(南武实验中学)2014学年九年级上期中考试
- 格式:doc
- 大小:101.50 KB
- 文档页数:12
广州市南武实验学校2016学年九年级上期中考数学试卷(问卷)考生注意:1.本次考试时间120分钟,满分150分,共三大题,25小题;2.把答案写在答卷规定位置上,在试卷上答题不得分;3.考试不准使用计算器.一、选择题(每小题3分,共30分)1.抛物线y=(x-2)2-1的顶点坐标是()A.(2, 1)B.(2,-1)C.(-2,1)D.(-2,-1)2.用配方法解一元二次方程x2-6x-4=0,下列变形正确的是()A.(x-6)2= - 4+36 B.(x-6)2= 4+36C.(x-3)2= - 4+9 D.(x-3)2= 4+93.下列图形中,既是轴对称图形有是中心对称图形的是()A.等边三角形B.平行四边形C.正五边形D.菱形4.一元二次方程4x2-4x+1=0的根的情况是()A.没有实数根B.只有一个实数根C.有两个相等实数根D.有两个不相等实数根5.如果将抛物线y=x2+2向下平移1个单位,那么所得新抛物线的表达式是()A.y=(x-1)2+2 B.y=(x+1)2+2 C.y=x2+1 D.y=x2+36.如图1,点A,B,C,P在⊙O上,CD⊥OA,CE⊥OB,垂足分别为D,E,∠DCE =40°,则∠P的度数为()A.140°B.70°C.60°D.40°7.如图2,将线段AB绕点O顺时针旋转90°得到线段A′B′,那么A(−2,5)的对应点A′的坐标是()A.(2,5)B.(5,2)C.(2,−5)D.(5,−2)图1 图2 图38.如图3,四边形ABCD内接于⊙O,如果它的一个外角∠DCE=64°,那么∠BOD=()A.128°B.100°C.64°D.32°9.关于抛物线y=x2-2x+1,下列说法错误的是()A.开口向上B.与x轴有两个重合的交点C.对称轴是直线x=1 D.当x>1时,y随x的增大而减小10.已知二次函数y=4x2-4x+m的图像与x轴的交点坐标为(x1,0),(x2,0)且(x1+x2)(4x12-5x1-x2)=8,则该函数的最小值是()A.2 B.-2 C.10 D.-10二、填空题(每小题3分,共18分)11.一元二次方程x2-3x=012.已知点P(1,4),它关于原点对称的点的坐标是.13.关于x的方程x2-2x+b=0有两个不相等的实数根,则实数b的取值范围是.14.已知⊙O的直径AB=10cm,弦CD=8cm,AB⊥CD,那么圆心O到CD的距离是.15.设x1,x2是方程x2-4x+m=0的两个根,且x1+x2-x1x2=1则x1+x2=,m= .16.如图,边长为4的正方形ABCD内接于⊙O,点E是弧AB上的一动点(不与A、B 重合),点F是弧BC上的一点,连接OE、OF,分别与AB、BC交于点G,H,且∠EOF =90°,有以下结论:①弧AE=弧BF;②△OGH是等腰直角三角形;③四边形OGBH的面积随着点E位置的变化而变化;④△GBH周长的最小值为其中正确的是.(把你认为正确结论的序号都填上).图4三、解答题(共102分)17.(满分9分)解方程:x2+2x-5=018.(满分9分)在下列网格图中,每个小正方形的边长均为1个单位.在Rt△ABC中,∠C=90°,AC=3,BC=4.(1)试在图中做出△ABC以A为旋转中心,沿顺时针方向旋转90°后的图形△AB1C1;(2)若点B的坐标为(−3,5),试在图中画出直角坐标系,并标出A、C两点的坐标;(3)根据(2)的坐标系作出与△ABC关于原点对称的图形△A2B2C2,并标出B2、C2两点的坐标.19.(满分10分)如图,△ABE和△ACD都是等边三角形,△AEC逆时针旋转一定角度后能与△ABD重合,EC与BD相交于点F.(1)旋转中心是,旋转角至少是度;(2)求∠DFC的度数.20.(满分10分)如图,有一块长方形铁皮,长40cm,宽30cm,在它的四角各切去一个同样的正方形,然后将四周突出的部分折起,就能制作一个无盖方盒.如果要制作的无盖方盒的底面积为600cm2,那么铁皮各角应切去多大的正方形?21.(满分12分)已知:如图,C,D是以AB为直径的⊙O上的两点,且OD∥BC.求证:AD=DC.22.(满分12分)已知关于x的一元二次方程x2−2mx+m2−m=0有两个实数根a、b;(1)求实数m的取值范围;(2)求代数式a2+b2−3ab的最大值.23.(满分12分)在⊙O中,AB为直径,点C为圆上一点,将劣弧AC沿弦AC翻折交AB于点D,连结CD.(1)如图1,若点D与圆心O重合,AC=2,求⊙O的半径r;(2)如图2,若点D与圆心O不重合,∠BAC=25°,请直接写出∠DCA的度数.24.(满分14分)在平面直角坐标系xOy中,抛物线y=ax2+bx+2过B(−2,6),C(2,2)两点.(1)试求抛物线的解析式;(2)记抛物线顶点为D,求△BCD的面积;(3)若直线y=−12x向上平移b个单位所得的直线与抛物线段BDC(包括端点B、C)部分有两个交点,求b的取值范围.25.(满分14分)已知,m,n是一元二次方程x2+4x+3=0的两个实数根,且|m|<|n|,抛物线y=x2+bx+c的图象经过点A(m,0),B(0,n),如图所示.(1)求这个抛物线的解析式;(2)设(1)中的抛物线与x轴的另一个交点为C,抛物线的顶点为D,试求出点C,D 的坐标,并判断△BCD的形状;(3)点P是直线BC上的一个动点(点P不与点B和点C重合),过点P作x轴的垂线,交抛物线于点M,点Q在直线BC上,距离点P P的横坐标为t,△PMQ的面积为S,求出S与t之间的函数关系式.广州市南武实验学校2016学年九年级上期中考答案一、选择题(本大题共有10小题,每小题3分,满分30分) 二、填空题(本大题共有6小题,每小题3分,满分18分)11.x 1=0,x 2=3 12.(-1,-4) 13.b <1 14.3cm 15.4,3 16.①②三、解答题(本大题共9小题,满分102 分.解答应写出文字说明、证明过程或演算步骤)17.解: x 2+2x-5=0(x+2)2=6………………………3分………………6分x 1=-2+ x 29分18.解:(1)△AB 1C 1如图所示;……………3分(2)如图所示,A (0,1),C (−3,1);……………6分(3)△A 2B 2C 2如图所示,B 2(3,−5),C 2(3,−1).……………9分19.解:(1)如图,∵△ABC 的等边三角形, ∴∠EAB =60°.……………1分∵△AEC 逆时针旋转一定角度后能与△ABD 重合, ∴点A 是旋转中心,∠EAB 是旋转角,……………3分∴,△AEC 逆时针旋转至少60°后能与△ABD 重合,……………5分(2)∵根据旋转的性质知,△AEC ≌△ABD , ∴∠AEC =∠ABD ,…………6分∵∠AGC =∠AEG +∠EAB =∠AEC +60°,∴∠AGC=∠GFB+∠ABD=∠GFB+∠AEC,∴∠AEC+60°=∠GFB+∠AEC,…………8分∴∠GFB=60°,∴∠DFC=∠GFB=60°.…………10分20.解:设切去的小正方形的边长为x.(40−2x)(30−2x)=600.解得x1=5,x2=30.当x=30时,30−2x<0,∴x=30不合题意,应舍去.答:铁皮各角应切去边长为5cm的正方形.21.解:证明:连结OC,如图,∵OD∥BC,∴∠1=∠B,∠2=∠3,又∵OB=OC,∴∠B=∠3,∴∠1=∠2,∴AD=DC.22.解:(1)根据题意得△=(−2m)2−4(m2−m)≥0,解得m≥0;…………4分(2)∵关于x的一元二次方程x2−2mx+m2−m=0有两个实数根a、b,∴a+b=2m,ab=m2−m,…………6分∴a2+b2−3ab=(a+b)2−5ab=(2m)2−5(m2−m)=−m2+5m=−(m−52)2+254,…………10分由(1)得m≥0,∴代数式a2+b2−3ab的最大值为254.…………12分23.解:(1)如图,过点O作OE⊥AC于E,则AE=12AC=12×2=1,∵翻折后点D与圆心O重合,∴OE=12r,…………3分在Rt△AOE中,AO2=AE2+OE2,即r2=12+(12r)2,解得r=3;…………6分(2)连接BC,∵AB是直径,∴∠ACB=90°,∵∠BAC=25°,∴∠B=90°−∠BAC=90°−25°=65°,…………9分根据翻折的性质,弧AC所对的圆周角为∠B,弧ABC 所对的圆周角为∠ADC,∴∠ADC+∠B=180°,∴∠B=∠CDB=65°,∴∠DCA=∠CDB−∠A=65°−25°=40°.…………12分24.解:25.解:(3)如图。
2024学年第一学期广州市南武教育集团九年级物理联合练习题(本试卷分第一部分和第二部分,总分90分,考试时间60分钟)注意事项:1.答题前,考生务必在答题卡上用黑色字迹的签字笔或钢笔填写自己的考生号、姓名;填写考点考场号、座位号;再用2B 铅笔把对应该两号码的标号涂黑。
2.第一部分每小题选出答案后,用2B 铅笔把答题卡上对应题目的答案标号涂黑;如需改动,用橡皮擦干净后,再选涂其他答案;不能答在试卷上。
3.第二部分答案必须写在答题卡各题目指定区域内的相应位置上;如需改动,先划掉原来的答案,然后再写上新的答案,改动的答案也不能超出指定的区域;除作图可用2B 铅笔外,其他都必须用黑色字迹钢笔或签字笔作答.不准使用涂改液.不按以上要求作答的答案无效。
4.考生必须保持答题卡的整洁.考试结束后,将本试卷和答题卡一并交回。
5.全卷共18小题,请考生检查题数。
第一部分(选择题,共30分)选择题(每小题3分,每小题给出的四个选项中,只有一项最符合题意)1.下列说法,正确的是( )A.物体的温度越高,它含有的热量越多B.热传递过程中甲自发地把热量传递给乙,此时甲的温度一定比乙高C.50℃水的内能一定比10℃水的内能多D.外界对物体做功,物体内能一定增大2.夏天,小明往玻璃杯倒水,一会儿杯壁上出现小水珠.一段时间后小水珠消失了。
关于这种现象,下列说法正确的是( )A.水珠的形成是汽化现象 B.倒入的可能是冰水C.水珠一定出现在玻璃杯的内壁上 D.水珠消失时放热3.某路灯系统的太阳能电池白天将太阳能转化为电能,对蓄电池充电,晚上蓄电池对路灯供电.下图方框中能量形式判断正确的是( )A.甲是“电能”B.乙是“太阳能”C.丙是“电能”D.丁是“机械能”4.如图所示,和是由同种材料制成的长度相同、横截面积不同的两段导体,将它们串联后连入电路中,下列说法正确的是( )A.段电阻大,电流小B.段电阻大,电流小AB BC AB BCC.段电阻大,电流与段相等D.段电阻大,电流与段相等图甲是一标准大气压下,一定质量的某种物质熔化过程的温度变化图像。
2014学年广州市南武中学上学期期中考试第一部分积累与运用(24分)1.下列加点字的注音全部正确的一项是()(2分)A、澄.清(chéng )酝酿.(niàng)葡萄蔓.(wàn)烘.(hōng)托B、倾.(qīn)向停滞.(zhì)水波粼粼.(lín)贮.(zhù)蓄C.、.威慑(..zhu.....à.n.)着...攥(...sh..è)...sh..à)间..黄晕(...y.ū.n.).一霎(D、枯涸.(hé)搓.(chuō)捻忍俊不禁(jīn)菡萏.(dàng)2.下列词语没有错别字的一项是()(2分)A、繁蜜絮絮叨叨棰打迷迷糊糊B、尴尬独具慧眼叛逆繁华嫩叶C、绽开恍然大悟喉咙各得其所D、发髻宽宏大量烂漫不求甚解3.下列语段中,加点词语运用不恰当的一项是()(2分)阳春三月,和煦的春风和沁人的花香相得益彰,广州处处春意盎然,美不胜收....,无论在增城的白水寨、南沙的百万葵园,还有市内的流花湖公园、云台花园,到处都是碧草连天、花团锦簇.......的景象。
在这美好的时节,与同学一起畅游花海,尽情享受天伦之....。
一派生机勃勃乐.,这是人生一大乐事。
A、美不胜收B、花团锦簇C、生机勃勃D、天伦之乐4,下列句子中,没有语病的一项是()(2分)A、这次送温暖活动中,社会各界给贫困山区学生捐赠了一批衣物、文具、图书等学习用品。
B、语文课堂上,积极创设有效的教学情境,有利于提高学生学习的感悟能力和创新精神。
C、谁都不能否认,汉字书写最终升华为一门艺术,这在世界的各种文字发展史上不是一个奇迹。
D、综合公众投票和专家评审的结果,“千年羊城、南国明珠”被正式定为广州城市形象的表述词。
5.下面各项对文学常识描述完全正确的一项是()(2分)A、律诗的四联按先后顺序分别是:首联、颈联、颔联、尾联。
B、《论语》和《诗经》《大学》《中庸》并称为“四书”,《论语》是孔子编写的。
江西省朝宗实验学校2013-2014学年度上学期九年级期中考试化学试卷一、单项选择题(本大题包括10小题,每小题2分,共20分。
)1. 下列变化中,前者属于物理变化,后者属于化学变化的是()A. 水结冰冰融化B. 铁生锈铁熔化C. 汽油挥发汽油燃烧D. 牛奶酸败牛奶煮沸2. 下列实验现象的描述中正确的是()A. 木炭在氧气中燃烧产生白烟B. 铁丝在空气中燃烧,火星四射C. 红磷在氧气中燃烧产生大量白雾D. 干冰在空气中升华周围出现白雾3. 决定元素种类的是()A. 质子数B. 中子数C. 最外层电子数D. 核外电子数4. 下列对水的叙述正确的是()A. 地球上淡水资源分布很均匀B. 水的污染会引起土壤污染C. 吸附能除去水中所有杂质D. 水由三个原子构成5. 下图所示实验操作正确的是()6. 下列说法正确的是()A. 分子的质量大,原子的质量小B. 分子可直接构成物质,原子不能直接构成物质C. 在化学反应中,分子可分,原子不可分D. 分子之间有间隔,原子之间没有间隔7. 下图是表示物质分子的示意图,图中“●”和“○”分别表示两种含有不同质子数的原子,则图中表示单质的是()8. 元素氟与人体健康密切相关。
下图是周期表中有关氟元素的信息,下列叙述不正确...的是( )A. 原子序数是9B. 元素名称是FC. 氟单质常温下为气态D. 相对原子质量是19.00 9. 以下对2O 、2CO 、2SO 、2MnO 四种物质组成的说法中,正确的是( )A. 都含有氧分子B. 都含有2个氧原子C. 都含有氧元素D. 都含有2个氧元素10. 下列所述情况①城市生活污水的任意排放;②农业生产中农药、化肥使用不当;③海上油轮石油泄漏;④工业生产中“三废”的任意排放,可能引起水污染的是( )A. 只有①③B. 只有①④C. 只有②④D. ①②③④二、选择填充题(本大题包括5小题,每小题3分,共15分。
先在ABC 中选一个正确选项填在括号内,然后在D 处再补充一个符合题意的答案,每小题的选择2分,填充1分)11. 下列符号中,既能表示一种元素,又能表示一个原子,还能表示一种物质的是( )A. CuB. 2OC. HD. __________ 12. 下列仪器中,能在酒精灯火焰上直接加热的是( )A. 集气瓶B. 烧杯C. 燃烧匙D. _______13. 下列化学反应属于分解反应的是( )A. 氧化镁点燃氧气镁−−→−+B. 氧气水二氧化锰过氧化氢+−−−−→−C. 四氧化三铁点燃氧气铁−−→−+D. _________________________14. 运送“天宫一号”的是“长征二号F —T1”运载火箭,火箭主要燃料是偏二甲肼(化学式为282N H C )。
2014-2015学年下海珠区九年级一模(六校联考)一、选择题(本大题共10小题,每小题3分,满分30分,在每小题给出的四个选项中,只有一项是符合题目要求的.)1、2-的相反数是( ) A.2- B.21- C.2 D.21 2、下图为主视图方向的几何体,它的俯视图是( )A. B. C. D.3、用科学记数法表示660000的结果为( )A.41066⨯B.5106.6⨯C.61066.0⨯D.6106.6⨯4、如图,直线b a 、被直线c 所截,且a ∥b ,如果0661=∠,那么2∠=( )A.066B.0114C.0124D.0245、一本笔记本a 元,一只笔比一本笔记本贵2元,则买3本笔记本,2只笔一共( )A.元)43(+aB.)45(+a 元C.)22(+a 元D.)25(+a 元6、下面计算正确的是( )A.3331052x x x =⋅B.1052x x x =⋅C.56x x x =÷D.853)(x x =7、如图,将三角尺ABC (其中0090,60=∠=∠C ABC)绕B 点按顺时针方向转动一个角度到11BC A ∆的位置,使得点A ,B ,1C 在同一条直线上,那么这个角度等于( )A.0120B.090C.060D.030第4题图 第7题图8、已知一次函数b kx y+=的图像如图,当0<x 时,y 的取值范围是( ) A.1<y B.0<y C.2-<y D.12<<-y9、如图,数轴上A ,B 两点表示的数分别为1和3,点B 关于点A 的对称点为点C ,则点C 所表示的数是( )A.13-B.31-C.32-D.23-10、如图,AB 为⊙O 的直径,AC 交⊙O 于E 点,BC 交⊙O 于D 点,CD=BD ,070=∠C.现给出以下四个结论:①045=∠A ;②AC=AB ;③弧AE=弧BE ;④22BD AB CE =⋅.其中正确结论的序号是( )A.①②B.②③C.②④D.③④第8题图 第9题图 第10题图二、填空题(本大题共6小题,每小题3分,满分18分)11、不等式1335≥+x 的解集是_____________.12、与055互补的角是______.13、分式方程:131=+x 的解为_________. 14、观察下列图形的排列规律(其中分别表示三角形、正方形、五角星).若第一个图形是三角形,则第18个图形是__________.(填图形名称)15、如图,ABC PQR ∆∆是经过某种变换后得到的图形.如果ABC ∆内部任意一点M 的坐标为(b a ,),那么经过相同变换得到它的对应点N 的坐标为______.16、如图,点M 是ABC ∆内一点,过点M 分别作直线平行于ABC ∆的各边,所形成的三个小三角形1∆、32∆∆、(图中阴影部分)的面积分别是4,9和49,则ABC ∆的面积是________.第15题图第16题图三、解答题(本大题共9小题,满分102分.解答应写出文字说明、证明过程或验算步骤.)17、(本小题满分9分)解方程组:23 43 x yx y+=⎧⎨-=⎩.18、(本小题满分9分)已知:如图,AD∥BC,AB∥CD,AC平分BAD∠.求证:四边形ABCD是菱形.19、(本小题满分10分)在一次捐款活动中,某班学生捐款额有5元、10元、15元、20元四种情况.根据统计数据绘制了图①和图②两幅尚不完整的统计图.(1)该班共有_______名学生,学生捐款的众数是______;(2)将图②的统计图补充完整;(3)计算该班学生平均捐款多少元?20、(本小题满分10分)甲、乙两人玩“石头、剪刀、布”游戏.若甲、乙两人都随意做出三种手势中的一种,则两人一次性分出胜负的概率是多少?请用列表或画树状图的方法加以说明.21、(本小题满分12分)已知,60tan )1(02013+--=a 求代数式)3(3)3)(2(---+a a a 的值.22、(本小题满分12分)某学校组织340名师生进行长途考察活动,带有行李170件,计划租用甲、乙两种型号的汽车10辆.经了解两种车型的载客限制和行李载重,若租用甲型汽车x 辆,则学校租车方案需满足条件:4030(10)3401620(10)170x x x x +-≥⎧⎨+-≥⎩.(1)学校可选的可行租车方案有几种,请说明理由;(2)如果甲车的租金为每辆2000元,乙车的租金为每辆1800元,问哪种可行方案使租车费用最省?23、(本小题满分12分)如图,ABC ∆中,以BC 为直径的圆交AB 于点D ,ABC ACD ∠=∠.(1)求证:CA 是圆的切线;(2)若点E 是BC 上一点,已知BD=6,35tan ,32tan =∠=∠AEC ABC ,求弦CD 的长.24、(本小题满分14分)已知抛物线c bx ax y ++=2与y 轴交于点A(0,3),与x 轴交于点B (1,0),C (5,0).(1)求抛物线的解析式;(2)若点D 为线段OA 的一个三等分点,求过点D 且与直线DC 垂直的直线解析式;(3)设M 为OA 的中点,x 轴上有一点E ,在抛物线对称轴上有一点F ,若FA EF ME s ++=,则求当s 最小时,E 、F 两点的坐标及此时s 的值.25、(本小题满分14分)如图①,在直角梯形ABCD 中,AD ∥BC ,顶点D ,C 分别在AM ,BN 上运动(点D 不与A 重合,点C 不与B 重合),E 是AB 上的动点(点E 不与A 、B 重合),在运动过程中始终保持DE ⊥CE ,且a AB DE AD ==+.(1)求证:ADE ∆∽BEC ∆;(2)当点E 为AB 边的中点时(如图②),求证: ①AD+BC=CD ;②DE 、CE 分别平分BCD ADC ∠∠、;(3)设BEC m AE ∆=问,的周长是否与m 值有关,若有关,请用含m 的代数式表示BEC ∆的周长;若无关,请说明理由.。
2020-2021学年广东省广州市海珠区南武中学、南武实验学校联考九年级(上)期中数学试卷1.下列图形是我国国产品牌汽车的标识,其中是中心对称图形的是()A. B. C. D.2.下列方程中,不属于一元二次方程的是()A. 4x2=9B. x2+3x=0C. 3y2−5y=7−yD. 2y2−y=3+2y23.点(−2,3)关于原点对称的点的坐标是()A. (2,3)B. (−2,−3)C. (2,−3)D. (−3,2)4.要得到抛物线y=2(x+4)2−1,可以将抛物线y=2x2()A. 向左平移4个单位,再向上平移1个单位B. 向左平移4个单位,再向下平移1个单位C. 向右平移4个单位,再向上平移1个单位D. 向右平移4个单位,再向下平移1个单位5.将一元二次方程x2−4x+1=0化成(x+ℎ)2=k的形式,则k等于()A. −1B. 3C. 4D. 56.若关于x的一元二次方程x2−2x+m=0有两个不相等的实数根,则m的取值范围是()A. m<−1B. m<1C. m>−1D. m>17.若一元二次方程(2m+6)x2+m2−9=0的常数项是0,则m等于()A. −3B. 3C. ±3D. 98.用一段20米长的铁丝在平地上围成一个长方形,求长方形的面积y(平方米)和长方形的一边的长x(米)的关系式为()A. y=−x2+20xB. y=x2−20xC. y=−x2+10xD. y=x2−10x9.已知点A(−3,y1),B(−1,y2),C(2,y3)在二次函数y=x2+2x+c的图象上,则y1,y2,y3的大小关系是()A. y1>y2>y3B. y2>y3>y1C. y3>y1>y2D. 无法确定10.如图所示,已知二次函数y=ax2+bx+c(a≠0)的图象过原点,如图所示.给出以下四个结论:①abc=0;②a+b+c>0;③a>b;④4ac−b2<0.正确的有()A. 1个B. 2个C. 3个D. 4个11.抛物线y=3(x−2)2+5的顶点坐标是______ .12.设m、n是一元二次方程x2+2x−7=0的两个根,则m+n=______.13.抛物线y=x2−2x−3与x轴的交点坐标为______.14.如图,把Rt△ABC绕点A逆时针旋转40°,得到Rt△AB′C′,点C′恰好落在边AB上,连接BB′,则∠BB′C′=______度.15.已知二次函数y=x2−3x+m(m为常数)的图象与x轴的一个交点为(1,0),则关于x的一元二次方程x2−3x+m=0的两实数根是_______________.16.已知关于x的一元二次方程x2−(2m+1)x+m2−1=0有实数根a,b,则代数式a2−ab+b2的最小值为______.17.解方程:(1)x2−4x=0;(2)x2−x−1=0.18.如图,在平面直角坐标系中,每个小正方形的边长为1,△ABC各顶点都在格点上,点A,C的坐标分别为(−1,2)、(0,−1),结合所给的平面直角坐标系解答下列问题:(1)求AC的长;(2)将△ABC绕点C按逆时针方向旋转90°,画出旋转后的△A1B1C,直接写出A点对应点A1的坐标.19.“绿水青山就是金山银山”,为加快城乡绿化建设,某市2018年绿化面积约1000万平方米,预计2020年绿化面积约为1210万平方米.假设每年绿化面积的平均增长率相同.(1)求每年绿化面积的平均增长率;(2)若2021年的绿化面积继续保持相同的增长率,那么2021年的绿化面积是多少?20.如图,△ABC中,∠B=15°,∠ACB=25°,AB=4cm,△ABC按逆时针方向旋转一定角度后与△ADE重合,且点C恰好成为AD的中点,①指出旋转中心,并求出旋转的度数;②求出∠BAE的度数和AE的长.21.已知关于x的方程x2+2x+a−2=0.(1)若该方程有两个不相等的实数根,求实数a的取值范围;(2)当该方程的一个根为1时,求a的值及方程的另一根.22.已知二次函数y=−x2+4x+5,完成下列各题:(1)求出该函数的顶点坐标.(2)求出它的图象与x轴的交点坐标.(3)直接写出:当x为何值时,y>0.23.如图,在一面靠墙的空地上用长为24米的篱笆,围成中间隔有一道篱笆的长方形花圃,设花圃的宽AB为x米,面积为y平方米.(1)求y与x的函数关系式及自变量x的取值范围;(2)若墙的最大可用长度为9米,求此时当AB为多少米时长方形花圃的面积最大,最大面积是多少?24.已知在△ABC中,∠ACB=90°,AC=BC=4,现将一块边长足够大的直角三角板的直角顶点置于AB的中点O,两直角边分别经过点B、C,然后将三角板绕点O 按顺时针方向旋转一个角度α(0°<α<90°),旋转后,直角三角板的直角边分别与AC、BC相交于点K、H,四边形CHOK是旋转过程中三角板与△ABC的重叠部分(如图所示).那么,在上述旋转过程中:(1)线段BH与CK具有怎样的数量关系?四边形CHOK的面积是否发生变化?证明你发现的结论;(2)连接HK,设BH=x.①当△CHK的面积为3时,求出x的值.2②试问△OHK的面积是否存在最小值,若存在,求出此时x的值,若不存在,请说明理由.25.已知抛物线y=x2+kx+k−1.(1)当k=3时,求抛物线与x轴的两个交点坐标;(2)无论k取任何实数,抛物线过x轴上一定点,求定点坐标;(3)当k=5时,设抛物线与y轴交于C点,与x轴交于A,B(点A在点B的左边)两点,连接AC,在线段AC上是否存在点D,使△ABD是直角三角形,若存在,求出点D的坐标,若不存在,请说明理由.(4)点E(−1,1),点F(−2,2),抛物线与线段EF只有一个交点,求k的取值范围答案和解析1.【答案】D【解析】解:A、不是中心对称图形,故本选项不合题意;B、不是中心对称图形,故本选项不合题意;C、不是中心对称图形,故本选项不合题意;D、是中心对称图形,故本选项符合题意.故选:D.把一个图形绕某一点旋转180°,如果旋转后的图形能够与原来的图形重合,那么这个图形就叫做中心对称图形.本题考查了中心对称图形的概念,把一个图形绕某一点旋转180°,如果旋转后的图形能够与原来的图形重合,那么这个图形就叫做中心对称图形,这个点叫做对称中心.2.【答案】D【解析】解:A.是一元二次方程,故本选项不符合题意;B.是一元二次方程,故本选项不符合题意;C.是一元二次方程,故本选项不符合题意;D.是一元一次方程,故本选项符合题意;故选:D.根据一元二次方程的定义得出即可.本题考查了一元二次方程的定义,能熟记一元二次方程的定义的内容是解此题的关键.3.【答案】C【解析】解:∵点(−2,3)关于原点对称,∴点(−2,3)关于原点对称的点的坐标为(2,−3).故选:C.平面直角坐标系中任意一点P(x,y),关于原点的对称点是(−x,−y),即:求关于原点的对称点,横纵坐标都变成相反数.本题主要考查了平面直角坐标系中任意一点P(x,y),关于原点的对称点是(−x,−y),即:求关于原点的对称点,横纵坐标都变成相反数,比较简单.4.【答案】B【解析】解:∵y=2(x−4)2−1的顶点坐标为(−4,−1),y=2x2的顶点坐标为(0,0),∴将抛物线y=2x2向左平移4个单位,再向下平移1个单位,可得到抛物线y=2(x+ 4)2−1.故选:B.找到两个抛物线的顶点,根据抛物线的顶点即可判断是如何平移得到.本题考查了二次函数图象与几何变换,解答时注意抓住点的平移规律和求出关键点顶点坐标.5.【答案】B【解析】【分析】此题考查了解一元二次方程−配方法,熟练掌握完全平方公式是解本题的关键.方程配方得到结果,即可确定出k的值.【解答】解:方程x2−4x+1=0,配方得:x2−4x+4=3,即(x−2)2=3,则k=3,故选:B.6.【答案】B【解析】解:根据题意得△=22−4m>0,解得m<1.故选:B.根据根的判别式的意义得到△=22−4m>0,然后解不等式即可.本题考查了一元二次方程ax2+bx+c=0(a≠0)的根的判别式△=b2−4ac:当△>0,方程有两个不相等的实数根;当△=0,方程有两个相等的实数根;当△<0,方程没有实数根.7.【答案】B【解析】解:由题意,得m2−9=0且2m+6≠0,解得m=3,故选:B.一元二次方程ax2+bx+c=0(a,b,c是常数且a≠0)的a、b、c分别是二次项系数、一次项系数、常数项.本题考查了一元二次方程的一般形式:ax2+bx+c=0(a,b,c是常数且a≠0)特别要注意a≠0的条件.这是在做题过程中容易忽视的知识点.在一般形式中ax2叫二次项,bx叫一次项,c是常数项.其中a,b,c分别叫二次项系数,一次项系数,常数项.8.【答案】C【解析】解:∵长方形一边的长度为x米,周长为20米,∴长方形的另外一边的长度为(10−x)米,则长方形的面积y=x(10−x)=−x2+10x,故选:C.先由长方形一边的长度为x米,周长为20米,得出另外一边的长度为(10−x)米,再利用长方形的面积公式可得答案.本题主要考查根据实际问题列二次函数的关系式,根据实际问题确定二次函数关系式关键是读懂题意,建立二次函数的数学模型来解决问题.需要注意的是实例中的函数图象要根据自变量的取值范围来确定.9.【答案】C=−1,【解析】解:对称轴为直线x=−22×1∵a=1>0,∴x<−1时,y随x的增大而减小,x>−1时,y随x的增大而增大,∴y2<y1<y3.故选:C.求出二次函数的对称轴,再根据二次函数的增减性判断即可.本题考查了二次函数图象上点的坐标特征,求出对称轴解析式,然后利用二次函数的增减性求解更简便.10.【答案】C【解析】解:∵抛物线开口向下,∴a<0,∵抛物线经过原点,∴c=0,则abc=0,所以①正确;当x=1时,函数值是a+b+c<0,则②错误;∵抛物线的对称轴为直线x=−b2a =−32<0,∴b=3a<0,又∵a<0,∴a>b,则③正确;∵抛物线与x轴有2个交点,∴△=b2−4ac>0,即4ac−b2<0,所以④正确.故选:C.由抛物线开口方向得到a<0以及函数经过原点即可判断①,由抛物线的对称轴方程得到为b=2a<0,以及a的符号即可判断③;根据x=1时的函数值可以判断②;根据抛物线与x轴交点个数得到△=b2−4ac>0,则可对④进行判断.本题考查了二次函数图象与系数的关系:对于二次函数y=ax2+bx+c(a≠0),二次项系数a决定抛物线的开口方向和大小:当a>0时,抛物线向上开口;当a<0时,抛物线向下开口;一次项系数b和二次项系数a共同决定对称轴的位置:当a与b同号时(即ab>0),对称轴在y轴左;当a与b异号时(即ab<0),对称轴在y轴右;常数项c 决定抛物线与y轴交点位置:抛物线与y轴交于(0,c);抛物线与x轴交点个数由△决定:△=b2−4ac>0时,抛物线与x轴有2个交点;△=b2−4ac=0时,抛物线与x轴有1个交点;△=b2−4ac<0时,抛物线与x轴没有交点.11.【答案】(2,5)【解析】【分析】此题主要考查了二次函数的性质,解题的关键是熟练掌握抛物线y=a(x−ℎ)2+k的顶点坐标为(ℎ,k).由于抛物线y=a(x−ℎ)2+k的顶点坐标为(ℎ,k),由此即可求解.【解答】解:∵抛物线y=3(x−2)2+5,∴顶点坐标为:(2,5).故答案为:(2,5).12.【答案】−2【解析】解:∵m、n是一元二次方程x2+2x−7=0的两个根,∴m+n=−2.故答案为−2.直接根据根与系数的关系求解.本题考查了根与系数的关系:若x1,x2是一元二次方程ax2+bx+c=0(a≠0)的两根时,x1+x2=−ba ,x1x2=ca.13.【答案】(3,0),(−1,0)【解析】解:令y=0,则x2−2x−3=0,解得x=3或x=−1.则抛物线y=x2−2x−3与x轴的交点坐标是(3,0),(−1,0).故答案为(3,0),(−1,0).要求抛物线与x轴的交点,即令y=0,解方程.本题考查了抛物线与x轴的交点.求二次函数y=ax2+bx+c(a,b,c是常数,a≠0)与x轴的交点坐标,令y=0,即ax2+bx+c=0,解关于x的一元二次方程即可求得交点横坐标.14.【答案】20【解析】解:∵Rt△ABC绕点A逆时针旋转40°得到Rt△AB′C′,∴AB=AB′,∠BAB′=40°,在△ABB′中,∠ABB′=12(180°−∠BAB′)=12(180°−40°)=70°,∵∠AC′B′=∠C=90°,∴B′C′⊥AB,∴∠BB′C′=90°−∠ABB′=90°−70°=20°.故答案为:20.根据旋转的性质可得AB=AB′,∠BAB′=40°,然后根据等腰三角形两底角相等求出∠ABB′,再利用直角三角形两锐角互余列式计算即可得解.本题考查了旋转的性质,等腰三角形的性质,直角三角形的两锐角互余,比较简单,熟记旋转变换只改变图形的位置不改变图形的形状与大小得到等腰三角形是解题的关键.15.【答案】x1=1,x2=2【解析】【分析】关于x的一元二次方程x2−3x+m=0的两实数根就是二次函数y=x2−3x+m(m为常数)的图象与x轴的两个交点的横坐标.本题考查了抛物线与x轴的交点.解答该题时,也可以利用代入法求得m的值,然后来求关于x的一元二次方程x2−3x+m=0的两实数根.【解答】解:∵二次函数的解析式是y=x2−3x+m(m为常数),∴该抛物线的对称轴是:x=32.又∵二次函数y=x2−3x+m(m为常数)的图象与x轴的一个交点为(1,0),∴根据抛物线的对称性质知,该抛物线与x轴的另一个交点的坐标是(2,0),∴关于x的一元二次方程x2−3x+m=0的两实数根分别是:x1=1,x2=2.故答案是:x1=1,x2=2.16.【答案】916【解析】解:∵关于x的一元二次方程x2−(2m+1)x+m2−1=0有实数根a,b,∴a+b=2m+1,ab=m2−1,△≥0,∴△=[−(2m+1)]2−4×1×(m2−1)=4m 2+4m +1−4m 2+4=4m +5≥0,∴m ≥−54.∴a 2−ab +b 2=(a +b)2−3ab=(2m +1)2−3(m 2−1)=4m 2+4m +1−3m 2+3=m 2+4m +4=(m +2)2,∴a 2−ab +b 2的最小值为:(−54+2)2=916.故答案为:916.由韦达定理得出a ,b 与m 的关系式、由一元二次方程的根与判别式的关系得出m 的取值范围,再对代数式a 2−ab +b 2配方并将a +b 和ab 整体代入化简,然后再配方,结合m 的取值范围可得出答案.本题考查了配方法在代数式求值中的应用,熟练掌握配方法及一元二次方程的根与系数的关系及根与判别式的关系是解题的关键. 17.【答案】解:(1)x 2−4x =0,分解因式得:x(x −4)=0,解得:x 1=0,x 2=4;(2)x 2−x −1=0,∵a =1,b =−1,c =−1,∴△=b 2−4ac =1−4×1×(−1)=5,∴x =−b±√b 2−4ac 2a=1±√52×1, ∴x 1=1+√52,x 2=1−√52.【解析】(1)利用因式分解法求解即可;(2)利用公式法求解即可.此题分别考查了解一元二次方程,解题的关键是根据不同方程的形式选择最佳方法解决问题.18.【答案】解:(1)如图,AC=√12+32=√10.(2)如图,△A1B1C即为所求,A1(−3,−2).【解析】(1)利用勾股定理计算即可.(2)分别作出A,B的对应点A1,B1即可解决问题.本题考查作图−旋转变换,勾股定理等知识,解题的关键是理解题意,灵活运用所学知识解决问题.19.【答案】解:(1)设每年绿化面积的平均增长率为x.可列方程:1000(1+x)2=1210.解方程,得x1=0.1x2=−2.1(不合题意,舍去).所以每年绿化面积的平均增长率为10%.(2)1210×(1+10%)=1331(万平方米).答:2021年的绿化面积是1331万平方米.【解析】(1)先设每年小区绿化面积的增长率为x,根据2018年的绿化面积×(1+增长率)2=2020年的绿化面积,列出方程求解即可;(2)根据(1)得出的增长率列出算式,进行计算即可.此题考查了一元二次方程的应用;求平均变化率的方法为:若设变化前的量为a,变化后的量为b,平均变化率为x,则经过两次变化后的数量关系为a(1±x)2=b.20.【答案】①∵△ABC逆时针旋转一定角度后与△ADE重合,A为顶点,∴旋转中心是点A,根据旋转的性质可知:∠CAE=∠BAD=180°−∠B−∠ACB=140°,∴旋转角度是140°;②由旋转可知:△ABC≌△ADE,∴AB =AD ,AC =AE ,∠BAC =∠EAD =140°,∴∠BAE =360°−140°×2=80°,∵C 为AD 中点,∴AC =AE =12AB =12×4=2cm .【解析】①由旋转的性质可求解;②由旋转的性质可得AB =AD ,AC =AE ,∠BAC =∠EAD =140°,由周角的性质和中点的性质可求解.本题考查了旋转的性质,掌握旋转的性质是本题的关键.21.【答案】解:(1)∵方程有两个不相等的实数根,∴Δ=b 2−4ac =22−4×1×(a −2)=12−4a >0,解得:a <3.∴a 的取值范围是a <3;(2)设方程的另一根为x 1,由根与系数的关系得:{1+x 1=−21⋅x 1=a −2, 解得:{a =−1x 1=−3, 则a 的值是−1,该方程的另一根为−3.【解析】本题考查了一元二次方程根的判别式,一元二次方程根的情况与判别式Δ的关系:①Δ>0⇔方程有两个不相等的实数根;②Δ=0⇔方程有两个相等的实数根;③Δ<0⇔方程没有实数根.(1)关于x 的方程x 2+2x +a −2=0有两个不相等的实数根,即判别式Δ=b 2−4ac >0.即可得到关于a 的不等式,从而求得a 的范围.(2)设方程的另一根为x 1,根据根与系数的关系列出方程组,求出a 的值和方程的另一根.22.【答案】解:(1)y =−x 2+4x +5=−(x −2)2+9,则抛物线的顶点坐标为(2,9);(2)令y =−x 2+4x +5=0,解得x =5或−1,故图象与x 轴的交点坐标为(5,0)、(−1,0);(3)∵a=−1<0,故抛物线开口向下,故当−1<x<5时,y>0.【解析】(1)由y=−x2+4x+5=−(x−2)2+9即可求解;(2)令y=−x2+4x+5=0,解得x=5或−1,即可求解;(3)a=−1<0,则抛物线开口向下,即可求解.本题考查的是抛物线与x轴的交点,主要考查函数图象上点的坐标特征,要求学生非常熟悉函数与坐标轴的交点、顶点等点坐标的求法,及这些点代表的意义及函数特征.23.【答案】解:(1)设花圃的宽AB为x米,则BC=(24−3x)m,根据题意得出:y=x(24−3x)=−3x2+24x;∵墙的可用长度为9米,∴0<24−3x≤9,解得:5≤x<8,∴y=−3x2+24x(5≤x<8).(2)y=−3x2+24x=−3(x2−8x)=−3(x−4)2+48,∵5≤x<8,∴当x=5时,y最大值=45平方米.答:当AB为5米时,长方形花圃的面积最大,最大面积是45平方米.【解析】(1)求出y=AB×BC代入即可;利用0<24−3x≤9进而解出即可;(2)把解析式化成顶点式,再利用二次函数增减性即可得到答案.本题主要考查对二次函数的最值,二次函数的解析式,能把实际问题转化成数学问题是解此题的关键.24.【答案】解:(1)在旋转过程中,BH=CK,四边形CHOK的面积始终保持不变,其值为△ABC面积的一半.理由如下:连接OC∵△ABC为等腰直角三角形,O为斜边AB的中点,CO⊥AB∴∠OCK=∠B=45°,CO=OB,又∵∠COK与∠BOH均为旋转角,∴∠COK=∠BOH=α∴△COK≌△BOH∴BH=CK,S四边形CHOK =S△COK+S△COH=S△BOH+S△COH=S△COB=12S△ABC=4.(2)①由(1)知CK=BH=x,∵BC=4,∴CH=4−x,根据题意,得12CH⋅CK=32,即(4−x)x=3,解这个方程得x1=1,x2=3,此两根满足条件:0<x<4所以当△CKH的面积为32时,x的取值是1或3;②设△OKH的面积为S,由(1)知四边形CHOK的面积为4,于是得关系式:S=4−S△CKH=4−12x(4−x)=12(x2−4x)+4=12(x−2)2+2当x=2时,函数S有最小值2,∵x=2时,满足条件0<x<4,∴△OKH的面积存在最小值,此时x的值是2.【解析】(1)连接OC,可以证得:△COK≌△BOH,根据S四边形CHOK=S△COK+S△COH=S△BOH+S△COH=S△COB=12S△ABC即可证得:四边形CHOK的面积始终保持不变;(2)①BC=4,CH=4−x,三角形的面积公式可以得到:12CH⋅CK=32,即(4−x)x=3,从而求得x的值;②设△OKH的面积为S,根据三角形的面积公式,即可得到关于x的函数关系式,然后根据函数的性质即可求解.本题考查了三角形全等的判定与性质,以及二次函数的性质,正确列出函数解析式是解题的关键.25.【答案】(1)解:∵y=x2+kx+k−1,∴当k=3时,y=x2+3x+2,令y=0,得x2+3x+2=0,解得x1=−1,x2=−2,∴抛物线与x轴的交点坐标是(−1,0),(−2,0).(2)证明:∵y=x2+kx+k−1,∴当y=0时,x2+kx+k−1=0,解得x1=−1,x2=1−k,∴无论k取任何实数,抛物线过x轴上一定点(−1,0).(3)解:k=5时,抛物线的解析式为y=x2+5x+4,令y=0,可得x2+5x+4=0,解得x=−1或−4,∴A(−4,0),B(0,−1),令x=0,得到y=4,可得C(0,4),如图1中,∵OA=OC=4,∠AOC=90°,∴∠CAO=45°,当∠ABD′=90°时,AB=BD′=3,∴D′(−1,3),当∠ADB=90°时,AD=BD,可得D(−2.5,1.5).综上所述,满足条件的点D的坐标为(−1,3)或(−2.5,1.5).(4)如图2或图3中,观察图象可知,当x=−2时,y≥2即可满足条件,∴4−2k+k−1≥2,∴k≤1,∴k≤1时,抛物线与线段EF只有一个交点.【解析】(1)把k=3代入y=x2+kx+k−1,得到y=x2+3x+2,令y=0,得x2+ 3x+2=0,再解方程求出x的值,即可求解;(2)令x2+kx+k−1=0,解方程求得两根有一常数,问题得证;(3)k=5时,抛物线的解析式为y=x2+5x+4,求出抛物线与坐标轴的交点坐标,分两种情形,根据等腰直角三角形的性质求解即可;(4)观察图象可知,当x=−2时,y≥2即可满足条件,构建不等式,即可解决问题.本题属于二次函数综合题,考查了二次函数的性质,直角三角形的判定和性质等知识,解题的关键是理解题意,学会用分类讨论的思想思考问题,属于中考压轴题.。
广州市南武中学2014学年第一学期期中考问卷初二英语设计者:wen-ku 设计时间:2020年设计用途:公开文档类型:word Document source network, if there is infringement, contact the author to delete.考试时间120分钟满分135分一、听力(满分35分)略二、语言知识与运用第一节单项选择(每题1分,共10分)16. ---I’m quite busy these days. I don’t have ________ time to play chess with you.---That’s OK. But I think you may need ________ help.A. some; someB. any; anyC. some; anyD. any; some17. ---Thank you very much for your encyclopedia, Jane.---________.A. I’m so sorry.B. You’re welcome.C. How do you do?D. Never mind.18. There are ________ seasons in a year. My favourite one is the ________ winter.A. four; fourB. fourth; fourthC. four; fourthD. fourth; four19. He asked the question three times, but ________ answered it.A. somebodyB. anybodyC. nobodyD. everybody20. The new camera is _______ than the old one but it’s ________.A. small; expensiveB. smaller; more expensiveC. smaller; most expensiveD. small; more expensive21. All of us are looking forward to ________ the great musician.A. seeB. sawC. seeingD. seen22. ---How fast can a cheetah run?---________ a speed of over 100 kilometers an hour.A. AtB. WithC. ByD. On23. He ________ to Guangzhou in 2007. Since then, he ________ as a manage in the company.A. comes; worksB. came; workedC. came; has workedD. has come; worked24. --- Which kind of computers are ________. desktops or laptops?---Laptops, I think.A. goodB. betterC. bestD. the best25. Parents must do something to stop their children from ________ too much.A. watchB. watchingC. watchesD. watched第二节语法选择(每题1分,共10分)We don’t have electrical accidents very often. But ___26___ they happen, you should know what to do. It can make a ___27___ of “being alive or dead”. Maybe you won’t be in a fire all ___28___ life, but you can still tell the people around you how to save themselves. So it is very important for everyone ___29___ something about them.Sometimes electrical accidents can lead to fires. Electrical fires are different ___30___ other fires. Water conducts(传导) electricity. So throwing water in an electrical fire can only make the fire ___31___ than before. Here is ___32___ you should remember:1. NEVER use water in an electrical fire;2. Turn ___33___ the power in the house;3. If the fire is not a large one, tell an adult ___34___ it out properly(正确地). If the fire isa very large one, leave the house and take everyone with you;4. Call 119 and tell the police about ___35___ electrical fire. At last, leave the fire address and your name.26. A. why B. how C. what D. when27. A. differ B. difference C. differences D. different28. A. yourself B. you C. your D. yours29. A. to learn B. learn C. learning D. learnt30. A. to B. from C. of D. with31. A. strong B. the stronger C. stronger D. strongest32. A. what B. how C. which D. that33. A. on B. out C. off D. down34. A. put B. putting C. to put D. puts35. A. the B. an C. a D. /三、完形填空(每小题1分,共10分)The bicycle is one of the most useful inventions in the world. The great inventor Leonardo Da Vinci ___36___ pictures for bicycles but people began to ___37___ and ride them long afterhe died.When a person rides a bicycle, it ___38___ very little energy to move, and there is no ___39___ at all when you are riding. Even so, it developed ___40___. Most people don't travel or work by ___41___. It is not because bicycles are expensive or people feel ___42___ if they ride them to work. It is because the number of cars on the roads becomes larger. It certainly is ___43___ to ride a bicycle. So, more people put their bicycles away and go to work in their cars. In this way, the traffic is ___44___. Maybe the best way to make riding safer and more popular is to ___45___ roads only for bicycles, and to make it difficult and expensive for drivers to take their cars into the city.36. A. took B. drew C. saw D. found37. A. return B. decide C. check D. produce38. A. needs B. gets C. makes D. drives39. A. noise B. water C. pollution D. air40. A. gradually B. fast C. quickly D. slowly41. A. bike B. car C. bus D. taxi42. A. excited B. tired C. surprised D. interested43. A. slow B. dangerous C. busy D. boring44. A. worst B. worse C. good D. better45. A. build B. make C. produce D. create四、阅读理解(每小题2分,共40分)ATwenty-First Century BooksProbably you have seen someone reading a book on the electronic reading device(设备). Over the past few years, these small computers have become more popular. For that reason, more companies that make traditional paper books are now making electronic books (ebooks). Most ebooks are the same as paper books, but people download a file into a reading device rather than buying the paper book. In this way they can carry many books.Book companies are adding special features to some ebooks. These extra features might include sound files, picture files, or video files. When the readers click on these files they learn more about the book, the story, or the writer.The latest electronic readers are smaller and cheaper, but they are also much more powerful. They can store much more information, so writers and book companies can do more with their ebooks. They do not want to just add files to a completed book. They are making the sound, picture, and video files part of the story. Readers need these files to understand the whole story. Readers can even change the story.Readers already have a lot of books to choose from. If they can change the way stories end, they will have even more choices!46. This reading is about ________.A. books about the futureB. books written after 1999C. electronic booksD. popular writers today47. Which sentence is true about the devices described in the passage?A. You can use them to read ebooks.B. They change paper books into ebooks.C. You can use them to make videos.D. They weight less than a paper book.48. According to the passage, what special feature might some ebooks include?A. Copies of the paper book.B. Devices for other ebooks.C. Extra files.D. Other writers’ ebooks.49. Which of the following ebook is NOT mentioned in the passage?A. An ebook that has sold over million copies.B. An ebook that is only text.C. An ebook with a sound file that tells part of the storyD. An ebook with a video about writer.50. How are some ebooks today different than older ebooks?A. Companies sell them in many files.B. Readers can change the stories.C. Devices make them easier to read.D. Writers do not finish them.BA Computer ProblemComputers make people’s lives easier. People can use their computers for working, shopping, or playing games. Laptop computers make people’s lives even easier! Instead of just using a computer at home, people can take laptops anywhere. They can work, shop, or play games any place at any time. But there is a problem with laptops. People can be burned by them!People who sit with laptops on their legs for hours and hours have noticed they get dark marks on their legs. The hot laptop is toasting the skin. Doctors have noticed more people show up with “toasted skin syndrome(综合症).” They use their laptops every day for hours and hours for a month or more and this results in a burn. The marks are not dangerous, but they look strange because they are just in one spot on people’s legs.Companies that make computers tell people not to let warm computers touch bare skin for a long time. Wearing pants and putting a laptop’s case under the laptop is usually enough to protect one’s skin from the computer’s heart. But the best way to avoid(避免) toasted skin is not to put a laptop on your lap when you use it for a long time.51. This reading is about ________.A. a problem that companies may haveB. a problem that laptops may haveC. a problem that electronic devices may haveD. a problem that people may have52. What does toasted skin syndrome result in?A. A burn.B. A hot laptop.C. A dangerous problem.D. A way to protect your skin.53. How long does a person need to sit with a laptop on his or her lap to experience this problem?A. Less than 30 minutes.B. A few hours.C. About one week.D. More than a month.54. Which of the following is NOT true about toasted skin syndrome?A. It covers a person’s whole leg.B. It is not a dangerous problem.C. It is a burn.D. It looks like a brown spot.55. What can be guessed about the people who got toasted skin syndrome?A. They did not protect their laps well while using their laptops.B. They felt pain when their pants touched the burns on their legs.C. They tried to make the laptop companies pay the doctor’s bills.D. They were working outdoors with laptops.CThe World CupEvery four years, the world turns its attention to soccer and the FIFA World Cup. The most successful teams have traditionally come from South America and Europe. However, over theyears, there have been a number of surprising results.In a famous match in 1950, the USA came up against England, one of the favorites to win the tournament(锦标赛). Many of the American players were from college teams. Surprisingly, the USA won 1-0. Other World Cup surprises were North Korea's win over Italy in 1966, and Cameroon's win over Argentina in 1990.The 2002 FIFA World Cup stands out as probably the most surprising World Cup tournaments of all time. In the opening match, Senegal surprised everyone by beating France, the World Cup winner in 1998. South Korea, the co-host country that year with Japan, made it all the way to the final four, before finally losing to Germany.In the final game, Brazil ended up winning 2-0 against Germany. Brazil set a World Cup record by becoming the first team to win seven games in a row. Also, Brazil's most talented player, Ronaldo, scored eight goals in one tournament--more than any other player since 1970.The tournament of 2010, which was held in South Africa, ended in a match between two teams that had never won the World Cup before. In the final match, Spain beat the Netherlands 1-0 in extra time. This was also the first FIFA World Cup tournament in an African country.56. What is the best title for this passage?A. How the World Cup Is PlayedB. The History of SoccerC. The Greatest World Cup Players of All TimeD. Surprises in the World Cup57. According to the passage, which team has NOT had a surprising win in a World Cup match?A. Cameroon.B. Italy.C. North Korea.D. The United States.58. Which team probably surprise people the most in the 2002 World Cup?A. Germany.B. Spain.C. Japan.D. South Korea.59. What record did Ronaldo set in the 2002 tournament?A. First player to score eight goals.B. Most games played in a World Cup.C. Most goals scored in a World Cup since 1970.D. Oldest player to score in a World Cup.60. What is NOT true about the 2010 World Cup?A. A past winner of the World Cup won the tournament.B. Spain played in the finals.C. The Netherlands won in extra time.D. This was the first time the World Cup was held in South Africa.DBest Invention in 2013 on Times61. What is the article mainly about?A. Some rich companies in the world.B. Some amazing photos on Times.C. Some smart designers of Times.D. Some wonderful inventions around the world.62. According to the article, what can we learn about Anki?A. It is a company from the UK.B. It is a factory that makes toys for children.C. The sensors of its toy cars can connect with iPhones.D. The Anki Car can change the movement of other cars in the race.63. Who would probably be most interested in the 3D printing pen?A. An artist.B. A writer.C. A driver.D. An athlete.64. What will the small alarm do when it is almost out of power?A. It will give you a call.B. It will change batteries itself.C. It will tell you in human voice.D. It will leave a message on your phone.65. Which of the following is NOT the name of a company?A. Wobble WorksB. DilworthC. AnkiD. Nest五、写作第一节单词拼写(每小题1分,共5分)66. Could you tell me the d__________ between the Sun and the Moon?67. A c__________ is a period of 100 years.68. Does the shop s__________ this kind of sweets?69. A t__________ accident happened on Chunmu Road. A driver and two students died.70. Don’t c__________ Lily’s homework, John! Do it yourself.第二节完成句子(每小题2分,共10分)71. 请勿触摸。
广州市南武中学2014-2015学年第一学期期中考试问卷初三数学一、 选择题(本题有10小题,每小题3分,满分30分,下面每题给出四个选项,只有一个正确。
)1.下列汽车标志中,是中心对称图形的是( )A. B. C. D.2.如图,A 、B 、C 是⊙O 上的三点,已知∠0=60°,则∠C=( )。
A. 30°B.25°C.20°D.45°3.方程0)4(=+x x 的根是( )A. x =4B.x 1=0,x 2=-4C. x =0D.x 1=0,x 2=44.抛物线122-=x y 的顶点坐标是( )A. (0,1)B.(-1,0)C.(1,0)D.(0,-1)5.将抛物线23x y =向上平移3个单位,再向上平移2个单位,那么得到的抛物线的解析式为( )A. 3)2(32++=x yB.3)2(32+-=x yC. 3)2(32-+=x yD.3)2(32--=x y6.如图,在半径为5cm 的⊙O 中,直线l 交⊙O 于A 、B 两点,且弦AB=8,要使直线l 与⊙O 相切,则需要将直线l 向下平移( )A. 1B. 4C. 3D. 27.已知两圆的半径R 、r 分别为方程0652=+-x x 的两根,两圆的圆心距为1,两圆的位置关系是( )A. 外离B. 内切C. 相交D.外切8.已知二次函数)0(2≠++=a c bx ax y 的图像如图所示,则下列结论中正确的是( )A. 0 abcB. 当x <-1或x >3时,y >0C. 3是方程02=++c bx ax 的一个根D.当x <1时,y 随x 的增大而减少9.函数b ax y +=和bx ax y +=2在同一直角坐标系内的图像大致是( )A. B. C. D.10. 如图,直线AB 与半径为2的⊙O 相切于点C ,D 是⊙O 上一点,且∠EDC=30°,弦EF//AB ,则EF 的长度为( )A. 2B. 32C.3D. 22二、填空题(本题共6小题,每题3分,共18分)11.点A (3,-1)关于坐标原点对称点A ´坐标是12.如图,△ABC 以点A 为旋转中心,按逆时针方向旋转60°,得△AB ´C ´,则△ABB ´是 三角形。
北京五中分校2013—2014学年度初三第一学期期中考试数学试题一、选择题(共10个小题,每小题4分,共40分) 1.下列图案中,不是中心对称图形的是( )2. 将抛物线21y x =+向左平移2个单位,再向下平移3个单位,得到的 新抛物线的解析式为( )A.()223y x =+- B.()223y x =-- C.()222y x =+- D.()222y x =--3.已知:如图,B C A 、、是⊙O 上的三点,若︒=∠40AOC ,则ABC ∠ 的度数是( )A .︒10B .︒20C .︒40D .︒804. 已知:如图,某学生想利用标杆测量一棵大树的高度,如果标杆EC 的高 为1.6 m ,并测得BC=2.2 m ,CA=0.8 m, 那么树DB 的高度是( ) A .6 m B .5.6 m C .5.4 m D . 4.4 m5. 如图, ⊙O 的直径为cm 10,圆心O 到弦AB 的距离OM 的长为cm 3, 则弦AB 的长是( )cmA .4B .6C .7D .8 6. 在Rt △ABC 中,∠C=90°,CD ⊥AB 于点D ,已知AC=4,BC=3,那么 sin ∠ACD=( )A.35 B.45 C.74 D.347.若抛物线26y ax x =-经过点(2,0),则该抛物线顶点坐标为( ) A.(-1, 3) B. (0, 0) C.(-1,-3) D.(1,-3) 8. 如图,在四边形ABCD 中,︒=∠=∠90ABC ADC ,CD AD =,AB DP ⊥与P. 若四边形ABCD 的面积是16,则DP 的长为( )A. 8B. 42C. 4D. 28 9.如图,P A 、PB 分别与⊙O 相切,切点分别为A 、B ,P A =3,∠P =60°,若AC 为⊙O 的直径,则图中阴影部分的面 积为( ) A.2π B.36π C.33π D. πA. B. C. D. 第3题图第4题图第5题图第8题图第9题图10.如图,在矩形ABCD中,AB=3,BC=2,E为AD中点,动点P从点A向点B运动,动点Q从点B开始沿BC-CD运动,这两点的运动速度均为每秒1个单位.点P和点Q同时开始运动,如果其中一个点停止运动,则另一个点也停止运动.设运动时间为x(秒),△EPQ的面积为y,则能够正确反映y与x之间的函数关系的图象大致是()A B C D二、填空题(共6个小题,每小题4分,共24分)11.已知圆锥的底面半径为3,母线长为4,则圆锥的侧面积为.12. 如图,⊙O的直径是AB,CD是⊙O的弦,若∠D=70°,则∠ABC等于.13. 抛物线1C:21y x=+与抛物线2C关于x轴对称,则抛物线2C的解析式为.14.已知二次函数2y ax bx c=++(0a≠)的图象如图所示,下列结论中,①240b ac->;②0abc>;③20a b+<;④024>+-cba.其中,正确结论是_________.15.Rt△ABC中,已知∠C=90°,∠B=50°,点D在边BC上.将△ABC绕着点D逆时针旋转m(0<m<180)度后,如果点B的对应点B'恰好落在AB边上,那么m=_________.16.小明遇到这样一个问题:如图1,直线a∥b∥c,a与b之间的距离是2,b与c之间的距离是3,试画出一个等边△ABC,使三个顶点分别在直线a,b,c上,并求出所画等边△ABC的面积.图1 图2小明是这样思考的:要想解决这个问题,首先应想办法利用平行线之间的距离,根据所求图形的性质尝试用旋转的方法构造全等三角形解决问题.具体作法如图2所示:在直线a上任取一点A,作AD⊥bC BAECDAyxO1x=1-2-于点D ,作∠DAE=60°,使AE=AD ,过点E 作EB ⊥AE 交c 于点B ,连接AB ,在b 上截取CD=BE ,连接AC ,即可得到等边△ABC .请你回答:图2中等边△ADE 的面积等于 ; 等边△ABC 的面积等于 .三、解答题(共6个小题,20题10分,21题6分,其余4题每小题5分,共36分) 17.计算:︒-︒+︒60tan 45sin 230cos 218.如图,正方形DEFG 内接于△ABC ,AH ⊥BC 于H ,BC=6,AH=5,求正方形DEFG 的边长.19.已知:如图,AB 是⊙O 的直径,CD E ,BC 、AE 的延长线交于点F ,20.已知函数6422--=x x y (1)抛物线的开口方向是 ; (2)对称轴为直线 ; (3)顶点坐标是( );(4)画出该函数图象,并根据图象回答:①当x 满足 时,y 当x 满足 时,y ②当04x <<时,则y (5)该抛物线与两坐标轴交点所围成的三角形面积是 ; (6)若关于x 的方程2246x x k --=k 的取值范围是 .21. 要围成一个一边靠墙,其它三边用30,矩形ABCD 的边AB=x 米,面积为S(1)写出S 与x 之间的函数关系式.(2)当x 取何值时,面积S 最大,最大值是多少?22. 如图,已知直线P A 交⊙O 于A 、B 两点,AE 是⊙O 的直径,C 为⊙O 上一点,且AC 平分∠P AE ,过点C 作CD ⊥P A 于D . (1)求证:CD 是⊙O 的切线;(2)若AD :DC =1:3,AB =8,求⊙O 的半径.四、解答题(共3个小题, 23题4分、24题8分、25题8分,共20分)23.在已知ABC ∆所在平面上求一点F ,使它到三角形三顶点的距离之和为最小.这个问题是法国数学家费马1640年前后向意大利物理学家托里拆利提出的,这个问题中所求的点被人们称为“费马点”.(1)如图①,当ABC ∆三内角均小于120°时,F 在ABC ∆内部,此时︒=∠=∠=∠120CFA BFC AFB ;(2)如图②,当ABC ∆有一角(不妨设为A ∠)︒≥120时,F 点与A 点重合.图① 图② 图③对于(1)给出分析与证明:即当︒=∠=∠=∠120CFA BFC AFB 时,FB FA FC ++的值最小. 如图③,将AFC ∆绕点A 逆时针旋转60°得C F A ''∆,连接F F ',则AFC ∆≌AF C ''∆,AC C A =',C F FC ''=,A F FA '=.∵︒='∠60F FA ,A F FA '= ∴F FA '∆为等边三角形 ∴F F A F FA '='=,C F F F FB FC FB FA ''+'+=++, ∵︒=∠=∠=∠120CFA BFC AFB ,︒='∠60F AF , ∴B 、F 、F '、C '在一条直线上 ∵C B C F F F FB '=''+'+的值最小 ∴即FB FA FC ++的值最小.B阅读以上材料并回答下列问题: (1)在图③中,若︒=∠75BAC ,则BAC '∠=_______°.(2)在图④ABC ∆中,4=AB ,22=AC ,︒=∠75BAC ,F 为费马点,则=++FC FB FA _______.图④ 24.如图,已知抛物线y =ax 2+bx (a ≠0)经过A (3,0)、B (4,4)两点. (1)求抛物线的解析式;(2)将直线OB 向下平移mD 的坐标;(3)在(2)的条件下,P25. 在Rt △ABC 中,∠ACB =90°,BC =30,AB =50.点P 是AB 边上任意一点,直线PE ⊥AB ,与边AC 或BC 相交于E .点M 在线段AP 上,点N 在线段BP 上,EM =EN ,12sin 13EMP ∠=. (1)如图1,当点E 与点C 重合时,求CM 的长;(2)如图2,当点E 在边AC 上时,点E 不与点A 、C 重合,设AP =x ,BN =y ,求y 关于x 的函数关系式,并写出自变量x的取值范围;(3)若△AME与以E、N、B为顶点的三角形相似,直接写出AP的长.图1 图2 备用图。
2024学年第一学期广州市南武教育集团九年级化学联合练习题说明:1.本试卷分为选择题部分和非选择题部分,全卷共两大题20小题,共90分。
考试时间60分钟。
2.答题前,考生务必将自己的姓名、考生号、考试科目用2B铅笔涂在答题卡上。
3.本卷分“问卷”和“答卷”,本试卷选择题部分必须填在答题卡上,否则不给分;非选择题部分的试题,学生在解答时必须将答案写在“答卷"。
上指定的位置(方框)内,写在其他地方答案无效,“问卷”上不可以用来答题。
4.考试结束后,考生须将本试卷和答题卡一并交回。
5.考生解答填空题和解答题必须用黑色宇迹钢笔或签字笔作答,如用铅笔作答的试题一律以零分计算。
6.选择题要求用规定型号铅笔填涂,涉及作围的题目,用题目中规定型号的铅笔作图。
一、选择题(本题包括14小题,每小题3分,共42分,每小题只有一个选项符合愿意)1.《中国诗词大会》弘扬了中国传统文化,特别是“飞花令”环节让人看得热血沸腾,大呼过瘾。
下列含“生”字的诗句中涉及化学变化的是A.荡胸生层云,决眦入归鸟B.叶落槐庭院,冰生竹阁池C.海上生明月,天涯共此时D.野火烧不尽,春风吹又生2.下列物质的用途所利用的性质与另外三种有根本区别的是A.氧气用于炼钢B.铜丝用做电线C.酒精做燃料D.氮气用作保护气3.空气质量日报能及时准确地反映空气质量状况,下表是某市连续两天的空气质量日报(4月15日晚下了一场大雨)。
下列说法错误的是日期2024年4月15日2024年4月16日污染物CO SO2NO2可吸入颗粒物CO SO2NO2可吸入颗粒物污染指数2184312520231211质量级别ⅡⅠA.空气中的污染物SO2和NO2会导致酸雨B.造成该市空气污染的首要污染物是SO2C.雨后CO含量变化不大,说明CO难溶于水D.空气质量级别越大(Ⅱ>Ⅰ),空气质量状况越好4.空气是人类宝贵的自然资源,下列有关空气的说法正确的是A.洁净的空气是混合物,二氧化碳不是空气污染物B酥脆的饼干在空气中放置一段时间后变软,是因为发生了缓慢氧化C.稀有气体的化学性质很不活泼,可以做多种用途的电光源D.氮气约占空气总质量的78%,可用于制造硝酸和化肥5.在实践活动中感悟化学原理。
2014学年广州市南武中学九年级上学期期中试卷物理本试卷分第一部分(选择题)和第二部分(非选择题).第一部分1至3页,第二部分4至7页,共7页。
总分100分。
考试时间80分钟。
注意事项:1.答题前,考生务必在答题卡上用黑色字迹的钢笔或签字笔填写自己的考生号、姓名;填写考场试室号、座位号;再用2B铅笔把对应该两号码的标号涂黑。
2.选择题每小题选出答案后,用2B铅笔把答题卡上对应题目的答案标号涂黑;如需改动,用橡皮擦干净后,再选涂其他答案;不能答在试卷上。
3.非选择题答案必须写在答题卡各题目指定区域内的相应位置上;如需改动,先划掉原来的答案,然后再写上新的答案,改动的答案也不能超出指定的区域;除作图可用2B铅笔外,其他都必须用黑色..字迹钢笔或签字笔作答。
不准使用涂改..工具..。
不按以上要求作答的答案无效。
4.考生必须保持答题卡的整洁。
考试结束后,将答卷和答题卡一并交回。
5.全卷共30小题,请考生检查题数。
第一部分 (选择题共36分)一、选择题(每小题3分,共36分)1、将两个铅柱的底面削平、削干净,然后紧紧地压在一起,这时两块铅就会结合起来,甚至下面可以吊一个重物都不能将它们拉开(如图1)这一现象说明()A.分子在做无规则运动B.分子间存在扩散现象C.分子间存在斥力来D.分子间存在引力2、如图2所示是人们在生活中常用的各种简单机械,其中费力的是()A.斜面B.钓鱼杆C.滑轮组D.剪树枝的剪刀3、如图3所示,通草球甲、乙相互排斥,甲、丙相互吸引,如果已知甲带正电,那么乙、丙的带电情况是()A.乙带正电、丙带负电图1 图2B.乙带负电、丙带正电C.乙带正电、丙带负电或不带电D.乙带负电、丙带正电或不带电4、下列电路中,会造成电源短路的是:()A BC D5、如图5所示电路,把两个金属夹子夹在下面哪个物体的两端,闭合开关后小灯泡能发光()A.铁钉B.塑料尺C.橡皮D.玻璃棒6、关于热现象,下列说法正确的是()A.物体的温度越高,所含热量越多B.当两个物体温度相同时它们不会发生热传递C.温度高的物体,内能一定大D.燃料燃烧得越充分,燃料的热值就越大7、密封的烧瓶中装有某种气体,如图6所示,图中的“○”表示气体分子,用抽气筒抽出该烧瓶中部分气体后仍密封,描述烧瓶内剩余气体分子的四个示意图如图7所示,其中正确的是().8、用两段导线、一节电池设法使一只小灯泡发光,某同学尝试了如图8所示的几种连接,你认为不能使小灯泡发光的是()A.B.C.D.图5图图6 图7图89、在部分公交车后门两侧的扶手上,各装有一个按钮开关,想要下车的乘客只要按下任何一个按钮,装在驾驶台上的电铃(用表示)都会发声,提醒司机有乘客需要下车.如图9 )A .B .C .D .10、某机器的能量流向图如图10所示, 据此推测该机器可能是:( ) A .电动机 B .热机C .发电机D .电热水器11、园艺师傅使用如图11所示的剪刀修剪树枝时,常把树枝尽量往剪刀轴O 处靠近,这样做的目的是为了( )A .增大阻力臂,减小动力移动的距离B .减小阻力臂,省力C .增大动力臂,省力D .减小动力臂,减小动力移动的距离12、如图12所示,用两个同规格的滑轮(滑轮的质量比物体质量小很多)分别匀速提升同一个物体,在相同时间内,物体上升的距离也相等,绳重及摩擦不计,甲的拉力为F 甲,有用功为W 甲,机械效率为η甲,拉力的功率为P 甲;乙的拉力为F 乙,有用功为W 乙,机械效率为η乙,拉力的功率为P 乙.比较甲、乙两个装置可知( ) A .F 甲>F 乙 B .W 甲>W 乙 C . P 甲>P 乙 D . η甲>η乙图12 图10图9图11第二部分 (非选择题 共64分)二、填空、作图题(共25分)13、用热水袋使身体变暖,是利用__________的方法使人身体的内能增加;给自行车打气时,打气筒会发热,这是通过__________的方法使打气筒的内能增加。
2025-2025学年广东省广州市南武中学九年级数学上学期期中考试卷1.围棋起源于中国,古代称之为“弈”,至今已有四千多年的历史.以下是在棋谱中截取的四个部分,由黑白棋子摆成的图案是中心对称图形的是()A.B.C.D.2.抛物线的顶点坐标是()A.B.C.D.3.用配方法解一元二次方程x2﹣4x﹣6=0时,配方后的方程是()A.(x+2)2=2B.(x﹣2)2=2C.(x+2)2=10D.(x﹣2)2=104.已知二次函数,随的增大而减小,则的取值范围是()A.B.C.D.5.如图,△AOB绕点O逆时针旋转65°得到△COD,若∠AOB=30°,∠BOC的度数是()A.30°B.35°C.45°D.60°6.某航空公司有若干个飞机场,每两个飞机场之间都开辟一条航线,一共开辟了21条航线,则这个航空公司共有个飞机场,根据题意,可列方程为()A.B.C.D.7.若是方程的两根,则()A.2022B.2023C.2024D.20258.若点三点在抛物线上,则,,的大小关系是()A.B.C.D.9.已知关于的方程的一个根,且这个方程的两个根恰好是等腰的两条边长,则的周长为().A.8B.10C.8或10D.6或1010.二次函数的图象如图所示,对称轴是,下列结论正确的是().A.B.C.D.11.方程的解是_____.12.若抛物线向左平移1个单位长度,向下平移2个单位长度,则所得的抛物线的解析式是_____.13.如图,已知点的坐标是,,点的坐标是,,菱形的对角线交于坐标原点,则点的坐标是______.14.某件羊毛衫的售价为1000元,因换季促销,在经过连续两次降价后,现售价为810元,设平均每次降价的百分率为x,根据题意可列方程为_______________.15.若抛物线与轴有两个公共点,则的取值范围是______.16.如图,中,,,点为边上一点(不与点,重合),连接,将线段绕点逆时针旋转得到,连接.下列结论:①≌;②四边形的面积是;③若,则;④.其中正确的结论是_____.(填写所有正确结论的序号)17.解方程:(1);(2).18.如图,平面直角坐标系中,画出关于原点对称的,并.写出、、的坐标.19.如图,在中,,将绕点A顺时针旋转得到,点C的对应点E恰好落在边的延长线上,求证:..20.已知关于x的方程x2+2mx+m2﹣1=0.①不解方程,判别方程根的情况;②若方程有一个根为﹣1,求m的值.21.如图,平面直角坐标系中,直线与坐标轴交于,两点,点在轴上,点在轴上,抛物线经过点,.(1)求抛物线的解析式;(2)根据图象,写出不等式的解集.22.已知关于的一元二次方程有两个实数根.(1)求的取值范围;(2)设是方程的一个实数根,且满足,求的值.23.用一段长32m的篱笆和长8m的墙,围成一个矩形的菜园.(1)如图1,如果矩形菜园的一边靠墙AB,另三边由篱笆CDEF围成①设DE等于xm,直接写出菜园面积y与x之间的函数关系式,并写出自变量的取值范围;②菜园的面积能不能等于110m2?若能,求出此时x的值;若不能,请说明理由;(2)如图2,如果矩形菜园的一边由墙AB和一节篱笆BF构成,另三边由篱笆ADEF围成,求菜园面积的最大值.24.如图,在和中,,,.点、、分别为、、的中点,绕点在平面内自由旋转.(1)求证:;(2)求证:;(3)求面积的最大值.25.已知抛物线过点和两点,交轴于另一点.(1)求抛物线解析式;(2)如图1,点是上方抛物线上一点,连接,,,当平分时,求点坐标;(3)将抛物线图象绕原点顺时针旋转形成如图2的“心形”图案,其中点,分别是旋转前后抛物线的顶点,点、是旋转前后抛物线的交点.①直线的解析式是________;②点、是“心形”图案上两点且关于对称,当线段的最长时,直接写出点和点的坐标分别为________.。
2023-2024学年广东省广州市南武教育集团九年级(上)期中英语试卷语法选择阅读下面短文,按照句子结构的语法性和上下文连贯的要求。
从各题所给的 A.B.C和D项中选出最佳选项,并在答题卡上将该项涂黑。
1.(15分)Fred had something important to tell his family.Everyone in his family (1)to sit at the dinner table and listen."I'm going to take part in the Olympics," he said."(2) a fourth﹣grader do that?"asked Anna,his younger sister."I'm not going now.I'll go when I'm a little (3)."Fred shook his head."I've studied how the athletes(运动员)become the best.That is practice.If I practice (4)enough,I can't fail.""Sounds like a big challenge,"said Dad. "Which sport will you take up?""I (5)up my mind yet,"said Fred.After a month's practice,Fred got hurt again and again when he (6)to find out which sport fit him."I don't think I can find a sport right (7)me,"said Fred.The following Sunday,the family sat down for dinner as usual."I've decided not to play a sport," said Fred.Everyone was (8)."You're giving up on (9)Olympic dream?"said Anna."I didn't say I was giving up,"said Fred."I'm still going to the Olympics."Anna looked puzzled."How can you go (10)you don't do a sport?"Fred held up a book titled "Is Sports Medicine the Career for You?" Over the past few weeks,I've discovered that athletes need (11)medical help.So I am going to become (12)sports doctor.I'll still go to the Olympics ﹣(13)as a doctor,not an athlete." Fred answered confidently."Now that is (14)challenge,Fred!"said Dad."I'm sure you would do as well as you can(15)your dream."(1)A.asks B.asked C.was asked D.were asked(2)A.Need B.Would C.Shall D.Can(3)A.old B.older C.elder D.elderly(4)A.hardly B.hard C.harder D.hardest(5)A.didn't make B.don't make C.haven't made D.won't make(6)A.tries B.was trying C.is trying D.will try(7)A.for B.of C.with D.on(8)A.surprise B.surprised C.surprises D.surprising(9)A.you B.yours C.your D.yourself(10)A.unless B.because C.although D.if(11)A.a number of B.a lot C.much D.many(12)A.a B.an C.the D./(13)A.and B.but C.or D.so(14)A.another B.other C.the other D.others(15)A.finish B.finishing C.finished D.to finish完形填空阅读下面短文,掌握其大意,然后从各题所给的A、B、C和D项中选出最佳选项。
2023-2024学年广东省广州市南武教育集团九年级(上)期中物理试卷一、选择题(每小题只有一个正确答案,每小题3分,共36分)1.(3分)把一小块干冰放在纸上,干冰很快就会消失不见,但是纸并不会变湿。
下列现象与此物态变化相同的是()A.水烧开后壶嘴附近冒“白气”B.衣箱里的樟脑球逐渐变小C.阳光下的湿衣服逐渐变干D.燃烧的蜡烛在“流泪”2.(3分)在防控“新冠”期间,学校要求每位同学测体温,9班值日生小井同学用如图所示的同一只体温计分别依次测了甲、乙、丙、丁四位同学的体温,记录如下:①甲同学36.8℃,②乙同学37.1℃,③丙同学37.1℃,④丁同学37.3℃。
请判定上述情况中可能不是准确体温的有()A.①和③B.③和④C.②和④D.①和②(多选)3.(3分)如图,一杯绿茶端到客人面前,茶香四溢,下列说法正确的是()A.温度越高的茶水的热量越多B.温度越高的水,泡茶越快,说明温度越高,茶水分子的扩散越快C.同一杯茶水的分子无规则运动越剧烈,则它的温度越高,内能越大D.烧水时水蒸气将壶盖顶起是机械能转化为内能4.(3分)夏天将杯中的液态氮(沸点为:﹣196℃)倒入常温的水中,水面上会产生固体(如图),这固体产生的原因是()A.液态水放热升华B.液态水放热凝固C.液态氮吸热凝固D.液态氮放热凝华5.(3分)关于电现象的一些知识,下列说法中错误的是()A.将摩擦过的气球靠近头发,头发会被吸引,说明带电体能够吸引轻小物体B.铜片既可以带电,也可以导电。
带电时,铜片的一半带电,另一半不带电C.给充电宝充电时,充电宝相当于用电器D.电池能为用电器提供电能,但是整个电池是不带电的6.(3分)如图甲所示,规格相同的容器中装了不同质量的纯净水,用相同的加热器加热,忽略散热,得到如图乙的图像,下列说法正确的是()A.甲烧杯中的水温上升快,说明甲杯中的水的比热容比乙杯中的水的比热容小B.甲杯的水加热2min与乙杯的水加热3min吸收的热量相同C.吸收相同热量,甲杯的水升高的温度比乙杯的多D.升高相同的温度,甲杯水吸收的热量多7.(3分)某路灯照明系统的太阳能电池白天将太阳能转化为电能,对蓄电池充电,晚上蓄电池对路灯供电,对如图方框中能量形式判断正确的是()A.甲是“电能”B.乙是“太阳能”C.丙是“电能”D.丁是“机械能”8.(3分)如图所示为甲、乙、丙三部汽油机燃料完全燃烧释放的内能和汽油机输出机械能的二维柱状图。
2023-2024学年广东省广州市海珠区南武中学九年级(上)期末物理试卷一、单选题(每题2分,共28分)1.(2分)下列关于物理量的估测,最符合实际情况的是()A.让人感觉舒适的环境温度约为37℃B.两节干电池串联在一起的电压约为1.5VC.常见家用电风扇的功率约为50WD.正常工作的电视机电流约为10A2.(2分)学校开展“给父母送上一道家常菜”为主题的劳动实践教育活动。
小明在妈妈指导下走进厨房进行劳动实践,她发现厨房里涉及到很多物理知识。
下列说法正确的是()A.冷冻室取出的排骨表面的“白霜”,是水凝固形成的冰晶B.排骨汤煮沸后冒出大量的“白气”,是水汽化形成的水蒸气C.汤沸腾后排骨上下翻滚,说明温度越高分子运动越剧烈D.排骨汤沸腾过程中,汤的内能减小3.(2分)如图所示,对于图片中所描述的物理过程,下列分析中正确的是()A.图甲,活塞下压过程,玻璃管内气体的内能减少,这个过程中的能量转化与汽油机中做功冲程相同B.图乙,塞子跳起过程,玻璃瓶瓶内空气的内能增大C.图丙,试管内的水蒸气推动塞子冲出,试管内水蒸气的内能减少D.图丁,汽缸内的气体推动活塞向下运动,活塞的机械能减小4.(2分)取口香糖锡纸,剪成如图甲所示形状,其中AB和CD段等长。
戴好防护手套,将锡纸条(带锡的一面)两端连接电池正、负极,如图乙所示,发现锡纸条很快开始冒烟、着火。
下列分析正确的是()A.通过AB和CD段的电流相等B.AB和CD段的电压相等C.正常情况下,CD段会先着火D.AB和CD段的电阻相等5.(2分)学校走廊的消防应急灯由蓄电池、两个LED灯及一个自动控制开关组成。
照明电路停电时,应急灯的两个LED灯发光;照明电路正常工作时,为应急灯内的蓄电池充电,应急灯不发光。
下列说法正确的是()A.两个LED灯一定串联B.LED灯是用超导材料制成的C.对蓄电池充电,电能转化为化学能D.应急灯发光时,蓄电池是消耗电能的装置6.(2分)“金箔工艺”是国家级非物质文化遗产,手工打造的金箔轻薄柔软,不能用手直接拿取,正确拿取的方法是:先手持羽毛轻轻扫过纸垫,如图甲所示;再将羽毛靠近工作台上方的金箔,羽毛即可将金箔吸住,如图乙所示。
(南武实验中学)2014学年第一学期期中检测(九年级)二、语言知识及运用第一节. 单项选择(每小题1.5分,共15分)()16. Sam has ________ unusual girlfriend. She’s ________ girl in red over there.A. a; aB. an; theC. a; theD. an; a()17. There is serious air pollution in the city. We’d better ________ cars too often.A. driveB. to driveC. not driveD. not to drive()18. It’s shy ________ Jack ________ in front of so many people.A. of; to speakB. of; speakingC. for; to speakD. of; speak ()19. Lily won the 100-metre race, because she ran ________ of all.A. the most fastlyB. fastliestC. fastestD. the fastest()20. We should ________ the tools before we leave the workshop.A. put outB. put downC. put awayD. put off()21. Some students hope to enter the best universities while ________ only want to learn skills.A. the othersB. othersC. anotherD. the other()22. --- May I take this book out?--- No, you ________.A. can’tB. don’tC. needn’tD. shouldn’t()23. --- Your shoes are so old. Why don’t you buy a new pair?--- Because I ________ all my money on an MP5.A. spendB. have spentC. am spendingD. was spending ()24. --- I hear Jason Chan will come to Beijing next week.--- Really? ________ he comes, my younger sister will be very happy.A. IfB. UntilC. UnlessD. Before()25. --- Excuse me, what’s this for?--- It’s a cleaner and it ________ to pick up dirt.A. useB. usesC. usedD. is used第二节. 语法选择(每小题1分,共10分)The United States covers a large part of the North American continent. Its neighbors are Canada to the north and Mexico to the south. Although the United States is a big country, it is not ____26____ in the world. In 1964, its population was over 185,000,000.When this land first became a nation, after ____27____ his independence form England, it had thirteen states. Each of the states ____28____ represented on the American flag by a star. All these states were in the eastern part of the continent. As the nation grew towards the west, new states ____29____ and new stars appeared on the flag. For a long time, there were 48 stars. In 1959, however, two more stars appeared on the flag, representing the new states of Alaska and Hawaii.Indians were the first people of the land. It is now the United States. There ____30____ still many thousands of Indians now living in all parts of the country. ____31____ it is said that the Indians are “the only real Americans”. Most Americans ____32____ all over the world. ____33____ the language of the United States is English, ____34____ culture and customs are ____35____ like those of England than those of any other country in the world.()26. A. large B. largest C. larger D. the largest()27. A. winning B. won C. wins D. has won()28. A. are B. were C. was D. is()29. A. added B. were added C. had added D. have added ()30. A. were B. had C. are D. have()31. A. Sometimes B. Some times C. Some time D. Sometime()32. A. from B. came from C. comes from D. are from()33. A. Because of B. If C. Because D. So()34. A. its B. it C. it’s D. their()35. A. much B. most C. more D. very三、完型填空(每小题1分,共10分)One Friday night, a poor young man stood at a gate of the railway station, playing his violin. Many people put money into the ____36____ lying in front of him.The next day, the young man came to the gate again, and put his hat on the ground. But ____37____ from what he always did in the past days, he took out a large piece of ____38____ with some words in it and laid it on the ground. It said, "Last night, a gentleman ____39____ George Miller put an important thing into my hat by mistake. Please come soon, Mr. Miller"About half an hour later, a middle-aged man ran to the young man in a hurry and said, "It's you! You do come here. I know that you're an ____40____ man and will certainly come here." The young man asked, "Are you Mr. Miller? Did you lose anything?" "A lottery ticket," answered the middle-aged man. The young man took out a lottery ticket and ____41____ it to the man.Yesterday when the man knew the fact that his lottery ticket was worth$500,000, he was so ____42____ that he threw the ticket together with the money into the young man’s hat!Someone asked the young man, "You play the violin in the railway station every day to make ____43____. Why didn't you just take the prize for yourself?" The young man said, "Although I don't have much ____44____, I live happily. But if I ____45____ honesty, I won't be happy forever."()36. A. hat B. paper C. bag D. ground()37. A. next B. away C. far D. different()38. A. wood B. paper C. chocolate D. meat()39. A. liked B. named C. sent D. gave()40. A. interesting B. useful C. honest D. old()41. A. gave B. kept C. sold D. bought()42. A. angry B. excited C. worried D. surprised()43. A. fun B. friends C. music D. money()44. A. knowledge B. friends C. time D. money()45. A. have B. make C. lose D. find四、阅读理解(每小题2分,共40分)(A)In a surprising result, the No. 69 Middle School girls' football team yesterday beat their school's boys' team. The boys' team often helped the girls with their training. They had never lost to the girls before, but this time the girls beat them 4-3.After the game, Wu Nai, head of the boys' team, was very unhappy. "We all thought this would be an easy game," he said. "We never thought a team of girls could beat us. This is the saddest day of my life."But Mr Hu, the boys' PE teacher, said he thought the girls should win. "The boys were too confident," he said. "I told them before the match that they needed to play well. They all thought that girls' football was a joke. Now they know better. They didn't play care-fully, and they lost."The match had started well for the boys. After 30 minutes, they were winning 2-0. Their best player, Lu Ming, scored in the thirtieth minute. Earlier, the mid-field player, Ma Zhengquan, had scored the first goal in only the second minute of the match.After the first half hour, the boys seemed to become too confident. At first, the girls had felt a bit nervous, but then they became more and more confident. Just before half time, Li Xiaolin made the score 2-1.In the second half, the boys were the first to score. It was from Lu Ming. After that the boys became lazy, but the girls kept on working hard. Hao Meiling scored in the 68th minute, to make the score 3-2. Then LiXiaolin scored twice in the last six minutes to make the last score 4-3. It was a surprising finish.The girls' PE teacher, Miss Wang, was very pleased with their work. "They were great!" She said. "I told them they could win. I told them that the most important thing was teamwork. The boys' team had some goodplayers, but my girls were a better team!"()46. Who scored the first goal in the match?A. Lu Ming.B. Ma Zhengquan.C. Li Xiaolin.D. Hao Meiling.()47. How many goals did Li Xiaolin score?A. One.B. Two.C. Three.D. Four.()48. Why could the girls' team beat the boys' in the football match?A. Because the boys' team helped the girls with their training.B. Because the boys had never lost to the girls before.C. Because the boys' team won the first half.D. Because the girls played together better and worked harder.()49. Which of the following is TRUE?A. The girls made only one goal in the first half.B. The girls even made 3 more goals than the boys in the second half.C. Many people thought the girls could beat the boys before the match.D. The girls' team had some better players than the boys'.()50. Choose the right order according to the passage.a. The girls' PE teacher told them that they could win.b. Wu Nai, head of the boys' team was very unhappy.c. The match started well for the boys.d. The girls kicked the second goal in the match.A. a-b-c-dB. b-c-d-aC. d-c-a-bD. a-c-d-b(B)A good heartDikembe Mutombo grew up in Africa among great poverty (贫穷) and disease.He came to Georgetown University on a scholarship to study medicine - but CoachJohn Thompson got a look at Dikembe and had a different idea. Dikembe became astar in the NBA. But he never forgot the land of his birth, or the duty to share hisfortune with others. He built a new hospital in his old hometown in the Congo. A friend has said of this good-hearted man: "Mutombo believes that God has given him this chance to do great things."Success and kindnessAfter her daughter was born, Julie Aigner-Clark searched for ways to share her loveof music and art with her child. So she began filming children's videos in her own house. The Baby Einstein Company was born, and in just five years her business grew to more than $20million in sales. And she is using her success to help others - producing child safety videos with John Walsh of the National Center for Missing and Exploited(受剥削的) Children. Julie says of her new program: "I believe it's the most important thing that I have ever done. I believe that children have the right to live in a world that is safe."Bravery and courageA few weeks ago, Wesley Autrey was waiting at a Harlem subway station with his two little girls when he saw a man fall into the path of a train. With seconds to act, Wesley jumped onto the tracks, pulled the man into the space between the rails (铁轨), and held him as the train passed right above their heads. He insists he's not a hero. He says: "We have got to show each other some love."()51. The underlined word “bravery” means “________” in Chinese.A. 鼓励B. 冲动C. 勇敢D. 害怕()52. Mulombo believes that building the new hospital is ________.A. helpful to himselfB. something he should do for his homelandC. a chance for his friends to share his moneyD. a way of showing his respect to the NBA()53. What did the Baby Einstein Company do at its beginning?A. Produce safe videos for children.B. Make videos to help protect children.C. Sell children's music and artwork.D. Look for missing and exploited children.()54. Why was Wesley Autrey praised as a hero?A. He helped a man get across the rails.B. He stopped a man from destroying the rails.C. He protected two little girls from getting hurt.D. He saved a person without considering his own safety.()55. What should we learn from the heroes of our time?A. A good heartB. Success and KindnessC. Bravery and courageD. A, B and C(C)"USA? Britain? Which country is better to study in?" We often hear such discussions. As China opens its doors, studying abroad has become a dream for many Chinese students. They want to learn about the world. It's true that studying abroad can help students develop themselves. Language skills (技能) will improveand it may be easier to find jobs.But there are problems that should be considered. Language is the first. Students must spend a lot of time learning another language and getting used to a different culture.Students must also learn to live without parents' care and deal with all kinds of things they haven't had to do before, like looking after themselves. There are reports about Chinese students abroad sinking into an ocean of difficulties and giving up easily. When they have to take care of themselves, it is hard for students to study well.Finally, studying abroad brings a heavy burden (负担) to the family. For most Chinese parents, the cost of studying abroad is very high. But is it worth it?We know that there are many famous people who succeed in great things throughtheir hard work in China. Liu Xiang is a good example. Once an American teacherinvited him there but he refused. He kept training hard with his Chinese teacher. Hesurprised the world when he won a gold medal at the Athens Olympics. So when youwonder which country is better to study in, consider whether studying abroad is theright choice.()56. From the passage, we learn that many Chinese students dream about studying abroad to ________.A. taste a new lifeB. make a lot of moneyC. learn about the worldD. learn to look after themselves()57. The writer thinks ________ should be considered first before students study abroad.A. placesB. timeC. moneyD. language()58. The writer mentions Liu Xiang in the passage in order to tell us that ________.A. Chinese teachers are better than American onesB. studying abroad is not the right choiceC. people can also be successful in China if they work hardD. Liu Xiang was a gold medal winner()59. Which of the following is NOT true?A. Studying abroad will cost students' families a lot of money.B. Studying abroad will make it easy for students to learn well.C. Studying abroad will help students to improve language skills.D. Studying abroad will bring students a lot of difficulties in their life.()60. This passage is mainly about ________.A. the question of studying abroadB. the dream of studying abroadC. the choice of studying abroadD. the story of studying abroad(D)At 7:35 pm March 28To:The manager Clothes Horse StoreDear Madam/Sir,I am writing to tell you about an annoying experience I have just had in your store.Yesterday morning I bought a shirt from your store. The product was a red shirt, size 12, prize $140. When I returned home and took it out of the bag, the sleeve was almost completely off. I had traveled home in the train with the bag and treated it carefully.I went back to the store in the afternoon to return the shirt and exchange it for another. The shop assistant refused to exchange the shirt or return my money. She told me that I must have worn it already and caused the damage. I told her this was impossible because I had bought it that morning. She still refused to give me my money.I have bought things from your store many times and my friends also went here.I am extremely disappointed with your shop assistant. This should have been a simpler.I look forward to hearing from you and working out this problem as soon as possible.Yours sincerely,Jenny Moms()61. What was wrong with the shirt the writer bought?A. It was the wrong color.B. It had no sleeves.C. One sleeve was almost off.D. It was the wrong size.()62. When did the writer return to the store to talk about her problem?A. Morning of March 27.B. Afternoon of March 27.C. Morning of March 28.D. Afternoon of March 28.()63. The assistant refused to help because she thought ________.A. the writer had bought the shirt at another shopB. there was nothing wrong with the shirtC. the writer had damaged the shirt himselfD. the writer was very rude()64. Why does the writer use the underlined sentence “I have bought things...?”A. To warn the manager that he may lose some customers.B. To show the manager how popular she is.C. To express how much she usually likes this store.D. To show that she enjoys shopping very much.()65. Which of the following does the writer probably want?A. To get presents for her friends.B. To have her shirt exchanged.C. To get the store closed.D. To have her shirt repaired.第Ⅱ卷写作第一节单词拼写,根据句子意思及所给单词的首字母写出单词。