七年级上8-9单元易错题练习
人教新目标七年级英语上册Unit9易错题31题汇总(含答案)
七年级英语上册Unit9易错题31题汇总1.What’s your (mother) favorite food?2.He always (play) games with us.3.Friday is the (sixth/fifth) day of a week.4.What (be) your favorite sports?5.Do you want (play) basketball with us?6.The storybook is (非常有趣)7.She likes art because it’s relaxing. (对画线部分提问)she like art?8.I like yellow best.(同义句) is yellow.9.The first day of school is interesting. (对画线部分提问)the first day of school?10.What about you? (同义句) ?11.He likes P.E. best at school. (同义句)His P.E. at school.12.你今天上什么科目?you today?13.I think history is interesting.(改为否定句)I think history interesting.14.We have math Friday .It’s difficult interesting .A. on ; andB. on ; butC. in; butD. in; and15.--- ? ---It’s Monday.A. What’s the timeB. What day is it todayC. What’s the date todayD. Is it Monday today16.Mr.Chen teaches math. We all like very much.A. us ,hisB. our ,hisC. us ,himD. our, him17.I don’t like English it’s difficult.A. whyB. butC. andD. because18.Do you have a history lesson the afternoon of Tuesday ?A. inB. atC. onD. for19.Bob and Linda’s favorite subject geography.A. beB. isC. areD. am20.---What you do after dinner?---I do my homework for an hour. A. is B. are C. do D. does21. We play basketball two hours every day.A. forB. onC. inD. to22. 选词的适当形式填空(1)I’m not busy today. I’m . (2)---When do you have music? ---We have them on Wednesday and Friday. (3)Our P.E. lesson at 3:30 on Monday afternoon. (4)YuMei has an art lesson for two .23.Mike needs (a/an) hour to do homework.24.The book are (real) interesting.25. Bob’s and Linda’s favorite subjects geography and history.A. beB. isC. areD. am26.The teacher says math(难但是有用)。
七年级数学上册全册单元试卷易错题(Word版 含答案)
七年级数学上册全册单元试卷易错题(Word版含答案)一、初一数学上学期期末试卷解答题压轴题精选(难)1.如图,已知:点不在同一条直线, .(1)求证: .(2)如图②,分别为的平分线所在直线,试探究与的数量关系;(3)如图③,在(2)的前提下,且有,直线交于点,,请直接写出 ________.【答案】(1)证明:过点C作,则,∵∴∴(2)解:过点Q作,则,∵,∴∵分别为的平分线所在直线∴∴∵∴(3):1:2:2【解析】【解答】解:(3)∵∴∴∵∴∵∴∴∴∴ .故答案为: .【分析】(1)过点C作,则,再利用平行线的性质求解即可;(2)过点Q作,则,再利用平行线的性质以及角平分线的性质得出,再结合(1)的结论即可得出答案;(3)由(2)的结论可得出,又因为,因此,联立即可求出两角的度数,再结合(1)的结论可得出的度数,再求答案即可.2.点O为直线AB上一点,过点O作射线OC,使∠BOC=65°,将一直角三角板的直角顶点放在点O处.(1)如图①,将三角板MON的一边ON与射线OB重合时,则∠MOC=________;(2)如图②,将三角板MON绕点O逆时针旋转一定角度,此时OC是∠MOB的角平分线,求旋转角∠BON和∠CON的度数;(3)将三角板MON绕点O逆时针旋转至图③时,∠NOC=∠AOM,求∠NOB的度数.【答案】(1)25°(2)解:∠BOC=65°,OC平分∠MOB∠MOB=2∠BOC=130°∠BON=∠MOB-∠MON=130°-90°=40°∠CON=∠COB-∠BON=65°-40°=25°(3)解:∠NOC= ∠AOM ∠AOM=4∠NOC ∠BOC=65°∠AOC=∠AOB-∠BOC=180°-65°=115°∠MON=90°∠AOM+∠NOC=∠AOC-∠MON=115°-90°=25°4∠NOC+∠NOC=25°∠NOC=5°∠NOB=∠NOC+∠BOC=70°【解析】【解答】解:(1)∠MON=90,∠BOC=65°∠MOC=∠MON-∠BOC=90°-65°=25°【分析】(1)根据∠MON和∠BOC的度数可以得到∠MON的度数;(2)根据角平分线的性质,由∠BOC=65°,可以求得∠BOM的度数,然后由∠NOM-90°,可得∠BON的度数,从而得解;(3)由∠BOC=65°,∠NOM=90°,∠NOC= ∠AOM,从而可求得∠NOC的度数,然后由∠BOC=65°,从而得解.3.已知,∠AOB=∠COD=90°,射线OE,FO分别平分∠AOC和∠BOD.(1)当OB和OC重合时,如图(1),求∠EOF的度数;(2)当∠AOB绕点O逆时针旋转至图(2)的位置(0°<∠BOC<90°)时,求∠EOF的度数.【答案】(1)解:当OB和OC重合时,∠AOD=∠AOC+∠BOD=180°,又∵射线OE,FO分别平分∠AOC和∠BOD,∴∠COE= ∠AOC,∠BOF= ∠BOD,∴∠EOF=∠COF+∠BOF= (∠AOC+∠BOD)= ×180°=90°(2)解:∵∠AOB=∠COD=90°,∠COE= ∠AOC,∠BOF= ∠BOD,∴∠EOF=∠COE+∠BOF﹣∠BOC= ∠AOC+ ∠BOD﹣∠BOC= (∠AOC+∠BOD)﹣∠BOC= (∠AOB+∠BOC+∠COD+∠BOC)﹣∠BOC= (180°+2∠BOC)﹣∠BOC=90°+∠BOC﹣∠BOC=90°【解析】【分析】(1)由角平分线的性质可得∠COE=∠AOC,∠BOF=∠BOD;由平角的定义可得∠AOC+∠BOD=180°,由角的构成可得∠EOF=∠COE+∠BOF,代入计算即可求解;(2)同理可求解。
七年级上册语文单元测试卷易错题
第一单元第一课.《在山的那一边》1.注音:痴(chī)想隐秘(mì)凝(níng)成铁青喧(xuān)腾诱(yòu)惑一瞬(shùn)间2.解释:隐秘:隐蔽,不外露一瞬间:一眨眼第二课.《走一步,再走一步》1.注音:训诫(jiè)耸(sǒng)立迂(yūn)回啜(chuò)泣瘦骨嶙峋(lín)(xún)心惊肉跳头晕(yūn)目眩(xuàn)小心翼翼(yì)2.解释:训诫:告诫,教导嶙峋:形容人瘦削头晕目眩:头晕眼睛昏花啜泣:抽噎,抽抽搭搭地哭。
纳罕:惊奇,诧异小心翼翼:谨慎小心,丝毫不敢疏忽的样子。
翼翼,谨慎、严肃。
第三课.《短文两篇》1.注音:收敛(liǎn)宽恕(shǜ)卑(bēi)微零落(luò)一丝不苟(gǒu)聒聒(guō)2.解释:收敛:收拢、合拢聒聒:持续嘈杂,使人厌烦宽恕:宽容,饶恕。
恕,饶恕。
卑微:卑贱,微小,地位低下。
一丝不苟:形容办事认真,连最细微的地方也不马虎。
苟,敷衍了事,马马虎虎。
第四课.《紫藤萝瀑布》1.注音:嚷(rāng)穗(suì)舱(cāng)绽(zhàn)凑(còu)酿(niàng)迸溅(bèng)挑(tiǎo)逗繁(fán)密伫(zhǜ)立凝(níng)望笼(lǒng)罩伶仃(dīng)稀零(líng)忍俊不禁( jīn)仙露琼(qióng)浆盘虬(qúu)卧龙2.解释:忍俊不禁:忍不住笑。
第五课《童趣》1.注音项为之强(jiāng)鹤唳(lì)云端怡(yí)然称快第一单元词语集锦:痴想,隐秘,凝成,铁青,喧腾,诱惑,一瞬间训诫,耸立,迂回,凝视,啜涕,瘦骨嶙峋,心惊肉跳,头晕目眩,小心翼翼收敛,宽恕,卑微,零落,聒聒,断续,一丝不苟终极,迸溅,繁密,伫立,凝望,伶仃,稀零,忍俊不禁,仙露琼浆,蜂围碟阵,盘虬卧龙明察秋毫,怡然称快,怡然自得,庞然大物,夏蚊成雷第二单元第六课《理想》⒈ 给下列加点字注音:倔强()()洗濯()玷污()诅咒()碌碌终生()缀()连扒()窃2. 解释下面的词语,并指出加点字的含义。
七年级上册数学全册单元试卷易错题(Word版 含答案)
七年级上册数学全册单元试卷易错题(Word版含答案)一、初一数学上学期期末试卷解答题压轴题精选(难)1.点在线段上, .(1)如图1,,两点同时从,出发,分别以,的速度沿直线向左运动;①在还未到达点时,求的值;②当在右侧时(点与不重合),取中点,的中点是,求的值;(2)若是直线上一点,且 .求的值.【答案】(1)解:①AP=AC-PC,CQ=CB-QB,∵BC=2AC,P、Q速度分别为1cm/s、2cm/s,∴QB=2PC,∴CQ=2AC-2PC=2AP,∴②设运动秒,分两种情况A: 在右侧,,分别是,的中点,,∴B: 在左侧,,分别是,的中点,,∴(2)解:∵BC=2AC.设AC=x,则BC=2x,∴AB=3x,①当D在A点左侧时,|AD-BD|=BD-AD=AB= CD,∴CD=6x,∴;②当D在AC之间时,|AD-BD|=BD-AD= CD,∴2x+CD-x+CD= CD,x=- CD(不成立),③当D在BC之间时,|AD-BD|=AD-BD= CD,∴x+CD-2x+CD= CD,CD= x,∴;|AD-BD|=BD-AD= CD,∴2x-CD-x-CD= CD,∴CD=;④当D在B的右侧时,|AD-BD|=BD-AD= CD,∴2x-CD-x-CD= CD,CD=6x,∴ .综上所述,的值为或或或【解析】【分析】(1)由线段的和差关系,以及QB=2PC,BC=2AC,即可求解;(2)设AC=x,则BC=2x,∴AB=3x,D点分四种位置进行讨论,①当D在A点左侧时,②当D在AC之间时,③当D在BC之间时,④当D在B的右侧时求解即可.2.如图1,已知∠AOB=120°,∠COD=60°,OM在∠AOC内,ON在∠BOD内,∠AOM=∠AOC,∠BON=∠BOD.(1)∠COD从图1中的位置绕点O逆时针旋转到OC与OB重合时,如图2,∠MON=________°;(2)∠COD从图2中的位置绕点O逆时针旋转n°(0<n<120且n≠60),求∠MON的度数;(3)∠COD从图2中的位置绕点O顺时针旋转n°(0<n<120),则n=________时,∠MON=2∠BOC.【答案】(1)100(2)解:①当0<n<60°时,∠AOC=∠AOB-∠BOC=120°-n,∠BOD=60°-n,∴∠MON=∠MOC+∠COB+∠BON= ∠AOC+n+ ∠BOD= (120°-n)+n+ (60°-n)=100°;②当60°<n<120°时,∠AOC=120°-n,∠COD=60°,∠BOD=n-60°,∠MOC= ∠AOC,∠DON= ∠BOD,∴∠MON=∠MOC+∠COD+∠DON= (120°-n)+60°+ (n-60°)=100°.综上所述:∠MON的度数恒为100°(3)解:①当0<n<60°时,∠BOC=n,∠MON=2n,∴∠MON= (120°+n)+60°-(60°+n)=100°;解得:n=50°;②当60°<n<120°时,∠AOC=360°-(120°+n)=240°-n,∠BOD=60°+n,∴∠MON=360°-∠AOM-∠AOB-∠BON=360°-(240°-n)-120°-(60°+n)=140°,解得:n=70°.综上所述:n=50°或70°【解析】【解答】解:(1)∠MON= ∠AOB+ ∠COD=100°;【分析】(1)由∠AOM=∠AOC,∠AOC= ∠AOB,∠AOC=∠AOM+∠MOC得出∠MOC= ∠AOB,又∠BON=∠BOD,从而由∠MON= ∠AOB+ ∠COD即可算出答案;(2)需要分类讨论:①当0<n<60°时,根据旋转的性质得出∠AOC=∠AOB-∠BOC=120°-n,∠BOD=60°-n,由∠MON=∠MOC+∠COB+∠BON整体替换再化简即可得出答案;②当60°<n<120°时,根据旋转的性质得出∠AOC=120°-n,∠COD=60°,∠BOD=n-60°,∠MOC= ∠AOC,∠DON= ∠BOD,由∠MON=∠MOC+∠COD+∠DON整体替换再化简即可得出答案;(3)分类讨论:①当0<n<60°时,∠BOC=n,∠MON=2n,又∠MON=∠MOB+∠BOC-∠NOC = (120°+n)+60°- (60°+n)=100°,从而列出方程,求解得出n的值;②当60°<n<120°时,∠BOC=n,∠MON=2n,∠AOC=360°-(120°+n)=240°-n,∠BOD=60°+n,又∠MON=360°-∠AOM-∠AOB-∠BON,从而整体整体代入化简并列出方程,求解即可。
初一数学上册易错题整理完整版(值得收藏)
初一数学上册易错题整理完整版有理数易错题练习(一)一.判断⑴ a 与-a 必有一个是负数 .⑵在数轴上,与原点0相距5个单位长度的点所表示的数是5.⑶在数轴上,A 点表示+1,与A 点距离3个单位长度的点所表示的数是4.⑷在数轴的原点左侧且到原点的距离等于6个单位长度的点所表示的数的绝对值是-6. ⑸ 绝对值小于4.5而大于3的整数是3、4. ⑺ 如果-x =- (-11),那么x = -11.⑻ 如果四个有理数相乘,积为负数,那么负因数个数是1个.⑼ 若0,a =则0ab=.⑽绝对值等于本身的数是1. 二.填空题⑴若1a -=a -1,则a 的取值范围是: .⑵式子3-5│x │的最 值是 .⑶在数轴上的A 、B 两点分别表示的数为-1和-15,则线段AB 的中点表示的数是 . ⑷水平数轴上的一个数表示的点向右平移6个单位长度得到它的相反数,这个数是________.⑸在数轴上的A 、B 两点分别表示的数为5和7,将A 、B 两点同时向左平移相同的单位长度,得到的两个新的点表示的数互为相反数,则需向左平移 个单位长度.⑹已知│a │=5,│b │=3,│a +b │= a +b ,则a -b 的值为 ;如果│a +b │= -a -b ,则a -b 的值为 .⑺化简-│π-3│= . ⑻如果a <b <0,那么1a 1b. ⑼在数轴上表示数-113的点和表示152-的点之间的距离为: .⑽11a b⋅=-,则a 、b 的关系是________.⑾若a b <0,bc<0,则ac 0. ⑿一个数的倒数的绝对值等于这个数的相反数,这个数是 . 三.解答题⑴已知a 、b 互为倒数,- c 与2d互为相反数,且│x │=4,求2ab -2c +d +3x 的值.⑵数a 、b 在数轴上的对应点如图,化简:│a -b │+│b -a │+│b │-│a -│a ││.⑶已知│a +5│=1,│b -2│=3,求a -b 的值. ⑷若|a |=4,|b |=2,且|a +b |=a +b ,求a - b 的值.⑸把下列各式先改写成省略括号的和的形式,再求出各式的值.①(-7)- (-4)- (+9)+(+2)- (-5); ②(-5) - (+7)- (-6)+4.⑹改错(用红笔,只改动横线上的部分):⑺比较4a和-4a的大小①已知5.0362=25.36,那么50.362=253.6,0.050362=0.02536;②已知7.4273=409.7,那么74.273=4097,0.074273=0.04097;③已知3.412=11.63,那么(34.1)2=116300;④近似数2.40×104精确到百分位,它的有效数字是2,4;⑤已知5.4953=165.9,x3=0.0001659,则x=0.5495.⑻在交换季节之际,商家将两种商品同时售出,甲商品售价1500元,盈利25%,乙商品售价1500元,但亏损25%,问:商家是盈利还是亏本?盈利,盈了多少?亏本,亏了多少元?⑼若x、y是有理数,且|x|-x=0,|y|+y=0,|y|>|x|,化简|x|-|y|-|x+y|.⑽已知abcd≠0,试说明ac、-ad、bc、bd中至少有一个取正值,并且至少有一个取负值.⑾已知a<0,b<0,c>0,判断(a+b)(c-b)和(a+b)(b-c)的大小.⑿已知:1+2+3……+33=17×33,计算1-3+2-6+3-9+4-12+……+31-93+32-96+33-99的值.四.计算下列各题:⑴(-42.75)×(-27.36)-(-72.64)×(+42.75) ⑵12133344⎛⎫---+----⎪⎝⎭⑶77(35)9-÷+⑷523120001999400016342⎛⎫⎛⎫-+-++-⎪ ⎪⎝⎭⎝⎭⑸221.430.57()33⨯-⨯-⑹6(5)(6)()5-÷-÷-⑺91118×18 ⑻-15×12÷6×5 ⑼24221(10.5)2(3)3⎡⎤---⨯÷---⎣⎦⑽-24-(-2)4⑾33(32)32-⨯+⨯有理数易错题练习(二)一.多种情况的问题(考虑问题要全面) (1)已知:,3=x 则x=_______;,5=-x 则x=_______;(2)绝对值不大于4的负整数是________; (3)绝对值小于4.5而大于3的整数是________.(4)在数轴上,与原点相距5个单位长度的点所表示的数是________;(5)在数轴上,A 点表示+1,与A 点距离3个单位长度的点所表示的数是________;(6) 平方得412的数是____;此题用符号表示:已知,4122=x 则x=_______; (7)若|a|=|b|,则a,b 的关系是________;(8)若|a|=4,|b|=2,且|a +b|=a +b ,求a -b 的值.二.特值法帮你解决含字母的问题(此方法只适用于选择、填空)有理数中的字母表示 ,从三类数中各取1——2个特值代入检验,做出正确的选择 (1)若a 是负数,则a________-a ;a --是一个________数;(2)已知,x x -=则x 满足________;若,x x =则x 满足________;若x=-x, x 满足________;若=-<2,2a a 化简____ ;(3)有理数a 、b 在数轴上的对应的位置如图所示: 则( 0-11abA .a + b <0B .a + b >0;C .a -b = 0D .a -b >0 (4)如果a 、b 互为倒数,c 、d 互为相反数,且,3=m ,则代数式2ab-(c+d )+m 2=_______。
七年级上册数学全册单元试卷易错题(Word版 含答案)
七年级上册数学全册单元试卷易错题(Word版含答案)一、初一数学上学期期末试卷解答题压轴题精选(难)1.已知:O是直线AB上的一点,是直角,OE平分.(1)如图1.若.求的度数;(2)在图1中,,直接写出的度数(用含a的代数式表示);(3)将图1中的绕顶点O顺时针旋转至图2的位置,探究和的度数之间的关系.写出你的结论,并说明理由.【答案】(1)解:∵是直角,,,,∵OE平分,,.(2)解:是直角,,,,∵OE平分,,(3)解:,理由是:,OE平分,,,,,即【解析】【分析】(1)根据平角的定义得出∠BOD,∠COB的度数,根据角平分线的定义得出∠BOE=∠BOC=75°,根据角的和差,由∠DOE=∠BOE−∠BOD即可算出答案;(2)根据平角的定义得出∠BOD90°−a ,∠COB180°−a ,根据角平分线的定义得出∠BOE=∠BOC=90°−a,根据角的和差,由∠DOE=∠BOE−∠BOD即可算出答案;(3)∠AOC=2∠DOE ,根据平角的定义得出∠BOC=180°−∠AOC,根据角平分线的定义得出∠BOE=∠BOC=90°−∠AOC ,根据角的和差得出∠BOD=90°−∠BOC=90°−(180°−∠AOC)=∠AOC−90° ,∠DOE=∠BOD+∠BOE,再整体替换即可得出答案。
2.已知线段AB=6.(1)取线段AB的三等分点,这些点连同线段AB的两个端点可以组成多少条线段?求这些线段长度的和;(2)再在线段AB上取两种点:第一种是线段AB的四等分点;第二种是线段AB的六等分点,这些点连同(1)中的三等分点和线段AB的两个端点可以组成多少条线段?求这些线段长度的和。
【答案】(1)解:如图:点C、D为线段AB的三等分点,可以组成的线段为:3+2+1=6(条),∵AB=6,点C、D为线段AB的三等分点,∴AC=CD=DB=2,AD=BC=4,∴这些线段长度的和为:2+2+2+4+4+6=20.(2)解:再在线段AB上取两种点:第一种是线段AB的四等分点D1、D2、D3;第二种是线段AB的六等分点E1、E2,∴这些点连同(1)中的三等分点和线段AB的两个端点可以组成多少条线段共有1+2+3+…+8=36(条);根据题意以A为原点,AB为正方向,建立数轴,则各点对应的数为:A:0;B:6;C:2;D:4;D1:1.5;D2:3;D3:4.5;E1:1;E2:5;∴①以A、B为端点的线段有7+7+1=15(条),长度和为:6×8=48;②不以A、B为端点,以E1、E2为端点的线段有5+5+1=11(条),长度和为:4×6=24;③不以A、B、E1、E2为端点,以D1、D3为端点的线段有3+3+1=7(条),长度和为:3×4=12;④不以A、B、E1、E2、D1、D3为端点,以C、D为端点的线段有1+1+1=3(条),长度和为:2×2=4;∴这些线段长度的和为:48+24+12+4=88.【解析】【分析】(1)如图,根据线段的三等分点可分别求得每条线段的长度,再由线段的概念先找出所有线段,从而求得它们的和.(2)再在线段AB上取两种点:第一种是线段AB的四等分点D1、D2、D3;第二种是线段AB的六等分点E1、E2;根据线段定义和数线段的规律求得线段条数;根据题意以A为原点,AB为正方向,建立数轴,则各点对应的数为:A:0;B:6;C:2;D:4;D1:1.5;D2:3;D3:4.5;E1:1;E2:5;再分情况讨论,从而求得所有线段条数和这些线段的长度.3.一副三角板OAC、OBD如图(1)放置,(∠BDO=30°、∠CAO=45°)(1)若OM、ON分别平分∠BOA、∠DOC,求∠MON的度数;(2)将三角板OBD从图(1)绕O点顺时针旋转如图(2),若OM、ON分别平分∠BOA、∠DOC,则在旋转过程中∠MON如何变化?(3)若三角板OBD从图(1)绕O点逆时针旋转如图(3),若其它条件不变,则(2)的结论是否成立?(4)若三角板OBD从图(1)绕O点逆时针旋转,其它条件不变,在旋转过程中,∠MON是否一直不变,在备用图中画图说明.【答案】(1)解:∵OM、ON分别平分∠BOA、∠DOC∴∠AOM=∠BOA,∠AON=∠AOC∵∠MON=∠AOM+∠AON=(∠BOA+∠AOC)∵∠BDO=30°、∠CAO=45°∴∠AOB=90°,∠AOC=45°∴∠MON= (90°+45°)=67.5°答:∠MON的度数为67.5°.(2)解:设∠AOM=∠BOM=x,∠CON=∠DON=y,∠AOD=α则:2x+α=90°,2y+α=45°,∴2x+2y+2α=135°,∴∠MON=x+y+α=67.5°(3)解:(2)的结论成立理由:设∠AOM=∠BOM=x,∠CON=∠DON=y,∠AOD=α则:2x-α=90°,2y-α=45°,∴2x+2y-2α=135°,∴∠MON=x+y-α=67.5°∠MON=x+y-α=67.5°(4)解:在变化,有时∠MON=112.5°。
七年级数学上册全册单元测试卷易错题(Word版 含答案)
七年级数学上册全册单元测试卷易错题(Word版含答案)一、初一数学上学期期末试卷解答题压轴题精选(难)1.在数轴上、两点分别表示有理数和,我们用表示到之间的距离;例如表示7到3之间的距离.(1)当时,的值为________.(2)如何理解表示的含义?(3)若点、在0到3(含0和3)之间运动,求的最小值和最大值.【答案】(1)5或-3(2)解:∵ = ,∴表示到-2的距离(3)解:∵点、在0到3(含0和3)之间运动,∴0≤a≤3, 0≤b≤3,当时, =0+2=2,此时值最小,故最小值为2;当时, =2+5=7,此时值最大,故最大值为7【解析】【解答】(1)∵,∴a=5或-3;故答案为:5或-3;【分析】(1)此题就是求表示数a的点与表示数1的点之间的距离是4,根据表示数a的点在表示数1的点的右边与左边两种情况考虑即可得出答案;(2)此题就是求表示数b的点与表示数-2的点之间的距离;(3)此题就是求表示数a的点与表示数2的点之间的距离及表示数b的点与表示数-2的点之间的距离和,而0≤a≤3, 0≤b≤3, 借助数轴当时,的值最小;当时,的值最大.2.已知线段AB= ,点P从点A出发沿射线AB以每秒3个单位长度的速度运动,同时点Q 从点B出发沿射线AB以每秒2个单位长度的速度运动,M、N分别为AP、BQ的中点,运动的时间为(1)若求的值,并写出此时P、Q之间的距离;(2)点M、N能否重合为一点,若能,请直接写出此时线段PQ与线段AB之间的数量关系;若不能,说明理由。
【答案】(1)解:设A点表示的数为原点,则B点表示的数为12,P点表示的数为3t,则M点表示的数为 t,点Q表示的数为12+2t,点N表示的数为12+t,M在N左侧,MN=12+t- t=12- t,∵MN= =4,∴12- t=4,解得t=16;此时PQ的距离为 =4M在N右侧,MN= t-12-t-= t-12,∵MN= =4,∴ t-12=4,解得t=32;此时PQ的距离为 =20(2)解:AB的距离为a,则B点表示的数为a,P点表示的数为3t,则M点表示的数为t,点Q表示的数为a+2t,点N表示的数为a+t,∵M,N重合∴ t=a+t,得t=2a,则P点表示的数为3t=6a, Q表示的数为a+2t=5a,∴PQ的距离为a,故PQ=AB【解析】【分析】(1)设A点表示的数为原点,则B点表示的数为12,P点表示的数为3t,则M点表示的数为 t,点Q表示的数为12+2t,点N表示的数为12+t,再根据,分情况讨论即可.(2)AB的距离为a,则B点表示的数为a,P点表示的数为3t,则M点表示的数为 t,点Q表示的数为a+2t,点N表示的数为a+t,根据MN重合可得出a,t之间的关系,即可解出PQ与AB之间的关系.3.如图1,是直线上的点,线段,点分别是线段的中点.(1)求线段的长;(2)若,点在直线上,,求线段的长;(3)若,点在直线上,,请直接写出线段的长________ .(用含的式子表示)【答案】(1)解:∵点分别是线段的中点,∴,∴(2)解:由(1)知由,当点在点左侧时,,当点在点右侧时,;∴OE的长为8cm或18cm.(3)或或【解析】【解答】解:(3)∵E为BC中点,∴BE= ,当点O在点A左边时,OE=16- +b,当点O在线段AE上时,OE=16- -b,当点O在线段BE上时,OE= -(16-b)=b+ -16,当点O在B点右边时,OE=b+ -16,故答案为:或或 .【分析】(1)由中点的定义可得DC= AC,BE= BC,根据DE=DC+CE即可得答案;(2)由中点定义可求出BE的长,分别讨论点O在点A左边和右边两种情况,根据线段间的和差关系求出OE的长即可;(3)分别讨论点O在点A左边、线段AE上、线段BE上和点B 右边的情况,根据线段的和差关系即可得答案.4.如图,OM是∠AOC的平分线,ON是∠BOC的平分线.(1)如图1,当∠AOB=90°,∠BOC=60°时,∠MON的度数是多少?为什么?(2)如图2,当∠AOB=70°,∠BOC=60°时,∠MON=________度.(直接写出结果)(3)如图3,当∠AOB=α,∠BOC=β时,猜想:∠MON的度数是多少?为什么?【答案】(1)解:如图1,∵∠AOB=90°,∠BOC=60°,∴∠AOC=∠AOB+∠BOC=90°+60°=150°,∵OM是∠AOC的平分线,ON是∠BOC的平分线,∴∠MOC=∠AOC=75°,∠NOC=∠BOC=30°,∴∠MON=∠MOC﹣∠NOC=75°﹣30°=45°;(2)35(3)解:如图3,∵∠AOB=α,∠BOC=β,∴∠AOC=∠AOB+∠BOC=α+β,∵OM是∠AOC的平分线,ON是∠BOC的平分线,∴∠MOC=∠AOC=(α+β),∠NOC=∠BOC=β,∴∠MON=∠MOC﹣∠NOC=(α+β)﹣β=α.【解析】【解答】解:(2)如图2,∵∠AOB=70°,∠BOC=60°,∴∠AOC=70°+60°=130°,∵OM平分∠AOC,ON平分∠BOC,∴∠MOC=∠AOC=65°,∠NOC=∠BOC=30°,∴∠MON=∠MOC﹣∠NOC=65°﹣30°=35°.故答案为:35.【分析】(1)求出∠AOC度数,求出∠MOC和∠NOC的度数,代入∠MON=∠MOC﹣∠NOC求出即可;(2)求出∠AOC度数,求出∠MOC和∠NOC的度数,代入∠MON=∠MOC﹣∠NOC求出即可;(3)表示出∠AOC度数,表示出∠MOC和∠NOC的度数,代入∠MON=∠MOC﹣∠NOC求出即可.5.我们学过角的平分线的概念类比给出新概念:从一个角的顶点出发把这个角分成1:2的两个角的射线,叫做这个角的三分线显然,一个角的三分线有两条,例如:如图1,若∠BOC=2∠AOC,则OC是∠AOB的一条三分线。
数学七年级上册全册单元试卷易错题(Word版 含答案)
数学七年级上册全册单元试卷易错题(Word版含答案)一、初一数学上学期期末试卷解答题压轴题精选(难)1.如图,数轴上点 A、B 到表示-2 的点的距离都为 6,P 为线段 AB 上任一点,C,D 两点分别从 P,B 同时向 A 点移动,且 C 点运动速度为每秒 2 个单位长度,D 点运动速度为每秒 3 个单位长度,运动时间为 t 秒.(1)A 点表示数为________,B 点表示的数为________,AB=________.(2)若 P 点表示的数是 0,①运动 1 秒后,求 CD 的长度;②当 D 在 BP 上运动时,求线段 AC、CD 之间的数量关系式.(3)若 t=2 秒时,CD=1,请直接写出 P 点表示的数.【答案】(1)-8;4;12(2)解:①运动一秒后,C点为-2,D点为1,所以CD=3;②当点D在BP上运动时, ,此时C在线段AP上,AC=8-2t,CD=2t+4-3t=4-t,所以AC=2CD(3)解:若 t=2秒时,D点为-2,若 CD=1,则 C=-3 或-1,①当 C=-3 时,CP=4,此时 P=1;②当 C=-1 时,P=3.【解析】【解答】解:⑴故答案为:-8;4;12;【分析】(1)由已知数轴上点 A、B 到表示-2 的点的距离都为 6 ,且点A在点B的左边,就可求出点A和点B表示的数,再利用两点间的距离公式求出AB的长。
(2)①由点A、B表示的数及点C、D的运动速度和方向,可得出运动1秒后点C、D分别表示的数,再求出CD的长;②当点D在BP上时,根据t的取值范围,分别用含t的代数式表示出AC、CD的长,就可得出AC、CD的数量关系。
(3)根据t的值及CD的长,就可得出点C表示的数,从而就可求出点P所表示的数。
2.如图1,已知∠AOB=140°,∠AOC=30°,OE是∠AOB内部的一条射线,且OF平分∠AOE.(1)若∠EOB=30°,则∠COF=________;(2)若∠COF=20°,则∠EOB=________;(3)若∠COF=n°,则∠EOB=________(用含n的式子表示).(4)当射线OE绕点O逆时针旋转到如图2的位置时,请把图补充完整;此时,∠COF与∠EOB有怎样的数量关系?请说明理由.【答案】(1)20°(2)40°(3)80°-2n°(4)如图所示:∠EOB=80°+2∠COF.证明:设∠COF=n°,则∠AOF=∠AOC-∠COF=30°-n°,又∵OF平分∠AOE,∴∠AOE=2∠AOF=60°-2n°.∴∠EOB=∠AOB-∠AOE=140°-(60°-2n°)=(80+2n)°即∠EOB=80°+2∠COF.【解析】【解答】(1)∵∠AOB=140°,∠EOB=30°,∴∠AOE=∠AOB-∠EOB=140°-30°=110°,∵OF平分∠AOE,∴∠AOF= ∠AOE= ×110°=55°,∴∠COF=∠AOF-∠AOC,=55°-30°,=25°;故答案为:25°;(2)∵∠AOC=30°,∠COF=20°,∴∠AOF=∠AOC+∠COF=30°+20°=50°,∵OF平分∠AOE,∴∠AOE=2∠AOF=2×50°=100°,∴∠EOB=∠AOB-∠AOE=140°-100°=40°;故答案为:40°;(3)∵∠AOC=30°,∠COF=n°,∴∠AOF=∠AOC+∠COF=30°+n°,∵OF平分∠AOE,∴∠AOE=2∠AOF=2(30°+n°)=60°+2n°,∴∠EOB=∠AOB-∠AOE=140°-(60°+2n°)=80°-2n°;故答案为:80°-2n°;【分析】(1)根据∠AOE=∠AOB-∠EOB先求出∠AOE,再根据角平分线的定义求出∠AOF,最后根据∠COF=∠AOF-∠AOC解答即可;(2)根据∠AOF=∠AOC+∠COF先求出∠AOF,再根据角平分线的定义求出∠AOE,最后根据∠EOB=∠AOB-∠AOE解答即可;(3)与(2)的思路相同求解即可;(4)设∠COF=n°,先表示出∠AOF,再根据角平分线的定义求出∠AOE,最后根据∠EOB=∠AOB-∠AOE解答即可.3.如图,两个形状、大小完全相同的含有30°、60°的直角三角板如图①放置,PA、PB与直线MN重合,且三角板PAC、三角板PBD均可绕点P逆时针旋转.(1)直接写出∠DPC的度数.(2)如图②,在图①基础上,若三角板PAC的边PA从PN处开始绕点P逆时针旋转,转速为5°/秒,同时三角板PBD的边PB从PM处开始绕点P逆时针旋转,转速为1°/秒,(当PA转到与PM重合时,两三角板都停止转动),在旋转过程中,当PC与PB重合时,求旋转的时间是多少?(3)在(2)的条件下,PC、PB、PD三条射线中,当其中一条射线平分另两条射线的夹角时,请直接写出旋转的时间.【答案】(1)解:∠DPC=180°-∠APC-∠BPD=180°-60°-30°=90°故答案为:90°(2)解:设旋转的时间是t秒时PC与PB重合,根据题意列方程得5t-t=30+90解得t=30又∵180÷5=36秒∴30<36故旋转的时间是30秒时PC与PB重合(3)解:设t秒时其中一条射线平分另两条射线的夹角,分三种情况:①当PD平分∠BPC时,5t-t=90-30,解得t=15②当PC平分∠BPC时,,解得t=26.25③当PB平分∠DPC时,5t-t=90-2×30,解得t=37.5故15秒或26.25秒或37.5秒时其中一条射线平分另两条射线的夹角【解析】【分析】(1)易得∠DPC=180°-∠APC-∠BPD即可求(2)只需设旋转的时间是t 秒时PC与PB重合,列方程解可得(3)一条射线平分另两条射线的夹角,分三种情况:当PD平分∠BPC时;当PC平分∠BPC时;当PB平分∠DPC时,计算每种情况对应的时间即可.4.如图1,在四边形ABCD中,点E为AB延长线上一点,连接并延长交AD延长线于点,, .(1)求证:;(2)如图2,连接交于点,连接,若为的角平分线,为的角平分线,过点作交于点,求证:;(3)在(2)的条件下,若,,求的度数.【答案】(1)证明:,,,,,;(2)证明:过点作为的角平分线,为的角平分线,设由(1)问可知,,,,,,,,,,,,;(3)解:由(2)得,,,,,,,,,,,,,,过点作,【解析】【分析】(1)先根据平行线的判定证明AF∥BC,可得∠FDC=∠DCB,由已知可得∠CBE=∠DCB,由平行线的判定可得结论;(2)先根据垂直得∠HBC=90°=∠CBE+∠ABH,设,则∠ABH ,由平行线和角平分线的定义可推出,;,即可得结论;(3)根据第(2)的结论,可得,由三角形的内角和得,根据已知可得,过点作,由平行线的性质及已知条件可得∠BFE=30°.5.如图 1,射线 OC在∠AOB的内部,图中共有 3个角:∠AOB、∠AOC 和∠BOC,若其中有一个角的度数是另一个角度数的两倍,则称射线 OC是∠AOB的奇妙线.(1)一个角的角平分线________这个角的奇妙线.(填是或不是);(2)如图 2,若∠MPN=60°,射线 PQ绕点 P从 PN位置开始,以每秒 10°的速度逆时针旋转,当∠QPN首次等于 180°时停止旋转,设旋转的时间为 t(s).①当 t为何值时,射线 PM是∠QPN 的奇妙线?②若射线 PM 同时绕点 P以每秒 5°的速度逆时针旋转,并与 PQ同时停止旋转.请求出当射线 PQ是∠MPN的奇妙线时 t的值.【答案】(1)是(2)解:①∠MPN=60,∠QPM=10t-60,∠QPN=10t(最大角),当∠MPN=2∠QPM时,60=2(10t-60),解得t=9;当∠QPN=2∠MPN时,10t =2×60,解得t=12;当∠QPM=2∠MPN时,10t-60=2×60,解得t=18;综上,当t的值是9或12或18时,射线 PM是∠QPN 的奇妙线.②∠QPN=10t,∠QPM=60-10t+5t=60-5t,∠MPN=60+5t(最大角),当∠QPM=2∠QPN时, 60-5t =2×10t ,解得t= ;当∠MPN=2∠QPN时,60+5t =2×10t,解得t=4;当∠QPN=2∠QPM时,10t =2×(60-5t),解得t=6;综上,当射线 PQ是∠MPN的奇妙线时 t的值为或4或6.故答案为:(1)是;(2) ①当t的值是9或12或18时,射线PM是∠QPN 的奇妙线;②当射线 PQ是∠MPN的奇妙线时 t的值为或4或6.【解析】【分析】(1)根据奇妙线定义即可求解;(2)①分3种情况,根据奇妙线定义列方程求解即可;②分3种情况,根据奇妙线定义列方程求解即可.6.如图,O为直线AB上一点,∠BOC=36°.(1)若OD平分∠AOC,∠DOE=90°,如图(a)所示,求∠AOE的度数:(2)若∠AOD=∠AOC,∠DOE=60°,如图(b)所示,求∠AOE的度数:(3)若∠AOD=∠AOC,∠DOE=(n≥2,且n为正整数),如图(c)所示,请用n含的代数式表示∠AOE的度数________(直接写出结果).【答案】(1)解:∵∠BOC=36°,OD平分∠AOC,∴∠AOD=∠DOC=72°,∵∠DOE=90°,则∠AOE=90°−72°=18°;故答案为:18°(2)解:设∠AOD=x,则∠DOC=2x,∠BOC=180°−3x=36°,解得:x=48°,∴∠AOE=60°-x=60°−48°=12°(3) .【解析】【解答】(3)设∠AOD=x,则∠DOC=(n−1)x,∠BOC=180°-nx=36°,解得:x=,∴∠AOE=-=.【分析】(1)利用角平分线的性质得出∠AOD=∠DOC=72°,进而得出∠AOE的度数;(2)设∠AOD=x,则∠DOC=2x,∠BOC=180°−3x=36°,得出x的值,进而得出∠AOE 的度数;(3)利用(2)中作法,得出x与α的关系,进而得出答案.7.如图,E是直线AC上一点,EF是∠AEB的平分线.(1)如图1,若EG是∠BEC的平分线,求∠GEF的度数;(2)如图2,若GE在∠BEC内,且∠CEG=3∠BEG,∠GEF=75°,求∠BEG的度数.(3)如图3,若GE在∠BEC内,且∠CEG=n∠BEG,∠GEF=α,求∠BEG(用含n、α的代数式表示).【答案】(1)解:∵EF是∠AEB的平分线,∴∠BEF= ∠AEB,∵EG是∠BEC的平分线,∴∠BEG= ∠BEC,∴∠GEF=∠BEF+∠BEG= (∠AEB+∠BEC)=90°(2)解:∵∠GEF=75°,∴∠BEF=75°-∠BEG,∵EF是∠AEB的平分线,∴∠AEB=2∠BEF=150°-2∠BEG,∵∠CEG=3∠BEG,∴∠BEG+3∠BEG+150°-2∠BEG=180°,∴∠BEG=15°(3)解:∵∠GEF=α,∴∠BEF=α-∠BEG,∵EF是∠AEB的平分线,∴∠AEB=2∠BEF=2α-2∠BEG,∵∠CEG=n∠BEG,∴∠BEG+n∠BEG+2α-2∠BEG=180°,∴∠BEG=【解析】【分析】(1)由角平分线的性质可得∠BEF=∠AEB;∠BEG=∠BEC;然后结合图形得∠GEF=∠BEF+∠BEG=(∠AEB+∠BEC),根据平角的意义即可求解;(2)由角的构成可得∠BEF=∠GEF-∠BEG,由角平分线的性质可得∠AEB=2∠BEF=2(∠GEF-∠BEG),由平角的意义可得∠CEG+∠BEG+∠AEB=180°,于是把∠CEG、∠BEG、∠AEB代入等式可得关于∠BEG的方程,解方程即可求解;(3)用(2)的方法可求解。
人教版数学七年级上册全册单元试卷易错题(Word版 含答案)
人教版数学七年级上册全册单元试卷易错题(Word版含答案)一、初一数学上学期期末试卷解答题压轴题精选(难)1.(1)如图①,已知:Rt△ABC中,AB=AC,直线m经过点A,BD⊥m于D,CE⊥m于E,求证:DE=BD+CE;(2)如图②,将(1)中的条件改为:△ABC中,AB=AC,并且∠BDA=∠AEC=∠BAC=α,α为任意锐角或钝角,请问结论DE=BD+CE是否成立?如成立,请证明;若不成立,请说明理由;(3)应用:如图③,在△ABC中,∠BAC是钝角,AB=AC,∠BAD>∠CAE,∠BDA=∠AEC=∠BAC,直线m与BC的延长线交于点F,若BC=2CF,△ABC的面积是12,求△ABD与△CEF的面积之和.【答案】(1)证明:∵BD⊥直线m,CE⊥直线m,∴∠BDA=∠CEA=90°,∵∠BAC=90°,∴∠BAD+∠CAE=90°,∵∠BAD+∠ABD=90°,∴∠CAE=∠ABD,在△ADB和△CEA中,∴△ADB≌△CEA(AAS),∴AE=BD,AD=CE,∴DE=AE+AD=BD+CE;(2)解:结论DE=BD+CE成立;理由如下:∵∠BDA=∠BAC=α,∴∠DBA+∠BAD=∠BAD+∠CAE=180°-α,∴∠CAE=∠ABD,在△ADB和△CEA中,∴△ADB≌△CEA(AAS),∴AE=BD,AD=CE,∴DE=AE+AD=BD+CE;(3)解:∵∠BAD>∠CAE,∠BDA=∠AEC=∠BAC,∴∠CAE=∠ABD,在△ABD和△CEA中,∴△ABD≌△CEA(AAS),∴S△ABD=S△CEA,设△ABC的底边BC上的高为h,则△ACF的底边CF上的高为h,∴S△ABC= BC•h=12,S△ACF= CF•h,∵BC=2CF,∴S△ACF=6,∵S△ACF=S△CEF+S△CEA=S△CEF+S△ABD=6,∴△ABD与△CEF的面积之和为6.【解析】【分析】(1)根据BD⊥直线m,CE⊥直线m得∠BDA=∠CEA=90°,而∠BAC=90°,根据等角的余角相等得∠CAE=∠ABD,由AAS证得△ADB≌△CEA,则AE=BD,AD=CE,即可得出结论;(2)由∠BDA=∠BAC=α,则∠DBA+∠BAD=∠BAD+∠CAE=180°-α,得出∠CAE=∠ABD,由AAS证得△ADB≌△CEA即可得出答案;(3)由∠BAD>∠CAE,∠BDA=∠AEC=∠BAC,∴∠CAE=∠ABD,得出∠CAE=∠ABD,由AAS证得△ADB≌△CEA,得出S△ABD=S△CEA,再由不同底等高的两个三角形的面积之比等于底的比,得出S△ACF即可得出结果.2.如图,已知AB∥CD,现将一直角三角形PMN放入图中,其中∠P=90°,PM交AB于点E,PN交CD于点F(1)当△PMN所放位置如图①所示时,则∠PFD与∠AEM的数量关系为________;(2)当△PMN所放位置如图②所示时,求证:∠PFD−∠AEM=90°;(3)在(2)的条件下,若MN与CD交于点O,且∠DON=30°,∠PEB=15°,求∠N的度数.【答案】(1)∠PFD+∠AEM=90°(2)过点P作PG∥AB∵AB∥CD,∴PG∥AB∥CD,∴∠AEM=∠MPG,∠PFD=∠NPG∵∠MPN=90°∴∠NPG-∠MPG=90°∴∠PFD-∠AEM=90°;(3)设AB与PN交于点H∵∠P=90°,∠PEB=15°∴∠PHE=180°-∠P-∠PEB=75°∵AB∥CD,∴∠PFO=∠PHE=75°∴∠N=∠PFO-∠DON=45°.【解析】【解答】(1)过点P作PH∥AB∵AB∥CD,∴PH∥AB∥CD,∴∠AEM=∠MPH,∠PFD=∠NPH∵∠MPN=90°∴∠MPH+∠NPH=90°∴∠PFD+∠AEM=90°故答案为:∠PFD+∠AEM=90°;【分析】(1)过点P作PH∥AB,然后根据平行于同一条直线的两直线平行可得PH∥AB∥CD,根据平行线的性质可得∠AEM=∠MPH,∠PFD=∠NPH,然后根据∠MPH+∠NPH=90°和等量代换即可得出结论;(2)过点P作PG∥AB,然后根据平行于同一条直线的两直线平行可得PG∥AB∥CD,根据平行线的性质可得∠AEM=∠MPG,∠PFD=∠NPG,然后根据∠NPG-∠MPG=90°和等量代换即可证出结论;(3)设AB与PN 交于点H,根据三角形的内角和定理即可求出∠PHE,然后根据平行线的性质可得∠PFO=∠PHE,然后根据三角形外角的性质即可求出结论.3.点A、B在数轴上分别表示实数a、b,A、B两点之间的距离记作AB.当A、B两点中有一点为原点时,不妨设A点在原点.如图①所示,则AB=OB=|b|=|a﹣b|.当A、B两点都不在原点时:⑴如图②所示,点A、B都在原点的右边,不妨设点A在点B的左侧,则AB=OB﹣OA=|b|﹣|a|=b﹣a=|b﹣a|=|a﹣b|⑵如图③所示,点A、B都在原点的左边,不妨设点A在点B的右侧,则AB=OB﹣OA=|b|﹣|a|=﹣b﹣(﹣a)=a﹣b=|a﹣b|⑶如图④所示,点A、B分别在原点的两边,不妨设点A在点O的右侧,则AB=OB+OA=|b|+|a|=a+(﹣b)=|a﹣b|回答下列问题:(1)综上所述,数轴上A、B两点之间的距离AB=________.(2)数轴上表示2和﹣4的两点A和B之间的距离AB=________.(3)数轴上表示x和﹣2的两点A和B之间的距离AB=________,如果AB=2,则x的值为________.(4)若代数式|x+2|+|x﹣3|有最小值,则最小值为________.【答案】(1)(2)6(3);0或-4(4)5【解析】【解答】(1)综上所述,数轴上A、B两点之间的距离 (2)数轴上表示2和-4的两点A和B之间的距离 (3)数轴上表示和-2的两点A和B之间的距离如果,则的值为或由题意可知:当x在−2与3之间时,此时,代数式|x+2|+|x−3|取最小值,最小值为故答案为:(1);(2)6;(3),0或-4;(4)5.【分析】(1)发现规律:在数轴上两点之间的距离为这两点所表示的数的差的绝对值,故可求解;(2)根据(1),即可直接求出结果;(3)先根据(1)即可表示出AB;当AB=2时,得到方程,解出x的值即可;(4)|x+2|+|x-3|表示数轴上一点到-2与3两点的距离的和,当这点是-2或5或在它们之间时和最小,最小距离是-2与3之间的距离。
七年级上册数学易错题精选及讲解答案
七年级上册数学易错题精选及讲解答案集团标准化工作小组 #Q8QGGQT-GX8G08Q8-GNQGJ8-MHHGN#有理数部分1.填空:(1)当a________时,a与-a必有一个是负数;(2)在数轴上,与原点0相距5个单位长度的点所表示的数是________;(3)在数轴上,A点表示+1,与A点距离3个单位长度的点所表示的数是________;(4)在数轴的原点左侧且到原点的距离等于6个单位长度的点所表示的数的绝对值是_______.错解 (1)a为任何有理数;(2)+5;(3)+3;(4)-6.2.用“有”、“没有”填空:在有理数集合里,________最大的负数,________最小的正数,________绝对值最小的有理数.错解有,有,没有.3.用“都是”、“都不是”、“不都是”填空:(1)所有的整数________负整数;(2)小学里学过的数________正数;(3)带有“+”号的数________正数;(4)有理数的绝对值________正数;(5)若|a|+|b|=0,则a,b________零;(6)比负数大的数________正数.错解 (1)都不是;(2)都是;(3)都是;(4)都是;(5)不都是;(6)都是.4.用“一定”、“不一定”、“一定不”填空:(1)-a________是负数;(2)当a>b时,________有|a|>|b|;(3)在数轴上的任意两点,距原点较近的点所表示的数________大于距原点较远的点所表示的数;(4)|x|+|y|________是正数;(5)一个数________大于它的相反数;(6)一个数________小于或等于它的绝对值;错解 (1)一定;(2)一定;(3)一定不;(4)一定;(5)一定;(6)不一定.5.把下列各数从小到大,用“<”号连接:并用“>”连接起来.8.填空:(1)如果-x=-(-11),那么x=________;(2)绝对值不大于4的负整数是________;(3)绝对值小于而大于3的整数是________.错解 (1)11;(2)-1,-2,-3;(3)4.9.根据所给的条件列出代数式:(1)a,b两数之和除a,b两数绝对值之和;(2)a与b的相反数的和乘以a,b两数差的绝对值;(3)一个分数的分母是x,分子比分母的相反数大6;(4)x,y两数和的相反数乘以x,y两数和的绝对值.10.代数式-|x|的意义是什么错解代数式-|x|的意义是:x的相反数的绝对值.11.用适当的符号(>、<、≥、≤)填空:(1)若a是负数,则a________-a;(2)若a是负数,则-a_______0;(3)如果a>0,且|a|>|b|,那么a________ b.错解 (1)>;(2)<;(3)<.12.写出绝对值不大于2的整数.错解绝对值不大2的整数有-1,1.13.由|x|=a能推出x=±a吗错解由|x|=a能推出x=±a.如由|x|=3得到x=±3,由|x|=5得到x=±5.14.由|a|=|b|一定能得出a=b吗错解一定能得出a=b.如由|6|=|6|得出6=6,由|-4|=|-4|得-4=-4.15.绝对值小于5的偶数是几错解绝对值小于5的偶数是2,4.16.用代数式表示:比a的相反数大11的数.错解-a-11.17.用语言叙述代数式:-a-3.错解代数式-a-3用语言叙述为:a与3的差的相反数.18.算式-3+5-7+2-9如何读错解算式-3+5-7+2-9读作:负三、正五、减七、正二、减九.19.把下列各式先改写成省略括号的和的形式,再求出各式的值.(1)(-7)-(-4)-(+9)+(+2)-(-5);(2)(-5)-(+7)-(-6)+4.解(1)(-7)-(-4)-(+9)+(+2)-(-5)=-7-4+9+2-5=-5;(2)(-5)-(+7)-(-6)+4=5-7+6-4=8.20.计算下列各题:(2)5-|-5|=10;21.用适当的符号(>、<、≥、≤)填空:(1)若b为负数,则a+b________a;(2)若a>0,b<0,则a-b________0;(3)若a为负数,则3-a________3.错解 (1)>;(2)≥;(3)≥.22.若a为有理数,求a的相反数与a的绝对值的和.错解-a+|a|=-a+a=0.23.若|a|=4,|b|=2,且|a+b|=a+b,求a-b的值.错解由|a|=4,得a=±4;由|b|=2,得b=±2.当a=4,b=2时,a-b=2;当a=4,b=-2时,a-b=6;当a=-4,b=2时,a-b=-6;当a=-4,b=-2时,a-b=-2.24.列式并计算:-7与-15的绝对值的和.错解 |-7|+|-15|=7+15=22.25.用简便方法计算:26.用“都”、“不都”、“都不”填空:(1)如果ab≠0,那么a,b________为零;(2)如果ab>0,且a+b>0,那么a,b________为正数;(3)如果ab<0,且a+b<0,那么a,b________为负数;(4)如果ab=0,且a+b=0,那么a,b________为零.错解 (1)不都;(2)不都;(3)都;(4)不都.27.填空:(3)a,b为有理数,则-ab是_________;(4)a,b互为相反数,则(a+b)a是________.错解 (1)负数;(2)正数;(3)负数;(4)正数.28.填空:(1)如果四个有理数相乘,积为负数,那么负因数个数是________;错解 (1)3;(2)b>0.29.用简便方法计算:解30.比较4a和-4a的大小:错解因为4a是正数,-4a是负数.而正数大于负数,所以4a>-4a.31.计算下列各题:(5)-15×12÷6×5.解=-48÷(-4)=12;(5)-15×12÷6×5错解因为|a|=|b|,所以a=b.=1+1+1=3.34.下列叙述是否正确若不正确,改正过来.(1)平方等于16的数是(±4)2;(2)(-2)3的相反数是-23;错解 (1)正确;(2)正确;(3)正确.35.计算下列各题;(1)-;(2)2×32.解36.已知n为自然数,用“一定”、“不一定”或“一定不”填空:(1)(-1)n+2________是负数;(2)(-1)2n+1________是负数;(3)(-1)n+(-1)n+1________是零.错解 (1)一定不;(2)不一定;(3)一定不.37.下列各题中的横线处所填写的内容是否正确若不正确,改正过来.(1)有理数a的四次幂是正数,那么a的奇数次幂是负数;(2)有理数a与它的立方相等,那么a=1;(3)有理数a的平方与它的立方相等,那么a=0;(4)若|a|=3,那么a3=9;(5)若x2=9,且x<0,那么x3=27.38.用“一定”、“不一定”或“一定不”填空:(1)有理数的平方________是正数;(2)一个负数的偶次幂________大于这个数的相反数;(3)小于1的数的平方________小于原数;(4)一个数的立方________小于它的平方.错解 (1)一定;(2)一定;(3)一定;(4)一定不.39.计算下列各题:(1)(-3×2)3+3×23;(2)-24-(-2)4;(3)-2÷(-4)2;解(1)(-3×2)3+3×23=-3×23+3×23=0;(2)-24-(-2)4=0;40.用科学记数法记出下列各数:.000034.错解.14×106;(2)=×10-4.41.判断并改错(只改动横线上的部分):(1)用四舍五入得到的近似数有4个有效数字.(2)用四舍五入法,把精确到千分位的近似数是.(3)由四舍五入得到的近似数和是一样的.(4)由四舍五入得到的近似数万,它精确到十分位.42.改错(只改动横线上的部分):(1)已知=,那么=,=;(2)已知=,那么=4097,=;(3)已知=,那么2=116300;(4)近似数×104精确到百分位,它的有效数字是2,4;(5)已知=,x3=,则x=.有理数·错解诊断练习正确答案1.(1)不等于0的有理数;(2)+5,-5;(3)-2,+4;(4)6.2.(1)没有;(2)没有;(3)有.3.(1)不都是;(2)不都是;(3)不都是;(4)不都是;(5)都是;(6)不都是.原解错在没有注意“0”这个特殊数(除(1)、(5)两小题外).4.(1)不一定;(2)不一定;(3)不一定;(4)不一定;(5)不一定;(6)一定.上面5,6,7题的原解错在没有掌握有理数特别是负数大小的比较.8.(1)-11;(2)-1,-2,-3,-4;(3)4,-4.10.x绝对值的相反数.11.(1)<;(2)>;(3)>.12.-2,-1,0,1,2.13.不一定能推出x=±a,例如,若|x|=-2.则x值不存在.14.不一定能得出a=b,如|4|=|-4|,但4≠-4.15.-2,-4,0,2,4.16.-a+11.17.a的相反数与3的差.18.读作:负三、正五、负七、正二、负九的和,或负三加五减七加二减九.19.(1)原式=-7+4-9+2+5=-5;(2)原式=-5-7+6+4=-2.21.<;>;>.22.当a≥0时,-a+|a|=0,当a<0时,-a+|a|=-2a.23.由|a+b|=a+b知a+b≥0,根据这一条件,得a=4,b=2,所以a-b=2;a=4,b=-2,所以a-b=6.24.-7+|-15|=-7+15=8.26.(1)都不;(2)都;(3)不都;(4)都.27.(1)正数、负数或零;(2)正数、负数或零;(3)正数、负数或零;(4)0.28.(1)3或1;(2)b≠0.30.当a>0时,4a>-4a;当a=0时,4a=-4a;当a<0时,4a<-4a.(5)-150.32.当b≠0时,由|a|=|b|得a=b或a=-b,33.由ab>0得a>0且b>0,或a<0且b<0,求得原式值为3或-1.34.(1)平方等于16的数是±4;(2)(-2)3的相反数是23;(3)(-5)100.36.(1)不一定;(2)一定;(3)一定.37.(1)负数或正数;(2)a=-1,0,1;(3)a=0,1;(4)a3=±27;(5)x3=-27.38.(1)不一定;(2)不一定;(3)不一定;(4)不一定.40.(1)×108;(2)×10-5.41.(1)有3个有效数字;(2);(3)不一样;(4)千位.42.(1)2536,;(2)409700,;(3)341;(4)百位,有效数字2,4,0;(5).整式的加减例1 下列说法正确的是()A. 的指数是0B. 没有系数C. -3是一次单项式D. -3是单项式分析:正确答案应选D。
七年级数学上册全册单元测试卷易错题(Word版 含答案)
七年级数学上册全册单元测试卷易错题(Word版含答案)一、初一数学上学期期末试卷解答题压轴题精选(难)1.结合数轴与绝对值的知识回答下列问题:(1)探究:①数轴上表示5和2的两点之间的距离是多少.②数轴上表示﹣2和﹣6的两点之间的距离是多少.③数轴上表示﹣4和3的两点之间的距离是多少.(2)归纳:一般的,数轴上表示数m和数n的两点之间的距离等于|m﹣n|.应用:①如果表示数a和3的两点之间的距离是7,则可记为:|a﹣3|=7,求a的值.②若数轴上表示数a的点位于﹣4与3之间,求|a+4|+|a﹣3|的值.③当a取何值时,|a+4|+|a﹣1|+|a﹣3|的值最小,最小值是多少?请说明理由.(3)拓展:某一直线沿街有2014户居民(相邻两户居民间隔相同):A1, A2, A3,A4, A5,…A2014,某餐饮公司想为这2014户居民提供早餐,决定在路旁建立一个快餐店P,点P选在什么线段上,才能使这2014户居民到点P的距离总和最小.【答案】(1)解:①数轴上表示5和2的两点之间的距离是3.②数轴上表示﹣2和﹣6的两点之间的距离是4.③数轴上表示﹣4和3的两点之间的距离是7.(2)解:①如果表示数a和3的两点之间的距离是7,则可记为:|a﹣3|=7,a=10或﹣4.②若数轴上表示数a的点位于﹣4与3之间,|a+4|+|a﹣3|=a+4+3﹣a=7;③当a=1时,|a+4|+|a﹣1|+|a﹣3|取最小值,|a+4|+|a﹣1|+|a﹣3|最小=5+0+2=7,理由是:a=1时,正好是3与﹣4两点间的距离.(3)解:点P选在A1007A1008这条线段上【解析】【分析】(1)根据两点间的距离公式:数轴上表示数m和数n的两点之间的距离等于|m﹣n|,分别计算可得出答案。
(2)① 利用绝对值等于7的数是±7,就可得出a-3=±7,解方程即可;② 由已知数轴上表示数a的点位于﹣4与3之间,可得出a+4>0,a-3<0,先去掉绝对值,再合并同类项即可;③ 根据线段上的点到线段两端的距离的和最短,可得出答案。
七上Unit8-9易错题整理
Unit8-9检测卷一.单选题(每道题的答案分别从后面的一、二两个括号里选择)1.-_____do you have P.E.?–We have P.E ______Tuesday and Thursday.( when/what) (on/in/at/of)2.I don’t _______anything(任何事情) to do today, so I’m very_______.(have/has) (busy/free).3.The third day of a week is ________. (Tuesday/Thursday)4.-______is music?-I think it’s interesting______ relaxing.(what/How) (and/but)5.-______is your English teacher, Nina? –Miss Smith (who/what)6.-______your father like sports?-Yes. He _________every morning.(Does/Do) (gets up/plays sports)7.-Let’s play soccer after we finish ______the TV play. –It ______great.(watching/to watch) (listens/sounds)8.Science is very________. -______________.(interesting/interested) (You’re welcome/That’s for sure)9. Which is ________day of a week? –Thursday. (five/fifth/the fifth)10.LiuMei goes to school_____7:00 ____the morning. (at/in/on)11.Ken and Kate’s favorite subject____ P.E.(is/are)12. Every day I can play computer games _____one hour. (for/at/on/in)13. Do your parents like HangZhou? –No, they don’t like that ______. The houses (房子)are very dear(昂贵的)(City/home/school/classroom)14. March is ___________month of a year. ( third /the three / three /the third )15.My mother is ________________.(forty years old/fortieth years old /forty year old / forty years)16.-Is Jim’s birthday in July? –Yes,________. (he is /it is)17.Today is the boy’s _______birthday. ( nine / nineth / nine’s /ninth)18..Is workers’Day ________. (the May 1st /May 1st /May one/one of May)19.Are there ______months in a year? (twenty /twelve/twelfth /twentieth)20.Lucy’s birthday is September ______. (2th /3th / 3rd /21th)21.________ is after August. (October/December /July /September)22.How old_____ your parents? ( is /are /am /)be23.How old ______your cousin? He is fourteen _____ old.(is/are) (year/years)24.11.-When is _____________birthday party?-Her birthday is on October fifth.(your brother’s /Jack sister / his sister’s / Lucy’s brother’s )25.When is your birthday? –It’s February_______. (twenty/twentyth/20th)26.Alan’s cousin is only eighteen but this girl looks very______.(interesting/old /boring /big)27.There are two_____ about parents. They’re father’s Day and Mother’s Day.(festivals /ages / parties / families)28.Mom says the _____month of the year is November.( ninth /tenth/ eleventh /twelfth)29.Today is my daughter’s birthday. I want to __________ for her. Can you come to it?( have a look / have a party/look at / have parties )30.-Is Jim’s birthday on March 21st?-________________. It’s on May 12th.(Yes, it is/ No, he isn’t / Yes, he is / no, it isn’t)31.–Tom is a Middle school student. How old is he? -_______.(The thirteen / Thirteenth/ Thirty /Thirteen )32.-What’s the date today?-______________. (July 7th/ Tuesday /June)33.We have an English concert _______July 5th each year. (in/on/at/of)34.The boy is only________. Today is his ______ birthday. (five/fifth)35.Tony’s birthday is _______January and peter’s birthday is _______March 26th.(on /in)二.单词拼写1.I don’t go to school on S________ or Sundays2.How many l_______ do you have at school every day?3.There are 24 h______ in a day.4.I spend(花费)two h______ doing my homework.5.How many s_______ do you learn at school.6.Which s______ do you like best, science, math, or geography?-Math.7. The first class begins(开始) at 8:00 am and f________ at 8:45.8. The last class f________ at 4:30 pm at our school.9.-When do you classes f_______?-At 4:30 pm.10.I.m very b_______ because I have many classes/I have to work from morning to evening.11.Do you f______ your work, Jack?12.There are 28 0r 29 days in F___________.13. Breakfast is the f________ meal in a day.14.Sunday is the f______ day of a week and Tuesday is the t_______ day of a week.15. Four people are in front of(在…前面) me. So I’m the f________.16. We have lots of school t ________at good prices.17.The Art F______ is in March at our school.18.My birthday is on January_________(二十日)19.December is the t________ month of a year.20.There are usually 30 or 31 days in a m________.21.A______ is the eighth month of a year.22.A_______ is the f_______ month of a year.23.March eighth is W___________ Day and September 10th is T_________ Day.24.There are twelve m________ in a year.25.Monday is the s_________ day in a week.26.J________1st is New Year’s Day.27.The n_______ month of a year is September.28. Do you often have a school t_______? You can go to many places.30.S_________ is the ninth month of a year.。
七年级上册数学全册单元试卷易错题(Word版 含答案)
七年级上册数学全册单元试卷易错题(Word版含答案)一、初一数学上学期期末试卷解答题压轴题精选(难)1.已知,,点E是直线AC上一个动点(不与A,C重合),点F是BC边上一个定点,过点E作,交直线AB于点D,连接BE,过点F作,交直线AC于点G.(1)如图①,当点E在线段AC上时,求证:.(2)在(1)的条件下,判断这三个角的度数和是否为一个定值?如果是,求出这个值,如果不是,说明理由.(3)如图②,当点E在线段AC的延长线上时,(2)中的结论是否仍然成立?如果不成立,请直接写出之间的关系.(4)当点E在线段CA的延长线上时,(2)中的结论是否仍然成立?如果不成立,请直接写出之间的关系.【答案】(1)解:∵∴∵∴∴(2)解:这三个角的度数和为一个定值,是过点G作交BE于点H∴∵∴∴∴即(3)解:过点G作交BE于点H∴∵∴∴∴即故的关系仍成立(4)不成立| ∠EGF-∠DEC+∠BFG=180°【解析】【解答】解:(4)过点G作交BE于点H∴∠DEC=∠EGH∵∴∴∠HGF+∠BFG=180°∵∠HGF=∠EGF-∠EGH∴∠HGF=∠EGF-∠DEC∴∠EGF-∠DEC+∠BFG=180°∴(2)中的关系不成立,∠EGF、∠DEC、∠BFG之间关系为:∠EGF-∠DEC+∠BFG=180°故答案为:不成立,∠EGF-∠DEC+∠BFG=180°【分析】(1)根据两条直线平行,内错角相等,得出;两条直线平行,同位角相等,得出,即可证明.(2)过点G作交BE于点H,根据平行线性质定理,,,即可得到答案.(3)过点G作交BE于点H,得到,因为,所以,得到,即可求解.(4)过点G作交BE于点H,得∠DEC=∠EGH,因为,所以,推得∠HGF+∠BFG=180°,即可求解.2.将一副三角板中的两个直角顶点叠放在一起(如图①),其中,, .(1)猜想与的数量关系,并说明理由;(2)若,求的度数;(3)若按住三角板不动,绕顶点转动三角,试探究等于多少度时,并简要说明理由.【答案】(1)解:,理由如下:,(2)解:如图①,设,则,由(1)可得,,,(3)解:分两种情况:①如图1所示,当时,,又,;②如图2所示,当时,,又,.综上所述,等于或时, .【解析】【分析】(1)由∠BCD=∠ACB+∠ACD=90°+∠ACD,即可求出∠BCD+∠ACE的度数.(2)如图①,设∠ACE=a,可得∠BCD=3a,结合(1)可得3a+a=180°,求出a的度数,即得∠BCD的度数.(3)分两种情况讨论,①如图1所示,当AB∥CE时,∠BCE=180°-∠B=120°,②如图2所示,当AB∥CE时,∠BCE=∠B=60°,分别求出∠BCD的度数即可.3.已知 (本题中的角均大于且小于 )(1)如图1,在内部作,若,求的度数;(2)如图2,在内部作,在内,在内,且,,,求的度数;(3)射线从的位置出发绕点顺时针以每秒的速度旋转,时间为秒( 且 ).射线平分,射线平分,射线平分 .若,则 ________秒.【答案】(1)解:∵∠AOD+∠BOC=∠AOC+∠COD+∠BOD+∠COD=∠AOB+∠COD又∵∠AOD+∠BOC=160°且∠AOB=120°∴(2)解:,设,则,则,(3) s或15s或30s或45s【解析】【解答】(2)解:当OI在直线OA的上方时,有∠MON=∠MOI+∠NOI= (∠AOI+∠BOI))= ∠AOB= ×120°=60°,∠PON= ×60°=30°,∵∠MOI=3∠POI,∴3t=3(30-3t)或3t=3(3t-30),解得t= 或15;当OI在直线AO的下方时,∠MON═(360°-∠AOB)═ ×240°=120°,∵∠MOI=3∠POI,∴180°-3t=3(60°- )或180°-3t=3( -60°),解得t=30或45,综上所述,满足条件的t的值为 s或15s或30s或45s【分析】(1)利用角的和差进行计算便可;(2)设,则,,通过角的和差列出方程解答便可;(3)分情况讨论,确定∠MON在不同情况下的定值,再根据角的和差确定t的不同方程进行解答便可.4.如图1,纸上有五个边长为1的小正方形组成的图形纸,我们可以把它剪开拼成一个正方形.(1)拼成的正方形的面积为________,边长为________.(2)如图2,以数轴的单位长度的线段为边作一个直角三角形,以数轴上表示的﹣1点为圆心,直角三角形的最大边为半径画弧,交数轴正半轴于点A,那么点A表示的数是________ .(3)如图3,网格中每个小正方形的边长为1,若把阴影部分剪拼成一个正方形,那么新正方形的边长是 ________.【答案】(1)5;;(2)(3)【解析】【解答】解:(1)5个小正方形拼成一个大正方形后,面积不变,所以拼成的正方形的面积是:5×1×1=5,边长= ,(2)根据勾股定理可求出图中直角三角形的斜边长= ,然后根据线段和差关系求出A点表示的数是,(3)根据图可知:阴影部分的面积是6个小正方形的面积,即为6,所以拼成的新正方形的面积是6,则新正方形的边长= .【分析】(1)剪拼前后两个图形的形状发生了变化,但总面积不会变化,从而得出拼成的正方形的面积,再根据正方形的面积等于边长的平方即可算出其边长;(2)直角三角形的最大的边就是斜边,根据勾股定理可以算出其斜边的长度是,根据同圆的半径相等得出表示-1的点到A点的距离是,利用线段的和差得OA=-1,从而得出A点所表示的数;(3)利用三角形的面积计算方法可以算出图中阴影部分的面积是6个小正方形的面积,剪拼前后两个图形的形状发生了变化,但总面积不会变化,从而得出拼成的正方形的面积,再根据正方形的面积等于边长的平方即可算出其边长。
2024-2025学年七年级英语上册单元重难点易错题精练(含解析)牛津深圳版2024
2024-2025学年七年级上学期第一次月考英语第一部分选择题(50分)一、完型填空(10分)阅读下面短文, 从短文后所给的 A、B、C、D 四个选项中选出能填入相应空白处的最佳选项, 并在答题卡上将相应字母编号涂黑。
(共 10 小题, 每小题1分)Hello, I’m Tom. I’m a middle school student. It’s nice to meet you here. First, let me 1 you about my family. Five people are in my 2 . They are my mother, my father, my two sisters and me. But I have 3 brothers. My father is a worker. My mother is an English 4 . Her students all like her. My sisters are sixteen. I’m fourteen. We go to the same school. We all like 5 football games. We think they’re interesting. I also have a cat. Its 6 is Mimi. There are some 7 around my house. The big one is a pear tree and the small ones are apple trees. 8 a photo of my room. Please have a look. When you 9 my room, you can see three English dictionaries on my desk. I 10 them very much.1.A.tell B.talk C.speak D.say2.A.school B.family C.bedroom D.classroom3.A.not B.no C.two D.three4.A.student B.woman C.teacher D.worker5.A.seeing B.looking C.reading D.watching6.A.family B.card C.name D.color7.A.desks B.pears C.trees D.apples8.A.He’s B.Here’s C.They’re D.She’s9.A.come to B.ask for C.come on D.come here10.A.study B.work C.do D.like二、阅读理解(40分)第一节阅读下列短文, 从每小题所给的 A、B、C、D 四个选项中选山最佳选项, 并在答题卡上将相应字母编号涂黑。
七年级上册数学全册单元试卷易错题(Word版 含答案)
七年级上册数学全册单元试卷易错题(Word版含答案)一、初一数学上学期期末试卷解答题压轴题精选(难)1.如图,线段AB=20cm.(1)点P沿线段AB自A点向B点以2cm/秒运动,同时点Q沿线段BA自B点向A点以3cm/秒运动,几秒后,点P、Q两点相遇?(2)如图,AO=PO=2cm,∠POQ=60°,现点P绕着点O以30°/秒的速度顺时针旋转一周后停止,同时点Q沿直线BA自B点向A点运动,若P、Q两点也能相遇,求点Q运动的速度.【答案】(1)解:设x秒点P、Q两点相遇根据题意得:2x+3x=20,解得x=4答:4秒后,点P、Q两点相遇。
(2)解:①当点P.Q在OB与圆的交点处相遇时:P点运动所用的时间为:① (秒),P点的运动速度为:(20-4)÷2=8cm/秒②当点P,Q在A点处相遇时:P点运动所用的时间为:②(60+180)÷30=8(秒),P点运动的速度为:20÷8-2.5cm/秒【解析】【分析】(1)此题是一道相遇问题,根据相遇的时候,P点所走的路程+Q点运动的路程等于AB两地之间的距离,列出方程,求解即可;(2)分①当点P.Q在OB与圆的交点处相遇时,②当点P,Q在A点处相遇时两类讨论,分别根据路程除以速度等于时间算出P点运动的时间,即Q点运动的时间,再根据路程除以时间等于速度即可算出Q点的运动速度。
2.如图,OD平分∠BOC,OE平分∠AOC.若∠BOC=70°,∠AOC=50°.(1)求出∠AOB及其补角的度数;(2)请求出∠DOC和∠AOE的度数,并判断∠DOE与∠AOB是否互补,并说明理由.【答案】(1)解:∠AOB=∠BOC+∠AOC=70°+50°=120°,其补角为180°-∠AOB=180°-120°=60°(2)解:∠DOC= ×∠BOC= ×70°=35°,∠AOE= ×∠AOC= ×50°=25°.∠DOE与∠AOB互补,理由:∵∠DOE=∠DOC+∠COE=35°+25°=60°,∴∠DOE+∠AOB=60°+120°=180°,故∠DOE与∠AOB互补【解析】【分析】(1)由∠BOC、∠AOC的度数,求出∠AOB=∠BOC+∠AOC的度数,再求出∠AOB补角的度数;(2)根据角平分线定义求出∠DOC、∠AOE的度数,再由(1)中的度数得到∠DOE与∠AOB互补.3.如图,在数轴上A点表示数a,B点表示数b,AB表示A点和B点之间的距离,C是AB的中点,且a、b满足|a+3|+(b+3a)2=0.(1)求点C表示的数;(2)点P从A点以3个单位每秒向右运动,点Q同时从B点以2个单位每秒向左运动,若AP+BQ=2PQ,求时间t;(3)若点P从A向右运动,点M为AP中点,在P点到达点B之前:① 的值不变;②2BM﹣BP的值不变,其中只有一个正确,请你找出正确的结论并求出其值.【答案】(1)解:∵|a+3|+(b+3a)2=0,∴a+3=0,b+3a=0,解得a=﹣3,b=9,∴=3,∴点C表示的数是3(2)解:∵AB=9-(-3)=12,点P从A点以3个单位每秒向右运动,点Q同时从B点以2个单位每秒向左运动,∴AP=3t,BQ=2t,PQ=12﹣5t.∵AP+BQ=2PQ,∴3t+2t=24﹣10t,解得t=;还有一种情况,当P运动到Q的左边时,PQ=5t﹣12,方程变为2t+3t=2(5t﹣12),求得t=(3)解:∵PA+PB=AB为定值,PC先变小后变大,∴的值是变化的,∴①错误,②正确;∵BM=PB+,∴2BM=2PB+AP,∴2BM﹣BP=PB+AP=AB=12【解析】【分析】(1)根据非负数之和为,则每一个数都是0,建立关于a、b的二元一次方程组,解方程组求出a、b的值,再根据点C是AB的中点,因此点C表示的数为,列式计算可求出点C表示的数。
人教版七年级上册数学全册单元试卷易错题(Word版 含答案)
人教版七年级上册数学全册单元试卷易错题(Word版含答案)一、初一数学上学期期末试卷解答题压轴题精选(难)1.数轴上A, B, C, D四点表示的有理数分别为1, 3, -5, -8(1)计算以下各点之间的距离:①A、B两点, ②B、C两点,③C、D两点,(2)若点M、N两点所表示的有理数分别为m、n,求M、N两点之间的距离.【答案】(1)AB=3-1=2;BC=3-(-5)=8;CD=-5-(-8)=-5+8=3.(2)MN=【解析】【分析】(1)数轴上两点间的距离等于数值较大的数减去数值较小的数,据此计算即可;(2)因为m、n的大小未知,则M、N两点间的距离为它们所表示的有理数之差的绝对值.2.如图,直线SN与直线WE相交于点O,射线ON表示正北方向,射线OE表示正东方向.已知射线OB的方向是南偏东m°,射线OC的方向是北偏东n°,且m+n=90°.(1)①若m=50,则射线OC的方向是________,②图中与∠BOE互余的角有________,与∠BOE互补的角有________.(2)若射线OA是∠BON的角平分线,则∠SOB与∠AOC是否存在确定的数量关系?如果存在,请写出你的结论以及计算过程;如果不存在,请说明理由.【答案】(1)北偏东40°;∠BOS,∠EOC;∠BOW(2)解:∠AOC= ∠SOB.理由如下:∵OA平分∠BON,∴∠NOA= ∠NOB,又∵∠BON=180°-∠SOB,∴∠NOA= ∠BON=90°- ∠SOB,∵∠NOC=90°-∠EOC,由(1)知∠BOS=∠EOC,∴∠NOC=90°-∠SOB,∠AOC=∠NOA-∠NOC=90°- ∠SOB-(90°-∠SOB),即∠AOC= ∠SOB.【解析】【解答】解:(1)①∵m+n=90°,m=50°,∴n=40°,∴射线OC的方向是北偏东40°;②∵∠BOE+∠BOS=90°,∠BOE+∠EOC=90°,∴图中与∠BOE互余的角有∠BOS,∠EOC;∠BOE+∠BOW=180°,∴图中与∠BOE互补的角有∠BOW,故答案为:①北偏东40°;②∠BOS,∠EOC;∠BOW.【分析】(1)①由m+n=90°,m=50°可求得n值,从而可得射线OC的方向.②根据余角定义可知∠BOE+∠BOS=90°,∠BOE+∠EOC=90°,从而可得图中与∠BOE互余的角;由补角定义可得∠BOE+∠BOW=180°,从而可得图中与∠BOE互补的角.(2)∠AOC=∠SOB.理由如下:由角平分线定义和领补角定义可得∠NOA= ∠BON=90°-∠SOB,结合(1)中条件可得∠NOC=90°-∠SOB;由∠AOC=∠NOA-∠NOC即可求得它们之间的数量关系.3.如图,以直线AB上一点O为端点作射线OC,使∠BOC=70°,将一个直角三角形的直角顶点放在点O处.(注:∠DOE=90°)(1)如图①,若直角三角板DOE的一边OD放在射线OB上,则∠COE=________°;(2)如图②,将直角三角板DOE绕点O逆时针方向转动到某个位置,若OC恰好平分∠BOE,求∠COD的度数;(3)如图③,将直角三角板DOE绕点O转动,如果OD始终在∠BOC的内部,试猜想∠BOD和∠COE有怎样的数量关系?并说明理由.【答案】(1)20(2)解:如图②,∵OC平分∠EOB,∠BOC=70°,∴∠EOB=2∠BOC=140°,∵∠DOE=90°,∴∠BOD=∠BOE-∠DOE=50°,∵∠BOC=70°,∴∠COD=∠BOC-∠BOD=20°(3)解:∠COE-∠BOD=20°,理由是:如图③,∵∠BOD+∠COD=∠BOC=70°,∠COE+∠COD=∠DOE=90°,∴(∠COE+∠COD)-(∠BOD+∠COD)=∠COE+∠COD-∠BOD-∠COD=∠COE-∠BOD=90°-70°=20°,即∠COE-∠BOD=20°【解析】【解答】⑴如图①,∠COE=∠DOE-∠BOC=90°-70°=20°;【分析】(1)根据角度的换算可知∠COE和∠BOC互余,那么根据∠COB=70°可得∠COE=20°;(2)根据角平分线和∠BOC可得∠BOE=140°,∠COE=∠BOC=90°,所以它的余角∠COD=20°;(3)一个是直角∠EOD,,一个是70°∠BOC,这两个角里都包含了同一个角∠COD,那么大家都减去这个∠COD的度数,剩下的两角差与原两角差是一致的,所以可得出结论∠COE-∠BOD=20°。
七年级英语上册Unit8Whenisyourbirthday易错题集锦(带答案)
七年级英语上册Unit8Whenisyourbirthday易错题集锦单选题1、John is ________ years old. Today is his ________ birthday.A.nine; nineB.ninth; ninthC.nine; ninthD.ninth; nine答案:C句意:约翰9岁。
今天是他的第九个生日。
考查数词。
nine是基数词,ninth是序数词;空格1在复数名词years前,判断用基数词,意为“9岁”;空格2在单数名词birthday前,判断用序数词,意为“第九个生日”;故选C。
2、—________ is the model plane(飞机模型)?—It’s on the sofa.A.WhatB.WhoC.WhenD.Where答案:D句意:——飞机模型在哪儿?——在沙发上。
考查疑问词辨析。
What什么;Who谁;When什么时候;Where哪里。
“It’s on the sofa.”是表示地点的句子。
对地点提问要用where。
故选D。
3、Last Sunday my aunt ________ at home with me. We were watching TV all day. A.wasB.wereC.isD.are答案:A句意:上个星期天,我姑姑和我在家。
我们一整天都在看电视。
考查时态。
由“Last Sunday”可知,用一般过去时。
句中主语为my aunt,为第三人称单数,故选A。
4、—________ you stay at home last Sunday afternoon?—No, I ________ a kite with my friends in the park.A.Do; flyB.Did; flyC.Did; flewD.Were; flew答案:C句意:——上周日下午你待在家里吗?——不,我和朋友在公园里放风筝。
七年级英语上册Unit8 易考易错题巩固提优训练
7A Unit8易考易错题巩固提优训练一、单项选择1.He has _______ homework and she doesn’t know _______ first.A.much too; what to doB. too much; to do whatC. much too; to do whatD. too much; what to do2.I’m interested in animals, so I _______ every Saturday _______ in an pet hospital(宠物医院).A.spend; to workB. take; to workC. spend, workingD. take; working3.______ of the students in our class has two storybooks. We _____ reading them.A. Each, all likeB. Every, like allC. Some, both likeD. All, like both4.--Would you like apples? -- , please.A. some more; Another twoB.any more; Two moreC.another; Two moreD.some more; Other5.—Your sweater looks nice. _______ is it _______? —Wool.A. How; made fromB. What; made fromC. How; made ofD. What; made of6.What size____________ your pair of trousers?I want to try_____ on.A.are; itB. is; themC. is; itD. are; them7.Mum looks ____at the photo of our fashion show.She says everyone looks______at the show.A.happy; happilyB.happily; happyC.happily; happilyD.happy; happy8.Practising running is_______,but the runners always_________.A.a hard work;hard workB.hard work;work hardC.a hard work;work hardD.hard work;hard work9.Her father went to the clothes shop to buy a ______ jacket for her on her birthday.A. leather brown beautifulB. beautiful leather brownC. beautiful brown leatherD. brown beautiful leather10.Sandy looks good_______ blue and red clothes look nice _______her.A.on; onB. in; inC. on; inD. in; on11 The lady wants to try the______on and she is putting her______into them now.A. boots; footsB. beets; feetC. boots; feetD. beet; foots12. ----I think I'm____ to go to school today, Mum.---- Oh, dear. I'm afraid you need to stay ___for another day.A. good enough; on bedB. enough good; in bedC. well enough; in bedD. enough well; in the bed13.-I sometimes don't have enough time ________ with my parents.-You should spend more time ________with them at home.A. to chat; to stayB. to chat; stayingC. chatting; to stayD. chatting; staying14. ---Can I _______your dictionary?----Sorry, I'm using it; I can't _______it to you.A. lend; lendB. lend; borrowC. borrow; borrowD. borrow; lend15 —These ________dresses are very beautiful.— But the price is a little________.A. purple cotton; highB. purple cotton; expensiveC. cotton purple; highD. cotton purple; expensive二.完形填空In a small town, a shopkeeper works hard every day. But one day he closed his shop in the__1__ and went home. He was very__2___, he didn't___3___supper and went to bed at once. At that time the telephone___4___. A man said,“____5___do you open your___6___,sir?” The shopkeeper was unhappy. He thought the man____7___a trick on him. He did not answer it and went___8____to bed. A few minutes___9__ the telephone rang again. He___10__ and went to pick up the phone and found that voice (声音) was the___11___man and he asked the same question. The shopkeeper___12___ answered. “You needn't ask m e that because I can't let you __13_____my shop. It's late now.”“No. I want to go out.” the man___14__ ,“My wife__15____ me at home for dinner now.”1. A. evening B. morning C. afternoon D. noon2. A. happy B. not happy C. not tired D. tired3. A .has B. had C. have D. \4. A. rings B. rang C. calls D. called5. A. How B. Why C What D. What time6. A .window B. door C. shop D. eyes7. A. played B. plays C tells D. told8. A. up B. back C./ D. again9. A. later B. after C. ago D. before10. A. stood up B. got up C. stayed in bed D. sat down11. A. same B. different C. friendly D. friend12. A. happy B happily C angry D. angrily13. A. come into B. go out of C. live in D. go out14. A. smiled B. answer C. said D. asked15.A. waits for B. waits C. is waiting forD. waited for三.阅读理解AThere is an old saying: Early to bed, early to rise, makes a man healthy, wealthy and wise. It means that we should go to bed early and get up early the next morning. By doing this, we will be in good health. And we'll also be rich and clever.H's true that our bodies (身体)need to have enough sleep to be healthy. Children should have a ten-hour sleep every night. Those who do not have enough sleep cant do their work very well. The body needs exercise too. Exercise helps to keep the body strong and fit. It also helps the blood (血液)to move (移动)to all parts of the body. The head needs blood, too. So exercise helps people think better.1. What does the underlined word "rise" mean?A. To do exercise.B. To get up.C. To stand up.D. To put up.2. If children don't sleep for 10 hours every night, they may _____________.A. not be late for school B become cleverC. not do well in their workD. become rich3. A person needs exercise because _____________________.A. it makes him healthyB. he has lots of work to doC. he is strongD. he does exercise4. Which of the following is NOT true?A. Exercise is good for people.B. It's good for you to get up early and go to bed early.C. If you have enough blood, you will be wise.D. A student should have 10 hours' sleep every night.5. Exercise helps people think better because __________________.A. exercise helps the blood to move to the head B, exercise makes people tiredC. exercise can make people careful D, exercise can make people few mistakes(错误)BDetective(探长)Dino is on holiday. He travels to another city and goes into a hotel. The keeper gives him a one-bed room. All the rooms on his floor are one-bed ones. The keeper says to him,“One room is for one person only. Don't bring anyone else to your room Your room is on the third floor.” Dino takes the r oom card and goes to the third floor.A young lady lives next door to Dino. When Dino goes by the lady's room, the lady is telephoning the keeper. She says that her wallet in the room is missing. She just comes back from the cinema.In the evening, someone knocks on Dino's door. He opens the door. A young man stands in front of him.“Oh! Eh… Isn't it Room 408? "the young man asks“No, it is Room 308,"Dino answers.“I’m sorry.”Dino closes the door and calls the police. The police come and catch the man in another one-bed room. He is the thief.1. Why does Dino go to another city?A. To enjoy his holiday.B. To meet the keeper.C. To help the young lady.D. To catch the thief2. When does the lady find her wallet in the room missing?A. When the police come.B. When the keeper telephones her.C. When Dino goes by her roomD. When she comes back from the cinema3. What is a “thief” in Chinese?A.服务员B.客人C.小偷D.店主4.The detective does a few things in the hotel. What's the right order(顺序) of them?a. hear a Lady making a callb. get the room cardc. call the police.d. talk with the keepere. meet a young manA, d-b-a-e-c. B. b-d-a-e-c C. d-b-e-a-c D. b-d-e-a-c5. What can we lean about the hotel?A. All the rooms in the hotel are one-bed rooms.B. You can’t live with others in a one bed red.C. Only men can set one-bed rooms in the hotel.D. The room next to Dino's is a two- bed room.CI ask my classmates about what they think of fashion. Here are some of their answers:Sarah BradyI am interested in fashion. I enjoy reading fashion books and going to clothes shops. But I seldom buy fashionable(流行的) clothes. They are too expensive. I have two or three silk dresses and I often wear them to go for a party. But most of the time I wear jeans and a T-shirt. My sister Jenny and I often borrow each other’s clothes. That way we can both wear something new but without spending too much.Mary WilsonFashi on isn’t for me. I don’t care about fashion and models. I usually wear comfortable clothes, like jeans, T-shirts and sports shoes. Most of my friends wear the same kind of clothes. We seldom talk about famous models. We talk about music a lot.Kate FreemanFashion is important because it says something about your personality(个性). I am a lovely girl and I wear my clothes to reflect this. Usually I buy some cheap clothes and then change them at home. I like designing my own clothes.1. Sarah Brady seldom buys fashionable clothes because ____________.A. she doesn’t care about fashionB. she doesn’t have enough moneyC. she can’t borrow her sister’sD. she hates spending money on clothes2. Mary and her friends often talk about ____________.A. fashionB. modelC. musicD. sports3. The underlined word “reflect” means ___________ in Chinese.A. 适合B. 反映C. 与…般配D. 装扮4. Kate Freeman thinks that ________________.A.fashionable clothes don’t cost too muchB. it’s not smart to wear fashionable clothes at homeC. designing your own clothes is out of fashionD. what you wear can say a lot about you5. Which of the following is TRUE according to the passage?A. Sarah seldom wears jeans and a T-shirt when she goes out.B. Mary never wears the same clothes as her friends.C. Kate enjoys making her own clothes.D. Both Mary and Kate are interested in fashion.四、词汇运用1. In winter people cover their faces with their________________ (围巾).2. Thank you for ___________________(借)books to me.3.Young women enjoy wearing different kinds____________(靴子) of in winter.4. All the radios are those ________________________(先生).5. My design ___________ (包括) a dress and a pair of long leather boots.6. Look! Sandy _____________ (look) very pretty in yellow.7. Young people think trainers make them feel ________________(comfort).8. The nice leather skirts in the bags are those _________________ (model).9. We are talking about ___________________( tomorrow ) fashion show.10. —What about ______________ ( lie) on the grass? —That’s a good idea.五. 任务型阅读My dream home is a flying home. I get the idea from the film up《飞屋环游记》.Look at the photo! Isn't it a cool home? Do you think it i s a strange idea?It is a wooden house, so it is light. I am going to tie(系)some helium balloons(氦气球) to the house, so it can fly in the air. They bring the house up into the air. It can fly for one hour at a time. It takes us to a different place every season.The house is no t very big in size. We only need six comfortable rooms--two bedrooms a living room, a kitchen, a dining room, and a modern bathroom. The room flies to warm places in winter and cool places in summer.Where can we get energy and water? We get energy from the sun and we collect rainwater to use. So it is a green house.I think it would be a cool home. But my parents say it is a crazy idea. They ask me what school I can study in if I live in that home. And they also say they must work in Yangzhou. They cannot live in a different place every month. They must live in the sa me place all the time. But I still hope my dream can come true one day. This is a great idea, right? Do you like the flying home?Many boys and girls love to watch TV. They s____1___many hours a day in front of the TV sets. But many parents let their c____2___ watch TV only at special times.TV shows are l____3___books or movies. There are many k___4____of TV shows, such as sitcoms, soap operas, sports shows, fashion shows, etc. A child can learn good things and bad things from t ___5___. Some shows h___6___children to know the news all over the world. Children don't have to go to the zoo to see a___7___. Boys and girls can see sitcoms, sports shows and game shows at h__8__. Some shows t__9___children how to cook or how to use tools(工具). Many boys and girls think it is interesting to watch TV, but it is a___10____fun to read books, to play games or to visit friends.参考答案选择题DCAAD BBBCD CCBDA完形填空ADCBD BABAB ADADC阅读理解BCACA ADCAB BCBDC词汇1.scarves2.lending3.boots4.gentlemen’s5.includes6.looksfortable8.models’9.tomorrow’s 10.lying任务型阅读1. flying2. up3. heavy4. seasons5. size6. number7. modern8. green9. school 10. leave 短文填空1.spend2.children3.like4.kinds5.them6.help7.animals8.home9.tell 10.also。
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七年级上8-9单元易错题练习Unit8()1.We have________ school trip________ this week.A.a; / B.an; at C.a; at D.an; /()2.There are usually________ days in February.A.twentyeight B.twenty nine()3.—How many friends will come to your ________ birthday party?—About ________.A.fifteen; fifteen B.fifteenth; fifteenthC.fifteen; fifteenth D.fifteenth; fifteen()4.The New Year party is________ the evening of January 1st.A.in B.on C.at D.old()5.—Which month is ________ month of a year?—________.A.fifth; May B.the fifth; May C.five; March D.the five; March()6.—How ________ is your father?—He is ________.A.much; four B.many; forty C.old; fortieth D.old; forty()7.In May, many Chinese have a _________to Yellow Mountain.A.festival B.Party C.game D. trip()8. This is ________ bedroom. The twin(孪生的) sisters like it very much.A.Lucy and Lily B.Lucy's and Lily'sB.C.Lucy's and Lily D.Lucy and Lily's()9.My brother is ________ years old. His ________ birthday is on March 3rd.A.nine; nine B.nine; ninth C.ninth; nine D.ninth; ninth()10.Sunday is the ________ day of a week.A.third B.Second C.first D.last()11.—When are your father's and mother's birthdays?—They are ________ November 12th and July 2nd.A.in B.at C.on D.For()12.—Is Kate's birthday on March 19th?—Yes, ________.()13.—________ is your friend?—He is eleven.A.When B.What C.Where D.How old()14.My birthday is on May ________.A.fifteen B.Fifty C.the fifteenth D.the fiftieth()15.—________ is your mother's birthday?—It's on May ________.A.When; twenty B.What; the twentiethC.When; the twentieth D.What; twenty()16.There are ________ months in a year. The ________ month is September.A.twelfth; ninth B.twelve; nine C.twelve; ninth D.twelve; ninth()17.I'm 14 ________. And he is a ________ boy.A.year old; 15 years old B.yearold; 15 year-oldC.years old; 15 years old D.years old; 15-year-old()18.—Would you like ________ basketball with me?—I'd love to, but I'm busy ________ my homework now.A.playing; to do B.to play; to doC.to play; doing D.playing; doingⅡ.用in,on,at或for填空1.There is(有) a book sale________ June 8th.2.You must get there________ 10:30. Don't be late.3.I plan(计划) to go to Sanya________ August.4.We have nice clothes________ you in our store.5.Do you like to play volleyball________ the afternoon?适当形式填空7.Which month is the________ (nine) one?8.Do you want ________ (go) shopping with me?9.Mr. Wang is on the ________ (twelve) floor(楼层) of the building. 10.May 10th is her brother's________ (thirty-one) birthday. 11.September is the n________ month of a year.12.S________ is the first day of a week.13.There are________ (sixty-two) students in our class.14.Our________ (birthday) are all in April.15.There are 900 ________ (student) in Yucai Middle School. 16.The baby is three m________ old.17.It's October ________ (five) today.26.How old is he?(改为同义句)What's ________ ________?27.They have an art festival every year.(改为一般疑问句)________ they ________ an art festival every year?28.—Is Nick's birthday next week? (补全答语)—No,________ ________.29.Mr. Hand's birthday party is on_May_2nd.(对画线部分提问) ________ ________ Mr. Hand's birthday party?30.We have a book sale in_the_school_library. (对画线部分提问) ________ ________ you have a book sale?31.Mary's birthday party is at_ten. (对画线部分提问)________ ________ is Mary's birthday party?Unit9()1.Art is ________ interesting subject.A.a B.the C.an D./()2.Because music is relaxing, ________ I like it very much.A.so B.For C./ D.and()3.Why ________ your mother like July?A.do B.is C.are D.does()4.I have P. E. ________ the afternoon of Tuesday.A.for B.on C.at D.in()5.Are those ________ books on the ________ desk?A.math; teacher B.math's; teacher'sC.math; teacher's D.math's; teacher5.We like ________ ________ ________ every day.()6.We don't go to school ________ Sunday.A.at B.in C.on D.for()7.—________ today?—It's Monday.A.What day is it B.What's the dateC.When is D.What time is()8.We have Chinese and math ________ Monday to Friday.A.from B.of C.in D.on()9.—Can you finish________ these books before 10 o'clock?—Yes, I can.A.to read B.read C.reads D.reading ()10.—________ will Mrs. Lin go to Germany?—To see her daughter there.A.How B.When C.Why D.What()11.When ________ the girl ________ her homework?A.does; does B.does; do C.do; does D.do; doⅡ.对画线部分提问,每空一词1.Jim's favorite movie star is Jackie_Chan.________ is Jim's favorite movie star?2.It's Sunday today.________ ________ is it today?3.He likes science because_it's_interesting.________ ________ he like science?4.I have music on_Monday_and_Friday.________ ________ you have music?5.He usually has P.E. in the afternoon.________ ________ ________ he usually________ in the afternoon? 6.I like geography because_it's_fun.(对画线部分提问)________ ________ you like geography?7.Mr._Zhang is our math teacher.(对画线部分提问)________ ________ your math teacher?8.Amy's favorite month is March.(对画线部分提问)________ ________ Amy's favorite month?9.Jane has Chinese on_Friday.(对画线部分提问)________ ________ Jane have Chinese?10.My parents watch_TV_at night.(对画线部分提问)________ do your parents ________ at night?11.He likes English because__it's_fun.(对画线部分提问)________ does he ________ English?12.Kate's_sister likes history best. (对画线部分提问)________ ________ history best?13.We have_eight_classes every day. (对画线部分提问)________ ________ ________do you ________ every day?10.He doesn't like eggs for breakfast.(改为肯定句)He________ eggs for breakfast.11.Tom likes meat and vegetables for supper.(对画线部分提问)________ ________ Tom ________ for supper?12.His father plays pingpong well.(改为一般疑问句)________ his father ________ ping-pong well?13.Jack eats hamburgers for dinner.(改为否定句)Jack ________ ________ hamburgers for dinner.14.My brother likes broccoli and bananas.(改为一般疑问句)________ your brother ________ broccoli and bananas?15.They eat lots of healthy food every day.(改为否定句)They ________ ________ lots of healthy food every day.16.They like some_broccoli for dinner. (对画线部分提问)________ do they ________ for dinner?17.The volleyball star eats well.(改为一般疑问句)________ the volleyball star ________ well?18.Her father likes vegetables.(改为否定句)Her father________ ________ vegetables.五,用方框中所给词的正确形式填空,使短文通顺、连贯Tom Brown is 1.________ good friend. He has a healthy eating 2.________. He usually has an egg, some 3.________ and milk for breakfast. Tom doesn't have 4.________ at home. He 5.________ it at school. He thinks the food at school 6.________ delicious. In the afternoon, he has some 7.________. He loves apples and oranges. For dinner, he 8.________ rice and vegetables. He never 9.________ hamburgers. He thinks 10.________ are not healthy.。