2012学年八年级竞赛试卷

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实验学校2012学年八年级上学期数学竞赛试题(含答案)

实验学校2012学年八年级上学期数学竞赛试题(含答案)

ABC第5题实验学校2012学年八年级上期数学竞赛题(时间90分钟 满分100分)一、填空(30分) 1、函数y =12-+x x 中自变量x 的取值范围是 。

2、已知等腰三角形三边的长分别是4x -2,x +1,15-6x ,则它的周长是 。

3、若实数x 、y满足6y =,则2x y +的立方根是_____________。

4、如图,数轴上A B ,两点表示的数分别是1A 关于点B 的对称点是点C ,则点C 所表示的数是 。

EDCABHFG第8题5、如图,△ABC 是不等边三角形,现以B 、C 为两个顶点作位置不同的三角形,与△ABC 全等,这样的三角形最多可以作_________个。

6、直线y =45x -495与x 轴、y 轴的交点分别为A 、B ,则线段AB 上(包括端点A 、B )横坐标和纵坐标都是整数的点有 个。

二、选择(20分)7、下列说法中正确的有 ( )(1)三边对应相等的两个三角形全等;(2)两个等边三角形全等;(3)两个等腰三角形全等;(4)两个直角三角形全等;(5)全等三角形对应边相等。

A.1个 B.2个 C.3个 D.4个8、如图,C 、E 和B 、D 、F 分别在∠GAH 的两边上,且AB = BC = CD = DE = EF ,若∠A =18°,则∠GEF 的度数是 ( ) A .108° B .100° C .90° D .80°9、如果一条直线l 经过不同的三点(,),(,),(,)A a b B b a C a b b a --,那么直线l 经过 ( )A.第二、四象限B.第一、二、三象限C.第一、三象限D.第二、三、四象限12第4题10、某公司的员工分别住在A 、B 、C 三个小区,A 区住员工30人,B 区住员工15人,C 区住员工10人,三个小区在一条直线上,位置如图所示。

若公司的班车只设一个停靠点,为使所有员工步行到停靠点的路程总和最短,那么停靠点的位置应在 ( ) A. A 区 B. B 区 C. C 区 D. A 、B 、C 区以外的一个位置 三、解答题11、(10分)I 是ABC 三条角平分线的交点,且CA+AI=BC 。

2012年下学期八年级数学竞赛试题.doc

2012年下学期八年级数学竞赛试题.doc

2012年下学期八年级数学竞赛试题 姓名____________ 班级__________一、 选择题(每小题3分,共30分)1、函数y=121--x ,自变量x 的取值范围是( )A.x >1B.x ≠1C.x ≥1且x ≠5D.x >1且x ≠52、关于函数y= -x -5的图像,有如下说法:①.图像过点(0,-5) , ②图像与x 轴的交点是(-5,0), ③ 由图象可知y 随x 的增大而增大 , ④图像不经过第一象限 , ⑤图像是与y= -x+2平行的直线 ,其中正确说法有( )A .5个 B. 4个 C. 3个 D. 2个3、已知x1+y 1=3,则y xy x y xy x +-++33的值等于 ( ) A 、5 B 、10 C 、15 D 、204、已知整数a 、b 满足ab=12,则a +b 结果的可能值的个数是( )A 、3个B 、4个C 、5个D 、6个5、一次函数y=kx-b 和正比例函数y=kbx 在同一坐标系内的大致图像不可能...的是( )6、形如d c b a 的式子叫做二阶行列式,它的运算法则用公式表示为d cb a =ad -bc ,依此法则计算4132-的结果为( )A .11B .-11C .5D .-27、由4个2组成的数中,最大的一个数是 ( )A 、2222B 、2222C 、2222D 、22228、的值( )(A )在1到2之间(B )在2到3之间(C )在3到4之间(D )在4到5之间9、已知⊿ABC 中AB=10,BC=15,CA=20,O 是⊿ABC 内角平分线的交点,则⊿ABO,⊿BCO,⊿CAO 的面积比是 ( )A 、1:1:1;B 、1:2:3;C.2:3:4; D.3:4:5 10、对于任意x 的允许取值范围,p=∣1-2x ∣+∣1-3x ∣+∣1-4x ∣+∣1-5x ∣+∣1-6x ∣+∣1-7x ∣+∣1-8x ∣+∣1-9x ∣+∣1-10x ∣是一个定值,则这个定值是( )A 、2B 、3C 、4D 、5二、填空题(每小题3分,共30分)11、等腰三角形一腰的高等于腰的一半,则顶角是______________度。

2012年株洲市初中数学竞赛初二试卷和答案

2012年株洲市初中数学竞赛初二试卷和答案

2012年株洲市初中数学竞赛试题(初二年级)时量:120分钟 总分:100分 注意事项:1.用黑色.蓝色钢笔或圆珠笔作答;2.在密封线内答题,答题内容不要超过密封线; 3.不准使用计算器.1.点93P a +-+,则点P 所在象限为A. 第一象限B. 第二象限C. 第三象限D. 第四象限2.下列各式计算正确的是A . 236236a a a ⋅= B . (-2a 2)3=-6a 6C . 2a =- D .(a -2)2=a 2-43.某商店为了促销,决定全场按标价的6折销售,该店某商品的进价为300元,为了要保持利润率为20%,则标价应为 ( )元.A . 600B .500C .400D .3604.某轮船往返于A .B 两地之间,设轮船在静水中的速度不变,那么,当水的流速增大时,轮船往返一次所用的时间 A .不变 B.增加 C.减少 D.增加或减少都有可能则这个小组成员年龄的平均数和中位数分别是 A .15,16 B .13,15 C .13,14 D .14,146.有大小两种游艇,2艘大游艇与3艘小游艇一次可载游客57人,3艘大游艇与2艘小游艇一次可载游客68人,则3艘大游艇与6艘小游艇一次可载游客的人数为 A .129 B .120 C .108D .967.如图为某企业标志图案,在△ABC 中,∠ACB=900,∠A=200, 将△ABC 绕点C 按逆时针方向旋转角α到△A′B′C 的位置,其中A′,B′分别是A, B 的对应点,B 在A′B′上,CA′交AB 于D ,则∠BDC 的度数为A.300B.450C.600D.100NMC BACFDE BA8.如图,等腰直角三角形ABC中,∠ACB=90°,在斜边AB上取两点M、N,使∠MCN=45°.设MN=x,BN=n,AM=m,则以x、m、n为边的三角形的形状为A.锐角三角形B.直角三角形C.钝角三角形D.随x.m.n的值而定二.填空题(每题5分,共30分,请将答案填在表格内)9.已知点P1(a-1,5)和P2(2,b-1)关于x轴对称,则(a+b)的值为____________. 10.一次函数y=ax+b的图象如图所示,则化简|1||||3|b b a a++--+=得________.11.关于x的不等式组513412x xx m x->-⎧⎪⎨-≤-⎪⎩的整数解的和是9,则整数m的值是. 12.小高从家骑自行车去学校上学,先走上坡路到达点A,再走下坡路到达点B,最后走平路到达学校,所用的时间与路程的关系如图所示.放学后,如果他沿原路返回,且走平路.上坡路.下坡路的速度分别保持和去上学时一致,那么他从学校到家需要的时间是___________分钟.13.如图,等腰直角三角形ABC中,∠C=90°,D为BC中点,△ABC折叠,使A点与D点重合.若EF为折痕,则CFAF为.,14. 如图,第(1)个多边形是由正三角形“扩展“而来,第(2)个多边形是由正四边形“扩展”而来,……(第13题图)(第12题图)A(第10题图)(第7题图)(第8题图)如此类推.设由正n 边形“扩展”而来的多边形的边数为n a ,则345991111a a a a +++⋅⋅⋅+= .三.解答题(本大题共4个小题,共38分,解答应写出必要的文字说明,证明过程或演算步骤) 15.(本题满分8分)已知三角形三边为a 、b 、c,且满足|24|a -2482b b a -+= , 求c 的取值范围。

人教版2012-2013八年级上竞赛题(含答案)

人教版2012-2013八年级上竞赛题(含答案)

丽江市涛源中学 2012-2013学年度上学期初二数学竞赛试卷(满分:120分,时间:120分钟)一、细心择一择,你一定很准!(本大题共8小题,每小题3分,共24分.每小题给出四个答案,其中只有一个是正确的). 1.38-等于 ( )A 、2B 、-2C 、 ±2D 、 B 不存在 、 2.下列各数中,有理数是 ( )A 、2B 、8C 、2πD 、0、212212221… 3.已知点P 1(a -1,5)和P 2(2,b -1)关于x 轴对称,则(a +b )2012的值为( ) A 、0 B 、-1 C 、1 D 、 32012 4.观察下面的汽车标志图,不是轴对称图形的是( )A B C D5.如图,在△ABC 中,边AB 的垂直平分线分别交于AB 、BC 于点E 、D ,AE=3cm , △ADC 的周长为9cm ,则△ABC 的周长是( )A 、15 cmB 、12 cmC 、17 cmD 、10 cm 6.已知等腰三角形的两条边长分别为4和8,则它的周长为( )A . 16B . 20C . 16或20D .147. 如图3,△ABC 是等边三角形,BC ⊥CD ,且AC =CD ,则∠BAD 的度数为( )A 、50°B 、45°C 、40°D 、35°8. 已知一次函数y =kx +b ,y 随着x 的增大而减小,且kb <0,则在直角坐标系内它的大致图象是 ( )A B C D二、仔细审题,认真填写哟!(本大题共9小题,每小题3分,共27分.请你把答案填在横线的上方). 9.命题“全等三角形的对应角相等”的逆命题是_____________________________, 这个逆命题是______(填“真”或“假”)。

10.据宁波市假日办统计数据显示,今年五一黄金周期间,全市旅游总收入达10.9亿元人民币,创历年新高,用科学计数法可记作 元.11.(2011•铜仁)小明从家里骑自行车到学校,每小时骑15km ,可早到10分钟,每小时骑12km 就会迟到5分钟.问他家到学校的路程是多少km ?设他家到学校的路程是xkm ,则据题意列出的方程是1281的平方根是 ,比较大小: 8____60。

2012学年第二学期八年级数学竞赛试题卷

2012学年第二学期八年级数学竞赛试题卷

2012学年第二学期八年级数学竞赛试题卷分值:120分 测试时间:120分钟一、选择题(6×4′=24′)以下每题的四个选项中,仅有一个是正确的,请将表示正确答案的英文字母写在下面的表格内。

1、已知21+=m ,21-=n ,则代数式mn n m 322-+的值为( ) A.9 B.±3 C.3 D. 52、已知关于x 的方程(a -1)x 2-2x+1=0有实数根,则a 的取值范围是( ) A.a ≤2 B,a>2 C.a ≤2且a ≠1 D.a<-2 3、足球一般是用黑白两种颜色的皮块缝制而成,如图所示黑色皮块是正五边形,白 色皮块是正六边形.若一个球上共有黑白皮块32块,请你计算一下,黑色皮块和白 色皮块的块数依次为( )A .16块、16块B .8块、24块C .20块、12块D .12块、20块 4、如图,等腰直角三角形ABC 中,∠ACB =90°,在斜边AB 上取两点M 、N ,使 ∠MCN =45°.设MN =x ,BN =n ,AM =m ,则以x 、m 、n 为边的三角形的形状为( )A.锐角三角形B.直角三角形C.等腰直角三角形D.随x 、m 、n 的值而定5、某人才市场2012年下半年应聘和招聘人数排名前5个类别的情况如下图所示,若用同一类别中应聘人数与招聘人数比值的大小来衡量该类别的就业情况,则根据图中信息,下列对就业形势的判断一定..正确的是( )A .医学类好于营销类B .建筑类好于法律类C .外语类最紧张D .金融类好于计算机类6、在面积为15的平行四边形ABCD 中,过点A 作AE 垂直于直线BC 于点E ,作AF 垂直于直线CD 于点F ,若AB =5,BC =6,则CE +CF 的值为( )A .11+ 11 3 2B .11- 11 32C .11+ 11 3 2或11- 11 3 2D .11+ 11 3 2或1+ 32二、填空题(10×5′=50′)7、为了估计鱼塘中有多少条鱼,先从鱼塘捕捞100条鱼做上标记,然后放回鱼塘,经过一段时间,待有标记的鱼完全混合于鱼群后,又捕捞了两次,第一次捕捞了200条鱼,其中有24条有标记,第二次捕捞了220条,其中有18条有标记.估计鱼塘中鱼的数量为 条.8、有下列命题:①两条直线被第三条直线所截,同旁内角互补; ②已知两边及其中一边的对角能作出唯一一个三角形;③已知x 1、x 2中关于x 的方程2x 2+px +P +1=0的两根,则x 1+x 2+x 1x 2的值是负数;ABCMN类别(第8题)④某细菌每半小时分裂一次(每个分裂两个),则经过2小时它由1个分裂为16个; ⑤若方程210x mx +-=中0m >,则方程有一正根和一负根,且负根的绝对值较大. 其中正确的命题是 .9、在纸上画一个正六边形,在六边形外画一条直线a ,从六个顶点分别向直线a 引垂线可以得到k 个不同的垂足,那么k 的值在3,4,5,6这四个数中不可能取得的是_________. 10、如图所示,△ABC 中,AD ⊥BC 于D ,点E 、F 、G 分别是AB 、BD 、AC 的中点,EG=32EF,EF+AD=12,则△ABC 的面积为__________. 11、商场某种商品平均每天可销售30件,每件盈利50元. 为了尽快减少库存,商场决定采取适当的降价措施. 经调查发现,每件商品每降价1元,商场平均每天可多售 出 2件.每件商品降价_________元时,商场日盈利可达到2100元。

2012学年八年级竞赛试卷

2012学年八年级竞赛试卷

2012学年第一学期八年级英语竞赛试卷一、完型填空(60%)A little boy invited his mother to attend his school’s first teacher-parent meeting. To the little boy’s1 ,she said she would go. This2 be the first time that his classmates and teacher3 his mother and he felt ashamed of her4 . Although she was a beautiful woman, there was a scar(疤痕)that5 nearly the right side of her face. The boy never wanted to6 why or how she got the scar.At the meeting, the people were 7 by the kindness and natural beauty of his mother in spite of the scar, but the little boy was still 8 and hid himself from everyone, 9 a conversation between his mother and 10 .The teacher asked 11 ,“How did you get the scar on your face?”The mother answered, “12 my son was a baby, he was in a room that caught fire. Everyone was 13 afraid to go in because the fire was 14 ,so I went in. As I was running toward his bed, I saw a piece of wood coming down and I placed myself over him trying to protect him. I was knocked senseless but 15 , a fireman came in and saved both of us.”She touched the 16 side of her face. “This scar will be 17 ,but to this day, I have never 18 what I did.”At this point, the little boy came out running toward his mother with tears in his eyes. He held her mother in his arms and 19 a great sense of the sacrifice(牺牲)that his mother had made for him. He held her hand tightly for the 20 of the day.1 A. enjoyment B. disappointment C. surprise D. excitement2. A. would B. could C. should D. must3. A. noticed B. greeted C. accepted D. met4 . A. look B. appearance C. clothes D. smile5. A. included B. passed C. covered D. decorated6. A. talk about B. think about C. care about D. hear about7. A. impressed B. surprised C. excited D. comforted8. A. surprised B. sad C. happy D. embarrassed(尴尬)9. A. listening to B. looking at C. hearing D. watching10. A. understanding B. the parents C. the teacher D. his classmates11. A. carefully B. seriously C. nervously D. anxiously(焦急的)12. A. As B. When C. Since D. While13. A. so B. much C. quite D. too14. A. out of control B. under control C. in control D. over control15. A. surely B. hopefully C. luckily D. unluckily16. A left B. crying C. wiped D. burned17. A. ugly B. lasting (持久的) C. serious D. frightening18. A. forgot B. recognized C. considered D. regretted19. A. felt B. realized C. enjoyed D. told20. A. others B. other C. rest D. followingBWe know that trees are useful in our everyday life. They 21us many things,such as wood,oxygen,rubber,medicines and many other things. They can 22tell us a lot about our climate. The following are the reasons.If you 23 a tree,you can see that it has many rings. Most trees grow one new ring 24 year. Because of this reason,we know 25 a tree is. A tree over a hundred years old means that it has more than a hundred 26. When the climate is dry or very cold,the trees do not grow very much and their rings are usually 27. When it is wet and warm,the rings are much thicker. If the rings are suddenly very thin or suddenly very thick,this means that the 28 changed suddenly. If we look at the rings on this tree,we can learn about the 29for a hundred years. We can see 30our climate is changing today.21. A. tell B. ask C. give D. get22. A. not B. too C. to D. also23. A. cut across B. climb up C. walk past D. look at24. A. every B. many C. the first D. from25. A. how big B. how long C. how old D. how much26. A. trees B. leaves C. people D. rings27. A. big B. thick C. small D. thin28. A. climate B. trees C. rings D. animal29. A. people B. things C. climate D. life30. A. how B. why C. when D. while二、阅读理解(32%)AOur village carpenter, John Hill, came one day and made a dining table for my wife. He made it just the right size to fill in the space between the two windows. When I got home that evening, John was drinking a cup of tea and writing out his bill for the job.My wife said to me, quietly, "That's his ninth cup of tea today." But she said, in a loud voice, "It's a beautiful table, dear, isn't it?""I'll decide about that when I see the bill," I said.John laughed and gave me his bill for the work. I read:One dining table 10 November 1989Cost of wood &17.00Paint 1.50Work, 8 hours(&1 an hour) 8.00Total(合计) &36.50When I was looking at the bill, John said. "Let's been a fine day, hasn't it? Quite sunny. "Yes," I said, 'I’m glad it's only the 10th of November.""Me, too." Said John. “You wait--- it'll be a lot colder by the end of the month.""Yes, colder-and more expensive! Dining tables will be &20 more expensive on November 30th, won't they, John?"John looked hard at me for half a minute. Was there a little smile in his two blue eyes? I gave his bill back to him."If it isn't too much trouble, John," I said, "Please add it up again, You can forget the date-."I paid him & 26,5 and he was happy to got it.31. Why did John talk about the weather when the writer was looking at the bill?A. Because he didn't want the writer to go through the bill carefully.B. Because it was really a fine day.C. Because he wanted the writer to check the bill carefully.D. Because he wanted to tell the writer what the weather was it be.32. Why did the writer say that dining tables would be &20 more expensive on November 30th?A. Because it was difficult to make dining tables in cold weather.B. Because paint would be more expensive.C. Because the cost of wood would be more expensive.D. Because he thought John would almost certainly add the date to the cost of the dining table.33. The writer thought John would ask for-if he made a dining table on the last day of November.A. & 20.00B. & 46.50C. &56.50D.& 26.5034. When the writer gave him the money, John was happy becauseA. he got what he should get for his work.B. he got much more money for his work.C. he got the money easily.D. he didn't have to add up the costs again35. From the story we know that______A John made a mistake in the bill.B John tried to fool the writer in order to get more money for his work.C John had written out the bill before the writer got home.D John still wanted to get &36.50 for his work in the end.BAny mistake made in the printing of a stamp raises its value to stamp collectors. A mistake on one inexpensive postage stamp has made the stamp worth a million and a half times its original value. The mistake was made more than a hundred years ago in the British colony of Mauritius, a small island in the Indian Ocean. In 1847 an order for stamps was sent to a London printer ---Mauritius was to become the fourth country in the world to issue(发行)stamps.Before the order was filled and delivered, a ball was planned at Mauritius’ Government House, and stamps were needed to send out the invitations. A local printer was instructed to copy thedesign for the stamps. He accidentally printed the words “Post Office” instead of “Post Paid” on the several hundred stamps.Today there are only twenty-six of these misprinted stamps left fourteen One Penny Orange-Reds and twelve Two Penny Blues. Because of the Two Penny Blue’s rareness and age, collectors have paid as much as $16 ,800 for it.36.Over a century ago, Mauritius ________.A. was an independent countryB. belonged to IndiaC. was one of the British coloniesD. was a small island in the Pacific Ocean37. The mistake on the stamps was made ________.A .in Mauritius B. at Mauritius Government House C. in a post office D. in London38. Stamp collectors have paid $16,800 for ________.A. fourteen One Penny Orange-RedsB. twelve Two Penny BluesC. one One Penny Orange-RedD. one Two Penny BlueCDear Joy,Thank you for agreeing to water our plants for us while we are away. Here is what you need to do.1. The vegetable in the garden need to be watered every day unless it rains. There is a large area of bare soil, but this needs to be watered, too. Betty planted some corn there. Please pick any vegetables that are ripe and use them. It’s a shame for them to go to waste.2. The garden at the front of the house only needs to be watered every two or three days. The plants there are quite strong and will survive a few days without water. The roses are starting to bloom. If you look after them, they should be all right for a week or more. They will last a bit longer if you put a little sugar in the water. That’s some advice my grandmother gave me a lon g time ago.3. There are a few plants in the pots on the porch, and these need to be watered well every day. I’ve left a couple of pots out in the sun, and these also need lots of water. You can pick any strawberries that are ripe and eat them. You’ll find they are delicious.4. You don’t need to do anything for the lemon tree. If you see any ripe lemons, just pick them and take them home. You can use them in cooking for to make lemonadeThanks again for helping out. We’ll see you in two weeks. You’ve got our telephone number, so please call us if there are any problems or if you need to ask any questions. We’ll send you a post-card.39. Lee wrote these instructions to Joy because Lee_______.A. would not grow plants wellB. gave Joy the gardenC. sold the house to JoyD. was going on holiday40. What does NOT need watering every day?A. The roomB. The lemon treeC. The strawberriesD. The vegetables41. Which of the following is TRUE according to the passage?A. Joy will send Lee a postcard.B. Lee will come home in three weeks.C. Lee likes to grow his own vegetables.D. Lee’s house is not very big. 42.How should Joy deal with the lemon tree? A. Cut it downB. Water it every two daysC. Pick ripe lemons, and take them home.D. Take good care of it. 43. What does “ripe fruit” mean? A. The fruit is ready to eat. B. The fruit is hard and bitter. C. The fruit is rotten.D. The fruit is starting to grow.DAnewreportintocomputer software usage says many people may be throwing awaytheirmoney.For the report, over 400 students and teachers from the University of Wollongongwereinterviewed and asked about what computer software they most oftenused and what functions they used on each software.It found that the most popular software was a web-browser, used for surfing the internet, with 78% using Microsoft Internet Explorer followed by 13% for Firefox. “This was the biggest difference from our last report in 2000” said Bill y Bragg, the report writer. “Software used over the internet such as browsers and e-mail have moved ahead of what was formerly the most popular one, word processors such as Microsoft Word used for typing documents.”The report also tried to measure how deeply each application was used. According to Bragg, “Most software has a large number of functions for the user, allowing them to do many different things, but we found that very few people ever use more than around 20% of them.”The report said that people were spending large amounts of money on advanced software when much simpler and cheaper ones were available. Bragg noted that for more specialized software, such as databases and web design software, the percentage of functions used was much higher. “Yes, it’s a little unusual really. We found that the more widely used the software is, the fewer functions people use on it” said Bragg. He suggested this was because the more general software was used by people with different levels of computer experience and also for a wider set of tasks. More specialized software was usually used for a narrower set of tasks and by people with a higher level of computer skill.44. Billy Bragg writes this report mainly __________.A. to discover how software use has changed over timeB. to learn what activities people use computers forC. to find out if software is too expensiveD. to learn what software people use and how they use them.45. What has had the biggest effect on peoples’ computer usage habits over the past 6 years?A. Better web-browsers.B. Cheaper computers.C. The growth of the internet.D. Better education.46. Using the information from the graph and passage decide which of the following software application is most commonly used.A. Dreamweaver.B. Photoshop.C. Oracle Database.D. Atlas.ti.People like to talk about “first”. They like to remember their first love or __47__first car. But not all firsts are happy __48___. Few people enjoy the firsts that __49___ bad.One of history’s bad but important firsts was the first car50 . Cars were still young __51___it happened. It___52__place in New York in May 1896. A man from Massachusetts was ___53___the city in his new car. At that time, bicycle__54____were still trying to get used to the new set of wheels on the road. No one was sure who was at fault(过错). Any way, a bike and the car collided(相撞). The man on the bike was___55___. The driver of the car had to stay in prison and wait for the hospital report __56___ the bike rider. It was ___57___that the bike rider was not killed.Three years__58__, another car accident took place. It was again in New York City. A man __59__Henry Bliss got off a street car. He was hit by a___60___car. Again no one was sure just how it happened or who was at fault. The___61___ of the car was put in prison. Poor Mr. Bliss became the first person to___62____in a car accident.2012学年第一学期八年级英语竞赛答题卷(100分)一、完型填空(60%)A1. 2. 3. 4. 5. 6. 7. 8. 9. 10.11. 12. 13. 14. 15.16. 17. 18. 19. 20.B21. 22. 23. 24. 25.26. 27. 28. 29. 30.二、阅读理解(32%)A31. 32. 33. 34. 35.B36. 37. 38.C39. 40. 41. 42. 43.D44. 45. 46.三、选词填空(8%)47. 48. 49. 50. 51. 52. 53. 53. 54. 55. 56. 57. 58. 59. 60. 61.。

2012年初中数学竞赛试卷(八年级)

2012年初中数学竞赛试卷(八年级)

2012年初中数学竞赛试卷(八年级)一.选择题(每小题5分,共30分)1.一次数学测试后随机抽取八(2)班5名同学的成绩如下:98, 91, 78, 85, 98.关于这组数据的错误说法是----------------------------------------------------------------------------------------------( ) A .极差是20 B .众数是98 C .中位数91 D .平均数是912.汽车经过启动、加速行驶、匀速行驶、减速行驶之后停车,若把这一过程中汽车的行驶路程看作时间的函数,其图像可能是------------------------------------------------------------------( )A .B .C .D .3.如图,D 是Rt △ABC 斜边AB 的中点,E ,F 分别在AC,BC 上,且DE ⊥DF ,设△ADE 的面积,△BDF 的面积,四边形CEDF 的面积分别为S 1,S 2,S 3,则S 1,S 2,S 3之间的关系是-------------------------------( ) A .S 1+S 2>S 3 B .S 1+S 2<S 3 C .S 1+S 2=S 3 D .不能确定4.已知一次函数y =(a -2)x +1的图像不经过第三象限,化简446922+-++-a a a a 的结果是-------------------------------------------------------------------------------------------------------( ) A .1 B .2a -5 C .5-2a D .-1 5.已知a ,b 为常数,若0>+b ax 的解集是31<x ,则0<-a bx 的解集是--------------( ) A .3-<xB .3->xC .3<xD .3>x6.已知a 是方程x 2-5x +1=0的一个根,则a 4+a -4的个位数字是-----------------------------( )A .3B .5C .7D .9S 3S 2S 1D F E C BA二.填空题(每小题5分,共30分)7.无论x 取何实数,点P(1-x ,1+x )都不可能在第 象限.8.已知直角坐标平面内四个点A (-1,0), B (3,0), C (0,3), D 是平行四边形的四个顶点,则点D 的坐标为 .9.假期学校组织360名师生外出旅游,某客车出租公司有两种大客车可供选择:甲种客车每辆车有40个座位,租金400元;乙种客车每辆有50个座位,租金480元。

浙江省杭州市2012学年八年级数学第一学期12月学科竞赛

浙江省杭州市2012学年八年级数学第一学期12月学科竞赛

12012学年第一学期八年级12月份学科竟赛数学试题卷考生须知:1. 本试卷满分120分,考试时间90分钟。

2. 必须在答题纸的对应答题位置上答题,写在其它地方无效。

答题方式详见答题纸上的说明。

一. 仔细选一选(本题有10个小题,每小题3分,共30分)1.如图,把一块含有45°角的直角三角板的两个顶点放在直尺的对边上.如果∠1=25o,那么∠2的度数是( ) A.30o B.25o C.20o D.15o2. 已知一个等腰三角形的两边长分别是2和5,那么这个等腰三角形的周长为( ) A. 9 B. 12 C. 9或12 D. 73. 若点P 在x 轴的上方、y 轴的左方,到每条坐标的距离均为4,则P 点坐标为( ) A. (4,4) B .(-4,-4) C .(-4,4) D .(4,-4)4.为考察某地区24000名学生的中考数学成绩,从中抽取了50袋试卷,每袋试卷30份,这个问题中样本容量是( )A .50B .30C . 24000D .15005.由四个大小相同的小正方体搭成的几何体的左视图如图所示,则这个几何体的搭法不能是( )6. 已知,62=-x a 要使x 是非负数,则a 的取值范围是( )A. 3>aB. 3<aC. 3≥aD. 3≤a7. 下列说法中:①有一个角为60°的等腰三角形是等边三角形; ②三边长为 14,5 ,3的三角形为直角三角形;③顶角和底边对应相等的两个等腰三角形全等; ④一边上的中线等于这边长的一半的三角形一定是等腰直角三角形。

其中正确的个数是( )A. 4个B. 3个C. 2个D. 1个8.已知点A ,B 的坐标分别是(2m+n ,2),(1,n -m). 若点A 与点B 关于y 对称,则m+2n 的值为( )A. 1 B. —1 C. 0 D.-39.如图,在△ABC 中,点D 、E 、F 分别在边BC 、AB 、AC 上,且BD=BE ,CD=CF ,∠A =70°,那么∠FDE 等于( )(第5题)2A .55° B.45° C.45° D.35°10. 如图,△ABC 和△ADE 都是等腰直角三角形,∠BAC =∠DAE =90°, 连结CE 交AD 于点F ,连结BD 交CE 于点G ,连结BE . 下列结论中,正确的结论有( )① CE =BD ; ② ∠ADC 是90°;③ ∠ADB =∠AEB ; ④ S BCDE =21BD ·CE ; ⑤2222CD BE DE BC +=+ A .1个 B .2个 C .3个 D .4个二. 认真填一填 (本题有6个小题, 每小题4分, 共24分)11.如图,直线b a ,被直线c 所截,给出下列条件:①∠1=∠2 , ②∠2=∠3,③∠3=∠4 , ④∠4=180°-∠1. 其中能判断a ∥b 的条件是 ▲ ( 填序号) .12. 如图,在△ABC 中,∠C =90°,AB 的中垂线DE 交AB 于E ,交BC 于D ,若∠B =28°,则∠CAD =____ ▲ ______° 13.在函数y =x 的取值范围是 ▲ ;并求当x=5时,函数y 的值是 ▲ .14.在平面直角坐标中,已知点P(4-m ,2m -6)在第一象限,则实数m 的取值范围是__▲_. 15.已知一组数据x 1,x 2,x 3,x 4,x 5的平均数是3,方差为13,那么另一组数据3x 1-2,3x 2-2,3x 3-2,3x 4-2,3x 5-2的平均数和方差分别是 ▲ ; ▲ .16. 自然数按如图规律排列,14这个数第4行,第三列,记作(4,3),那么69 这个数位记作 ▲ ; 1218这个数位记作 ▲ .1 2 5 1017 ……. 4 3 6 11 18 …... 9 8 7 12 19 …… 16 15 1 4A BCDEFG 12 abc3 4 第11题D BACE313 20 …… 25 24 23 22 21 ……三. 全面答一答 (本题有8个小题, 共66分)17.(本题8分)解下列不等式组;并把解集在数轴上表示⎩⎨⎧>--->+x x xx 5)1(3617218.(本题8分)等腰△ABC 中,8AB AC ==, ∠BAC =100°,AD 是BC 边上的中线,交BC 于D ,点E 是AB 的中点,连接DE . (1)求∠BAD 的度数; (2)求∠BED 的度数; (3)求线段DE 的长.19. (本题满分8分)(1)观察下列多面体,并把下表补充完整.20. (本题10分)△ABC (1) 作出与△ABC 关于y 轴对称的图形;并写出所得像△A 1B 1C 1各顶点坐标;(2) 将△ABC 向下平移3出所得像△A 2B 2C 2的各顶点坐标. 21.(本题满分10出参加比赛的人数相同,成绩分为A 、B 、C 、D 应等级的得分依次记为100分,90分,80分,70分,学校将八年级的一班和二班的成绩整理并绘制成统计图(如图).请你根据以上提供的信息解答下列问题:2n4(1)此次竞赛中二班成绩在C 级以上(包括C 级)的有多少人? (2)请你将表格补充完整:(3)请从下列不同角度对这次竞赛成绩的结果进行分析:①从平均数和众数的角度来比较一班和二班的成绩;②从B 级以上(包括B 级)的人数的角度来比较一班和二班的成绩.22.(本题满分10分)朝晖初中初一年级这个学期实施“先学后教”的教学模式,计划从白板公司购买A 、B 两种型号的小白板,经洽谈,购买一块A 型小白板比买一块B 型小白板多用20元.且购买5块A 型小白板和4块B 型小白板共需820元. (1)求购买一块A 型小白板、一块B 型小白板各需要多少元?(2)根据朝晖初中实际情况,需从白板公司购买A 、B 两种型号的小白板共60块,要求购买A 、B 两种型号小白板的总费用不超过5240元.并且购买A 型小白板的数量应大于购买A 、B 种型号小白板总数量的13.请你通过计算,求出朝晖初中从白板公司购买A 、B 两种型号的小白板有哪几种方案?23.(本题12分)如图1,Rt △ABC ≌Rt △EDF ,∠ACB =∠F =90°,∠A =∠E =30°.△EDF 绕着边AB 的中点D 旋转, DE ,DF 分别交线段..AC 于点M ,K . (1)观察: ①如图2、图3,当∠CDF =0° 或60°时,AM +CK _______MK (填“>”,“<”或“=”).(2分)②如图4,当∠CDF =30° 时,AM +CK ___MK (只填“>”或“<”).(2分)(2)猜想:如图1,当0°<∠CDF <60°时,AM +CK _______MK ,证明你所得到的结论.(6分)(3)如果222AM CK MK =+,请直接写出∠CDF 的度数和AMMK 的值.(2分)图1图2图3(第23题)EEE图452012学年第一学期八年级12月份学科竟赛数学答题卷 命题人:高宜昌 审核人:李卫星二、认真填一填(本题有6小题,每题4分,共24分)11. 12. 13. ;14. 15. ;16. ; 。

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2012学年第一学期八年级英语竞赛试卷一、完型填空(60%)A little boy invited his mother to attend his school’s first teacher-parent meeting. To the little boy’s1 ,she said she would go. This2 be the first time that his classmates and teacher3 his mother and he felt ashamed of her4 . Although she was a beautiful woman, there was a scar(疤痕)that5 nearly the right side of her face. The boy never wanted to6 why or how she got the scar.At the meeting, the people were 7 by the kindness and natural beauty of his mother in spite of the scar, but the little boy was still 8 and hid himself from everyone, 9 a conversation between his mother and 10 .The teacher asked 11 ,“How did you get the scar on your face?”The mother answered, “12 my son was a baby, he was in a room that caught fire. Everyone was 13 afraid to go in because the fire was 14 ,so I went in. As I was running toward his bed, I saw a piece of wood coming down and I placed myself over him trying to protect him. I was knocked senseless but 15 , a fireman came in and saved both of us.”She touched the 16 side of her face. “This scar will be 17 ,but to this day, I have never 18 what I did.”At this point, the little boy came out running toward his mother with tears in his eyes. He held her mother in his arms and 19 a great sense of the sacrifice(牺牲)that his mother had made for him. He held her hand tightly for the 20 of the day.1 A. enjoyment B. disappointment C. surprise D. excitement2. A. would B. could C. should D. must3. A. noticed B. greeted C. accepted D. met4 . A. look B. appearance C. clothes D. smile5. A. included B. passed C. covered D. decorated6. A. talk about B. think about C. care about D. hear about7. A. impressed B. surprised C. excited D. comforted8. A. surprised B. sad C. happy D. embarrassed(尴尬)9. A. listening to B. looking at C. hearing D. watching10. A. understanding B. the parents C. the teacher D. his classmates11. A. carefully B. seriously C. nervously D. anxiously(焦急的)12. A. As B. When C. Since D. While13. A. so B. much C. quite D. too14. A. out of control B. under control C. in control D. over control15. A. surely B. hopefully C. luckily D. unluckily16. A left B. crying C. wiped D. burned17. A. ugly B. lasting (持久的) C. serious D. frightening18. A. forgot B. recognized C. considered D. regretted19. A. felt B. realized C. enjoyed D. told20. A. others B. other C. rest D. followingBWe know that trees are useful in our everyday life. They 21us many things,such as wood,oxygen,rubber,medicines and many other things. They can 22tell us a lot about our climate. The following are the reasons.If you 23 a tree,you can see that it has many rings. Most trees grow one new ring 24 year. Because of this reason,we know 25 a tree is. A tree over a hundred years old means that it has more than a hundred 26. When the climate is dry or very cold,the trees do not grow very much and their rings are usually 27. When it is wet and warm,the rings are much thicker. If the rings are suddenly very thin or suddenly very thick,this means that the 28 changed suddenly. If we look at the rings on this tree,we can learn about the 29for a hundred years. We can see 30our climate is changing today.21. A. tell B. ask C. give D. get22. A. not B. too C. to D. also23. A. cut across B. climb up C. walk past D. look at24. A. every B. many C. the first D. from25. A. how big B. how long C. how old D. how much26. A. trees B. leaves C. people D. rings27. A. big B. thick C. small D. thin28. A. climate B. trees C. rings D. animal29. A. people B. things C. climate D. life30. A. how B. why C. when D. while二、阅读理解(32%)AOur village carpenter, John Hill, came one day and made a dining table for my wife. He made it just the right size to fill in the space between the two windows. When I got home that evening, John was drinking a cup of tea and writing out his bill for the job.My wife said to me, quietly, "That's his ninth cup of tea today." But she said, in a loud voice, "It's a beautiful table, dear, isn't it?""I'll decide about that when I see the bill," I said.John laughed and gave me his bill for the work. I read:One dining table 10 November 1989Cost of wood &17.00Paint 1.50Work, 8 hours(&1 an hour) 8.00Total(合计) &36.50When I was looking at the bill, John said. "Let's been a fine day, hasn't it? Quite sunny. "Yes," I said, 'I’m glad it's only the 10th of November.""Me, too." Said John. “You wait--- it'll be a lot colder by the end of the month.""Yes, colder-and more expensive! Dining tables will be &20 more expensive on November 30th, won't they, John?"John looked hard at me for half a minute. Was there a little smile in his two blue eyes? I gave his bill back to him."If it isn't too much trouble, John," I said, "Please add it up again, You can forget the date-."I paid him & 26,5 and he was happy to got it.31. Why did John talk about the weather when the writer was looking at the bill?A. Because he didn't want the writer to go through the bill carefully.B. Because it was really a fine day.C. Because he wanted the writer to check the bill carefully.D. Because he wanted to tell the writer what the weather was it be.32. Why did the writer say that dining tables would be &20 more expensive on November 30th?A. Because it was difficult to make dining tables in cold weather.B. Because paint would be more expensive.C. Because the cost of wood would be more expensive.D. Because he thought John would almost certainly add the date to the cost of the dining table.33. The writer thought John would ask for-if he made a dining table on the last day of November.A. & 20.00B. & 46.50C. &56.50D.& 26.5034. When the writer gave him the money, John was happy becauseA. he got what he should get for his work.B. he got much more money for his work.C. he got the money easily.D. he didn't have to add up the costs again35. From the story we know that______A John made a mistake in the bill.B John tried to fool the writer in order to get more money for his work.C John had written out the bill before the writer got home.D John still wanted to get &36.50 for his work in the end.BAny mistake made in the printing of a stamp raises its value to stamp collectors. A mistake on one inexpensive postage stamp has made the stamp worth a million and a half times its original value. The mistake was made more than a hundred years ago in the British colony of Mauritius, a small island in the Indian Ocean. In 1847 an order for stamps was sent to a London printer ---Mauritius was to become the fourth country in the world to issue(发行)stamps.Before the order was filled and delivered, a ball was planned at Mauritius’ Government House, and stamps were needed to send out the invitations. A local printer was instructed to copy thedesign for the stamps. He accidentally printed the words “Post Office” instead of “Post Paid” on the several hundred stamps.Today there are only twenty-six of these misprinted stamps left fourteen One Penny Orange-Reds and twelve Two Penny Blues. Because of the Two Penny Blue’s rareness and age, collectors have paid as much as $16 ,800 for it.36.Over a century ago, Mauritius ________.A. was an independent countryB. belonged to IndiaC. was one of the British coloniesD. was a small island in the Pacific Ocean37. The mistake on the stamps was made ________.A .in Mauritius B. at Mauritius Government House C. in a post office D. in London38. Stamp collectors have paid $16,800 for ________.A. fourteen One Penny Orange-RedsB. twelve Two Penny BluesC. one One Penny Orange-RedD. one Two Penny BlueCDear Joy,Thank you for agreeing to water our plants for us while we are away. Here is what you need to do.1. The vegetable in the garden need to be watered every day unless it rains. There is a large area of bare soil, but this needs to be watered, too. Betty planted some corn there. Please pick any vegetables that are ripe and use them. It’s a shame for them to go to waste.2. The garden at the front of the house only needs to be watered every two or three days. The plants there are quite strong and will survive a few days without water. The roses are starting to bloom. If you look after them, they should be all right for a week or more. They will last a bit longer if you put a little sugar in the water. That’s some advice my grandmother gave me a long time ago.3. There are a few plants in the pots on the porch, and these need to be watered well every day. I’v e left a couple of pots out in the sun, and these also need lots of water. You can pick any strawberries that are ripe and eat them. You’ll find they are delicious.4. You don’t need to do anything for the lemon tree. If you see any ripe lemons, just pick them and take them home. You can use them in cooking for to make lemonadeThanks again for helping out. We’ll see you in two weeks. You’ve got our telephone number, so please call us if there are any problems or if you need to ask any questions. We’ll send you a post-card.39. Lee wrote these instructions to Joy because Lee_______.A. would not grow plants wellB. gave Joy the gardenC. sold the house to JoyD. was going on holiday40. What does NOT need watering every day?A. The roomB. The lemon treeC. The strawberriesD. The vegetables41. Which of the following is TRUE according to the passage?A. Joy will send Lee a postcard.B. Lee will come home in three weeks.C. Lee likes to grow his own vegetables.D. Lee’s house is not very big. 42.How should Joy deal with the lemon tree? A. Cut it downB. Water it every two daysC. Pick ripe lemons, and take them home.D. Take good care of it. 43. What does “ripe fruit” mean? A. The fruit is ready to eat. B. The fruit is hard and bitter. C. The fruit is rotten.D. The fruit is starting to grow.DAnewreportintocomputer software usage says many people may be throwing awaytheirmoney.For the report, over 400 students and teachers from the University of Wollongongwereinterviewed and asked about what computer software they most oftenused and what functions they used on each software.It found that the most popular software was a web-browser, used for surfing the internet, with 78% using Microsoft Internet Explorer followed by 13% for Firefox. “This was the biggest difference from our last report in 2000” said Billy Bragg, the report writer. “Software used over the internet such as browsers and e-mail have moved ahead of what was formerly the most popular one, word processors such as Microsoft Word used for typing documents.”The report also tried to measure how deeply each application was used. According to Bragg, “Most software has a large number of functions for the user, allowi ng them to do many different things, but we found that very few people ever use more than around 20% of them.”The report said that people were spending large amounts of money on advanced software when much simpler and cheaper ones were available. Bragg noted that for more specialized software, such as databases and web design software, the percentage of functions used was much higher. “Yes, it’s a little unusual really. We found that the more widely used the software is, the fewer functions people use on it” said Bragg. He suggested this was because the more general software was used by people with different levels of computer experience and also for a wider set of tasks. More specialized software was usually used for a narrower set of tasks and by people with a higher level of computer skill.44. Billy Bragg writes this report mainly __________.A. to discover how software use has changed over timeB. to learn what activities people use computers forC. to find out if software is too expensiveD. to learn what software people use and how they use them.45. What has had the biggest effect on peoples’ computer usage habits over the past 6 years?A. Better web-browsers.B. Cheaper computers.C. The growth of the internet.D. Better education.46. Using the information from the graph and passage decide which of the following software application is most commonly used.A. Dreamweaver.B. Photoshop.C. Oracle Database.D. Atlas.ti.People like to talk about “first”. They like to remember their first love or __47__first car. But not all firsts are happy __48___. Few people enjoy the firsts that __49___ bad.One of history’s bad but important firsts was the first car50 . Cars were still young __51___it happened. It___52__place in New York in May 1896. A man from Massachusetts was ___53___the city in his new car. At that time, bicycle__54____were still trying to get used to the new set of wheels on the road. No one was sure who was at fault(过错). Any way, a bike and the car collided(相撞). The man on the bike was___55___. The driver of the car had to stay in prison and wait for the hospital report __56___ the bike rider. It was ___57___that the bike rider was not killed.Three years__58__, another car accident took place. It was again in New York City. A man __59__Henry Bliss got off a street car. He was hit by a___60___car. Again no one was sure just how it happened or who was at fault. The___61___ of the car was put in prison. Poor Mr. Bliss became the first person to___62____in a car accident.2012学年第一学期八年级英语竞赛答题卷(100分)一、完型填空(60%)A1. 2. 3. 4. 5. 6. 7. 8. 9. 10.11. 12. 13. 14. 15.16. 17. 18. 19. 20.B21. 22. 23. 24. 25.26. 27. 28. 29. 30.二、阅读理解(32%)A31. 32. 33. 34. 35.B36. 37. 38.C39. 40. 41. 42. 43.D44. 45. 46.三、选词填空(8%)47. 48. 49. 50. 51. 52. 53. 53. 54. 55. 56. 57. 58. 59. 60. 61.。

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