题组训练三

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高考数学总复习提素能高效题组训练3-3

高考数学总复习提素能高效题组训练3-3

[命题报告·教师用书独具]1.已知函数f (x )=sin x 在区间[a ,b ]上是增函数,且f (a )=-1,f (b )=1,则cos a +b2的值为( )A .0 B.22 C .1D .-1解析:因为由题易知[a ,b ]=⎣⎢⎡⎦⎥⎤2k π-π2,2k π+π2(k ∈Z ),所以cos a +b 2=cos2k π=1.答案:C2.(2013年蓬莱模拟)已知函数y =2sin(ωx +θ)为偶函数(0<θ<π),其图象与直线y =2的交点的横坐标为x 1,x 2,若|x 1-x 2|的最小值为π,则( )A.ω=2,θ=π2 B .ω=12,θ=π2 C .ω=12,θ=π4D .ω=2,θ=π4解析:y =2sin(ωx +θ)为偶函数且0<θ<π,则y =2cos ωx ,θ=π2,所以y =2cos ωx ,y ∈[-2,2].故y =2与y =2cos ωx 的交点为最高点,于是最小正周期为π.所以2πω=π,所以ω=2,故选A. 答案:A3.(2013年惠州模拟)函数y =log 12(cos x )的一个单调递减区间是( ) A .(-π,0) B .(0,π) C.⎝ ⎛⎭⎪⎫0,π2 D.⎝ ⎛⎭⎪⎫-π2,0 解析:由题易知cos x >0,当函数μ=cos x 为增函数时,函数y =log 12(cos x )为减函数,则函数y =log 12(cos x )的单调递减区间为⎝ ⎛⎦⎥⎤-π2+2k π,2k π(k ∈Z ),结合选项可知选D.答案:D4.M ,N 是曲线y =πsin x 与曲线y =πcos x 的两个不同的交点,则|MN |的最小值为( )A .π B.2π C.3πD .2π解析:本题是三角函数的最值问题.两函数的图象如图所示,则图中|MN |最小,设M (x 1,y 1),N (x 2,y 2),则x 1=π4,x 2=54π,|x 1-x 2|=π,|y 1-y 2|=|πsin x 1-πcos x 2|=22π+22π=2π,∴|MN |=π2+2π2= 3π.选C.答案:C5.(2013年北京海淀模拟)已知函数f (x )=cos 2x +sin x ,那么下列命题中是假命题的是( )A .f (x )既不是奇函数也不是偶函数B .f (x )在[-π,0]上恰有一个零点C .f (x )是周期函数D .f (x )在⎝ ⎛⎭⎪⎫π2,56π上是增函数解析:∵f ⎝ ⎛⎭⎪⎫π2=1,f ⎝ ⎛⎭⎪⎫-π2=-1,即f (-x )≠f (x ),∴f (x )不是偶函数.∵x ∈R ,f (0)=1≠0,∴f (x )不是奇函数,故A 为真命题;令f (x )=cos 2x +sin x =1-sin 2x +sin x =0,则sin 2x -sin x -1=0,解得sin x =1±52,当x ∈[-π,0]时,sin x =1-52,由正弦函数图象可知函数f (x )在[-π,0]上有两个零点,故B 为假命题;∵f (x )=f (x +2π),∴T =2π,故函数f (x )为周期函数,C 为真命题;∵f ′(x )=2cos x ·(-sin x )+cos x =cos x ·(1-2sin x ),当x ∈⎝ ⎛⎭⎪⎫π2,5π6时,cos x <0,12<sin x <1,∴f ′(x )=cos x ·(1-2sin x )>0,∴f (x )在⎝ ⎛⎭⎪⎫π2,56π上是增函数,D 为真命题.故选B.答案:B 二、填空题6.已知f (n )=sin n π3(n ∈N *),则f (1)+f (2)+…+f (2 012)=________. 解析:由题意知f (1)=sin π3=32,f (2)=sin 2π3=32,f (3)=sin π=0,f (4)=sin 4π3=-32,f (5)=sin 5π3=-32,f (6)=sin 2π=0,f (7)=sin 7π3=sin π3=32…由此可得函数f (n )的周期T =6,所以f (1)+f (2)+…+f (2 012)=335×[f (1)+f (2)+…+f (6)]+f (2 011)+f (2 012)=f (1)+f (2)= 3.答案: 37.函数f (x )=sin πx +cos πx +|sin πx -cos πx |对任意的x ∈R 都有f (x 1)≤f (x )≤f (x 2)成立,则|x 2-x 1|的最小值为________.解析:依题意得,当sin πx ≥cos πx 时,f (x )=2sin πx ;当sin πx <cos πx 时,f (x )=2cos πx .由已知可知f (x 1),f (x 2)分别是函数f (x )的最小值与最大值,结合函数y =f (x )的图象可知,|x 2-x 1|的最小值是34.答案:348.已知直线y =b (b >0)与曲线f (x )=sin x 在y 轴右侧依次的三个交点的横坐标x 1,x 2,x 3成等比数列,则b 的值为________.解析:依题意得,x 2=π-x 1,x 3=2π+x 1,∵x 22=x 3x 1,∴(π-x 1)2=x 1·(2π+x 1),解得x 1=π4,∴b =sin π4=22.答案:229.(2013年苏州模拟)有一种波,其波形为函数y =sin ⎝ ⎛⎭⎪⎫π2x 的图象,若在区间[0,t ]上至少有两个波峰(图象的最高点),则正数t 的最小值是________.解析:设函数的周期为T ,则由题意知54T ≤t ,即54×2ππ2≤t ,解得t ≥5.答案:5 三、解答题10.函数f (x )=cos x +2|cos x |在[0,2π]上与直线y =m 有且仅有2个交点,求m 的取值范围.解析:f (x )=⎩⎪⎨⎪⎧3cos x ,x ∈⎣⎢⎡⎦⎥⎤0,π2∪⎣⎢⎡⎦⎥⎤32π,2π,-cos x ,x ∈⎝ ⎛⎭⎪⎫π2,32π,如图:由图可知:当m =0或1<m ≤3时,直线y =m 与f (x )的图象有且仅有2个交点.11.设函数f (x )=sin(2x +φ)(-π<φ<0),y =f (x )的图象的一条对称轴是直线x =π8.(1)求φ;(2)求函数y =f (x )的单调递增区间.解析:(1)∵x =π8是函数y =f (x )的图象的对称轴, ∴sin ⎝ ⎛⎭⎪⎫2×π8+φ=±1.∴π4+φ=k π+π2,k ∈Z .∴φ=k π+π4,k ∈Z . 又∵-π<φ<0,∴φ=-3π4. (2)由(1)知y =sin ⎝ ⎛⎭⎪⎫2x -3π4,由题意得2k π-π2≤2x -3π4≤2k π+π2,k ∈Z , ∴k π+π8≤x ≤k π+5π8,k ∈Z .∴函数y =sin ⎝ ⎛⎭⎪⎫2x -3π4的单调递增区间为⎣⎢⎡⎦⎥⎤k π+π8,k π+5π8,k ∈Z . 12.(能力提升)已知函数f (x )=3sin 2x +sin x cos x , x ∈⎣⎢⎡⎦⎥⎤π2,π (1)求f (x )的零点;(2)求f (x )的最大值和最小值.解析:(1)令f (x )=0,得sin x ·(3sin x +cos x )=0, 所以sin x =0或tan x =-33.由sin x =0,x ∈⎣⎢⎡⎦⎥⎤π2,π,得x =π;由tan x =-33,x ∈⎣⎢⎡⎦⎥⎤π2,π,得x =5π6.综上,函数f (x )的零点为5π6或π. (2)f (x )=32(1-cos 2x )+12sin 2x =sin ⎝ ⎛⎭⎪⎫2x -π3+32. 因为x ∈⎣⎢⎡⎦⎥⎤π2,π,所以2x -π3∈⎣⎢⎡⎦⎥⎤2π3,5π3.所以当2x -π3=2π3,即x =π2时,f (x )的最大值为3; 当2x -π3=3π2,即x =11π12时,f (x )的最小值为-1+32.[因材施教·学生备选练习]1.已知函数f (x )=A cos(ωx +φ)(A >0,ω>0,0<φ<π)为奇函数,该函数的部分图象如图所示,△EFG 是边长为2的等边三角形,则f (1)的值为( )A .-32 B .-62 C. 3D .- 3解析:因为函数f (x )=A cos(ωx +φ)(A >0,ω>0,0<φ<π)是奇函数,所以f (0)=A cos φ=0,解得φ=π2.因为△EFG 是边长为2的等边三角形,所以A =2×32=3,T2=2,即T =4,所以ω=2π4=π2,所以f (x )=-3sin π2x ,故f (1)=-3sin π2=- 3. 答案:D2.(2013年郑州模拟)已知曲线y =2sin ⎝ ⎛⎭⎪⎫x +π4·cos ⎝ ⎛⎭⎪⎫π4-x 与直线y =12相交,若在y 轴右侧的交点自左向右依次记为P 1,P 2,P 3,…,则|P 1P 5→|等于( )A .πB .2πC .3πD .4π解析:注意到y =2sin ⎝ ⎛⎭⎪⎫x +π4cos ⎝ ⎛⎭⎪⎫π4-x =2sin 2⎝ ⎛⎭⎪⎫x +π4=1-cos 2(x +π4)=1+sin2x ,又函数y =1+sin 2x 的最小正周期是2π2=π,结合函数y =1+sin 2x 的图象(如图所示)可知,|P 1P 5→|=2π,选B.答案:B3.(2013年保定摸底)在区间⎝ ⎛⎭⎪⎫-π2,π2上随机取一个数x ,则使得tan x ∈⎣⎢⎡⎦⎥⎤-33,3的概率为( ) A.13 B.2π C.12D.23解析:区间⎝ ⎛⎭⎪⎫-π2,π2的长度为π,当tan x ∈⎣⎢⎡⎦⎥⎤-33,3时,x 的取值范围是⎣⎢⎡⎦⎥⎤-π6,π3,区间长度为π2,故由几何概型的概率计算公式可得所求的概率为12.答案:C。

高中物理一案+题组训练_3.1 重力 基本相互作用 含答案

高中物理一案+题组训练_3.1 重力 基本相互作用 含答案

学案1重力基本相互作用[目标定位]1。

知道力的概念及矢量性,会作力的图示.2.了解重力产生的原因,会确定重力的大小和方向,理解重心的概念。

3。

了解自然界中四种基本相互作用.一、力和力的图示[问题设计]做一做以下实验,看看会发生什么现象,总结力有哪些作用效果.图1图2(1)小钢球在较光滑的玻璃板上做直线运动,在小钢球的正前方放一磁铁(如图1),小钢球靠近磁铁时;(2)在与小钢球运动方向垂直的位置放一块磁铁(如图2);(3)分别用手拉和压弹簧.答案(1)小钢球的速度越来越大;(2)小钢球的速度方向发生了变化;(3)用手拉弹簧,弹簧伸长;用手压弹簧,弹簧缩短.力的作用效果有:使物体的运动状态发生变化或使物体发生形变.[要点提炼]1.力的特性(1)力的物质性:力是物体间的相互作用,力不能脱离物体而独立存在.我们谈到一个力时,一定同时具有受力物体和施力物体.(2)力的相互性:力总是成对出现的.施力物体同时又是受力物体,受力物体同时又是施力物体.(3)矢量性:力不仅有大小而且有方向.2.力的作用效果:改变物体的运动状态或使物体发生形变.说明只要一个物体的速度变化了,不管是速度的大小还是速度的方向改变了,物体的运动状态就发生变化.3.力的表示方法(1)力的图示:用一条带箭头的线段(有向线段)来表示力.①线段的长短(严格按标度画)表示力的大小;②箭头指向表示力的方向;③箭尾(或箭头)常画在力的作用点上(在有些问题中为了方便,常把物体用一个点表示).注意(1)标度的选取应根据力的大小合理设计.一般情况下,线段应取2~5个整数段标度的长度.(2)画同一物体受到的不同力时要用同一标度.(2)力的示意图:用一条带箭头的线段表示力的方向和作用点.[延伸思考]是否只有接触的物体之间才有力的作用?举例说明.答案不是.例如:两个相距一定距离的同种电荷相互排斥,异种电荷相互吸引;同名磁极相互排斥,异名磁极相互吸引等.二、重力[问题设计]秋天到了,金黄的树叶离开枝头总是落向地面;高山流水,水总是由高处流向低处;无论你以多大的速度跳起,最终总会落到地面上……试解释产生上述现象的原因.答案地面附近的一切物体都受到地球的吸引作用.正是由于地球的吸引才会使物体落向地面,才会使水往低处流.[要点提炼]1.重力定义:由于地球的吸引而使物体受到的力,叫做重力.2.产生原因:重力是由于地球的吸引而使物体受到的力.但不能说成“重力就是地球对物体的吸引力".3.大小:G=mg,g为重力加速度,g=9.8 m/s2,同一地点,重力的大小与质量成正比,不同地点重力的大小因g值不同而不同.(注意:重力的大小与物体的运动状态无关,与物体是否受其他力无关)4.方向:重力的方向总是竖直向下的(竖直向下不是垂直于支撑面向下,也不是指向地心).5.作用点:在重心上.(1)重心是物体各部分所受重力的等效作用点.(2)重心位置与质量分布和物体形状有关,质量分布均匀、形状规则的物体的重心在物体的几何中心上.重心可以不在(填“可以不在”或“一定在”)物体上.一、对力的概念的理解例1下列关于力的说法中正确的是()A.甲用力把乙推倒,说明甲对乙有力的作用,乙对甲没有力的作用B.只有有生命或有动力的物体才会施力,无生命或无动力的物体只会受力,不会施力C.任何一个物体,一定既是受力物体,也是施力物体D.两个力的大小都是5 N,则这两个力一定相同解析甲推乙的同时,乙也在推甲,力的作用是相互的,A错;不论物体是否有生命或是否有动力,它们受到别的物体作用时都会施力.例如马拉车时,车也拉马;书向下压桌子,桌子也向上支撑书,B错;由于自然界中的物体都是相互联系的,找不到一个孤立的、不受其他物体作用的物体,所以每一个物体都受到别的物体的作用,是受力物体,同时也对其他物体施力,即又是施力物体,C对;力是矢量,比较两个力是否相同,除了比较其大小还要比较其方向,D错.答案C二、力的图示和示意图例2在图3甲中木箱P点,用与水平方向成30°角斜向右上的150 N的力拉木箱;在图乙中木块的Q点,用与竖直方向成60°角斜向左上的20 N的力把木块抵在墙壁上.试作出甲、乙两图中所给力的图示,并作出图丙中电灯所受重力和拉力的示意图.图3答案如图所示三、重力和重心的特点例3关于重力和重心,下列说法正确的是()A.当物体漂浮在水面上时重力会减小B.放置在水平面上的物体对水平面的压力就是物体的重力C.物体的重心位置总是在物体的几何中心上D.物体的重心位置可能随物体形状的变化而改变解析物体的重力与物体所处状态无关,A错;物体对水平面的压力与物体的重力的施力物体及受力物体不同,B错;物体的重心位置与物体的形状及质量分布有关,只有质量分布均匀、形状规则的物体的重心才在其几何中心,C错,D对.答案D1.(对力的概念的理解)关于力,下列说法正确的是()A.有的物体自己就有力,如爆炸的手榴弹,所以这个力可以没有施力物体B.力不能离开物体而存在C.不接触的物体之间一定没有力的作用D.有的物体只是施力物体而不是受力物体答案B解析此题可根据力的产生条件来判断,抓住“力是物体与物体之间的相互作用”,要想有力,必须同时存在施力物体和受力物体,两者缺一不可.一个物体在对其他物体施加力的同时一定受到其他物体力的作用,即是施力物体同时又是受力物体,故A、D错误.C项则歪曲了力产生的条件,只要两物体发生相互作用即可产生力,不一定非得接触,故C错误.2.(重力的特点)关于物体所受的重力,以下说法正确的是() A.物体只有在地面上静止时才受到重力作用B.物体落向地面时,它受到的重力大于它静止时所受到的重力C.物体在向上抛出时受到的重力小于它静止时所受到的重力D.同一物体在同一地点,不论其运动状态如何,它所受到的重力都是一样大的答案D解析物体所受的重力是由于地球对物体的吸引而产生的,重力的大小为G=mg。

小学奥数培优题组(经典题库)

小学奥数培优题组(经典题库)

经典题库(一)题组训练1计算:999……99×999……99=9个9 9个9999……99×999……96=2008个9 2007个9999……99×777……78=2008个9 2007个7333……3×666……6=2008个3 2008个6题组训练21、车站每5分钟发一辆车,从上午6:00——上午6:30共发_________辆车。

2.车站每20分钟发一辆车,从上午6:00——上午8:00共发_________辆车。

3.四轮小汽车有一个备用胎,五个轮子轮流行驶,这辆车共行驶了10分钟,每个轮子平均行驶了________分钟。

4.四轮小汽车有一个备用胎,五个轮子轮流行驶,这辆车共行驶了20分钟,每个轮子平均行驶了________分钟。

5.有13人打牌比赛,四人一组,选一人继续比赛,淘汰3人,现要决出冠军,问要共比赛_________场(每一个四人小组当着一场来计算)。

6.有124人打牌比赛,四人一组,选一人继续比赛,淘汰3人,现要决出冠军,问要共比赛_________场(每一个四人小组当着一场来计算)。

题组训练31.一个六位数6□5能被7整除,这样的数是______2.一个两位数除以8,商是A,余数是B,A+B的最大值是_______.3.用10,10,4,4,四个数在它们之间添上运算符号“+,-,×,÷”及括号,使它们的结果等于24(每个数只能用一次)题组训练41、把四位数2abc扩大3倍后便成了另一个四位数abc8。

求abc=__________2.六位数1abcde扩大3倍后便成了abcde1,求1abcde=___________3.八位数2abcdefg×3= abcdefg4,求abcdefg=____________题组训练51.某商店规定,3个空汽水瓶换一瓶汽水,某人在这个商店至少需购买_______汽水,就可以喝到21瓶汽水。

七年级语文上册单元题组训练3点训人教福建课件

七年级语文上册单元题组训练3点训人教福建课件
一二三
一二三
3. 联系上下文,赏析句子。(5分) (1)而校园墙上画的孩子们,也一个个像我了。(3分) 答案:和开头“可没有一个画的是我”形成对比(1 分),突显在郭先生的影响下“我”成长了(1分),也说 明“我”对郭先生的偏见消失了(1分)。
一二三
(2)我心里像猛地被捅了一刀子。(2分) 答案:运用比喻的修辞手法(1分),形象地写出“我” 突然听到郭先生牺牲的噩耗时内心的悲痛(1分)。
人教福建 七年级上册
第三单元 单元题组训练
单元题组训练
一、[2024年1月泉州期末]阅读下面的文字,按要求作 答。(9分)
深秋的天空褪去了盛夏的( ),像大海一样 zhàn ① 蓝。早读课后,我漫步校园中,霎时被一派姹紫 嫣红的景象所吸引——那向阳而生的月菊随风摇摆, ( ),有的白如雪,恬静优雅;有的红胜火,绚烂夺 目……花儿竞相开放,毫不( )地展现它们的魅力。
一二三
三、[2024年1月漳州期末]阅读下面的文字,回答问题。 (20分)
请同学们看《点拨训练》第43-44页第1-5题。
一二三
1. 下列对文章的理解和分析不正确的一项是( C )(3分) A. 全文以郭先生的“笑”为行文线索,串联起作者对往事 的回忆。 B. 郭先生和《再塑生命的人》中的莎莉文都讲究教育 方法。 C. 当“我”询问郭先生行踪时,江先生为保守选择拒 绝回答。 D. 文章采用了欲扬先抑的手法,使得郭先生的形象显得更 加高大。
(3分)
①zhàn 湛 ⁠
②zhù 贮 ⁠
③匿. nì

一二三
2. 依次填入文中括号内的词语,全都恰当的一项是
( C )(3分)
A. 炽热
异彩纷呈
吝惜
B. 热烈

句子翻译训练题组(1-20)答案版

句子翻译训练题组(1-20)答案版

句子翻译训练——题组(一)1. A good book is equal to a good friend.【译】2. Never fear to think because we will benefit from thinking.【译】3. He hesitated for a long time before he made the decision to study in America.【译】4. You'd better go to the airport by underground, or you'll miss the flight.【译】5. Every one of us should do our part to make the world a better place to live in.【译】答案:1. 好书如益友。

2. 不要害怕思考,因为思考总能让人有所收益。

3. 他犹豫了好久才决定去美国留学。

4. 你最好乘地铁去机场,不然就要误点了。

5. 我们每一个人都应该尽自己的一份力使我们的生活环境更美好。

句子翻译训练——题组(二)1. The Chinese people warmly celebrate national Day on Oct. 1 every year.【译】2. It is obvious that the education of the young is vital to the future of a country.【译】3. Every one of us is sparing no effort to get prepared for the coming College Entrance Examination.【译】4. To his excitement, he realized his dream of becoming a volunteer for the 2010 World Expo in Shanghai.【译】5. Besides his routine work, he also has a part-time job at weekends and his monthly income adds up to 10,000 Yuan.【译】答案:1. 中国人民每年都要热烈庆祝十月一日的国庆节。

中考英语题组训练3 根据首字母提示及文意补全短文

中考英语题组训练3   根据首字母提示及文意补全短文

题组训练3 根据首字母提示及文意补全短文阅读下面的短文,根据短文内容及首字母提示,在短文空白处填入一个恰当的词,使短文内容完整、通顺。

A[2017·襄阳]Life will be peaceful if you always do kind things. I teach my daughters to 1.d________ a habit of helping others.We live in a rural(乡村) area. Most of what we see is beautiful nature. One of the exceptions(例外) to the beauty is the rubbish that some people throw out of their car windows. And there are no necessary public 2.s________,such as rubbish collection.A helping behavior(举动) that I often 3.p________ with my daughters is picking up rubbish in our neighborhood. My daughters often have a 4.m________ to see who can collect the most rubbish. They will often say to me in an excited voice, “There's some rubbish, —Daddy, stop the car!” Without 5.t________ more, we will often get out of our car and pick it up. Though it may seem 6.s________,we do it. In fact, we enjoy it. We pick up rubbish in parks, on sidewalks, almost 7.a________.One day I saw a man I had never met before picking up rubbish on the road. I stopped. He 8.r________ his head and said to me with a smile, “I saw you doing this with your family. It's a good idea to protect our natural world.”There are many other ways to 9.p________ kindness for others. You may share a dinner with a beggar(乞丐), visit lonely old people in the nursing home or help the blind cross the street. You can think of something that can be finished 10.e________ but helpful. It is fun, self-satisfying, and what's more, it can set a good example. Helping others is helping yourself.BSummer was coming and getting hotter. Mrs. King 1.g________ up early one morning and went to the market after she had breakfast. She knew that everything was cheap there 2.b________ eight o'clock. She wanted to buy many vegetables for her family. Suddenly she saw there were a lot of people around a farmer. She hurried there and 3.f________ that he was selling beef.“How 4.m________ is it?” a woman asked.“Two dollars a kilo.”“Oh, how cheap it is!” Mrs. King said to 5.h________. “John likes beef very much. I'd better buy some here.”When she got home with five kilos of beef, her son was happy but her husband got 6.a________. “What a silly woman!” said Mr. King. “How shall we keep it 7.f________ in such hot weather?”“Your aunt is very rich,” said Mrs. King. “Why not g o and 8.b________ some money from her? Then we'll be able to buy a fridge.” Mr. King 9.a________ and they began to teach their five-year-old son what to say when they were in his aunt's house.“John,” Mr. King said, “How can we keep the beef fresh?”“That's easy,” the boy said 10.h________. “By eating it!”C[2017·攀枝花]The Clever Learning MethodsWhy do you need study skills? Because they will make it 1.e________ for you to learn and do well in class, especially asyou move up to middle school and high school.◆Pay attention in classDo you have 2.d________ paying attention in class? Are you sitting next to a loud person? Is it hard to see the blackboard? Make sure you're sitting in a good seat that makes you pay attention. Tell your teacher or parents about any problem that is stopping you from paying attention and taking good notes.◆Take good notesNot sure how to take notes? Start by writing down facts that your teacher mentions 3.o________ writes on the blackboard in class. Try your best to use good handwriting so that you can read your notes later. It's also a good idea to keep your notes, quizzes, and papers 4.o________ by subject.◆Plan 5.b________ testsIt's not wise of you to wait until 6.T________ night to study for Friday's test. It also makes it hard to do your best. You'll feel sorry for 7.p________ off things often. One of the best ways is to plan ahead.◆Get a good night's sleepSo the test is tomorrow and you've followed your study plan, but 8.s________ you can't remember anything, not even 2+2! Don't worry. Your brain needs time to digest(消化) all the 9.i________ you've given it. Try to get a good night's sleep and you'll be 10.s________ by what comes back to you in the morning!参考答案A【主旨大意】本文是一篇记叙文。

3(题组训练)知识竞赛答对一道题得5分,答错一道题倒扣3分(

3(题组训练)知识竞赛答对一道题得5分,答错一道题倒扣3分(

3(题组训练)知识竞赛答对一道题得5分,答错一道题倒扣3分(摘要:一、知识竞赛规则介绍1.知识竞赛答对一题得5 分2.答错一题倒扣3 分二、竞赛中得分与扣分情况分析1.正确回答问题2.错误回答问题三、应对策略与建议1.提高答题正确率2.分析题目,确保理解题意3.答题时保持冷静正文:知识竞赛是一种常见的活动形式,通过竞赛,可以检验参与者的知识水平和学习成果。

在这种竞赛中,答对一题通常可以得到5 分,而答错一题则会倒扣3 分。

如何在知识竞赛中取得好成绩,以下是一些建议。

首先,我们要了解知识竞赛的规则。

在知识竞赛中,答对一题可以得到5 分,这是我们的目标。

然而,如果答错一题,将会倒扣3 分。

这意味着,错误回答问题将会使我们的得分减少8 分(5 分的得分和3 分的扣分)。

因此,在竞赛中,我们要尽量确保正确回答问题,避免答错题目。

其次,我们需要分析在竞赛中得分与扣分的情况。

如果我们能够正确回答问题,那么我们将会获得5 分的积分。

然而,如果我们错误回答问题,那么我们将会扣除3 分。

这意味着,在知识竞赛中,答错一题比正确回答一题少得8 分。

因此,在竞赛中,我们要尽量提高答题正确率,减少答错题目的情况。

最后,我们需要提出应对策略与建议。

为了在知识竞赛中取得好成绩,我们可以采取以下策略:1.提高答题正确率:通过充分准备和复习,提高自己的知识水平,确保在竞赛中能够正确回答问题。

2.分析题目,确保理解题意:在答题前,仔细阅读题目,确保理解题目的要求,避免因为误解题意而答错题目。

3.答题时保持冷静:在知识竞赛中,保持冷静和自信非常重要。

在答题过程中,不要因为紧张而影响自己的表现。

总之,知识竞赛是一种检验知识水平的有效方式。

在竞赛中,我们要尽量确保正确回答问题,避免答错题目。

3题组训练:概括要点

3题组训练:概括要点

文学作品阅读(三)概括要点(一)人生旅途崎岖修远,起点站是童年。

人第一眼看见的世界,就是生我育我的乡土。

他从母亲的怀抱,父亲的眼神,亲族的逗弄中开始体会爱。

乡土的一山一水,一草一木,都溶化为童年生活的血肉,不可分割。

而且可能祖祖辈辈都植根在这片土地上,有一部悲欢离合的家史。

在听祖母讲故事的同时,就种在小小的心坎里。

邻里乡亲,早晚在街头巷尾、桥上井边、田塍篱角相见,音容笑貌,闭眼塞耳也彼此了然,横竖呼吸着同一的空气,濡染着同一的风习,千丝万缕沾着边。

一个人为自己的一生定音定调定向定位,要经过千磨百折的摸索,前途充满未知数,但童年的烙印,却像春蚕作茧,紧紧地包着自己,又像文身的花纹,一辈子附在身上。

问题:从文中看,乡土都给人们打下了哪些“童年的烙印”?(不超过28个字)(4分)父母亲族的爱、家乡的山水草木、悲欢离合的家史、邻里乡情。

(二)“金窝银窝,不如家里的草窝。

”但人是不安分的动物,多少人仗着年少气盛,横一横心,咬一咬牙,扬一扬手,向恋恋不舍的家乡告别,万里投荒,去寻找理想,追求荣誉,开创事业,富有浪漫气息。

有的只是一首朦胧诗——为了闯世界。

多数却完全是沉重的现实主义格调:许多稚弱的童男童女,为了维持最低限度的生存要求,被父母含着眼泪打发出门,去串演各种悲剧。

人一离开乡土,就成了失根的兰花,逐浪的浮萍,飞舞的秋蓬,因风四散的蒲公英,但乡土的梦,却永远追随着他们。

浪荡乾坤的结果,多数是少年子弟江湖老,黄金、美人、虚名、实惠,都成了竹篮打水一场空。

问题:作者在第三段中所描写的少年离家的情况有哪几种?请概括说明(4分)①不少人富有浪漫气息,为追求理想开创事业去闯世界。

(2分)②多数人是沉重的现实主义格调,为维持最低的生活被打发出家门(2分)。

看树高林瑜在乡村学校,十多年了,我总喜欢看树。

在四季的轮回中,树像这幽静的村庄,呈现着它自己的色彩。

面对一棵树,我所追寻的只是树与天空构成的一种最纯朴的风景,然而这一切给人的感觉,却像心灵散发的一阵阵光芒。

人教版英语 七年级上册:Unit 3Self Check 单元重点练习

人教版英语 七年级上册:Unit 3Self Check  单元重点练习

Self Check§1 单元重难点题组训练题组训练一、some的用法Ⅰ. 单项选择。

1. Some ________ are in the pencil box.A. computersB. penC. pictureD. erasers2. An orange and ________ cards are in the box.A. aB. someC. oneD. an3. ________ in the school library.A. A teacher areB. A teachers areC. Some teachers isD. Some teachers are Ⅱ. 根据汉语意思完成句子,每空一词。

4. 我们在那幅图画中能看见一些手表。

We can see ________ ________ in the picture.5. 她们是些女孩。

They ________ ________ ________.6. 我有一些蓝色的盒子。

I have ________ blue ________.题组训练二、must的用法Ⅰ. 单项选择。

1. Bob must ________ his friend now.A. callsB. callC. to callD. calling2. —Must he find his lost dictionary?—Yes, he ________.A. canB. isC. mustD. are3. My English book is lost. I ________ find it.A. amB. doC. canD. mustⅡ. 根据汉语意思完成句子,每空一词。

4. 我们必须帮助他。

We ________ ________ ________.5. ——我必须用英语说吗?——是的。

—________ I ________ it in English?—Yes, you ________.题组训练三、thank的用法Ⅰ. 单项选择。

秋人教版英语八年级上册习题课件:Unit 6 重难点题组训练

秋人教版英语八年级上册习题课件:Unit 6 重难点题组训练

—Yes, I could.I believe I will A.Can; be able to
play better in the future. B.Could; be able to
C.Were able to; could
D.Could; could
( D )3.Tom is a clever boy.He
13、He who seize the right moment, is the right man.谁把握机遇,谁就心想事成。2021/9/192021/9/192021/9/192021/9/199/19/2021 •14、谁要是自己还没有发展培养和教育好,他就不能发展培养和教育别人。2021年9月19日星期日2021/9/192021/9/192021/9/19 •15、一年之计,莫如树谷;十年之计,莫如树木;终身之计,莫如树人。2021年9月2021/9/192021/9/192021/9/199/19/2021 •16、教学的目的是培养学生自己学习,自己研究,用自己的头脑来想,用自己的眼睛看,用自己的手来做这种精神。2021/9/192021/9/19September 19, 2021 •17、儿童是中心,教育的措施便围绕他们而组织起来。2021/9/192021/9/192021/9/192021/9/19
• You have to believe in yourself. That's the secret of success. 人必须相信自己,这是成功的秘诀。

二、根据所给提示完成句子,每空一词。 4.Mr Yang asked two students to report the result of their discussion (discuss). 5.李雷想和你一起讨论他的生活。 Li Lei wants to discuss his life with you. 6.他们商讨卖车一事。 They discussed selling the car.

高考数学总复习提素能高效题组训练3-7

高考数学总复习提素能高效题组训练3-7

[命题报告·教师用书独具]1.(2012年高考广东卷)在△ABC中,若∠A=60°,∠B=45°,BC=32,则AC=()A.43.2 3C. 3 .3 2解析:利用正弦定理解三角形.在△ABC中,ACsin B=BCsin A,∴AC=BC·sin Bsin A=32×2232=2 3.答案:B2.(2013年安阳模拟)在△ABC中,三个内角A,B,C所对的边为a,b,c,且b2=a2-ac+c2,C-A=90°,则cos A cos C=()A.14.24C.-14.-24解析:依题意得a 2+c 2-b 2=ac ,cos B =a 2+c 2-b 22ac =ac 2ac =12.又0°<B <180°,所以B =60°,C +A =120°.又C -A =90°,所以C =90°+A ,A =15°,cos A cos C =cos A cos(90°+A )=-12sin 2A =-12sin 30°=-14,选C.答案:C3.已知△ABC 的三边长为a ,b ,c ,且面积S △ABC =14(b 2+c 2-a 2),则A =( ) A.π4 .π6 C.2π3.π12解析:因为S △ABC =12bc sin A =14(b 2+c 2-a 2),所以sin A =b 2+c 2-a 22bc =cos A ,故A =π4.答案:A4.(2013年江西师大附中月考)在△ABC 中,∠A =60°,且角A 的角平分线AD 将BC 分成两段BD 、DC ,且BD ∶DC =2∶1,若AD =43,则C =( )A.π6 .π4 C.π2.π3解析:因为AD 是角A 的角平分线,所以AC ∶AB =CD ∶DB =1∶2.设AC =x ,则AB =2x .易知3S △ACD =S △ABC ,即3×12×43×sin 30°=12×2x 2sin 60°,解得x =6,所以AB =12.由余弦定理得BC =6 3.又因为AC 2+BC 2=AB 2,所以C =π2. 答案:C5.已知△ABC 的内角A ,B ,C 所对的边分别为a ,b ,c ,a =80,b =100,A =30°,则此三角形( )A .一定是锐角三角形B .一定是直角三角形C .一定是钝角三角形D .可能是直角三角形,也可能是锐角三角形解析:依题意得a sin A =b sin B ,sin B =b sin A a =100sin 30°80=58,12<58<32,因此30°<B <60°,或120°<B <150°.若30°<B <60°,则C =180°-(B +30°)>90°,此时△ABC 是钝角三角形;若120°<B <150°,此时△ABC 仍是钝角三角形.因此,此三角形一定是钝角三角形,选C.答案:C 二、填空题6.(2012年高考湖北卷)设△ABC 的内角A ,B ,C 所对的边分别为a ,b ,c .若(a +b -c )(a +b +c )=ab ,则角C =________.解析:应用余弦定理求角.由(a +b -c )(a +b +c )=ab ,得a 2+b 2-c 2=-ab ,则 cos C =a 2+b 2-c 22ab =-12.又因为角C 为△ABC 的内角,所以C =2π3. 答案:2π37.(2013年大同质检)在△ABC 中,内角A ,B ,C 依次成等差数列,AB =8,BC =5,则△ABC 外接圆的面积为________.解析:记△ABC 的外接圆半径为R .依题意得2B =A +C ,又A +C +B =π,因此有B =π3,所以AC =AB 2+BC 2-2AB ·BC ·cos B =7.又2R =AC sin B =7sin 60°,即R =73,故△ABC 的外接圆的面积是πR 2=49π3. 答案:49π38.(2012年高考重庆卷)设△ABC 的内角A ,B ,C 的对边分别为a ,b ,c ,且cos A =35,cos B =513,b =3,则c =________.解析:利用同角三角函数基本关系式、三角函数和角公式及正弦定理求解.在△ABC中,∵cos A=35>0,∴sin A=45.∵cos B=513>0,∴sin B=1213.∴sin C=sin[π-(A+B)]=sin(A+B) =sin A cos B+cos A sin B=45×513+35×1213=5665.由正弦定理知bsin B=csin C,∴c=b sin Csin B=3×56651213=145.答案:14 59.有一解三角形的题目因纸张破损有一个条件不清,具体如下:在△ABC中,已知a=3,2cos2A+C2=(2-1)cos B,c=________,求角A.(答案提示:A=60°,请将条件补充完整)解析:由题知1+cos(A+C)=(2-1)cos B,所以1-cos B=(2-1)cos B,解得cos B=22,∴B=45°,又A=60°,所以C=75°.根据正弦定理得3sin 60°=csin 75°,解得c=6+22.故应填6+2 2.答案:6+2 2三、解答题10.(2013年北京海淀模拟)在△ABC中,角A,B,C所对的边分别为a,b,c,A=2B,sin B=3 3.(1)求cos A及sin C的值;(2)若b=2,求△ABC的面积.解析:(1)因为A =2B , 所以cos A =cos 2B =1-2sin 2B . 因为sin B =33, 所以cos A =1-2×13=13.由题意可知,A =2B,0<A <π,所以0<B <π2. 所以cos B =1-sin 2B =63.因为sin A =sin 2B =2sin B cos B =223.所以sin C =sin[π-(A +B )]=sin(A +B )=sin A cos B +cos A sin B =539.(2)因为b sin B =asin A ,b =2, 所以233=a 223. 所以a =463.所以△ABC 的面积S △ABC =12ab sin C =2029.11.(2012年高考大纲全国卷)△ABC 的内角A ,B ,C 的对边分别为a ,b ,c ,已知cos(A -C )+cos B =1,a =2c ,求C .解析:由B =π-(A +C ),得cos B =-cos(A +C ).于是cos(A -C )+cos B =cos(A -C )-cos(A +C )=2sin A sin C , 由已知得sin A sin C =12.①由a =2c 及正弦定理得sin A =2sin C .② 由①②得sin 2C =14,于是sin C =-12(舍去)或sin C =12. 又a =2c ,所以C =π6.12.(能力提升)如图,在△ABC 中,AD ⊥BC ,垂足为D ,且BD ∶DC ∶AD =2∶3∶6.(1)求∠BAC 的大小;(2)设E 为AB 的中点,已知△ABC 的面积为15,求CE 的长. 解析:(1)由已知得tan ∠BAD =BD AD =13, tan ∠CAD =CD AD =12,则tan ∠BAC =tan(∠BAD +∠CAD )=13+121-13×12=1, 又∠BAC ∈(0,π),所以∠BAC =π4.(2)设BD =2t (t >0),则DC =3t ,AD =6t ,由已知得S △ABC =12×(2t +3t )6t =15,则t =1,故BD =2,DC =3,AD =6,所以AB =AD 2+BD 2=2 10,AC =AD 2+DC 2=35,则AE =AB2=10, 由余弦定理得CE =AE 2+AC 2-2AE ·AC ·cos ∠BAC =5.[因材施教·学生备选练习]1.(2012年高考安徽卷)设△ABC 的内角A ,B ,C 所对边的长分别为a ,b ,c ,且有2sin B cos A =sin A cos C +cos A sin C .(1)求角A 的大小;(2)若b =2,c =1,D 为BC 的中点,求AD 的长.解析:(1)解法一 由题设知,2sin B cos A =sin(A +C )=sin B . 因为sin B ≠0,所以cos A =12.由于0<A <π,故A =π3.解法二 由题设可知,2b ·b 2+c 2-a 22bc =a ·a 2+b 2-c 22ab +c ·b 2+c 2-a 22bc ,于是b 2+c 2-a 2=bc ,所以cos A =b 2+c 2-a 22bc =12. 由于0<A <π,故A =π3.(2)解法一 因为A D →2=⎝⎛⎭⎪⎫AB →+AC →22 =14(A B →2+A C →2+2AB →·AC →)=14⎝ ⎛⎭⎪⎫1+4+2×1×2×cos π3=74, 所以|AD→|=72.从而AD =72. 解法二 因为a 2=b 2+c 2-2bc cos A =4+1-2×2×1×12=3,所以a 2+c 2=b 2,B =π2.因为BD =32,AB =1,所以AD =1+34=72.2.(2013年南昌模拟)△ABC 的三个角A ,B ,C 所对的边分别是a ,b ,c 向量m =(2,-1),n =(sin B sin C ,3+2cos B cos C ),且m ⊥n .(1)求角A 的大小;(2)现给出以下三个条件:①B =45°;②2sin C -(3+1)·sin B =0;③a =2.试从中再选择两个条件以确定△ABC ,并求出所确定的△ABC 的面积.解析:(1)∵m ⊥n ,∴2sin B sin C -2cos B cos C -3=0, ∴cos(B +C )=-32, ∴cos A =32,又0<A <π,∴A =30°.(2)解法一 选择①③,∵A =30°,B =45°,C =105°,a =2且sin 105°=sin(45°+60°)=6+24,c =a sin Csin A =6+2, ∴S △ABC =12ac sin B =3+1.解法二 选②③,已知A =30°,a =2, ∵2sin C -(3+1)sin B =0, ∴2c =(3+1)b ,∴c =3+12b .由余弦定理,知a 2=4=b 2+⎝ ⎛⎭⎪⎫3+12b 2-2b ×3+12b ×32. ∴b 2=8,∴b =22,c =3+12b =6+2, ∴S △ABC =12bc sin A =3+1.注:不能选①②,因①②不能确定△ABC .。

七上英语unit5-9重难点题组训练

七上英语unit5-9重难点题组训练

Unit5 单元重难点题组训练Ⅰ. 单项选择。

( )1. —I can’t spell it.—Let me ________ you.A. helpingB. helpsC. to helpD. help( )2. —Let’s ________ volleyball now.—That sounds good.A. playsB. playC. playingD. to play( )3. Let ________ play computer games.A. theyB. theirC. themD. theirs( )4. —Let’s play ping-pong.—________ Let’s go.A. Great!B. That’s boring.C. I have a volleyball.D. I don’t like ping-pong. Ⅱ. 根据汉语意思完成句子,每空一词。

5. 让她给安娜打电话。

Let __________ __________ Anna.6. 让我们用英语说吧。

__________ __________ it in English.Ⅰ. 单项选择。

( )1. —Do you like ping-pong?—Yes, I do. It is easy ________ me.A. afterB. withC. onD. for( )2. I love sports. I play them ________ class.A. onB. forC. afterD. with( )3. The girl always goes to the school library ________ her classmates.A. withB. onC. forD. after( )4. His grandfather likes watching soccer games ________ TV.A. forB. onC. afterD. withⅡ. 用on, for, with或after填空。

中考历史题组练 非选择题题组训练(三)

中考历史题组练 非选择题题组训练(三)
——据贺国庆《中世纪大学和现代大学》
(1)根据材料一并结合所学知识,说说中世纪大学的课程有哪些?从课程 设置上看有什么特点?
课程:基础课程包括文法、修辞、逻辑、算术、 几何、天文和音乐;专业课程有法学、医学、神 学。(答出基础课程和专业课程即可)特点:一方 面仍受基督教会的影响,另一方面也反映了经济 和社会发展的要求。(答职业性和实用性亦可)
【 ×】(2)宋朝忽必烈时代,意大利旅行家马可·波罗通过丝绸之路来
到中国。
改正: 将“宋朝”改为“元 【 ×】朝(”3)印。度人担当了沟通东西方文化的角色,将中国的造纸术、指
南针、火药等重大发明传入欧洲。
改正: 将“印度人”改为“阿拉伯 【 √】人(”4)“。乒乓外交”打开了中美交往的大门,为中美关系走向正常
——《人民日报》1978 年 12 月 25 日社论
(2)材料二的这篇社论发表之前,中共中央召开了哪次重要会议?谈谈材 料中这一认识的重要历史意义。
会议:十一届三中全会。意义:是新中国成立以来党 的历史上具有深远意义的伟大转折,开启了改革开放 和社会主义现代化的伟大征程。 (3)结合以上材料和所学知识,你认为中国共产党的初心和使命是什么?
(2)根据上图,围绕其主题提炼一个观点,并结合所学知识加以论述。 (8 分,要求:观点明确,史论结合,表述清晰)
论点:新航路的开辟使世界开始连成一个整体, 世界的观念也从此初步确立起来。
论述:15世纪末,由于资本主义萌芽的出现, 商品经济的进一步发展,在西班牙、葡萄牙 王室的支持下,达伽马、迪亚士、哥伦布、 麦哲伦进行远洋航行,开辟新航路。新航路 的开辟使得全球贸易和物种交流发展起来, 粮食作物、牲畜物种的传播,使得人口增加, 人们生活得到改善。此外,新航路的开辟使 欧洲与亚洲、非洲、美洲之间建立起了直接 的商业联系,往来日益密切,世界开始连成 一个整体,世界的观念逐渐形成。

题组训练三 苏教版六上数学

题组训练三 苏教版六上数学

1题组训练(分数)三 1.一瓶果汁45升,喝了43,喝了多少升?总体积×43=喝的体积45×43=1615(升) 答:喝了1615升。

2.一瓶果汁45升,喝了43升,还剩多少升?总体积-喝的体积=剩下体积 45-43=21(升) 答:还剩下21升。

3.一瓶果汁45升,喝了43,还剩下多少升?总体积×(1-43)=剩下体积45×(1-43)=45×41=165(升) 答:还剩下165升。

4.一瓶果汁45升,喝了43,还剩下几分之几?1-喝的几分之几=剩下总体积的几分之几1-43=41答:还剩下总体积的41没有喝。

5.一瓶果汁45升,还剩21升,喝了多少升?总体积-剩下体积=喝的体积 45-21=43(升)答:喝了43升。

6.一瓶果汁45升,喝了一些后还剩43,还剩多少升? 总体积×43=剩下体积45×43=1615(升) 答:还剩1615升。

7.一瓶果汁45升,喝了一些后还剩43,喝了多少升? 总体积×(1-43)=喝的体积45×(1-43)=45×41=165(升) 答:喝了165升。

8.一瓶果汁45升,喝了43,剩下的比喝的少多少升?1-喝了总体积的几分之几=剩下总体积的几分之几喝了总体积的几分之几-剩下总体积的几分之=剩下比喝的少了总体积的几分之总体积×少了总体积的几分之几=少喝的体积① 剩下总体积的几分之几?1-43=41② 少了总体积的几分之几? 43-41=21 ③ 少喝的体积:45×21=85(升)答:剩下的比喝的少85升。

高考数学总复习提素能高效题组训练3-2

高考数学总复习提素能高效题组训练3-2

[命题报告·教师用书独具]1.(2013年深圳调研)tan 2 012°∈( ) A.⎝⎛⎭⎪⎫0,33B.⎝ ⎛⎭⎪⎫33,1 C.⎝⎛⎭⎪⎫-1,-33D.⎝ ⎛⎭⎪⎫-33,0 解析:tan 2 012°=tan(5×360°+212°)=tan 212°=tan(180°+32°)=tan 32°,又y =tan x 在⎝ ⎛⎭⎪⎫0,π2上为增函数,30°<32°<45°,∴tan 32°∈⎝ ⎛⎭⎪⎫33,1,故选B.答案:B2.(2013年聊城模拟)三角形ABC 是锐角三角形,若角θ终边上一点P 的坐标为(sin A -cos B ,cos A -sin C ),则sin θ|sin θ|+cos θ|cos θ|+tan θ|tan θ|的值是( )A .1B .-1C .3D .4解析:因为三角形ABC 是锐角三角形,所以A +B >90°,即A >90°-B ,则sin A >sin(90°-B )=cos B ,sin A -cos B >0,同理cos A -sin C <0,所以点P 在第四象限,sin θ|sin θ|+cos θ|cos θ|+tan θ|tan θ|=-1+1-1=-1,故选B.答案:B3.(2013年龙岩质检)已知sin(π-α)=log 8 14,且α∈⎝ ⎛⎭⎪⎫-π2,0,则tan(2π-α)的值为( )A .-255 B.255 C .±255D.52解析:sin(π-α)=sin α=log 8 14=-23,又α∈⎝ ⎛⎭⎪⎫-π2,0,得cos α=1-sin 2α=53, tan(2π-α)=tan(-α)=-tan α=-sin αcos α=255. 答案:B4.(2013年厦门质检)已知1+sin αcos α=-12,则cos αsin α-1的值是( )A.12 B .-12 C .2D .-2解析:由同角三角函数关系式1-sin 2 α=cos 2α及题意可得cos α≠0,且1-sin α≠0,∴1+sin αcos α=cos α1-sin α,∴cos α1-sin α=-12,即cos αsin α-1=12.答案:A5.(2013年太原模拟)已知α∈⎝ ⎛⎭⎪⎫π2,π,sin α+cos α=-15,则tan ⎝ ⎛⎭⎪⎫α+π4等于( )A .7B .-7 C.17D .-17解析:sin α+cos α=-15⇒2sin αcos α=-2425, 所以(sin α-cos α)2=1-2sin α·cos α=4925. 因为α∈⎝ ⎛⎭⎪⎫π2,π,所以sin α-cos α=75,所以sin α=35,cos α=-45⇒tan α=-34, 所以tan ⎝ ⎛⎭⎪⎫α+π4=tan α+tan π41-tan αtan π4=-34+11+34=17.答案:C 二、填空题 6.已知f (α)=sin (π-α)cos (2π-α)cos (-π-α)tan α,则f ⎝ ⎛⎭⎪⎫-163π=________.解析:∵f (α)=sin αcos α-cos αtan α=-cos α,∴f ⎝ ⎛⎭⎪⎫-16π3=-cos ⎝ ⎛⎭⎪⎫-16π3=-cos ⎝ ⎛⎭⎪⎫6π-2π3 =-cos 2π3=12. 答案:127.(2013年泰州模拟)若θ∈⎝ ⎛⎭⎪⎫π4,π2,sin 2θ=116,则cos θ-sin θ的值是________.解析:(cos θ-sin θ)2=1-sin 2θ=1516.∵π4<θ<π2,∴cos θ<sin θ.∴cos θ-sin θ=-154. 答案:-1548.已知tan α=2,则sin (π+α)-sin ⎝ ⎛⎭⎪⎫π2+αcos ⎝ ⎛⎭⎪⎫3π2+α+cos (π-α)的值为________.解析:sin (π+α)-sin ⎝ ⎛⎭⎪⎫π2+αcos ⎝ ⎛⎭⎪⎫32π+α+cos (π-α)=-sin α-cos αsin α-cos α=-tan α-1tan α-1=-2-12-1=-3.答案:-39.化简sin 2(π+α)-cos(π+α)cos(-α)+1的值为________. 解析:sin 2(π+α)-cos(π+α)cos(-α)+1 =(-sin α)2-(-cos α)cos α+1 =sin 2α+cos 2α+1=1+1=2. 答案:2 三、解答题10.(2013年合肥模拟)若α是第二象限角,sin(π-α)=1010.求2sin 2α2+8sin α2cos α2+8cos 2α2-52sin ⎝ ⎛⎭⎪⎫α-π4的值.解析:由sin(π-α)=1010可得sin α=1010,又α是第二象限角,∴tan α=-13,2sin 2α2+8sin α2cos α2+8cos 2α2-52sin ⎝ ⎛⎭⎪⎫α-π4=4sin α+3cos αsin α-cos α=4tan α+3tan α-1=-54.11.已知sin(π-α)-cos(π+α)=23⎝ ⎛⎭⎪⎫π2<α<π.求下列各式的值:(1)sin α-cos α; (2)sin 3⎝ ⎛⎭⎪⎫π2-α+cos 3⎝ ⎛⎭⎪⎫π2+α.解析:由sin(π-α)-cos(π+α)=23, 得sin α+cos α=23,①将①两边平方,得1+2sin α·cos α=29, 故2sin α·cos α=-79.又π2<α<π,∴sin α>0,cos α<0.(sin α-cos α)2=1-2sin α·cos α=1-⎝ ⎛⎭⎪⎫-79=169,∴sin α-cos α=43. sin 3⎝ ⎛⎭⎪⎫π2-α+cos 3⎝ ⎛⎭⎪⎫π2+α=cos 3α-sin 3α=(cos α-sin α)(cos 2α+cos α·sin α+sin 2α) =-43×⎝ ⎛⎭⎪⎫1-718=-2227.12.(能力提升)已知A ,B ,C 的坐标分别为(4,0),(0,4),(3cos α,3sin α). (1)若α∈(-π,0),且|A C →|=|B C →|,求角α的大小; (2)若A C →⊥B C →,求2sin 2α+sin 2α1+tan α的值.解析:(1)由已知得 A C →=(3cos α-4,3sin α), B C →=(3cos α,3sin α-4), ∴(3cos α-4)2+9sin 2α, =9cos 2α+(3sin α-4)2, 则sin α=cos α.∵α∈(-π,0), ∴α=-3π4. (2)∵A C →⊥B C →,∴(3cos α-4)·3cos α+3sin α·(3sin α-4)=0, 即sin α+cos α=34,平方得sin 2α=-716. 而2sin 2α+sin 2α1+tan α=2sin 2αcos α+2sin αcos 2 αsin α+cos α=2sin αcos α=sin 2α=-716.[因材施教·学生备选练习]1.(2013年揭阳模拟)若sin θ,cos θ是方程4x2+2mx+m=0的两根,则m 的值为()A.1+ 5 B.1- 5C.1±5 D.-1- 5解析:由题意知:sin θ+cos θ=-m2,sin θcos θ=m4,又(sin θ+cos θ)2=1+2sin θcos θ,∴m24=1+m2,解得:m=1±5,又Δ=4m2-16m≥0,∴m≤0或m≥4,∴m=1- 5.答案:B2.已知α为第二象限角,则cos α1+tan2α+sin α1+1tan2α=________.解析:原式=cos α1+sin2αcos2α+sin α1+cos2αsin2α=cos α1cos2α+sin α1sin2α=cos α1-cos α+sin α1sin α=0.答案:03.化简:sin(kπ-α)cos[(k-1)π-α]sin[(k+1)π+α]cos(kπ+α)(k∈Z).解析:当k=2n(n∈Z)时,原式=sin(2nπ-α)cos[(2n-1)π-α] sin[(2n+1)π+α]cos(2nπ+α)=sin(-α)·cos(-π-α)sin(π+α)·cos α=-sin α(-cos α)-sin α·cos α=-1;当k=2n+1(n∈Z)时,原式=sin[(2n+1)π-α]·cos[(2n+1-1)π-α] sin[(2n+1+1)π+α]·cos[(2n+1)π+α]=sin(π-α)·cos αsin α·cos(π+α)=sin α·cos αsin α(-cos α)=-1.。

3(题组训练)知识竞赛答对一道题得5分,答错一道题倒扣3分(

3(题组训练)知识竞赛答对一道题得5分,答错一道题倒扣3分(

3(题组训练)知识竞赛答对一道题得5分,答错一道题倒扣3分(
【实用版】
目录
1.题组训练的知识竞赛规则
2.答对题和答错题的得分情况
3.题组训练对知识掌握的重要性
正文
题组训练是一种有效的学习方式,它通过模拟竞赛环境,让学生在压力下更好地掌握知识。

在这类训练中,一道题目的正确与否会直接影响到学生的得分。

在题组训练的知识竞赛中,答对一道题可以得到 5 分,这是对学生努力学习的肯定和鼓励。

而答错一道题则会倒扣 3 分,这是对学生错误知识的纠正和提醒。

这样的得分设置,既激励了学生积极思考,又让他们在错误中找到正确的方向。

然而,无论是答对题还是答错题,都不能忽视题组训练的重要性。

通过题组训练,学生可以更好地发现自己的知识盲点,及时进行补充和巩固。

同时,题组训练的竞赛环境也能让学生提前适应考试的氛围,提高他们的应试能力。

总的来说,题组训练的知识竞赛是一种有效的学习方式,它能帮助学生更好地掌握知识,提高学习效率。

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2023届高考英语备考一轮复习七选五专题训练题组 (3)

2023届高考英语备考一轮复习七选五专题训练题组 (3)

全国百所名校2023年高考英语备考一轮复习资料七选五专练题组汇编(三)姓名:班级:得分:AIt is a common sight to see a teacher standing in front of the white board, giving explanations. Occasionally, some topics do require such a teacher-centered lesson. ___1____ They can neither remember nor recall the teachings of the day. How can this boredom be beaten?Cooperative learning is one effective classroom practice to make the lessons attractive and learners active. Interaction is key to any form of learning. Cooperative learning allows students to interact constructively in small groups to complete a structured task. ____2____ Cooperative learning is a learning style that promotes the four core skills: cooperation through team effort, communication through face-to-face interactions, critical thinking and creativity through reasoning and problem solving. Teachers are no longer the only source of information. The success of an assignment is dependent on combined efforts. __3____ Each member assigned a specific role or task must contribute to the completion of the team assignment to ensure equal distribution of labour.However, cooperative learning is not always smooth sailing. One main struggle would be personality conflicts. If passive and shy students are paired with perfectionists, the latter may end up dominating to the point of ruling out their chicken teammates. ___4___ The tendency to communicate just amongst themselves will lead to the shy students being left out, putting them at a disadvantage again.___5___ It shapes students to become active learners. Indeed, a constant cooperative learning environment equips young minds to become successful grown-ups in an increasingly diverse and interdependent world.A.Individual responsibility is equally important too.B.With teachers’ help, students can understand them better.C.However, if it is a daily routine, pupils will soon get bored.D.Students in groups of three or four work together to do a task.E.Another obstacle occurs when certain members are well familiar.F.In this way, lively participation and a better mastery of the subject are achieved. G.Although cooperative learning has some problems, its long term benefits outweigh problems.BLanguage is part of our daily lives, no matter where we live in the world. Similarly, music is a part of many people’s lives. ___1___ Here are some of their similarities.Both language and music have a writing systemIn English we record language using the alphabet, which is a collection of letters. Similarly, we use notes to keep a record of music. Just as you are reading this collection of letters on thepaper and find meaning in it, musicians read notes and create meaning in the form of music which we can hear. ___2___ For example, we can read the ideas or hear the composition of someone who lived hundreds of years ago, which is really quite exciting.Both vary with culture___3___ In the same way, we know that styles of music are different around the world, which gives us the opportunity to explore many different cultures through their music. This also means that there is something for everyone! Even if you don’t like Britpop melodies, you may love the energy of Latin American salsa music.Both share emotionHow do you know that I am angry? ___4___ Similarly, music can sound angry, sad or happy. Music can show you exactly how the composer was or is feeling, and allows us to share that emotion. When you feel happy, you might want to sing and dance to a happy song. ___5___ A.Different culture makes different music.B.Both language and music play a huge role in our lives.C.You can guess where someone is from by listening to their language.D.By reading pieces of text or music, we are able to share experiences through time.E.In contrast, you have probably also listened to sad music when you were feeling down.F.Of course, you may be able to see it in my face, but you will know for sure through my words. G.We have all used music to express our emotions, often combining it with language in the form of song lyrics.CLaughter has positive, quantifiable physiological and psychological effects on certain aspects of health. ____1____It provides low-intensity exercise and burn calories.___2___ It is particularly important for seniors as well as bedridden or wheelchair-bound people. It is a unique way to improve one’s daily health.____3____ The relaxation of the muscles in line with the increased heart rate allows the blood to flow more freely throughout your body. At the same time if your blood pressure is low it can be increased over time due to the aerobic(有氧的)exercise that it provides.It reduces pain. Endorphins(内啡肽)are your body’s natural painkillers. They are released into your body and then distributed throughout your nervous system when you laugh.___4__ It sharpens up the immune system. When you laugh, your heart serves as the central pump that puts blood through your blood vessels. This assists the lymphatic vessels(淋巴管)in carrying blood through your body and helps your lymph nodes to clean, removing waste products, dead cells, and even unwanted microorganisms.___5___ These are necessary for you to be at your best. Increased lymphatic flow equals a heightened, improved immune system.A.It regulates blood pressure.B.It provides more oxygen for the heart.C.Maintaining blood clean is important.D.Laughter has a positive influence on your heart.E.Here are some benefits of laughter on physical health.F.Regular laughter is often used to assist with pain management.G.When you laugh, all your body systems are affected positively.DWhat’s the use of language? Why does the human race learn to speak, write, and sign?___1__ Certainly the primary purpose of language is for communication. We use language to communicate our ideas and opinions to each other. We use it to tell others our thoughts. Sometimes we tell the truth. Sometimes we tell lies. But in all these cases, the basic aim is clear: to get the ideas in our head into someone else’s head. __2___ But there are several other uses of language where the basic aim has nothing to do with communicating ideas.____3____ Earlier in the book, I talked about accents and dialects. These tell people who we are and where we come from. In both ways we express our identities.Here’s another use of language: to express our emotions. Imagine you’re hammering a nail into a piece of wood, but something goes wrong and you hit your finger instead. What will come out of your mouth? ____4____ But quite a few would shout, “Stupid hammer!” as if it was the hammer’s fault. What sort of language is this? The hammer doesn’t have a brain, so it can’t possibly understand us. So what are we doing? Actually, we just want to get rid of our nervous energy. By shouting at the hammer, we feel a bit better.We also use language to avoid embarrassment and get on with other people. Imagine people sometimes say such things as “Looks like rain” or “Lovely day” when they meet each other. They don’t want to start a proper conversation, but they feel it would be rude to pass by in silence.____5____A.Therefore, they make a comment on the weather.B.One of these uses of language is to express identity.C.Of course, if you’re very brave you might not say anything.D.It shows that we’re getting on well with the people we’re talking to.E.And for that to happen, we must speak them, write them, or sign them.F.We might think the answer is very simple: to communicate with each other.G.Rather a large number of people, I suspect, would shout out something bad.EHow to Save Water During a Drought?The drought is happening because of climate change. California just had its driest year in a century. Gov. Gavin Newsom has declared a statewide drought emergency, asking all Californiansto save water in every way possible. ___1___ , though you can’t save California on your own Small things can add up. You’ve probably heard these tips before, but consider this a refresher course: Don’t let the water running while you wash dishes in the sink or washing, brushing or shaving. ___2__ . Water outdoor plants in the morning or evening, so you don’t lose as much water to evaporation in the midday sun.Replace old appliances. How old is your toilet? If it’s from before 1990, it could be using up to 6 gallons per flush. Newer toilets may use as little as 1.28 gallons or less. ___3__ . Upgrading your dishwasher and washing machine and any other water-intensive appliance will also pay savings dividends(红利), in both water and energy costs.__4_ . Keep an eye on your water bill. If it creeps higher than normal without a good reason, investigate whether you have a leak somewhere. Depending on the type of water meter(仪表)you have, you may be able to monitor the meter with all your water turned off and see whether anything is still moving through your system, __5__ .Consider your overall lifestyle of water usage and do everything within your power to use less water. Individual action can make a big change.A.Focus on the water billB.Individual action mattersC.Find out the potential problemD.They can save a lot per household per dayE.It’s political action that brings a significant changeF.You may also use a smart detector to tell you once there’s a problemG.Only run washing machines and dishwashers when you have a full load全国百所名校2023年高考英语备考一轮复习资料七选五专练题组汇编答案(三)CFAEG【导语】本文是一篇说明文。

高考英语 真题题组训练(三)

高考英语 真题题组训练(三)

高考真题题组训练(三)Ⅰ.完形填空(2017全国Ⅰ)While high school does not generally encourage students to explore new aspects of life,college sets the stage for that exploration.I myself went through this 1 process and found something that has changed my 2 at college for the better:I discovered ASL—American Sign Language (美式手语).I never felt an urge to 3 any sign language before.My entire family is hearing,and so are all my friends.The 4 languages were enough in all my interactions(交往).Little did I know that I would discover my 5 for ASL.The 6 began during my first week at college.I watched as the ASL Club 7 their translation of a song.Both the hand movements and the very 8 of communicating without speaking 9 me.What I saw was completely unlike anything I had experienced in the 10 .This newness just left me 11 more.After that,feeling the need to 12 further,I decided to drop in on one of ASL club’s meetings.I only learned how to 13 the alphabet that day.Yet instead of being discouraged by my 14 progress,I was excited.I then made it a point to 15 those meetings and learn all I could.The following term,I 16 an ASL class.The professor was deaf and any talking was 17 .I soon realized that the silence was not unpleasant. 18 ,ifthere had been any talking,it would have 19 us to learn less.Now,I appreciate the silence and the 20 way of communication it opens.1.A.searching B.planning C.natural D.formal2.A.progress B.experience C.major D.opinion3.A.choose B.read C.learn D.create4.A.official B.foreign C.body D.spoken5.A.love B.concern C.goal D.request6.A.meeting B.trip C.story D.task7.A.recorded B.performed C.recited D.discussed8.A.idea B.amount C.dream D.reason9.A.disturbed B.supported C.embarrassed D.attracted10.A.end B.past C.course D.distance11.A.showing B.acting C.saying D.wanting12.A.exercise B.explore C.express D.explain13.A.print B.write C.sign D.count14.A.slow B.steady C.normal D.obvious15.A.chair B.sponsor C.attend anize16.A.missed B.passed C.gave up D.registered for17.A.prohibited B.welcomed C.ignored D.repeatedstly B.Thus C.Instead D.However19.A.required B.caused C.allowed D.expected20.A.easy B.popular C.quick D.new语篇解读:本文是记叙文,主要讲述了作者在大学期间是怎样被美式手语所吸引并开始学习美式手语的。

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水坪镇中心学校初三物理2018年中考复习题组训练(三)
《质量与密度》
一、选择题
1. 【2013年 十堰市中考】下列图像中,正确反映物理量之间关系的是
2、【2015年 十堰市中考】如图,将同一密度计分别放入盛有甲、乙两种液体的烧杯中,它竖直立在液
体中,如果密度计受到的浮力分别为F 甲、F 乙,液体的密度分别为ρ甲、ρ乙。

则( ) A 、F 甲=F 乙 ρ甲>ρ乙 B 、F 甲=F 乙 ρ甲<ρ乙 C 、F 甲<F 乙 ρ甲<ρ乙
D 、F 甲<F 乙 ρ甲>ρ乙
3.【2016年 十堰市中考】小明是一名九年级学生,下面是一些关于他的数据,你认为符合实际的是( ) A .他的课桌高度约为75dm B .他步行的速度约为4m/s
C .他的质量约为50kg
D .他提起装有20个鸡蛋的塑料使用的力约为1N 5.(2016·桂林中考)下列事例中,物体的质量发生变化的是 ( ) A.由热变冷的铝锅 B.烧杯中正在沸腾的水 C.铁球被压成铁饼
D.从地球带到太空的食品
7.(2017·自贡中考)甲、乙两种物质的m-V 图象如图所示,分析图象可知 ( )
A.若甲、乙的质量相等,则甲的体积较大
B.若甲、乙的体积相等,则甲的质量较小
C.两物质的密度之比为4∶1
D.两物质的密度之比为1∶4 二、填空题 1. 【2017年 十堰市中考】如图所示,边长为a 正方体木块漂浮在密度为ρ的液体
中,有体积露出液面,则木块的密度为 ,木块下表面受到液体的压强为 ,若把木块露出液面的部分切去时,木块将 (选填“上浮”、“保持不动”或“下沉”)。

3. (2017·南充中考)容积为250mL 的容器,装满水后的总质量为300g,则容器质量为 g;若装满另一种液体后的总质量为250g,则这种液体的密度为 g/cm 3。

(ρ水=1.0×103
kg/m 3
)
4. (2017·哈尔滨中考)一个杯里装有200mL 牛奶,其中牛奶的质量是210g,那么牛奶的密度是 g/cm 3
;小聪喝了半杯,剩余半杯牛奶的密度 (选填“变大”“不变”或“变小”)。

三、实验探究题 1、【2014年 十堰市中考】小明用天平、小玻璃杯和水测量食用油的密度(水的密度为ρ水),实验步骤如下:
A 、将天平放在水平桌面上,分度盘指针如图所示。

接下来应该:先将游码移到标尺________刻度线处,并调节____________,使天平平衡;
B 、用天平测出空玻璃杯的质量为m 0;
C 、用记号笔在玻璃杯上做一个标记,向玻璃杯内加水到标记处,用天平测出水和杯的总质量为m 1;
D 、将杯内的水全部倒出,并用干抹布擦干,向玻璃杯内加入 _________________,用天平测出________________________。

(1)在上面横线上将步骤补充完整,用规定符号表示所测物理量。

(2)食用油密度的表达式(用所测物理量的符号表示)为:ρ油=_________。

(2分)
2、【2015年 十堰市中考】如图是小明用量筒、小玻璃杯和水测量某工艺品密度的示意图。

小明读出空玻璃杯漂浮在水面上时水面的示数是_______mL ,工艺品的质量是________g ,体积为_______cm 3,密度为______kg/m 3。

2题图 3题图
3.【2016年 十堰市中考】在探究影响浮力大小因素的实验中,同学们提出了如下猜想:
猜想1:浮力大小与物体排开液体的体积有关; 猜想2:浮力大小与液体的密度有关;
猜想3:浮力大小与物体浸没在液体中的深度有关. (1)实验中物体浸没在水中时受到的浮力为 N .
(2)分析实验B 、C 可知猜想1是正确的是,可以得到在同种液体中物体排开液体的体积越大,受到的浮力 .比较实验 可知,浮力大小还与液体的密度有关.
(3)图中F 3= N ,液体的密度ρ液= kg/m 3.(ρ水=1.0×103kg/m 3
).
(4)实验所用的科学研究方法是 .
4、【2014年 十堰市中考】如图甲是“探究浮力大小”的实验过程示意图。

(1)实验步骤C 和D 可以探究浮力大小与_______________的关系,步骤B 和______可以测出物块浸没在水中时受到的浮力F 浮,步骤A 和______可以测出物块排开的水所受重力G 排;比较F 浮与G 排,可以得到浮力的大小跟物体排开的水所受重力的关系。

(2)图乙是物块缓慢浸入水中时,弹簧测力计示数F 随浸入深度h 变化的关系图像。

分析图象,可得关于浮力大小的初步结论:
①物块浸没前,___________________________________,物块所受的浮力越大; ②物块浸没后,所受的浮力大小与____________________无关。

(3)此物块的密度是_______________g/cm 3。

(2分)
5.【2017年 十堰市中考】小芳在复习力学实验时,重温了部分实验,于是她选做测量苹果醋的密度,
(第5题图)
(1)她的主要实验步骤如下:
A .将天平放在水平台上,把游码放在零制度线处,发现指针如图甲所示,要使横梁平衡她应将平衡螺母向 (选填“左”或“右”)调;
B .用调好的天平称出空烧杯的质量为20g ;
C .在烧杯中倒入适量的苹果醋,用天平称出烧杯和苹果醋的总质量,天平平衡时,左盘中砝码的质量和游码的位置如图乙所示,则苹果醋和烧杯的总质量为 g ;
D .她将烧杯中的苹果醋倒入量筒中,量筒内液面静止时苹果醋的体积如图丙所示。

(2)小芳算出苹果醋的密度ρ= kg/m 3。

(3)同组的小明认为,小芳这种方法测出苹果醋密度会 (选填“偏大”或“偏小”).只需对小芳的实验步骤进行调整,就可减小实验误差,小明调整后的实验步骤为 (填序号)。

(4)小芳又设计了用浮力知识测量苹果醋密度的实验,她找来了弹簧测力计。

小铁块、细线。

她先用弹黄测力计称出了小铁块在空气中的重力为G ,然后将小铁块浸没在苹果醋中,记下弹簧测力计示数为
F .已如铁的密度为ρ铁,则苹果醋密度的表达式ρ= 。

6.(2017·连云港中考)为了测量一小石块的密度,小明用天平测量小石块的质量,平衡时右盘所加砝码及游码的位置如图甲所示;图乙是小石块放入量筒前后的液面情况。

由测量可得小石块质量为
g,小石块的体积为 mL,所测小石块的密度为 kg/m 3。

7.(2016·广安中考)如图所示,这是小强同学设计的测牛奶密度的实验步骤及他的操作示意图: A.测出空杯子的质量为m1(如图A); B.将一袋牛奶倒一部分在空杯中,测得总质量为m2(如图B);C.将杯中的牛奶再倒入量筒中,测得其体积为V(如图C); D.计算出牛奶的密度ρ。

(1)小强测得牛奶的质量m= g 。

(2)请你帮小强计算出牛奶的密度ρ= kg/m 3。

(3)其实小强设计的实验步骤有明显的瑕疵,由于往
量筒中倒牛奶时不可能倒尽,因此按他设计的步骤测出的牛奶密度值将 (选填“偏大”或“偏小”)。

(4)细心而聪明的你一定已经发现,只要调整一下操作顺序就可以避免这一瑕疵,说说你调整后的操作顺序 (请重新排列ABCD 的顺序)。

②用弹簧测力计悬挂金属块浸没在未知液体中(未接触烧杯底),其示数为F 1; ③用弹簧测力计悬挂金属块浸没在水中(未接触烧杯底),其示数为F 2;
④未知液体密度的表达式:ρ= 。

(用字母表示,已知水的密度为ρ水)。

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