,解得或舍去,故故答案为:设出直线MN,与双曲线渐近线方程联立,得到M,N点坐标,进而得到中点P的坐标,利用,列出方程,得到,从而求出离心率.本题主要考查双曲线的性质,考查转化能力,属于中档题.16.【答案】1【解析】解:由题意每个队伍都进行了四场比赛,因为B队得8分,C队得9分,所以B队2胜2平,C队3胜1负,又因A队2胜2负,则B队只能和D、E是平局,所以B队胜了A、C两队,因此C队负的一场,输给B队,即C队胜了A,D,E三队,所以A队赢D、E两队,又因为E队胜了D队,所以D队负了三场,平了一场,赢了零场,所以D队得分为1分.故答案为:根据B队得8分,C队得9分,可得B队2胜2平,C队3胜1负,先分析B队的情况,再分析C队的情况,再分析A队的情况,即可得出答案.本题主要考查简单的合情推理,完成本题的关键是抓住“A队2胜2负,B队得8分,C队得9分”这三个条件,以此为突破口,根据赛制与得分之间的逻辑关系进行推理分析,进而得出结论.17.【答案】证明:因为,所以,所以,即,所以;解:由余弦定理得:,,又,所以,,由角平分线定理可得,,,在中,由余弦定理得:,所以【解析】利用余弦定理结合条件即得;利用余弦定理结合条件可得,然后利用角平分线定理及余弦定理即得.本题主要考查解三角形,考查转化能力,属于中档题.18.【答案】解:记:事件A“业主对物业工作表示满意”,则,所以,人,故该小区业主对物业工作表示满意的人数约为375人;由已知得,每位代表投赞同票的概率均为,方案需至少3人投赞成票,方能予以通过,所以,故某个问题能够被解决的概率;设至少要访谈n位业主,由知,该小区业主对物业工作满意的概率为,要使业主满意的比例提高到,则有,故至少要访谈48位业主.【解析】根据红球与白球的个数比例以及问卷调査的情况,通过比例求解即可;由每位代表投赞同票的概率均为,且方案需至少3人投赞成票,方能予以通过,根据二项分布的概率公式运算求解即可;由知,该小区业主对物业工作满意的概率为,要使满意度提高到,可设至少要访谈n 位业主,列出关于n的不等式,解不等式即可.本题考查了二项分布的概率公式,属于中档题.19.【答案】解:证明:,,作交AB于E,如图,则可得四边形ADCE是菱形,,是等边三角形,,,,,即,又,,,平面,平面,又平面ABCD,平面平面;点在底面ABCD的射影为O,由得O在AC上,且,又,所以,而由知,因此,建立如图所示空间直角坐标系,则,,,,,,又,,,设,,,,设平面MBC的法向量为,则,取,又易知平面ABCD的法向量,,则负值舍去,,,设直线与平面MBC所成的角为,则,直线与平面MBC所成的角正弦值为【解析】根据线面垂直的判定定理,面面垂直判定定理,即可证明;建系,根据向量法,向量夹角公式,方程思想,即可求解.本题考查线面垂直的判定定理,面面垂直的判定定理,向量法求解面面角问题,向量法求解线面角问题,化归转化思想,方程思想,属中档题.20.【答案】解:,,所以,当时,,,,所以,所以不是“梦想数列”;,,,,,所以是“梦想数列”;①令,,,,所以,即:、、成等差数列,②令,,,,化简为:,,两式相减得:,所以,当,2,3时也成立,综上可得,“梦想数列”是等差数列.【解析】分析条件,可得,对于数列,取两两不等的正整数、、,验证不满足,则不是“梦想数列”;由数列的通项公式可求,从而验证满足,所以是“梦想数列”;先验证,,时,、、成等差数列,再令,,,得数列的前n项和的表达式,从而求得数列的通项公式,得证.本题主要考查了数列的应用,考查了分类讨论数学思想,属于中档题.21.【答案】解:解,可得,所以,x轴被抛物线截得的线段长为由已知可得,,解得所以椭圆的方程为,抛物线的方程为由知,设直线l的方程为,,联立直线l与抛物线的方程,可得,则又,,所以联立直线MA与抛物线的方程,可得,则同理:设,联立直线MA与椭圆的方程,可得,则,同理可得,由图象知,,,,所以,,当且仅当时,取等号,所以,的最小值为【解析】解,即可得出x轴被抛物线截得的线段长,进而列出方程组,求解即可得出答案;联立直线l与抛物线的方程,得到,根据韦达定理,即可得出斜率之间的关系,求出的值;联立方程组,表示出各个点的坐标.结合图象,将三角形的面积之比转化为坐标关系,即可得出表达式,然后根据基本不等式即可得出最小值.本题考查直线与圆锥曲线的综合运用,考查运算求解能力,属于中档题.22.【答案】解:的定义域为,,设切点坐标,则切线方程为:,把点代入切线得:,,得,所以的切线方程为:有两个不同零点,,则,构造函数,,所以为增函数,且,即有两个不等实根,,则,令,,则,,所以,则,,故,而两边取对数,可转化为,设,则在上恒成立,,设,,在递增,,则在递减,所以的最小值接近极限值,所以的最小值无限接近3,即得m的取值范围为【解析】设切点坐标,则切线方程为:,再把点代入切线可得参数即可得切线;有两个不同零点,构造函数,则有两个不等实根,令,设,由的值域可得m的取值范围为本题主要考查利用导数研究函数的最值,利用导数研究曲线上某点的切线方程,考查运算求解能力,属于难题.。