南京市、盐城市2020高考第一次模拟考试全部试卷(解析)汇总
13.已知集合 P={(x,y)| x|x|+y|y|=16},集合 Q={(x,y)| kx+b1≤y≤kx+b2},若 PQ,则|b1-b2| k2+1
的最小值为 ▲ .
14.若对任意实数 x∈(-∞,1],都有| ex |≤1 成立,则实数 a 的值为 ▲ . x2-2ax+1
二、解答题:本大题共 6 小题,计 90 分.解答应写出必要的文字说明,证明过程或演算步骤,请
y
P
A F1 O
F2
x
B
(第 18 题图)
高三数学试题第 3页(共 4 页)
19.(本小题满分 16 分) 定义:若无穷数列{an}满足{an+1-an}是公比为 q 的等比数列,则称数列{an}为“M(q)数列”. 设数列{bn}中 b1=1,b3=7. (1)若 b2=4,且数列{bn}是“M(q)数列”,求数列{bn}的通项公式; (2)设数列{bn}的前 n 项和为 Sn,且 bn+1=2Sn-1n+λ,请判断数列{bn}是否为“M(q)数列”, 2 并说明理由; (3)若数列{bn}是“M(2)数列”,是否存在正整数 m,n 使得4039<bm<4040?若存在,请求 2019 bn 2019 出所有满足条件的正整数 m,n;若不存在,请说明理由.
数学参考答案
一、填空题:本大题共 14 小题,每小题 5 分,计 70 分.
9.在三棱柱 ABC-A1B1C1 中,点 P 是棱 CC1 上一点,记三棱柱 ABC-A1B1C1 与四棱锥 P-ABB1A1
的体积分别为 V1 与 V2,则V2= ▲ . V1
10.设函数 f(x)=sin(ωx+φ)(ω>0,0<φ<π)的图象与 y 轴交点的纵坐标为 3,y 轴右侧第一个
2
2
盐城市、南京市 2020 届高三年级第一次模拟考试
数学
2020.01
注意事项: 1.本试卷共 4 页,包括填空题(第 1 题~第 14 题)、解答题(第 15 题~第 20 题)两部分.本
试卷满分为 160 分,考试时间为 120 分钟. 2.答题前,请务必将自己的姓名、学校、班级、学号写在答题卡的密封线内.试题的答案
(1)求圆形铁皮⊙P 半径的取值范围; (2)请确定圆形铁皮⊙P 与⊙Q 半径的值,使得油桶的体积最大.(不取近似值)
Q
A
D
O
B
C
P
(第 17 题图)
18.(本小题满分 16 分) 设椭圆 C:x2+y2=1(a>b>0)的左右焦点分别为 F1,F2,离心率是 e,动点 P(x0,y0)在椭圆 C 上 a2 b2 运动.当 PF2⊥x 轴时,x0=1,y0=e. (1)求椭圆 C 的方程; (2)延长 PF1,PF2 分别交椭圆 C 于点 A,B(A,B 不重合).设A→F1=λF→1P,B→F2=μF→2P, 求λ+μ的最小值.
写在答.题.卡.上对应题目的答案空格内.考试结束后,交回答题卡.
参考公式:
柱体体积公式:V=Sh,锥体体积公式:V=1Sh,其中 S 为底面积,h 为高. 3
样本数据
x1,x2,···,xn
的方差
s2=1
n
∑
(xi-)2,其中=1
n
∑
xi.
ni=1
ni=1
一、 填空题:本大题共 14 小题,每小题 5 分,计 70 分.不需写出解答过程,请把答案写在答题卡
(1)若 AC1//平面 PBD,求PC1的值; PC
(2)求证:BD⊥A1P.
D1
C1
A1
B1
P
D
C
A
B
(第 16 题图)
高三数学试题第 2页(共 4 页)
17.(本小题满分 14 分) 如图,是一块半径为 4 米的圆形铁皮,现打算利用这块铁皮做一个圆柱形油桶.具体做法是 从⊙O 中裁剪出两块全等的圆形铁皮⊙P 与⊙Q 做圆柱的底面,裁剪出一个矩形 ABCD 做圆 柱的侧面(接缝忽略不计),AB 为圆柱的一条母线,点 A、B 在⊙O 上,点 P、Q 在⊙O 的一 条直径上,AB∥PQ,⊙P、⊙Q 分别与直线 BC、AD 相切,都与⊙O 内切.
的指定位置上.
1.已知集合 A=(0,+∞),全集 U=R,则∁ A= ▲ .
U
2.设复数 z=2+i,其中 i 为虚数单位,则 z·—z = ▲ . 3.学校准备从甲、乙、丙三位学生中随机选两位学生参加问卷调查,
则甲被选中的概率为 ▲ . 4.命题“θ∈R,cosθ+sinθ>1”的否定是 ▲ 命题.(填“真”或“假”) 5.运行如图所示的伪代码,则输出的 I 的值为 ▲ . 6.已知样本 7,8,9,x,y 的平均数是 9,且 xy=110,则此样本的方差
把答案写在答题卡的指定区域内.
15.(本小题满分 14 分)
已知△ABC 满足 sin(B+π)=2cosB. 6
(1)若 cosC= 6,AC=3,求 AB;
3
(2)若 A∈(0,π),且 cos(B-A)=4,求 sinA.
3
5
16.(本小题满分 14 分)
如图,长方体 ABCD-A1B1C1D1 中,已知底面 ABCD 是正方形,点 P 是侧棱 CC1 上的一点.
20.(本小题满分 16 分) 若函数 f(x)=ex-ae-x-mx (m∈R)为奇函数,且 x=x0 时 f(x)有极小值 f(x0). (1)求实数 a 的值; (2)求实数 m 的取值范围; (3)若 f(x0)≥-2恒成立,求实数 m 的取值范围. e
高三数学试题第 4页(共 4 页)
南京市、盐城市 2020 届高三年级第一次模拟考试
S←0 I←0 While S≤10
S←S+I I←I+1 End While Print I
E(ND第 5 题图,若抛物线 y2=4x 上的点 P 到其焦点的距离为 3,则点 P 到点 O 的
距离为 ▲ .
8.若数列{an}是公差不为 0 的等差数列,lna1、lna2、lna5 成等差数列,则a2的值为 ▲ . a1
最低点的横坐标为π,则ω的值为 ▲ . 6
高三数学试题第 1页(共 4 页)
11.已知 H 是△ABC 的垂心(三角形三条高所在直线的交点),→ AH =1→ AB +1→ AC ,则 cos∠BAC
4
2
的值为 ▲ .
12.若无穷数列{cos(ωn)}(ω∈R)是等差数列,则其前 10 项的和为 ▲ .
盐城市、南京市2020届高三一模语文试卷答案
南京市、盐城市2020届高三年级第一次模拟考试语文Ⅰ参考答案1.D 2.A 3.D 4.B 5.D 6.C7.(1)(谢公)十四岁前往州学求学,学习《左氏春秋》,老师粗略传授其中的内容,他就能为学生们详细讲解,就像是他们的老师。
(共5分。
每句1分)(2)现在少府备办送葬用的泥车冥器,(1分)盛大而不合礼制,(2分)而且违背了遗诏追求节俭的意思,(1分)请求裁减。
(1分)(共5分)8.有谋略有胆识、体恤百姓、唯才是举、勇于担当。
(共4分。
每点1分)9.借景抒情,“雁”、“孤艇”写出了对友人的关切与不舍之情;(3分)用典,“故里鱼肥”用晋人张翰之典表达了对故乡的思念。
(2分)(共5分)10.“无限旧事,繁华似梦”寄予了作者的家国兴亡之悲;“短褐临流,幽怀倚石”透露了作者向往归隐的隐逸之情;“寄取相思”等表达了作者对友人的深情厚谊。
(共6分。
每点2分)11.(1)信誓旦旦(2)恐年岁之不吾与(3)苔痕上阶绿(4)只是朱颜改(5)云归而岩穴暝(6)渺沧海之一粟(7)不病人之不己知也(8)操千曲而后晓声(共8分。
每空1分)12.D13.对绘画狂热:开“个展”,因不能给“我”画像而疯等;盲目自信:反复称这是“艺术”,不许他人质疑等;水平低劣的伪艺术家:画人脸像大煤球,画鸡像黑球等。
(共6分。
每点2分,不结合文本分析得1分)14.①“第一天到会参观的有三千多人,气晕了多一半,当时死了四五十位。
”运用夸张的手法,讽刺了方二哥的画作水平低下。
②“方二哥的俩老头儿是一顺边坐着,大小一样,衣装一样,方向一样,活像是先画了一个,然后又照描了一个。
”运用排比的手法,讽刺画作内容单调,缺乏艺术魅力。
③“这是不是煤球上长着点青苔?”运用比喻的修辞,讽刺方二哥画作的拙劣。
④“这是艺术!”在文中多次出现,运用反复的修辞,讽刺了方二哥伪艺术家的形象。
⑤“他过来弹弹我的脑门,拉拉耳朵,往上兜兜鼻子,按按头发”,通过细致的动作描写,讽刺方二哥重形式而没有实质的绘画才能。
2020年1月江苏省南京市、盐城市2020届高三年级第一次高考模拟联考英语答案
6.如字迹难以辨认,以致影响交际,将分数降低一个档次。
二、内容要点
1.简要概述上述信息的主要内容(30词左右);
2.你对教育惩戒持什么样的观点,并简述理由;
3.请你对教育惩戒规则的实施提出合理建议(至少2个)。
第四部分任务型阅读(共10小题;每小题1分,满分10分)
71. adults72. including73. aging/ageing74. subjective
75. Trying76. tips/suggestions77. requires/demands/needs
78. effective79. absorb80. extends
41. B42. C43. A44. D45. B
46. B47. A48. C49. D50. C
51. D52. B53. C54. A55. D
第三部分阅读理解(共15小题;每小题2分,满分30分)
56. A57.B58.D59.B60.C
61.C62.B63.D64.A65.D
66.B67.C68.D69.A70.C
应用的语法结构和词汇能满足任务的要求。
语法结构和词汇方面应用基本准确,少许错误主要是因为尝试较复杂语法结构或词汇所致。
应用简单的语句间的衔接手段,全文结构紧凑,内容较连贯。
达到了预期的写作目的。
(好)
(16—20分)
第三档
基本完成了试题规定的任务。
虽漏掉一些内容,但基本覆盖主要内容。
应用的语法结构和词汇能满足任务的要求。
第二部分英语知识运用(共两节,满分35分)
江苏省南京市、盐城市-2020届高三年级第一次模拟考试英语试题(解析版)
江苏省南京市、盐城市-2020届高三年级第一次模拟考试英语试题第一部分听力(共两节,满分20 分)做题时,先将答案标在试卷上。
录音内容结束后,你将有两分钟的时间将试卷上的答案转涂到答题卡上。
第二部分英语知识运用(共两节,满分35分)第一节单项填空(共15小题;每小题1分,满分15分)请认真阅读下面各题,从题中所给的A、B、C、D四个选项中,选出最佳选项,并在答题卡上将该项涂黑。
21.The power of silence is much greater compared with ______ of instant attack.A. itB. oneC. thatD. the one【答案】C【解析】本题考点为代词。
与即时攻击相比,沉默的力量要大得多。
用that特指the power(instant attack),所以选C。
22.Within a personalized learning program, the learners’ pathway can be _____ to their needs.A. exposedB. tailoredC. resignedD. limited【答案】B【解析】本题考点为动词辨析。
在个性化的学习计划中,学习者的学习路径可以根据他们的需要进行调整。
A. exposed 暴露,接触;B. tailored剪裁,使合适;C. resigned辞职,放弃;D. limited局限,限制。
tailor sth to sth“改变......以适应......”所以选B。
23.—e price of the house advertised is rather reasonable, and I fancy it much...—Let’s be ________—we just can’t afford to pay that much money.A. optimisticB. realisticC. enthusiasticD. systematic【答案】B【解析】本题考点为形容词辨析。
江苏省南京市、盐城市2020届高三第一次模拟考试(1月)Word版含答案 英语试卷
南京市、盐城市2020届高三年级第一次模拟考试英语试题第一部分听力(共两节,满分20分)做题时,先将答案标在试卷上。
录音内容结束后,你将有两分钟的时间将试卷上的答案转涂到答题卡上。
第一节(共5小题;每小题1分,满分5分)听下面5段对话。
每段对话后有一个小题,从题中所给的A、B、C三个选项中选出最佳选项,并标在试卷的相应位置。
听完每段对话后,你都有10秒钟的时间来回答有关小题和阅读下一小题。
每段对话仅读一遍。
1. What did the woman fail to see?A. A sign.B. A parking lot.C. A disabled person.2. What will the man do?A. Take a course online.B. Call the same repairman.C. Fix the refrigerator himself.3. Who will the woman have dinner with tonight?A. Tommy’s family.B. Her grandmother.C. Her colleagues in Shanghai.4. Why does the boy like sharks?A. They are great swimmers.B. They make funny sounds.C. They are very smart.5. What is the time?A. 6:00 p.m.B. 9:00 p.m.C. 10:00 p.m.第二节(共15小题;每小题1分,满分15分)听下面5段对话或独白。
每段对话或独白后有几个小题,从题中所给的A、B、C三个选项中选出最佳选项,并标在试卷的相应位置。
听每段对话或独白前,你将有时间阅读各个小题,每小题5秒钟;听完后,各小题将给出5秒钟的作答时间。
每段对话或独白读两遍。
江苏省南京市、盐城市2020届高三第一次模拟考试语文试卷(含答案).doc
南京市、盐城市2020届高三年级第一次模拟考试语文试题1.本次试卷共160分,考试用时150分钟。
2.答题前,考生务必将学校、姓名、考试号写在答题卡上指定区域内,答案写在答题卡对应题目的横线上。
考试结束后,请交回答题卡。
一、语言文字运用(15 分)1. 在下面一段话空缺处依次填入词语,最恰当的一组是()(3分)我们初学为文,一看题目便接着搔首踟蹰,不知如何落笔,即便,敷衍成篇,自己也觉得索然寡味。
度过苦涩阶段便又是一种境界,提起笔来对于什么都有意见,有时一事未竟而枝节横生,有时旁征博引而轻重倒置,,下笔不能自休。
知道割爱才能进入第三阶段,对不恰当的内容要地加以削删,所谓“徇烂之极趋于平淡”就是这种境界。
A. 披肝沥胆纷纷扬扬大刀阔斧B. 搜索枯肠洋洋洒洒大刀阔斧C.披肝沥胆洋洋洒洒大张旗鼓D. 搜索枯肠纷纷扬扬大张旗鼓【解析】“披肝沥胆”:比喻真心相见,倾吐心里话;也形容非常忠诚。
“搜索枯肠”:比喻才思枯窘(含贬义)。
因此第一空选“搜索枯肠”。
“纷纷扬扬:形容雪、花等多而杂乱地在空中飘舞;也形容消息、流言广为传布。
“洋洋洒洒”:形容文章或谈话丰富明快,连续不断;也形容规模或气势盛大;还形容才思充沛;写起文章来很顺畅。
第二空提到“下笔”,因此选“洋洋洒洒”。
“大刀阔斧”:意思是比喻像使大刀、用阔斧那样,形容办事果断而有魄力。
“大张旗鼓”:形容进攻的声势和规模很大;也形容群众活动声势和规模很大;也比喻公开。
因此第三空选“大刀阔斧”。
所以本题选择B选项。
【点评】本题较为简单,考察的是词义相近的词语的辨析。
2. 下列语句中,所使用的修辞手法不同于其他三句的是()(3分)A.文艺是国民精神所发的火光,同时也是引导国民精神前途的灯火,文艺工作者要潜心探索,创造出鲜活、丰富的艺术形象来。
B.在硅谷这片热带雨林里,既有领军企业的大树,也有创业企业的小苗,即使大树或小苗死去,留下的腐殖质也会滋养创新的种子。
C.必须把纪律和规矩放在前面,让正常的批评和自我批评称为党内政治空气的清洁剂,坚决防止不正之风成为滋生腐败的温床。
南京盐城2020年高三一模数学试卷及答案
把答案写在答题卡的指定区域内.
15.(本小题满分 14 分)
已知△ABC 满足 sin(B+π)=2cosB. 6
(1)若 cosC= 6,AC=3,求 AB;
3
(2)若 A∈(0,π),且 cos(B-A)=4,求 sinA.
3
5
16.(本小题满分 14 分)
如图,长方体 ABCD-A1B1C1D1 中,已知底面 ABCD 是正方形,点 P 是侧棱 CC1 上的一点.
方法二:由点 A , B 不重合可知直线 PA 与 x 轴不重合,故可设直线 PA 的方程为 x my 1 ,
联立
x2 2
y2
1
,消去
x
得 (m2
2) y2
2my
1
0 (☆),
x my 1
设 A(x1, y1) ,则 y1 与 y0 为方程(☆)的两个实根,
高三数学答案 第 2 页 共 7 页
数学参考答案
一、填空题:本大题共 14 小题,每小题 5 分,计 70 分.
1. (, 0]
2. 5
3.
2 3
4.真
8. 3
9.
2 3
10. 7
11.
3 3
5. 6
12.10
6. 2 13. 4
7. 2 3
14.
1 2
二、解答题:本大题共 6 小题,计 90 分.解答应写出必要的文字说明,证明过程或演算步骤,请把答案写 在答题纸的指定区域内.
又由
x02 2
y02
1得
y02
1
x02 2
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江苏省南京市、盐城市2020届高三年级第一次模拟考试 数学(word版含答案)
盐城市、南京市 2020 届高三年级第一次模拟考试数学2020.01注意事项:1. 本试卷共 4 页,包括填空题(第 1 题~第 14 题)、解答题(第 15 题~第 20 题)两部分.本试卷满分为 160 分,考试时间为 120 分钟.2. 答题前,请务必将自己的姓名、学校、班级、学号写在答题卡的密封线内.试题的答案写在答.题.卡.上对应题目的答案空格内.考试结束后,交回答题卡. 参考公式:柱体体积公式:V =Sh ,锥体体积公式:V =1Sh ,其中 S 为底面积,h 为高.3n n样本数据 x 1,x 2,···,x n 的方差 s 2=1 ∑ (x i -)2,其中=1 ∑ x i .n i =1 n i =1一、 填空题:本大题共 14 小题,每小题 5 分,计 70 分.不需写出解答过程,请把答案写在答题卡的指定位置上.1.已知集合 A =(0,+∞),全集 U =R ,则∁ A = ▲. U2. 设复数 z =2+i ,其中 i 为虚数单位,则 z ·—z =▲.3. 学校准备从甲、乙、丙三位学生中随机选两位学生参加问卷调查, 则甲被选中的概率为 ▲ . 4. 命题“ θ∈R ,cos θ+sin θ>1”的否定是 ▲ 命题.(填“真”或“假”) 5. 运行如图所示的伪代码,则输出的 I 的值为 ▲ . 6. 已知样本 7,8,9,x ,y 的平均数是 9,且 xy =110,则此样本的方差是 ▲ .(第 5 题图)7. 在平面直角坐标系 xOy 中,若抛物线 y 2=4x 上的点 P 到其焦点的距离为 3,则点 P 到点 O的距离为 ▲ .8. 若数列{a n }是公差不为0 的等差数列,ln a 1、ln a 2、ln a 5 成等差数列,则a 2的值为 ▲ . a 19. 在三棱柱 ABC -A 1B 1C 1 中,点 P 是棱 CC 1 上一点,记三棱柱 ABC -A 1B 1C 1 与四棱锥 P -ABB 1A 1 的体积分别为 V 1 与 V 2,则V 2= ▲ .V 110. 设函数 f (x )=sin(ωx +φ)(ω>0,0<φ<π)的图象与 y y 轴右侧第一个22最低点的横坐标为π,则ω的值为 ▲.6S ←0I ←0 While S ≤10 S ←S +I I ←I +1End WhilePrint I→11.已知H 是△ABC 的垂心(三角形三条高所在直线的交点),AH =的值为▲.→AB +4→AC ,则cos∠BAC212.若无穷数列{cos(ωn)}(ω∈R)是等差数列,则其前10 项的和为▲.13.已知集合P={(x,y)|x|x|+y|y|=16},集合Q={(x,y)|kx+b1≤y≤kx+b2},若P Q,则|b1-b2|k2+1 的最小值为▲.14.若对任意实数x∈(-∞,1],都有| e xx2-2ax+1|≤1 成立,则实数a 的值为▲.二、解答题:本大题共 6 小题,计90 分.解答应写出必要的文字说明,证明过程或演算步骤,请把答案写在答题卡的指定区域内.15.(本小题满分14 分)已知△ABC 满足sin(B+π)=2cos B.6(1)若cos C AC=3,求AB;3(2)若A∈(0,π),且cos(B-A)=4,求sin A.3 516.(本小题满分14 分)如图,长方体ABCD-A1B1C1D1 中,已知底面ABCD 是正方形,点P 是侧棱CC1 上的一点.(1)若AC1//平面PBD,求PC1的值;PC(2)求证:BD⊥A1P.1A(第16 题图)11QA DOB CPyPA F1 O F2 xB如图,是一块半径为4 米的圆形铁皮,现打算利用这块铁皮做一个圆柱形油桶.具体做法是从⊙O 中裁剪出两块全等的圆形铁皮⊙P 与⊙Q 做圆柱的底面,裁剪出一个矩形ABCD 做圆柱的侧面(接缝忽略不计),AB 为圆柱的一条母线,点A、B 在⊙O 上,点P、Q 在⊙O 的一条直径上,AB∥PQ,⊙P、⊙Q 分别与直线BC、AD 相切,都与⊙O 内切.(1)求圆形铁皮⊙P 半径的取值范围;(2)请确定圆形铁皮⊙P 与⊙Q 半径的值,使得油桶的体积最大.(不取近似值)(第17 题图)18.(本小题满分16 分)设椭圆C:x2+y2=1(a>b>0)的左右焦点分别为F1,F2,离心率是e,动点P(x0,y0)在椭圆C 上a2 b2运动.当PF2⊥x 轴时,x0=1,y0=e.(1)求椭圆C 的方程;→→→→(2)延长PF ,PF 分别交椭圆C 于点A,B(A,B 不重合).设=,=,1 2AF1λF1P BF2 μF2P 求λ+μ的最小值.(第18 题图)定义:若无穷数列{a n}满足{a n+1-a n}是公比为q的等比数列,则称数列{a n}为“M(q)数列”.设数列{b n}中b1=1,b3=7.(1)若b2=4,且数列{b n}是“M(q)数列”,求数列{b n}的通项公式;(2)设数列{b n}的前n项和为S n,且b n+1=2S n-1n+λ,请判断数列{b n}是否为“M(q)数列”,2并说明理由;(3)若数列{b n}是“M(2)数列”,是否存在正整数m,n 使得4039<b m<4040?若存在,请求2019b n2019出所有满足条件的正整数m,n;若不存在,请说明理由.20.(本小题满分16 分)若函数f(x)=e x-a e-x-mx(m∈R)为奇函数,且x=x0时f(x)有极小值f(x0).(1)求实数a 的值;(2)求实数m 的取值范围;(3)若f(x0)≥-2恒成立,求实数m 的取值范围.e盐城市、南京市 2020 届高三年级第一次模拟考试数学附加题2020.01注意事项:1.附加题供选修物理的考生使用.2.本试卷共40 分,考试时间30 分钟.3.答题前,考生务必将自己的姓名、学校、班级、学号写在答题卡的密封线内.试题的答案写在答.题.卡.上对应题目的答案空格内.考试结束后,交回答题纸卡.21.【选做题】在A、B、C 三小题中只能选做2 题,每小题10 分,共计20 分.请在答.卷.卡.指.定.区.域.内.作答.解答应写出文字说明、证明过程或演算步骤.A.选修4—2:矩阵与变换a 3已知圆C 经矩阵M=3 -2 变换后得到圆C′:x2+y2=13,求实数a 的值.B.选修4—4:坐标系与参数方程在极坐标系中,直线ρcosθ+2ρsinθ=m 被曲线ρ=4sinθ截得的弦为AB,当AB 是最长弦时,求实数m 的值.C.选修4—5:不等式选讲已知正实数a,b,c 满足1+2+3=1,求a+2b+3c 的最小值.a b c【必做题】第22 题、第23 题,每题10 分,共计20 分.请在答.卷.卡.指.定.区.域.内.作答.解答应写出文字说明、证明过程或演算步骤.22.(本小题满分10 分)如图,AA1、BB1 是圆柱的两条母线,A1B1、AB 分别经过上下底面圆的圆心O1、O,CD 是下底面与AB 垂直的直径,CD=2.(1)若AA1=3,求异面直线A1C 与B1D 所成角的余弦值;(2)若二面角A1-CD-B1 的大小为π,求母线AA1 的长.3(第22 题图)23.(本小题满分10 分)2n设∑ (1-2x)i=a0+a1x+a2x2+…+a2n x2n(n∈N*),记S n=a0+a2+a4+…+a2n.i=1(1)求S n;(2)记T n=-S1C1+S2C2-S3C3+…+(-1)n S n C n,求证:|T n|≥6n3恒成立.n n n n盐城市、南京市2020 届高三年级第一次模拟考试数学参考答案及评分标准2020.01说明:1.本解答给出的解法供参考.如果考生的解法与本解答不同,可根据试题的主要考查内容比照评分标准制订相应的评分细则.2.对计算题,当考生的解答在某一步出现错误时,如果后续部分的解答未改变该题的内容和难度,可视影响的程度决定给分,但不得超过该部分正确解答应得分数的一半;如果后续部分的解答有较严重的错误,就不再给分.3.解答右端所注分数,表示考生正确做到这一步应得的累加分数.4.只给整数分数,填空题不给中间分数.一、填空题(本大题共14 小题,每小题 5 分,计70 分. 不需写出解答过程,请把答案写在答题纸的指定位置上)4.真5.6 6.2 7.2 31.(-∞,0] 2.5 3.238.3 9.210.7 1112.10 13.414.-1332二、解答题:本大题共 6 小题,计90 分.解答应写出必要的文字说明,证明过程或演算步骤,请把答案写在答题纸的指定区域内.15.(本小题满分14 分)解:(1)由sin(B+π)=2cos B,可知B+1cos B=2cos B,即sin B=3cos B.6 2 2因为cos B≠0,所以tan B=3.又B∈(0,π),故B=π......................................... 2 分3由cos C C∈(0,π),3可知sin C=1-cos2C................................... 4 分3AC =AB ,在△ABC 中,由正弦定理b = c ,可得sin Csin B sin C sinπ3所以AB=2................................................. 7 分(2)由(1)知B=π,所以A∈(0,π)时,π-A∈(0,π),3 3 3 3由 cos(B -A )=4,即 cos(π-A )=4,所以 sin(π-A )= 1-cos 2(π-A )=3, ................. 10 分3 3 5 所以 sin A =sin[π-(π-A )]=sin πcos(π-A )-cos πsin(π-A )3 3 3 3 3 3= 3×4-1×3=4 3-3. ............................. 14 分2 5 2 5 1016.(本小题满分 14 分)证明:(1)连结 AC 交 BD 于点 O ,连结 OP .因为 AC 1//平面 PBD ,AC 1 平面 ACC 1, 平面 ACC 1∩平面 BDP =OP ,所以 AC 1//OP . ............................. 3 分因为四边形 ABCD 是正方形,对角线 AC 交 BD 于点 O , 所以点 O 是 AC 的中点,所以 AO =OC ,所以在△ACC 1 中,PC 1=AO=1. ................ 6 分D 1C 1A 1B 1PD C(2)连结 A 1C 1.PC OC O因为 ABCD -A 1B 1C 1D 1 为长方体,所以侧棱 C 1C ⊥平面 ABCD . (第 16 题图)又 BD 平面 ABCD ,所以 CC 1⊥BD . ...................... 8 分因为底面 ABCD 是正方形,所以 AC ⊥BD . ................. 10 分又 AC ∩CC 1=C ,AC 面 ACC 1A 1, CC 1面 ACC 1A 1,所以 BD ⊥面 ACC 1A 1. .......................................... 12 分又因为 A 1P 面 ACC 1A 1,所以 BD ⊥A 1P . .......................... 14 分17.(本小题满分 14 分)解:(1)设⊙P 半径为 r ,则 AB =4(2-r ),所以⊙P 的周长 2πr =BC ≤2 16-4(2-r )2, ............................ 4 分 解 得 r ≤ 16 ,π2+4故⊙P 半径的取值范围为(0, 16 ]. ................................. 6 分π2+4 (2)在(1)的条件下,油桶的体积 V =πr 2·AB =4πr 2(2-r ). ..................... 8 分设函数 f (x )=x 2(2-x ),x ∈(0, 16 ],π2+4所以 f '(x)=4x-3x2,由于16 <4,π2+4 3所以 f '(x)>0 在定义域上恒成立,故f(x)在定义域上单调递增,即当r=16 时,体积取到最大值.................................. 13 分π2+4答:⊙P 半径的取值范围为(0,16 ].当r=16 米时,体积取到最大值. ....... 14 分18.(本小题满分16 分)π2+4 π2+4解:(1)由当PF2⊥x轴时,x0=1,可知c=1. ................................................... 2分将x0=1,y0=e 代入椭圆方程得1 +e2=1.a2 b2由e=c=1,b2=a2-c2=a2-1,所以1 + 1 =1,a a a2 a2(a2-1)解得a2=2,故b2=1,所以椭圆C 的方程为x2+y2=1...................................... 4分2→→1-x1=λ(x0+1),(2)方法一:设A(x1,y1),由AF1=λF1P y1=λy0,1=-λx0-λ-1,y1=-λy0,代入椭圆方程,得(-λx0-λ-1)2+(-λy)2=1....................... 8 分2x2(λx)2 2 2(λ+1)(2λx0+λ+1) 2又由0+y0=1,得20 +(λy0) =λ ,两式相减得2 2=1-λ .因为λ+1≠0,所以2λx0+λ+1=2(1-λ),故λ= 1 ................................................... 12 分3+2x0同理可得μ= 1 ,............................................ 14 分3-2x0故λ+μ= 1 + 1 = 6 ≥2,3+2x0 3-2x0 9-4x23当且仅当x0=0 时取等号,故λ+μ的最小值为2. ....................... 16 分3方法二:由点A,B 不重合可知直线PA 与x 轴不重合,故可设直线PA 的方程为x=my-1,x2 22+y =1,消去x,得(m2+2)y2-2my-1=0.x=my-1,设A(x1,y1),则y0y1=-1m2+2,所以y1=-1 ................. 8 分(m2+2)y0将点P(x ,y ) x2 y 2=1,0 0代入椭圆的方程得0+020 0 0 0代入直线 PA 的方程得 x 0=my 0-1,所以 m =x 0+1.y 0→ → y 1 1 1 由AF 1=λF 1P ,得-y 1=λy 0,故λ=- = =y 0 (m 2+2)y 2 (x 0+1)2+2y 2= 1= 1 . .................................... 12 分 (x 0+1)2+2(1-1x 2) 3+2x 02同理可得μ= 1 . ............................................. 14 分3-2x 0故λ+μ= 1 + 1 = 6 ≥2,3+2x 0 3-2x 0 9-4x 23 当且仅当 x 0=0 时取等号,故λ+μ的最小值为2. ...................... 16 分3注:(1)也可设 P ( 2cos θ,sin θ)得λ= 1 ,其余同理. 3+2 2cos θ(2)也可由1+1=6,运用基本不等式求解λ+μ的最小值.λ μ 19.(本小题满分 16 分)解:(1)因为 b 2=4,且数列{b n }是“M (q )数列”,所以 q =b 3-b 2=7-4=1,所以b n +1-b n =1,n ≥2,b 2-b 1 4-1b n -b n -1 即 b n +1-b n =b n -b n -1 ,n ≥2, .................................................................. 2 分 所以数列{b n }是等差数列,其公差为 b 2-b 1=3,所以数列{b n }通项公式为 b n =1+(n -1)×3,即 b n =3n -2. ............... 4 分 (2)由 b n +1=2S n -1n +λ,得 b 2=3+λ,b 3=4+3λ=7,故λ=1.2 2方法一:由 b n +1=2S n -1n +1,得 b n +2=2S n +1-1(n +1)+1,2 2 两式作差得 b n +2-b n +1=2b n +1-1,即 b n +2=3b n +1-1,n ∈N *.2 2又 b 2=5,所以 b 2=3b 1-1,22所以 b n +1=3b n -1对 n ∈N *恒成立, ............................................ 6 分2b n +1-1则 b n +1-1=3(b n -1).因为 b 1-1=3≠0,所以 b n -1≠0,所以4=3, 4 4 4 4 4 b n -14 即{b n -1}是等比数列, ....................................... 8 分4+ 所以 b n -1=(1-1)×3n -1=1×3n ,即 b n =1×3n +1,4 4 4 4 4(1×3n +2+1)-(1×3n +1+1)所以b n +2-b n +1= 44 4 4 =3, b n +1-b n(1×3n +1+1)-(1×3n +1)4444所以{b n +1-b n }是公比为 3 的等比数列,故数列{b n }是“M (q )数列”.………10 分 方法二:同方法一得 b n +1=3b n -1对 n ∈N *恒成立, ....................................... 6 分2 则 b n +2=3b n +1-1,两式作差得 b n +2-b n +1=3(b n +1-b n ). .............................. 8 分2因为 b 2-b 1=3≠0,所以 b n +1-b n ≠0,所以b n +2-b n +1=3,2b n +1-b n所以{b n +1-b n }是公比为 3 的等比数列,故数列{b n }是“M (q )数列”.………10 分(3)由数列{b n }是“M (2)数列”,得 b n 1-b n =(b 2-b 1)×2n -1. 又b 3-b 2=2,即7-b 2=2,所以 b 2=3,所以 b 2-b 1=2,所以 b n +1-b n =2n ,b 2-b 1 b 2-1 所以当 n ≥2 时,b n =(b n -b n -1)+(b n -1-b n -2)+…+(b 2-b 1)+b 1=2n -1+2n -2+…+2+1=2n -1.当 n =1 时上式也成立,所以 b n =2n -1. ...........................12 分 假设存在正整数 m ,n ,使得4039<b m <4040,则4039<2m-1<4040.2019 b n 2019 2019 2n -1 2019由2m-1>4039>1,可知 2m -1>2n -1,所以 m >n .2n -1 2019又 m ,n 为正整数,所以 m -n ≥1.又2m -1=2m -n (2n -1)+2m -n -1=2m -n +2m -n-1<4040, 2n -1 2n -1 2n -1 2019所以 2m -n <4040<3,所以 m -n =1, .............................................................. 14 分2019 所以2m-1=2+ 1 ,即4039<2+ 1 <4040,所以2021<2n <2020,2n -12n -1 2019 2n -1 2019 2 所以 n =10,m =11,故存在满足条件的正整数 m ,n ,其中 m =11,n =10. ................... 16 分20.(本小题满分 16 分)解:(1)由函数 f (x )为奇函数,得 f (x )+f (-x )=0 在定义域上恒成立,所以 e x -a e -x -mx +e -x -a e x +mx =0,化简可得 (1-a )·(e x +e -x )=0,所以 a =1. .................................................. 3 分(2)方法一:由(1)可得f(x)=e x-e-x-mx,所以f'(x)=e x+e-x-m=e2x-m e x+1.e x①当m≤2 时,由于e2x-m e x+1≥0 恒成立,即f '(x)≥0 恒成立,故不存在极小值............................ 5 分②当m>2 时,令e x=t,则方程t2-mt+1=0 有两个不等的正根t1,t2 (t1<t2),故可知函数f(x)=e x-e-x-mx在(-∞,ln t1),(ln t2,+∞)上单调递增,在(ln t1,ln t2)上单调递减,即在ln t2 处取到极小值,所以,m 的取值范围是(2,+∞).................................. 9分方法二:由(1)可得f(x)=e x-e-x-mx,令g(x)=f'(x)=e x+e-x-m,则g′(x)=e x-e-x=e2x-1.e x故当x≥0 时,g′(x)≥0;当x<0 时,g′(x)<0,........................... 5 分故g(x)在(-∞,0)上递减,在(0,+∞)上递增,所以g(x)min=g(0)=2-m.①若2-m≥0,则g(x)≥0 恒成立,所以f(x)单调递增,此时f(x)无极值点.……6 分②若2-m<0,即m>2 时,g(0)=2-m<0.取t=ln m,则g(t)=1 >0.m又函数g(x)的图象在区间[0,t]上不间断,所以存在x0∈(0,t),使得g(x0)=0.又g(x)在(0,+∞)上递增,所以x∈(0,x0)时,g(x)<0,即f '(x)<0;x∈(x0,+∞)时,g(x)>0,即f '(x)>0,所以f(x0)为f(x)极小值,符合题意.所以,m 的取值范围是(2,+∞).................................. 9 分(3)由x0满足e x0+e-x0=m,代入f(x)=e x-e-x-mx,消去m,可得f(x0)=(1-x0)e x0-(1+x0)e-x0. ................................................ 11分构造函数h(x)=(1-x)e x-(1+x)e-x,所以h′(x)=x(e-x-e x).当x≥0时,e-x-e x=1-e2x0,所以当x≥0 时,h′(x)≤0 恒成立,e x故h(x)在[0,+∞)上为单调减函数,其中h(1)=-2, ............................... 13 分e则f(x0)≥-2可转化为h(x0)≥h(1),故x0≤1..................... 15 分e由e x0+e-x0=m,设y=e x+e-x,可得当x≥0时,y’=e x-e-x≥0,所以y=e x+e-x在(0,1]上递增,故m≤e+1.e 综上,m 的取值范围是(2,e+1]. .............................. 16 分e≤盐城市、南京市 2020 届高三年级第一次模拟考试数学附加题参考答案及评分标准2020.01说明:1. 本解答给出的解法供参考.如果考生的解法与本解答不同,可根据试题的主要考查内容比照 评分标准制订相应的评分细则.2. 对计算题,当考生的解答在某一步出现错误时,如果后续部分的解答未改变该题的内容和难度,可视影响的程度决定给分,但不得超过该部分正确解答应得分数的一半;如果后续部分的 解答有较严重的错误,就不再给分.3. 解答右端所注分数,表示考生正确做到这一步应得的累加分数.4. 只给整数分数,填空题不给中间分数.21.【选做题】在 A 、B 、C 三小题中只能选做 2 题,每小题 10 分,共计 20 分.请在答.卷.纸.指.定.区.域.内.作答.解答应写出文字说明、证明过程或演算步骤. A. 选修 4—2:矩阵与变换解:设圆 C 上任一点(x ,y ),经矩阵 M 变换后得到圆 C’上一点(x’,y’),a 3所以 3 -2x =x′y y′ ax +3y =x′,3x -2y =y′. ......................... 5 分又因为(x′)2+(y′)2=13,所以圆 C 的方程为(ax +3y )2+(3x -2y )2=13, 化简得(a 2+9)x 2+(6a -12)xy +13y 2=13, a 2+9=13,6a -12=0 解得 a =2.所以,实数 a 的值为 2. ........................................... 10 分B. 选修 4—4:坐标系与参数方程解:以极点为原点,极轴为 x 轴的正半轴(单位长度相同)建立平面直角坐标系,由直线ρcos θ+2ρsin θ=m ,可得直角坐标方程为 x +2y -m =0.又曲线ρ=4sin θ,所以ρ2=4ρsin θ,其直角坐标方程为 x 2+(y -2)2=4, ........... 5 分所以曲线ρ=4sin θ是以(0,2)为圆心,2 为半径的圆.为使直线被曲线(圆)截得的弦 AB 最长,所以直线过圆心(0,2), 于是 0+2×2-m =0,解得 m =4.所以,实数 m 的值为 4. ............................................ 10 分C. 选修 4—5:不等式选讲解:因为1+2+3=1,所以1+ 4 + 9 =1. a b c a 2b 3c,由柯西不等式得a+2b+3c=(a+2b+3c)(1+4 +9 )≥(1+2+3)2,a 2b 3c即a+2b+3c≥36,....................................................... 5分1 4 9当且仅当a=2b=3c,即a=b=c 时取等号,解得a=b=c=6,a 2b 3c所以当且仅当a=b=c=6 时,a+2b+3c 取最小值36.......................... 10 分22.(本小题满分10分)解:(1)以CD,AB,OO1所在直线建立如图所示空间直角坐标系O-xyz.由CD=2,AA1=3,所以A(0,-1,0),B(0,1,0),C(-1,0,0),D(1,0,0),A1(0,-1,3),B1(0,1,3),→→从而A1C=(-1,1,-3),B1D=(1,-1,-3),→→-1×1+1×(-1)+(-3)×(-3) 7所以cos<A1C,B1D>==,(-1)2+12+(-3)2×12+(-1)2+(-3)2 11所以异面直线A1C 与B1D 所成角的余弦值为7 . ........... 4 分11(2)设AA1=m>0,则A1(0,-1,m),B1(0,1,m),→→→所以A1C=(-1,1,-m),B1D=(1,-1,-m),CD=(2,0,0),→n1·CD=2x1=0,设平面A1CD 的一个法向量n1=(x1,y1,z1),则所以x1=0,令z1=1,则y1=m,所以平面A1CD 的一个法向量n1=(0,m,1).→n1·A1C=-x1+y1-mz1=0,同理可得平面B1CD 的一个法向量n2=(0,-m,1).因为二面角A1-CD-B1 的大小为π,3所以|cos<n1,n2>|=|m×(-m)+1×1 |=1,m2+12×(-m)2+12 2解得m=3或m=3,3由图形可知当二面角A1-CD-B1 的大小为π时,m=3................ 10 分3注:用传统方法也可,请参照评分.23.(本小题满分10分)解:(1)令x=1,得a0+a1+a2+…+a2n=0.令x=-1,得a0-a1+a2-a3+…-a2n-1+a2n=31+32+…+32n=3(9n-1).2两式相加得2(a0+a2+a4+…+a2n)=3(9n-1),2所以S n=3(9n-1).......................... 3 分4(2)T n=-S1C1+S2C2-S3C3+…+(-1)n S n C nn n n n=3{[-91C1+92C2-93C3+…+(-1)n9n C n]-[-C1+C2-C3+…+(-1)n C n]}n n n4n n n n n=3{[90C0-91C1+92C2-93C3+…+(-1)n9n C n]-[C0-C1+C2-C3+…+(-1)n C n]} n n n n4n n n n n n =3[90C0-91C1+92C2-93C3+…+(-1)n9n C n]n n n n n4=3[C0(-9)0+C1(-9)1+C2(-9)2+…+C n(-9)n]n n n n4=3[1+(-9)]n=3×(-8)n....................................... 7 分4 4要证|T n|≥6n3,即证3×8n≥6n3,只需证明8n-1≥n3,即证2n-1≥n.4当n=1,2时,2n-1≥n显然成立.当n≥3时,2n-1=C0+C1+…+C n-1≥C0+C1=1+(n-1)=n,即2n-1≥n,n-1 n-1 n-1 n-1 n-1所以2n-1≥n对n∈N*恒成立.综上,|T n|≥6n3恒成立.......................................... 10 分注:用数学归纳法或数列的单调性也可证明2n -1≥n 恒成立,请参照评分.。
2020届江苏南京市、盐城市高三上学期第一次模拟考试数学(理)试题(解析版)
盐城市、南京市2020届高三年级第一次模拟考试数 学 理 试 题2020.01(总分160分,考试时间120分钟)一、填空题(本大题共14小题,每小题5分,共计70分.不需要写出解答过程,请将答案填写在答题卡...相应的位置上.......) 1.已知集合A =(0,+∞),全集U =R ,则U A ð= . 答案:(-∞,0] 考点:集合及其补集解析:∵集合A =(0,+∞),全集U =R ,则U A ð=(-∞,0]. 2.设复数2z i =+,其中i 为虚数单位,则z z ⋅= . 答案:5 考点:复数解析:∵2z i =+,∴2(2)(2)45z z i i i ⋅=+-=-=.3.学校准备从甲、乙、丙三位学生中随机选两位学生参加问卷调查,则甲被选中的概率为 . 答案:23考点:等可能事件的概率解析:所有基本事件数为3,包含甲的基本事件数为2,所以概率为23. 4.命题“θ∀∈R ,cos θ+sin θ>1 ”的否定是 命题(填“真”或“假”). 答案:真 考点:命题的否定解析:当θπ=-时,cos θ+sin θ=﹣1<1,所以原命题为假命题,故其否定为真命题. 5.运行如图所示的伪代码,则输出的I 的值为 .答案:6考点:算法(伪代码)解析:第一遍循环 S =0,I =1,第二轮循环S =1,I =2 ,第三轮循环S =3,I =3,第四轮循环S =6,I=4,第五轮循环S =10,I =5,第六轮循环S =15,I =6,所以输出的 I =6. 6.已知样本7,8,9,x ,y 的平均数是9,且xy =110,则此样本的方差是 . 答案:2考点:平均数,方差解析:依题可得x +y =21,不妨设x <y ,解得x =10,y =11,所以方差为22222210(1)(2)5+++-+-=2.7.在平面直角坐标系xOy 中,抛物线y 2=4x 上的点P 到其焦点的距离为3,则点P 到点O 的距离为 .答案:考点:抛物线及其性质解析:抛物线的准线为x =−1,所以P 横坐标为2,带入抛物线方程可得P(2,±),所以OP=8.若数列{}n a 是公差不为0的等差数列,ln 1a 、ln 2a 、ln 5a 成等差数列,则21a a 的值为 . 答案:3考点:等差中项,等差数列的通项公式 解析:∵ln 1a 、ln 2a 、ln 5a 成等差数列,∴2152a a a =,故2111(4)()a a d a d +=+,又公差不为0,解得12d a =,∴21111133a a d a a a a +===. 9.在三棱柱ABC —A 1B 1C 1中,点P 是棱CC 1上一点,记三棱柱ABC —A 1B 1C 1与四棱锥P —ABB 1A 1的体积分别为V 1与V 2,则21V V = . 答案:23考点:棱柱棱锥的体积解析:1111121123C ABB A C A B C V V V V V ==-=——,所以2123V V =.10.设函数()sin()f x x ωϕ=+ (ω>0,0<ϕ<2π)的图象与y轴交点的纵坐标为2, y 轴右侧第一个最低点的横坐标为6π,则ω的值为 . 答案:7考点:三角函数的图像与性质解析:∵()f x 的图象与y轴交点的纵坐标为2,∴sin ϕ=,又0<ϕ<2π,∴3πϕ=, ∵y 轴右侧第一个最低点的横坐标为6π, ∴3632ππωπ+=,解得ω=7. 11.已知H 是△ABC 的垂心(三角形三条高所在直线的交点),11AH AB AC 42=+u u u r u u u r u u u r,则 cos ∠BAC 的值为 .考点:平面向量解析:∵H 是△ABC 的垂心, ∴AH ⊥BC ,BH ⊥AC ,∵11AH AB AC 42=+u u u r u u u r u u u r,∴1131BH AH AB AB AC AB AB AC 4242=-=+-=-+u u u r u u u r u u u r u u u r u u u r u u u r u u ur u u u r则11AH BC (AB AC)(AC AB)042⋅=+⋅-=u u u r u u u r u u ur u u u r u u u r u u u r ,31BH AC (AB AC)AC 042⋅=-+⋅=u u u r u u u r u u ur u u u r u u u r ,即22111AC AB AC AB 0244--⋅=u u u r u u u r u u u r u u u r ,231AC AB AC 042-⋅+=u u ur u u u r u u u r ,化简得:22111cos BAC 0244b c bc --∠=,231cos BAC+042bc b -∠=则2222 cos BAC3b c bbc c-∠==,得3b c=,从而3cos BAC∠=.12.若无穷数列{}cos()nω(ω∈R)是等差数列,则其前10项的和为.答案:10考点:等差数列解析:若等差数列公差为d,则cos()cos(1)n d nωω=+-,若d>0,则当1cos1ndω->+时,cos()1nω>,若d<0,则当1cos1ndω-->+时,cos()1nω<-,∴d=0,可得cos2cosωω=,解得cos1ω=或1cos2ω=-(舍去),∴其前10项的和为10.13.已知集合P={}()16x y x x y y+=,,集合Q={}12()x y kx b y kx b+≤≤+,,若P⊆Q,则1221b bk-+的最小值为.答案:4考点:解析几何之直线与圆、双曲线的问题解析:画出集合P的图象如图所示,第一象限为四分之一圆,第二象限,第四象限均为双曲线的一部分,且渐近线均为y x=-,所以k=−1,所求式为两直线之间的距离的最小值,所以1b=,2y kx b=+与圆相切时最小,此时两直线间距离为圆半径4,所以最小值为4.14.若对任意实数x∈(-∞,1],都有2121xex ax≤-+成立,则实数a的值为.答案:12-考点:函数与不等式,绝对值函数解析:题目可以转化为:对任意实数x ∈(-∞,1],都有2211xx ax e -+≥成立,令221()x x ax f x e -+=,则(1)[(21)]()xx x a f x e --+'=,当211a +≥时,()0f x '≤,故()f x 在(-∞,1]单调递减,若(1)0f ≤,则()f x 最小值为0,与()1f x ≥恒成立矛盾;若(1)0f >,要使()1f x ≥恒成立,则(1)f =121a e -≥,解得12ea ≤-与211a +≥矛盾.当211a +<时,此时()f x 在(-∞,21a +)单调递减,在(21a +,1)单调递增,此时min ()(21)f x f a =+,若(21)0f a +≤,则()f x 最小值为0,与()1f x ≥恒成立矛盾;若(21)0f a +>,要使()1f x ≥恒成立,则min 2122()(21)a a f x f a e ++=+=1≥. 接下来令211a t +=<,不等式21221a a e++≥可转化为10te t --≤, 设()1tg t e t =--,则()1tg t e '=-,则()g t 在(-∞,0)单调递减,在(0,1)单调递增,当t =0时,()g t 有最小值为0,即()0g t ≥,又我们要解的不等式是()0g t ≤,故()0g t =,此时210a +=,∴12a =-. 二、解答题(本大题共6小题,共计90分.请在答题纸指定区域.......内作答,解答应写出文字说明,证明过程或演算步骤.) 15.(本题满分14分)已知△ABC 满足sin(B )2cos B 6π+=.(1)若cosC AC =3,求AB ; (2)若A ∈(0,3π),且cos(B ﹣A)=45,求sinA .解:16.(本题满分14分)如图,长方体ABCD —A 1B 1C 1D 1中,已知底面ABCD 是正方形,点P 是侧棱CC 1上的一点. (1)若A 1C//平面PBD ,求1PC PC的值; (2)求证:BD ⊥A 1P .证明:17.(本题满分14分)如图,是一块半径为4米的圆形铁皮,现打算利用这块铁皮做一个圆柱形油桶.具体做法是从⊙O 中剪裁出两块全等的圆形铁皮⊙P 与⊙Q 做圆柱的底面,剪裁出一个矩形ABCD 做圆柱的侧面(接缝忽略不计),AB 为圆柱的一条母线,点A ,B 在⊙O 上,点P ,Q 在⊙O 的一条直径上,AB ∥PQ ,⊙P ,⊙Q 分别与直线BC 、AD 相切,都与⊙O 内切.(1)求圆形铁皮⊙P 半径的取值范围;(2)请确定圆形铁皮⊙P 与⊙Q 半径的值,使得油桶的体积最大.(不取近似值)解:18.(本题满分16分)设椭圆C :22221x y a b+=(a >b >0)的左右焦点分别为F 1,F 2,离心率是e ,动点P(0x ,0y ) 在椭圆C上运动.当PF 2⊥x 轴时,0x =1,0y =e .(1)求椭圆C 的方程;(2)延长PF 1,PF 2分别交椭圆于点A ,B (A ,B 不重合).设11AF FP λ=u u u r u u u r ,22BF F P μ=u u u r u u u r,求λμ+的最小值.解:19.(本题满分16分)定义:若无穷数列{}n a 满足{}1n n a a +-是公比为q 的等比数列,则称数列{}n a 为“M(q )数列”.设数列{}n b 中11b =,37b =.(1)若2b =4,且数列{}n b 是“M(q )数列”,求数列{}n b 的通项公式; (2)设数列{}n b 的前n 项和为n S ,且1122n n b S n λ+=-+,请判断数列{}n b 是否为“M(q )数列”,并说明理由;(3)若数列{}n b 是“M(2)数列”,是否存在正整数m ,n ,使得4039404020192019mn b b <<?若存在,请求出所有满足条件的正整数m ,n ;若不存在,请说明理由. 解:20.(本题满分16分)若函数()x xf x e aemx -=--(m ∈R)为奇函数,且0x x =时()f x 有极小值0()f x .(1)求实数a 的值; (2)求实数m 的取值范围; (3)若02()f x e≥-恒成立,求实数m 的取值范围. 解:附加题,共40分21.【选做题】本题包括A ,B ,C 三小题,请选定其中两题作答,每小题10分共计20分,解答时应写出文字说明,证明过程或演算步骤.A .选修4—2:矩阵与变换已知圆C 经矩阵M = 33 2a ⎡⎤⎢⎥-⎣⎦变换后得到圆C ′:2213x y +=,求实数a 的值. 解:B .选修4—4:坐标系与参数方程在极坐标系中,直线cos 2sin m ρθρθ+=被曲线4sin ρθ=截得的弦为AB ,当AB 是最长弦时,求实数m 的值.解:C .选修4—5:不等式选讲已知正实数 a ,b ,c 满足1231a b c++=,求23a b c ++的最小值. 解:【必做题】第22题、第23题,每题10分,共计20分,解答时应写出文字说明,证明过程或演算步骤.22.(本小题满分10分)如图,AA 1,BB 1是圆柱的两条母线,A 1B 1,AB 分别经过上下底面的圆心O 1,O ,CD 是下底面与AB 垂直的直径,CD =2.(1)若AA 1=3,求异面直线A 1C 与B 1D 所成角的余弦值;(2)若二面角A 1—CD —B 1的大小为3,求母线AA 1的长.解:23.(本小题满分10分)设22201221(12)n i n n i x a a x a x a x =-=++++∑L (n N *∈),记0242n n S a a a a =++++L .(1)求n S ;(2)记123123(1)n nn n n n n n T S C S C S C S C =-+-++-L ,求证:36n T n ≥恒成立. 解:。
2020届江苏省南京市、盐城市高三第一次模拟考试(1月) 数学(理)(PDF版)【附参考答案】
南京市、盐城市2020届高三年级第一次模拟考试数 学 理 试 题(总分160分,考试时间120分钟)注意事项:1.本试卷考试时间为120分钟,试卷满分160分,考试形式闭卷. 2.本试卷中所有试题必须作答在答题卡上规定的位置,否则不给分.3.答题前,务必将自己的姓名、准考证号用0.5毫米黑色墨水签字笔填写在试卷及答题卡上.参考公式:柱体体积公式:V Sh =,锥体体积公式:13V Sh =,其中S 为底面积,h 为高.样本数据12,,,n x x x ⋅⋅⋅的方差2211()n i i s x x n ==-∑,其中11n i i x x n ==∑.一、填空题(本大题共14小题,每小题5分,计70分. 不需写出解答过程,请把答案写在答题纸的指定位置上)1.已知集合(0,)A =+∞,全集U R =,则 U A= ▲ . 2.设复数2z i =+,其中i 为虚数单位,则z z ⋅= ▲ .3.学校准备从甲、乙、丙三位学生中随机选两位学生参加问卷调查,则甲被选中的概率为 ▲ . 4.命题“R θ∀∈,cos sin 1θθ+>”的否定是 ▲ 命题.(填“真”或“假”)5.运行如图所示的伪代码,则输出的I 的值为 ▲ .6.已知样本y x ,,9,8,7的平均数是9,且110=xy ,则此样本的方差是▲ .7.在平面直角坐标系xOy 中,若抛物线24y x =上的点P 到其焦点的距离为3,则点P 到点O 的距离为 ▲ .0 101 S I While S S S I I I End ForPrint I←←≤←+←+(第5题图)8.若数列{}n a 是公差不为0的等差数列,1ln a 、2ln a 、5ln a 成等差数列,则21a a 的值为 ▲ . 9.在三棱柱111ABC A B C -中,点P 是棱1CC 上一点,记三棱柱111ABC A B C -与四棱锥11P ABB A -的体积分别为1V 与2V ,则21V V = ▲ . 10.设函数()sin()f x x ωϕ=+(0,02πωϕ><<)的图象与y轴交点的纵坐标为2, y 轴右侧第一个最低点的横坐标为6π,则ω的值为 ▲ . 11.已知H 是△ABC 的垂心(三角形三条高所在直线的交点),1142AH AB AC =+u u u r u u u r u u u r,则cos BAC ∠的值为 ▲ .12.若无穷数列{}cos()n ω()R ω∈是等差数列,则其前10项的和为 ▲ . 13.已知集合{(,)16}P x y x x y y =+=,集合12{(,)}Q x y kx b y kx b =+≤≤+,若P Q ⊆的最小值为 ▲ .14.若对任意实数]1,(-∞∈x ,都有1122≤+-ax x e x成立,则实数a 的值为 ▲ . 二、解答题(本大题共6小题,计90分.解答应写出必要的文字说明,证明过程或演算步骤,请把答案写在答题纸的指定区域内) 15.(本小题满分14分) 已知ABC ∆满足sin()2cos 6B B π+=.(1)若cos 3C =,3AC =,求AB ; (2)若0,3A π⎛⎫∈ ⎪⎝⎭,且()4cos 5B A -=,求sin A .如图,长方体1111D C B A ABCD -中,已知底面ABCD 是正方形,点P 是侧棱1CC 上的一点.(1)若1AC //平面PBD ,求PCPC 1的值; (2)求证:P A BD 1⊥.(第16题图)17.(本小题满分14分)如图,是一块半径为4米的圆形铁皮,现打算利用这块铁皮做一个圆柱形油桶.具体做法是从O e 中裁剪出两块全等的圆形铁皮P e 与Q e ,做圆柱的底面,裁剪出一个矩形ABCD 做圆柱的侧面(接缝忽略不计),AB 为圆柱的一条母线,点A 、B 在O e 上,点P 、Q 在O e 的一条直径上,P e 、Q e 分别与直线BC 、AD 相切,都与O e 内切. (1)求圆形铁皮P e 半径的取值范围;(2)请确定圆形铁皮P e 与Q e 半径的值,使得油桶的体积最大.(不取近似值)(第17题图)设椭圆2222:1(0)x y C a b a b+=>>的左右焦点分别为12,F F ,离心率是e ,动点00(,)P x y 在椭圆C 上运动,当2PF x ⊥轴时,01x =,0y e =. (1)求椭圆C 的方程;(2)延长12,PF PF 分别交椭圆C 于点,A B (,A B 不重合),设11AF F P λ=u u u r u u u r,22BF F P μ=u u u u r u u u u r,求λμ+的最小值.(第18题图)19.(本小题满分16分)定义:若无穷数列{}n a 满足{}1n n a a +-是公比为q 的等比数列,则称数列{}n a 为“()M q 数列”.设数列{}n b 中11b =,37b =.(1)若24b =,且数列{}n b 是“()M q 数列”,求数列{}n b 的通项公式; (2)设数列{}n b 的前n 项和为n S ,且1122n n b S n λ+=-+,请判断数列{}n b 是否为 “()M q 数列”,并说明理由;(3)若数列{}n b 是“()2M 数列”,是否存在正整数,m n 使得4039404020192019m n b b <<?若存在,请求出所有满足条件的正整数,m n ;若不存在,请说明理由.20.(本小题满分16分)若函数()xxf x e aemx -=--()m R ∈为奇函数,且0x x =时()f x 有极小值0()f x .(1)求实数a 的值;(2)求实数m 的取值范围; (3)若02()f x e≥-恒成立,求实数m 的取值范围.y南京市、盐城市2020届高三年级第一次模拟考试数学附加题部分(本部分满分40分,考试时间30分钟)21.[选做题](在A 、B 、C 三个小题中只能选做2题,每小题10分,计20分.请把答案写在答题纸的指定区域内) A .(选修4-2:矩阵与变换)已知圆C 经矩阵332a M ⎡⎤=⎢⎥-⎣⎦变换后得到圆22:13C x y '+=,求实数a 的值.B .(选修4-4:坐标系与参数方程)在极坐标系中,直线cos 2sin m ρθρθ+=被曲线4sin ρθ=截得的弦为AB ,当AB 是最长弦时,求实数m 的值.C .(选修4-5:不等式选讲)已知正实数,,a b c 满足1231a b c++=,求23a b c ++的最小值.[必做题](第22、23题,每小题10分,计20分.请把答案写在答题纸的指定区域内) 22.(本小题满分10分)如图,1AA 、1BB 是圆柱的两条母线, 11A B 、AB 分别经过上下底面圆的圆心1O 、O ,CD 是下底面与AB 垂直的直径,2CD =.(1)若13AA =,求异面直线1A C 与1B D 所成角的余弦值; (2)若二面角11A CD B --的大小为3π,求母线1AA 的长.23.(本小题满分10分)设22201221(12)nin n i x a a x a x a x =-=++++∑L (n N *∈),记0242n n S a a a a =++++L .(1)求n S ;(2)记123123(1)nnn n n n n n T S C S C S C S C =-+-++-L ,求证:3||6n T n ≥恒成立.南京市、盐城市2020届高三年级第一次模拟考试数学参考答案一、填空题:本大题共14小题,每小题5分,计70分. 1.(,0]-∞ 2.5 3.234.真 5.6 6.27.8.3 9.2310.7 11 12.10 13.4 14.12- 二、解答题:本大题共6小题,计90分.解答应写出必要的文字说明,证明过程或演算步骤,请把答案写在答题纸的指定区域内. 15.解:(1)由sin()2cos 6B B π+=可知B B B cos 2cos 21sin 23=+, 移项可得3tan =B ,又),0(π∈B ,故3π=B , (2)分又由cos 3C =,),0(π∈C 可知33cos 1sin 2=-=C C , ……………………………4分故在A B C ∆中,由正弦定理C c B b sin sin =可得 C AB AC sin 3sin =π,所以2=AB . ………………7分(2)由(1)知3π=B ,所以0,3A π⎛⎫∈ ⎪⎝⎭时,)3,0(3ππ∈-A ,由()4cos 5B A -=即54)3cos(=-A π可得53)3(cos 1)3sin(2=--=-A A ππ , ……………10分 ∴1033453215423)3sin(3cos )3cos(3sin ))3(3sin(sin -=⋅-⋅=---=--=A A A A ππππππ.…14分16.(1)证明:连结AC 交BD 于点O ,连结OP , 又因为1//AC 平面PBD ,⊂1AC 平面1ACC平面1ACC I 平面OP BDP =,所以1//AC OP ……………3分 因为四边形ABCD 是正方形,对角线AC 交BD 于点O , 所以点O 是AC 的中点,所以AO OC =,所以在1ACC ∆中,11PC AOPC OC==. ……………6分 (2)证明:连结11AC .因为1111ABCD A B C D -为直四棱柱,所以侧棱1C C 垂直于底面ABCD ,又BD ⊂平面ABCD ,所以1CC BD ⊥.…………………………………………………………………8分 因为底面ABCD 是正方形,所以AC BD ⊥. ……………………………………………………10分又1AC CC C =I ,AC ⊂面11ACC A , 1CC ⊂面11ACC A ,所以BD ⊥面11ACC A . ……………………………………… …………………………………………12分 又因为1111,P CC CC ACC A ∈⊂面,所以11P ACC A ∈面,又因为111A ACC A ∈面, 所以A 1P ⊂面ACC 1A 1,所以1BD A P ⊥. ………………………………………………14分17.解:(1)设P e 半径为r ,则)2(4r AB -=,所以P e 的周长2)2(41622r BC r --≤=π, ………………………………………………4分 解得4162+≤πr ,故Pe 半径的取值范围为]416,0(2+π. ……………………………………………6分 (2)在(1)的条件下,油桶的体积)2(422r r AB r V -=⋅=ππ, ……………………………………8分设函数),2()(2x x x f -=]416,0(2+∈πx , 所以234)(x x x f -=',由于 344162<+π, 所以()0f x '>在定义域上恒成立,故()f x 在定义域上单调递增, 即当4162+=πr 时,体积取到最大值. ………………………………………………13分答:P e 半径的取值范围为]416,0(2+π,当4162+=πr 时,体积取到最大值. ………………………14分18.解:(1)由当2PF x ⊥轴时01x =,可知1c =, …………………………………………………2分将01x =,0y e =代入椭圆方程得22211e a b+=(※),而1c e a a ==,22221b a c a =-=-,代入(※)式得222111(1)a a a +=-,解得22a =,故21b =,∴椭圆C 的方程为2212x y += (4)分(2)方法一:设11(,)A x y ,由11AF F P λ=u u u r u u u r 得10101(1)x x y y λλ--=+⎧⎨-=⎩,故10101x x y y λλλ=---⎧⎨=-⎩,代入椭圆的方程得2200(1)()12x y λλλ---+-=(#), ………………………………………………8分又由220012x y +=得220012x y =-,代入(#)式得222001(1)2(1)22x x λλλ+++-=,化简得203212(1)0x λλλλ+-++=,即0(1)(312)0x λλλ+-+=,显然10λ+≠,∴03120x λλ-+=,故0132x λ=+.……………………………………………………………………12分同理可得0132u x =-,故200011623232943x x x λμ+=+=≥+--, 当且仅当00x =时取等号,故λμ+的最小值为23. (16)分方法二:由点A ,B 不重合可知直线PA 与x 轴不重合,故可设直线PA 的方程为1x my =-,联立22121x y x my ⎧+=⎪⎨⎪=-⎩,消去x 得22(2)210m y my +--=(☆),设11(,)A x y ,则1y 与0y 为方程(☆)的两个实根,由求根公式可得0,122m y m =+,故01212y y m -=+,则121(2)y m y -=+,……………………8分将点00(,)P x y 代入椭圆的方程得220012x y +=,代入直线PA 的方程得001x my =-,∴001x m y +=,由11AF F P λ=u u u r u u u r 得10y y λ-=,故10y y λ=-2222000111(2)[()2]x m y y y ==+++ 2222000001111(1)232(1)2(1)2x y x x x ===+++++-.…………………………………………………12分同理可得0132u x =-,故200011623232943x x x λμ+=+=≥+--, 当且仅当00x =时取等号,故λμ+的最小值为23. (16)分注:(1)也可设,sin )P θθ得λ=.(2)也可由116λμ+=运用基本不等式求解λμ+的最小值.19.解:(1)∵24b =,且数列{}n b 是“()M q 数列”, ∴322174141b b q b b --===--,∴111n n n n b bb b +--=-,∴11n n n n b b b b +--=-, (2)分故数列{}n b 是等差数列,公差为213b b -=,故通项公式为1(1)3n b n =+-⨯,即32n b n =-. ………………………………………………4分(2)由1122n n b S n λ+=-+得232b λ=+,3437b λ=+=,故1λ=. 方法一:由11212n n b S n +=-+得2112(1)12n n b S n ++=-++,两式作差得211122n n n b b b +++-=-,即21132n n b b ++=-,又252b =,∴21132b b =-,∴1132n n b b +=-对n N *∈恒成立,……………………6分 则1113()44n n b b +-=-,而113044b -=≠,∴104n b -≠,∴114314n n b b +-=-, ∴1{}4n b -是等比数列, ………………………………………………………………………………8分∴1111(1)33444n n n b --=-⨯=⨯,∴11344n n b =⨯+,∴2121111111(3)(3)444431111(3)(3)4444n n n n n n n nb b b b ++++++⨯+-⨯+-==-⨯+-⨯+, ∴{}1n n b b +-是公比为3的等比数列,故数列{}n b 是“()M q 数列” (10)分方法二:同方法一得1132n n b b +=-对n N *∈恒成立, 则21132n n b b ++=-,两式作差得2113()n n n n b b b b +++-=-,而21302b b -=≠, ∴10n n b b +-≠,∴2113n n n nb b b b +++-=-,以下同方法一. ……………………………………10分(3)由数列{}n b 是“()2M 数列”得1121()2n n n b b b b -+-=-⨯,又32212b b b b -=-,∴22721b b -=-,∴23b =,∴212b b -=,∴12n n n b b +-=,∴当2n ≥时,112211()()()n n n n n b b b b b b b b ---=-+-++-+L12222121n n n --=++++=-L ,当1n =时上式也成立,故21nn b =-, (12)分假设存在正整数,m n 使得4039404020192019m n b b <<,则40392140402019212019m n -<<-, 由2140391212019m n->>-可知2121m n ->-,∴m n >,又,m n 为正整数,∴1m n -≥,又212(21)2121404022121212019m m n n m n m n m n n nn ------+--==+<---, ∴4040232019m n-<<,∴1m n -=,∴21122121m n n -=+--,∴40391404022019212019n <+<-, ∴2020222021<<n ,∴10n =,∴11m =,故存在满足条件的正整数,m n ,11m =,10n =. ……………………………………16分20.解:(1)由函数)(x f 为奇函数,得0)()(=-+x f x f 在定义域上恒成立, 所以 0=+-+----mx ae e mx ae e x x x x ,化简可得 0)()1(=+⋅--xxe e a ,所以1=a . (3)分(2)法一:由(1)可得mx ee xf xx--=-)(,所以xx x xxeme e m e e x f 1)(2+-=-+='-, 其中当2≤m 时,由于012≥+-x x me e 恒成立,即0)(≥'x f 恒成立,故不存在极小值. (5)分当2>m 时,方程012=+-mt t 有两个不等的正根)(,2121t t t t <, 故可知函数mx ee xf xx--=-)(在),(ln ),ln ,(21+∞-∞t t 上单调递增,在)ln ,(ln 21t t 上单调递减,即在2ln t 处取到极小值,所以,m 的取值范围是),2(+∞. (9)分法二:由(1)可得mx e e x f xx --=-)(,令m ee xf xg xx-+='=-)()(,则xx xxee e e x g 1)(2-=-='-, 故当0≥x 时,0)(≥'x g ;当0<x 时,0)(<'x g , (5)分故)(x g 在)0,(-∞上递减,在),0(+∞上递增, ∴m g x g -==2)0()(min ,若02≥-m ,则0)(≥x g 恒成立,)(x f 单调递增,无极值点;所以02)0(<-=m g ,解得2>m ,取m t ln =,则01)(>=mt g , 又函数)(x g 的图象在区间],0[t 上连续不间断,故由函数零点存在性定理知在区间),0(t 上,存在0x 为函数)(x g 的零点,)(0x f 为)(x f 极小值.所以,m 的取值范围是),2(+∞. ………………………………………………9分(3)由0x 满足m e e x x =+-00, 代入mx ee xf xx--=-)(,消去m 可得00)1()1()(000x x e x e x x f -+--=,……………………………………11分构造函数xxex e x x h -+--=)1()1()(,所以)()(xxe e x x h -='-,当0≥x 时,012≤-=--xxxxee e e , 所以当0≥x 时,0)(≤'x h 恒成立,故h (x )在[0,+∞)上为单调减函数,其中eh 2)1(-=, ……13分则02()f x e≥-可转化为0()(1)h x h ≥, 故10≤x ,由m e e x x =+-00,设xx e e y -+=,可得当0≥x 时,0≥-='-xxee y ,x x e e y -+=在]1,0(上递增,故ee m 1+≤,综上,m 的取值范围是]1,2(ee + . (16)分附加题答案21.(A )解:设圆C 上一点(,)x y ,经矩阵M 变换后得到圆C '上一点(,)x y '',所以332a x x y y '⎡⎤⎡⎤⎡⎤=⎢⎥⎢⎥⎢⎥'-⎣⎦⎣⎦⎣⎦,所以332ax y x x y y '+=⎧⎨'-=⎩,………………………………………………………5分又圆22:13C x y '+=,所以圆C 的方程为22(3)(32)13ax y x y ++-=, 化简得222(9)(612)1313a x a xy y ++-+=,所以29136120a a ⎧+=⎨-=⎩,解得2a =. ………………………………………………………10分21.(B )解:以极点为原点,极轴为x 轴的正半轴(单位长度相同)建立平面直角坐标系, 由直线cos 2sin m ρθρθ+=,可得直角坐标方程为20x y m +-=,又曲线4sin ρθ=,所以24sin ρρθ=,其直角坐标方程为22(2)4x y +-=, ………………5分所以曲线4sin ρθ=是以(0,2)为圆心,2为半径的圆,为使直线被曲线(圆)截得的弦AB 最长,所以直线过圆心(0,2),于是0220m +⋅-=,解得4m =. ……………………………………………………10分21.(C )解:因1231a b c ++=,所以149123a b c++=, 由柯西不等式得214923(23)()(123)23a b c a b c a b c++=++++≥++,即2336a b c ++≥, …………………………………………………………………………………5分当且仅当1492323a b c a b c==,即a b c ==时取等号,解得6a b c ===,所以当且仅当6a b c ===时,23a b c ++取最小值36. ……………………………………10分22.解:(1)以CD ,AB ,1OO 所在直线建立如图所示空间直角坐标系O xyz -,由2CD =,13AA =,所以(0,1,0)A -,(0,1,0)B ,(1,0,0)C -,(1,0,0)D ,1(0,1,3)A -,1(0,1,3)B ,从而1(1,1,3)AC =--u u u u r ,1(1,1,3)B D =--u u u u r,所以117cos ,11AC B D <>==u u u u r u u u u r , 所以异面直线1A C与1B D所成角的余弦值为711. …………………………………………4分 (2)设10AA m =>,则1(0,1,)A m -,1(0,1,)B m ,所以1(1,1,)AC m =--u u u u r ,1(1,1,)B D m =--u u u u r ,(2,0,0)CD =u u u r ,设平面1A CD 的一个法向量1111(,,)n x y z =u u r,所以1111111200n CD x n A C x y mz ⎧⋅==⎪⎨⋅=-+-=⎪⎩u u r u u u r u u r u u u u r, 所以10x =,令11z =,则1y m =,所以平面1A CD 的一个法向量1(0,,1)n m =u u r,同理可得平面1B CD 的一个法向量2(0,,1)n m =-u u r,因为二面角11A CD B --的大小为3π,所以121cos ,2n n <>=u u r u u r ,解得m =3m =, 由图形可知当二面角11A CDB --的大小为3π时,m . …………………………………10分注:用传统方法也可,请参照评分.23.解:(1)令1=x 得01220n a a a a ++++=L ,令1-=x 得12201232123333(91)2nn n n a a a a a a --+-+-+=+++=-L L , 两式相加得024232()(91)2nn a a a a ++++=-L ,∴3(91)4n n S =-.…………………………………3分(2)123123(1)n nn n n n n n T S C S C S C S C =-+-++-L{}1122331233[999(1)9][(1)]4n n n n nn n n n n n n n C C C C C C C C =-+-++---+-++-L L {}0011223301233[9999(1)9][(1)]4n n n n n n n n n n n n n n n C C C C C C C C C C =-+-++---+-++-L L 001122333[9999(1)9]4n n n n n n n n C C C C C =-+-++-L 0011223[(9)(9)(9)(9)]4n n n n n n C C C C =-+-+-++-L 33[1(9)](8)44n n =+-=⨯-…………………………………………………………………………………7分 要证3||6n T n ≥,即证384n ⨯36n ≥,只需证明138n n -≥,即证12n n -≥,当1,2n =时,12n n -≥显然成立;当3n ≥时,1011011111121(1)n n n n n n n C C C C C n n -------=+++≥+=+-=L ,即12n n -≥,∴12n n -≥对*n N ∈恒成立.综上,3||6n T n ≥恒成立.……………………………………………………………………………………10分 注:用数学归纳法或数列的单调性也可证明12n n -≥恒成立,请参照评分.。
2020年江苏省南京市、盐城市联考高考英语一模试卷解析版
高考英语一模试卷题号I II III IV V总分得分一、单项选择题(本大题共15 小题,共 15.0 分)1. The power of silence is much greater compared with ______ of instant attack .()A. itB. oneC. thatD. the one2.Within a personalized learning program , the learners' pathway can be _____ to theirneeds.()A. ExposedB. tailoredC. resignedD. limited3.--The price of the house advertised is rather reasonable , and I fancy it much--Let's be _____ we just can't afford to pay that much money .()A. optimisticB. realisticC. enthusiasticD. systematic4.--It's said that your company _____ in the project in the years ahead , right ?--Well , we are conducting a comprehensive evaluation of it .()A. investsB. investedC. will investD. would invest5.E-cigarette companies are ordered to close their stores and _____ ads online for the sakeof young people .()A. bring aboutB. put upC. take downD. hold out6.We should be aware that the degree ______ our diet is successful depends on ourwillpower .()A. thatB. whichC. to whichD. on whom7. ---Did you enjoy yourself in watching the film Frozen II last night ?---You bet! I ______ it for 6 years .()A. was to anticipateB. have been anticipatingC. was anticipatingD. had been anticipating8. Guizhou Province , _____ by Lonely Planet among the top 10 regions to visit in 2020 ,has become a promising travel destination .()A. rankedB. being rankedC. having rankedD. to be ranked9._____ I once made some mistakes, I won't spend a moment of the future regretting whatmight have been.()A. UntilB. WhileC. UnlessD. Because10. The ride sharing service is only a trial in limited regions , and will continue to improve______ feedback from the public .()A. in line withB. in contrast withC. in control ofD. in favor of11. With more importance attached to traditional culture these years , hanfu has become______ popular .()A. merelyB. entirelyC. frequentlyD. increasingly12. Examples has more followers than reason in that we unconsciously imitate _____ pleasesus.()A. thatB. whatC. whichD. who13. The project ______ possible had the relations of the two countries not reached theircurrent level .()A. weren'tB. weren't to beC. shouldn't beD. wouldn't have been14.We have been informed of the strict rules _____ for garbage sorting in the nearfuture.()A. adoptedB. to adoptC. to be adoptedD. having adopted15. --Do you think it's possible for the team to hit their target for fourth quarter?--_____! The majority of them are not that enterprising.()A. No doubtB. No problemC. Not a littleD. Not a chance二、阅读理解(本大题共15 小题,共30.0 分)ATwin Cities Campus ? Office of Admissions240 Williamson Hall ? 231 Pillsbury Drive SE , Minneapolis , MN 55455Dear Blair Connie ,Congratulations! You have been admitted to the University of Minnesota(U of M)Twin Cities . Your college of admission is the College of Science and Engineering.We believe your accomplishments have prepared you well to thrive here.When you step on campus as a Golden Gopher, you will be involved in our world-class academic programs and will shape your future in cutting-edge facilities .Choose a community bursting with Gopher pride . By choosing the U of M , you choose to work with classmates and professors who are "Driven to Discover ." When you choose the U of M , you will■Discover exceptional academics. With thousands of courses to pick from each semester ,you can engage with professors who are leaders in their fields and make meaningful connections with your fellow students in our technology-packed active learning classrooms .■Discover unique opportunities. At the U of M , your college experience goes beyond the classroom. Your knowledge and talents can shine in one of our 900+ student organizations .■Discover an ideal location. Campus is in the center of Minneapolis and St . Paul, whereyou can work as trainees at one of the 18 Fortune 500 companies or thousands of startupsand nonprofits in the Twin Cities .■Discover great value. The U of M is committed to four-year graduation , which lowers your costs and gets you an internationally recognized degree sooner . The University has been named "best value" by Forbes , Princeton Review , and Kiplinger's .On behalf of the U of M , we are honored to have you join our academic community . In the coming weeks you will receive additional information about your next steps to becoming a U of M student . Welcome to the Class of 2024!SincerelyHeidi MeyerExecutive Director of Admissions16. What does the underlined phrase "a Golden Gopher" refer to ? ______A. A freshman.B. A professor.C. An amateur.D. An inspector.17. Which of the following is the benefit of choosing the U of M ? ______A. The university invites leaders in different fields to teach on campus .B. There are numerous clubs which offer students various activities.C. It is so ideally located that you have easy access to famous top brands.D. Many magazines rank it among the top universities with high tuition .BYou are standing in a hall packed with friends , family , colleagues and peers. You are about to walk onto the stage and address theme. You're expected to say something meaningful and profound and everyone is hanging on your every word . You need to be clearly spoken , confident and calm , maybe even funny. How do you feel ?If you're shaking , sweating and looking for the exit , you're normal . Most of us are scared of public speaking and yet , as a society, we're becoming more obsessed with hearing what people have to say: we watch endless TED talks , download podcasts and screen hours of YouTube clips . Being able to address a crowd is no longer the domain of the brave----if you want to get ahead in your career, you need to master it. I've done enough public speaking to have picked up some tips and tricks , and these are the ones I rely on most.The most important thing is to prepare . You don't have to write out your speech word by word but get the headline, three key points and the concluding sentence on paper and put bullet points under each . Then run through it and note which of your bullet points made it in and what you added . Adapt your notes and try again . Keep going until you have a structure . Now it's time to watch yourself----yes , get out your camera and filmyourself . This is how you will see the points that need work and where you can polish it up .Most of the information the audience will take away will be from your energy and your tone , a little from your words . Once you have sorted out the words, focus on how to exude (发散)the right energy---do you need confidence or humor ? I go for confidence so , five minutes before a talk , I try to recall a success I've had. I focus on the details and aim to bring that feelings of competence to life .Finally , breathe, We cannot speak without breath, yet it is the first thing we let go of when we are nervous. Settle your breathing before you start . If you lose control of your breath in the middle , say "Let's take a moment to think about that last point . " That gives you a pause to collect your breath . The only way to get over a fear of public speaking is to do it , again and again. You will have good and bad experiences but, if you do it enough , you'll realize that , occasionally , it's fun .18.According to the author , why is public speech important to the average ? ______A.Friendships can be established through it .B.Public speeches can display our courage.C.There are more occasions for pubic speeches.D.It is beneficial to our way up the career ladder .19. Which of the following tips is recommended by the author?______A. Preparing and writing down every detail.B. Displaying right energy during the speech.C. Watching famous films of public speeches.D. Telling key points and bullet points apart.20.What view does the author hold about public speaking ? ______A.It creates more and more fun if we stick to practice .B.It is easier to practise at home than to perform outside .C.Experiences of public speaking can delight us sometimes .D. Attempts to give public speaking tend to fail in the end.CThrowing handfuls of bread to birds has long been seen as harmless enough . But in recent years, some scientists have suggested that bread might not do birds' digestive systems any good , saying that as uneaten food rots down, the water quality worsens and algal blooms can occur. Plus , by encouraging birds to gather in one place , the build-up of droppings may result in outbreaks of disease too. Meanwhile , many cities have signs telling us not to feed pigeons and gulls , which are considered an "annoyance" due to the mess they make ,and scattering bread inevitably attracts rats and mice .It seems that the public has accepted these warnings, and that fewer of us now feed birds this way. In October , a sign went up in a Derbyshire park claiming that the local birds were dying of starvation , and urging visitors to feed them as before. When online posts about the notice went viral , feathers flew as people debated the benefits of handing out bread to birds .Paul Stancliffe of the British Trust for Ornithology ( BTO ) points out that there's insufficient scientific evidence for bread harming birds , adding that , as little research has been done,it could even turn out to be beneficial .① "We just don't know ," he says. Although bread is a heavily processed "unnatural" food intended for humans , that alone may be insufficient grounds for not feeding it to birds .In the 1980s, the Wildfowl & Wetland Trust ( WWT ) carried out a comparative study of different flocks of mute swans , and the birds that consumed the most bread had weaker muscles, implying that a bread-heavy diet might be the cause. "Our official line is that bread is okay for ducks , geese and swans, but only in moderation , " says WWT's PeterMorris . "However , this advice comes with several other warnings . " ② The first is that it's best offered in winter , when there is less plant and insect food around .d In spring and summer, too much artificial food may not be a good idea , since young birds have to learn how to look after themselves and natural food will contain a wider range of nutrients to help them grow ."Just like us , birds need a varied diet to stay healthy , " says a spokesperson for the Royal Society for the Protection of Birds ( RSPB). "Although ducks , geese and swans can digest all types of bread , too much can leave them feeling full without giving them all of the important vitamins , minerals and nutrients they need ." ③When bird feeding first became popular in the UK in the 19th century , some Victorians encouraged tough love , arguing that such handouts would only make our feathered friends lazy and dependent on welfare .④ Morris says that there is a theory that wild birds can get "hooked" on easy meals, losing interest in other types of food . Another danger , he says,is that birds fed regularly end up accustomed to humans, placing themselves at greater risk of predation (捕食).21. How can feeding birds with bread affect our urban life?______A.Birds' mess can attract many rats and mice .B.Birds' gathering in one place disturbs our peace .C.Bread goes bad and the water quality will suffer .D. Human beings are likely to be infected with bird flu.22. If birds rely on a bread-heavy diet , there is a strong possibility that ______.A.they will become bigger in size with stronger musclesck of certain nutrients negatively influences their healthC.their digestive system will be damaged by artificial foodD.they would soon choose bread rather than natural food .23.Where does the sentence "Such moralizing sounds old-fashioned nowadays , but mayhave a grain of truth ." best suit ? ______A.①B.②C.③D.④24. What is the best title for this passage ? ______A.Is feeding birds a wise choice ?B.Why not feed our bird neighbours ?C.Can we treat birds as friends ?D.When do birds need our food aid ?DDespite all the ways we have to interact with others , people still feel isolated andlone. Loneliness is an increasing problem----so much so that , last year, the government introduced a loneliness strategy and minister for loneliness . We used to talk of the condition in relation to older people but rarely gender . It may come as a surprise then that so many of those affected by loneliness are men .A recent YouGov survey for Movember , a charity event that raises awareness of men's health issues, asked men about their friendships and whether they had people outside their homes they could swap their worries with . Half of men asked said they had two or fewer friends and one in eight had none---that's 2.5 million men with no close friends . Even worse, men's friendlessness doubles between their early 20s and late middle age .Isolation can have physical and mental health implications . A 2017 report by the Commission on Loneliness said loneliness is as harmful to health as smoking 15 cigarettes a day. Research shows correlation between loneliness and heart disease and strokes, and other studies associate loneliness with depression. However , why are so many men affected ? In our latest podcast,psychotherapist Noel Bell says some men feel they have to be self-reliant.Due to widespread social stereotypes(刻板印象), it can be viewed as a sign of weakness for men to admit they have a problem , express their deepest feelings or discuss a serious personal topic .Perhaps due to the way generations of men have been raised, it is often difficult to recognize feelings of loneliness in the first place . Behavioural differences between boys and girls arenot naturally born at birth , they are socialised. Girls are stereotypically seen as more emotional and talkative and so their communicative and expressive skills are more valued than those of boys by parents and teachers, according to researchers.For some men, having a partner and a family can somewhat shelter them from the negative effects of loneliness---but what if their personal circumstances change ? After a relationship breaks down or there is a loss of you beloved , some men find their friends have drifted away and they have no one to talk to. Social media can be beneficial if it leads to interaction in the real world , but online networks are no substitute for face-to-face friendships---the number of likes on your most recent post does not compare with genuine connection .Social activities such as team sports aren't for everyone and, if you're already feeling lonely or isolated, it can be difficult to build the confidence to enter those environments and connect over a shared interest. There is also the danger that some male-dominated social environments encourage drinking alcohol and may not be the right places for those who are feeling the mental health effects of isolation .That said,"shoulder to shoulder' active interactions for men ,such as exercise, especially running , are proven to be beneficial . But such activities do not interest all men and this is where psychotherapy (心理疗法) can be of particular use.Don't suffer in silence . A psychotherapist is not a friend , nor is therapy a substitute for a meaningful friendship . A therapist will , however, help a client identify what may be creating barriers to them building supportive friendships and determine the factors that may be causing their feelings of isolation . A therapist will work with the client to address their issues ,providing a fair , non-judgemental space in which a lonely person can work out what is best for them and how to move towards a more connected and contented life . Bell , a famous therapist, says too many men enter therapy only when a situation has reached crisis point and he encourages men not to bottle up their emotions. "Reflecting on your feelings is healthy and normal , " he says.25. Who used to be the prime victims of loneliness ? ______A. Junior students.B. Isolated ministers.C. Mature men.D. Senior citizens.26.What does the survey done by YouGov imply ? ______A.Men tend to expand their social circle after their adolescence .B.Young and middle-aged male adults suffer more from loneliness .C.Loneliness remains at the same level despite different ages .D.Deep friendships are difficult to maintain between the males .27.According to the Nobel Bell , men's loneliness is relevant to ______ .A.the fear of dying of heart disease and strokesB.the depression popular among men of all agesC.the conventional view on how men should behaveD.their reliance on outside assistance through hardships28. In terms of social stereotypes , girls are better at ______ .A.gaining sympathy from menB.hiding their true emotionsC.disciplining their own behaviorD.interacting with other people29.Why does the author mention social media in Paragraph 5 ? ______A.To stress the importance of real interaction to men .B.To introduce a possible way out of loneliness for men .C.To contradict the belief that men feel lonely onlineD.To illustrate how social media can relieve depression .30.When might a psychotherapist be of particular use ? ______A.When there is no substitute for the current therapy .B. Not until a man is fully conscious of the crisis point?C. When active interactions fail to attract a lonely man.D. After a man is excluded from a team of common interests.三、完形填空(本大题共20 小题,共20.0 分)When I was a child my father taught me five words that I've used all my life----in my acting career, as a mother, in my business activities . If I (31)that I was afraid of the dark , or if I seemed worried about meeting new people , Dad would say , "Stand porter to your(32) . "A porter is a gatekeeper , who stands at a door (33)people in or out . Dad would get meto(34)myself stopping destructive things ---such as fear---at the door , (35)saying "Come in"to faith , love and self-assurance.As a( n) (36), before I went on camera, I'd make sure anxiety stayed out and confidence in my ability came in . As a mother, when I was(37)about my children , I would try not tolet worry in but would (38)my mind with trust in them.Of course , there were always times I'd (39)those words .In 1972 my husband , Fillmore Crank , and I opened the doors to our own(40)in North Hollywood . This was a new business venture for us , and it was a lot more(41)and complicated than we had(42) .We were on call 24 hours a day . Something was always going(43) . Electricity went on the blink , food wasn't delivered , employees called in sick. Once, a flu epidemic(44)left us with no maids .Fillmore gave me a(45) :scrub floors or do the laundry .For 10 days I folded enough king-size sheets to(46)the whole state of California .Then there was the(47)crisis . The price of gasoline doubled , and tourism inCalifornia(48) . How could we fill our beds ? What if we kept losing money ? What if we failed ? Fear and worry were sneaking in . But I caught them just(49) . I stood porter . I stood in the door of my mind and sent fear packing .These days at the hotel,whenever fear tries to(50), I just smile and point to the sign that reads No Vacancy .31. A. complained B. announced C. recalled D. decided32. A. future B. find C. family D. studio33. A. letting B. urging C. inviting D. observing34. A. busy B. involve C. send D. picture35. A. so B. and C. but D. or36. A. official B. actress C. maid D. manager37. A. serious B. curious C. anxious D. cautious38. A. fill B. change C. read D. ease39. A. eat B. twist C. exchange D. forget40. A. clinic B. hotel C. laundry D. restaurant41. A. promising B. demanding C. convincing D. boring42. A. figured B. confirmed C. deduced D. suggested43. A. sour B. missing C. wrong D. pale44. A. hardly B. regularly C. specially D. suddenly45. A. warning B. command C. choice D. solution46. A. serve B. touch C. decorate D. blanket47. A. credit B. energy C. identity D. family48. A. ceased B. recovered C. dropped D. boomed49. A. in time B. on purpose C. at random D. by chance50. A. split B. shelter C. withdraw D. register四、任务型阅读(本大题共 1 小题,共10.0 分)51.This is a stranger truth that anyone older than 25 will already know : as life goes on, timeseems to speed up. Think back to childhood when holidays seemed to last forever andyou attended a school for what felt like decades . Now consider last year , by contrast,and it probably raced by. As those in their 30s and 40s will know , the effect gets worse with age---and , for people in their 70s , a year can flash by in what seems likedays. "Where did the time go ? " we wonder .One study found that if you're 40 , assuming you live to be 80 , your life , in terms ofyour subjective experience of time , is already 70 percent gone . It's all ratherterrifying . Fortunately , though , you have the power to change things .The best explanation is that memories seem longer when our brains have to process more information . Childhood and young adulthood are full of novelty---the first time you rode a bike , had a romance , go job---but , as we get older , things get more routine . You can test this out by recalling a recent experience of novelty in your life , such as travel . A few years back , I went skiing for the first time , and that four-day trip still feels"long" . But a four-day period in my ordinary life zooms by too quickly for me to notice .One solution , then , is obvious : do lots of new stuff . Travel more , if you can , andto unfamiliar places . Try new hobbies and meet new people---you'll be taxing your brain , and the result will be a life that feels longer , more expansive andmeaningful . But smaller changes work , too : even altering the route you take to the office , reading different kinds of novels or varying where you buy your sandwich at lunchtime will have some impact .But novelty can only go so far .Besides ,a fulfilling life requires routine :you can't build deep relationships , or rise through the ranks at work if you're always switching friends or jobs or even spouses . That's why the Buddhist teacher Shinzen Young suggests an additional strategy : learn to meditate (冥想). Even a few minutes a day will enhance your concentration , and the better you get at concentrating , the more information your brain will take in during any experience , no matter how boring .You'll be making your whole life a little more novel .You'll be more present and time will pass less quickly ; in effect , you'll extend your life----without magic pills or groundbreaking medical technology .Title : How to stop time speeding up Passage outlineSupporting details● Everything seemed to last longer in our childhood ,A truth familiar to ()(2)______ holidays .1______( ) ,the worsening effect● With people 3 ______.makes them believe time goes faster and fasterFindings of a previous There exists an explicit gap between our real age and studyour ().74 ______ understanding of how old we are( 5) ______ something fresh can make ourThe best explanationmemories last .● Doing new stuff ( 7) ______ much effort ofour brain ,causing a seeminglylonger and moremeaningful life .● Making minor changes is also an (8) ______ way to create longer feelings .● Meditation helps people concentrate on routine and ( 9)______ more information from boring experiences .Even without medication , people can live a more novelConclusion五、书面表达(本大题共Two possible (6) ______ on handling the problem1 小题,共25.0 分)第8页,共 19页52.请认真阅读下文信息,并按要求用英语写一篇150 词左右的文章.A new regulation by China's Ministry of Education aims to grant primary and middleschool teachers more room in punishing their students in order to achieve betterteaching results.The regulation lists punishments available to teachers in three categories based on the level of severity of the offense , including naming and shaming , forced standing that lasts no longer than one class session, and suspension of class for no longer than one week.Zhang Lifeng ,a 43-year-old parent,welcomed the move ."The regulation should have come earlier," she said."It will benefit both teachers and students as well as parents." However , a ninth grader at a middle school , disagreed. "It is normal for adolescent students to make mistakes. I don't think punishments are necessary . They may cause more trouble ," he said.Chen Xianzhe , a professor with the School of Education at South China NormalUniversity , said punishments are just a part of the teaching process.The regulation asks schools to draft their own regulations accordingly to clarify therules for teachers in taking disciplinary actions against their students .【写作内容】1、用约 30 个单词归纳上述信息的主要内容;2、说说你如何对待教育惩戒,并简述原由;3、请你对教育惩戒规则的实行提出合理建议(起码两点).【写作要求】1、写作过程中不可以直接引用原文语句;2、作文中不可以出现真切姓名和学校名称;3、不用写标题.【评分标准】内容完好,语言规范,语篇连结,词数适合答案和分析1.【答案】C【分析】答案: C 观察指示代词. it 取代前面的事物自己,它能够取代可数名词,也能够取代不行数名词; one 能够取代与前面同类不一样一的事物,能够取代某类事物中的任何一个,往常代指可数名词;that 取代与前面同类不一样一的事物,表特指,相当于the+ 名词,能够取代可数名词,也能够取代不行数名词.the one 指代上文的单数可数名词,指 "同类的那 /这一个 " ,表示特指的含义,即 the+单数可数名词.本句中所填代词代指前面不行数名词 power,依据后边修饰词可知,是同类不一样一的事物,所以选择指示代词that.应选: C.与即时攻击对比,缄默的力量要大得多.此题观察指示代词.在理解句意的基础上弄清楚各个代词的含义及用法,而后依据题意选择最切合题意的答案.2.【答案】B【分析】答案: B.观察动词辨析.句意:在个性化的学习计划中,学习者的路径能够依据他们的需要进行调整. A 裸露; B 量身定做; C 离职; D 限制.所以 B 选项切合句意.应选: B.在个性化的学习计划中,学习者的路径能够依据他们的需要进行调整.此题观察动词的词义辨析.动词词义题向来都是高考观察的一个热门,它侧重观察考生联合语境正确采纳词语和正确时态语态的的能力和.因为英语词汇丰富,且用法多变,考生掌握起来有较大难度,所以在平常应注意词汇的累积,理解词语的含义及其常有的习惯搭配,再联系句子所表述的意义和语境,选出正确的答案.3.【答案】B【分析】答案:.观察形容词辨析.句意:--广告上说的房屋价钱相当合理,我特别喜欢 --脚踏实地地说,我们付不起那么多钱. A 乐观的; B 脚踏实地的; C 热忱的; D 系统的.所以 B 选项切合句意.应选: B.--广告上说的房屋价钱相当合理,我特别喜爱--脚踏实地地说,我们付不起那么多钱.此题观察形容词的词义辨析.形容词词义辨析题向来都是高考观察的一个热门,它侧重观察考生联合语境正确采纳词语的能力.因为英语词汇丰富,且用法多变,考生掌握起来有较大难度,所以在平常应注意词汇的累积,理解词语的含义及其常有的习惯搭配,再联系句子所表述的意义和语境,选出正确的答案.4.【答案】C【分析】答案: C.观察时态.句意:听闻你们企业将在此后几年投资这个项目,对吗-- 我们正在对它进行全面评估.依据时间状语in the years ahead,可知本句用未来时,所以 C 选项切合.应选: C.听闻你们企业将在此后几年投资这个项目,对吗?--我们正在对它进行全面评估.高考题目对时态的观察是重点,谓语动词要与时间状语保持一致,时态与时间是密不行分的,各样时态却要遇到时间和语言环境的限制,依据题干供给的时间或许时间状语体现的时间来判断句子的时态是最直接的解题方法,扎实的语法功底加上正确的理解至关重要.5.【答案】C【分析】观察动词短语.bring about 致使;惹起;put up 建筑;搭起;张贴;为安排住所; take down(从高处)取下,拿下,够下来;拆掉;拆毁;写下; hold out 伸出(手等);(对)隐瞒信息.句意:为了年青人的利益,电子香烟企业被迫令封闭商铺并在网上撤下广告.应选: C.为了年青人的利益,电子香烟企业被迫令封闭商铺并在网上撤下广告.此题观察动词短语.在高中的学习中平常要多累积动词及动词固定搭配的用法,考试时只好依靠记忆力来答题,特别是单项选择很难推出某个搭配的意思,所以平常的累积记忆是特别重要的.6.【答案】C【分析】答案: C, " 抵达某种程度"翻译为 to some degree,先行词为degree,在定语从句中做介词to 的宾语,所以用which 指引.应选: C.我们应当意识到,我们的饮食成功的程度取决于我们的意志力.做定语从句题时:我们可先将不是关系代词或关系副词的选项去掉,而后采纳" 代入原则 "并同时联合定语从句的关系词之间的有关差别来进行解题.所谓" 代入原则 " 就是试着把先行词即被定语从句修饰限制的那个词放进从句中,能直接代入的就用关系代词(不包含 whose),不可以直接代入的可能有三种状况,要么用关系副词,要么用介词加关系代词 which 或 whom ,要么就用关系代词 whose.7.【答案】D【分析】答案: D.观察时态.句意:-- 你昨晚看电影《冰冻2》玩得高兴吗 --- 自然!我已经期望了 6 年了.依据句意判断到昨天夜晚为止向来在在期望这部电影,所以应当用过去达成进行时.切合过去达成进行时的定义.应选: D.--你昨晚看电影《冰冻 2》玩得高兴吗?---自然!我已经期望了 6 年了.高考题目对时态的观察是重点,谓语动词要与时间状语保持一致,时态与时间是密不行分的,各样时态却要遇到时间和语言环境的限制,依据题干供给的时间或许时间状语体现的时间来判断句子的时态是最直接的解题方法,扎实的语法功底加上正确的理解至关重要.8.【答案】A【分析】答案: A ,观察过去分词,rank 和它所修饰的名词Guizhou Province 之间是被动关系,所以用过去分词作后置定语.应选: A.贵州省被《孤单星球》评为 2020 年十大旅行目的地之一,已成为一个很有发展前程的旅行目的地.分词作定语要看和它修饰的词的关系,主动用此刻分词,被动用过去分词.分词作宾补要看和宾语的词的关系,主动用此刻分词,被动用过去分词.9.【答案】B。
