限时训练(25)
高考化学选择题专题
潮阳一中明光学校高考化学选择题限时训练25（限时40分钟）----------离子共存、离子方程式一、单项选择题(每小题4分）1、（2010广东理综7）能在溶液中大量共存的一组离子是A . 4NH + 、Ag + 、34PO - 、Cl - B.3Fe +、H +、I -、 3HCO -C.K +、 +Na 、 -3NO 、 -4MnO D.Al 3+、2+Mg 、2-4SO 、 2-3CO2、（2011广东理综8）能在水溶液中大量共存的一组离子是A. H ＋、I ―、NO 3―、SiO 32－B. Ag ＋、Fe 3＋、Cl ―、SO 42―C.K ＋、SO 42－、Cu 2＋、NO 3―D.NH 4＋、OH －、Cl －、HCO 3－3、（2010全国卷1）能正确表示下列反应的离子方程式是A ．将铜屑加入3+Fe 溶液中：3+2+2+2Fe +Cu=2Fe +CuB ．将磁性氧化铁溶于盐酸：+3+342Fe O +8H =3Fe +4H OC ．将氯化亚铁溶液和稀硝酸混合：2++332Fe +4H +NO =Fe +2H O+NO -+↑D ．将铁粉加入稀硫酸中：+322Fe+6H =2Fe 3H ++↑4、（2010天津卷5）下列实验设计及其对应的离子方程式均正确的是A ．用F e C l 3溶液腐蚀铜线路板：Cu + 2F e 3+ ＝ Cu 2+ + 2Fe 2+B ．Na 2O 2与H 2O 反应制备O 2 ：Na 2O 2 + H 2O ＝ 2N a + + 2O H － + O 2↑C ．将氯气溶于水制备次氯酸：C l 2 + H 2O ＝ 2H + + Cl － + ClO －D ．用浓盐酸酸化的K M n O 4溶液与H 2O 2反应，证明H 2O 2具有还原性：2MnO 4-+ 6H + + 5H 2O 2 ＝ 2Mn 2+ + 5O 2↑ + 8H 2O5、（2010安徽卷9）在pH=1的溶液中能大量共存的一组离子或分子是A.Na +、Mg 2+、ClO —、NO 3—B. Al 3+、 NH 4+、 Br - 、Cl -C. K + 、Cr 2O 72- 、CH 3CHO 、 SO 42-D. Na +、K + 、SiO 32-、Cl -6、（2010上海卷9）下列离子组一定能大量共存的是A ．甲基橙呈黄色的溶液中：I -、Cl -、NO 3-、Na +B ．石蕊呈蓝色的溶液中：Na +、AlO 2-、NO 3-、HCO 3-C ．含大量Al 3+的溶液中：K +、Na +、NO 3-、ClO -D ．含大量OH 一的溶液中：CO 32-、Cl -、F -、K +7、（2010上海卷19）下列反应的离子方程式正确的是A ．苯酚与碳酸钠溶液的反应B ．等体积、等浓度的Ca(HCO 3)2溶液和NaOH 溶液混合223332222Ca HCO OH CaCO CO H O +---++−−→↓++C ．硫酸亚铁溶液中加入用硫酸酸化的过氧化氢溶液2222222Fe H H O Fe H O +++++−−→+D ．淀粉碘化钾溶液在空气中变蓝2I - + O 2 + H 2O = I 2 + 2OH -8、（2010江苏卷3）下列离子方程式表达正确的是A ．用惰性电极电解熔融氯化钠：2222Cl +2H O Cl +H +2OH --=↑↑通电B ．用氢氧化钠溶液除去铝表面的氧化膜：2322Al O 2OH 2AlO H O --+=+C ．用稀氢氧化钠溶液吸收二氧化氮：2322OH 2NO NO +NO +H O --+=↑D ．用食醋除去水瓶中的水垢：233322CO +2CH COOH 2CH COO CO H O --=+↑+9、（2010江苏卷6）常温下，下列各组离子在指定溶液中能大量共存的是A ．pH=1的溶液中：2+Fe 、3NO -、24SO -、Na +B ．由水电离的()141H 110mol L c +--=⨯⋅的溶液中：2+Ca 、K +、Cl -、3HCO - C ．()()12H /OH 10c c +-=的溶液中：4NH +、3Al +、3NO -、Cl -D ．()31Fe 0.1mol L c +-=⋅的溶液中：K +、ClO -、24SO -、SCN -10、（2010浙江卷12）下列热化学方程式或离子方程式中，正确的是A.甲烷的标准燃烧热为-890.3kJ·mol -1，则甲烷燃烧的热化学方程式可表示为：CH 4(g)+2O 2(g)=CO 2(g)+2H 2O(g) △H=-890.3kJ·mol -1B. 500℃、30MPa 下，将0.5mol N 2和1.5molH 2置于密闭的容器中充分反应生成NH 3(g)，放热19.3kJ ，其热化学方程式为：N 2(g)+3H 2(g)= 2NH 3(g) △H=-38.6kJ·mol -1C. 氯化镁溶液与氨水反应：222()Mg OH Mg OH +-+=↓D. 氧化铝溶于NaOH 溶液：Al 2O 3 + 2OH - = 2AlO 2- + H 2O11、（2010四川理综卷9）下列离子方程式书写正确的是A.向明矾溶液中加入过量的氢氧化钡溶液：322442222422Al SO Ba OH BaSO AlO H O +-+--+++=↓++B.向氢氧化亚铁中加入足量的稀硝酸：()22222Fe OH H Fe H O +++=+ C.向磷酸二氢铵溶液中加入足量的氢氧化钠溶液：432NH OH NH H O +-+=⋅D.向2CH BrCOOH 中加入足量的氢氧化钠溶液并加热：222CH BrCOOH OH CH BrCOO H O ∆--+−−→+12、（2011江苏高考4）常温下，下列各组离子在指定溶液中一定能大量共存的是A.1.0 mol·L －1的KNO 3溶液：H ＋、Fe 2＋、Cl －、SO 42－B.甲基橙呈红色的溶液：NH 4＋、Ba 2＋、AlO 2－、Cl －C.pH ＝12的溶液：K ＋、Na ＋、CH 3COO －、Br －D.与铝反应产生大量氢气的溶液：Na＋、K＋、CO32－、NO3－13、（2011安徽高考8）室温下，下列各组离子在指定溶液中能大量共存的是A.饱和氯水中Cl－、NO3－、Na＋、SO32－B.c(H＋)=1.0×10－13mol/L溶液中C6H5O－、K＋、SO42－、Br－C.Na2S溶液中SO42－、K＋、Cl－、Cu2＋D.pH=12的溶液中NO3－、I－、Na＋、Al3＋14、(2011全国II卷11)将足量CO2通入下列各溶液中，所含离子还能大量共存的是A．K＋、SiO32－、Cl－、NO3－B．H＋、NH4＋、Al3＋、SO42－C．Na＋、S2－、OH－、SO42－D．Na＋、C6H5O－、CH3COO－、HCO3－15、（2011四川）甲、乙、丙、丁四种易溶于水的物质，分别由NH4＋、Ba2＋、Mg2＋、H＋、OH－、Cl－、HCO3－、SO42－中的不同阳离子和阴离子各一种组成。
九年级英语限时训练(附参考答案)
九年级英语限时训练（附参考答案）一．根据句意及首字母和汉语提示完成句子。
1.The official newspaper c_________the news of Tiangong-I,for it took a big step forward into space.2.The idiom(成语）:“Meng zi’s mother makes three moves”tells of a mother who did all she could to provide the best e_________for her child.3.The young lady w _______hair is blond comes from Australia.4.Sometimes, you won’t know the true value of a moment u_______it becomes a memory.5.Good _______(发音）will impress others and make yourself confident.二．完形填空（共10小题；每小题1分，满分10分）There was a garden full of plants. In the corner of the garden, a 6 rose grew. She was the most beautiful flower there. She was as white as snow, 7 the plants around her were shocked at her beauty. But the white rose couldn’t see 8 , so she didn’t know how beautiful she was.Sometimes, she was even a little envious (羡慕的) of the sunflowers around her. She hoped that she could be as 9 as them.One sunny day, a girl went into the 10 . She walked around and was amazed at the beauty of na ture. Suddenly, she saw the white rose. “It hasn’t rained for days,” said the girl. “And the weather report says it will continue to be 11 for a few days. If the rose stays here, it will 12 soon. I’ll take it home and put it in my beautiful vase(花瓶).”The white rose was put in a lovely vase by the window. From the reflection in the window, the white rose saw herself for the 13 time. “Is that me?” she was shocked. “Till now I didn’t 14 how beautiful I looked.”Sometimes, we think other people are very great and 15 know our own advantages. This makes us feel less confident of ourselves. Look into your heart, and you’ll find how great you are.6. A. white B. red C. blue7. A. or B. but C. and8. A. herself B. himself C. yourself9. A. quiet B. lovely C. lonely10. A. park B. corner C. garden11. A. rainy B. cloudy C. sunny12. A. leave B. die C. cancel13. A. first B. second C. third14. A. improve B. realize C. suppose15. A. always B. usually C. never三．综合填空（共10小题；每小题2分，满分20分）根据短文内容，用方框中所给词语的适当形式填空，使文章通顺、完整。
九年级英语限时训练(附参考答案)
九年级英语限时训练（附参考答案）（满分28分时间25分钟）一、还原型阅读（共5小题；每小题2分，满分10分）二、阅读理解（共4小题；每小题2分，满分8分）In 1987 a small company named Huawei was started in Shenzhen.After more than 30 years of development, the company has now beaten Apple and become the world's second largest maker of smartphones. It has also become the world's supplier(供应者)of 5G.In China and even in the world.Huawei is a wonder. Although it started producing mobile phones not many years ago,it has become one of the most famous phone companies.But recently,Huawei faces some difficulties. The US government made a law to stop its sales in America. American officials said Huawei gave information that it collected to the Chinese government. At the same time, the US government planned to stop selling parts and services to Huawei. They believed that Huawei's business would be hurt this way.“We have never received such a request from the Chinese government and we have never tried to get into other systems to collect information," Ren Zhengfei, Huawei's president said. "The law would have little effect on our company. Huawei has enough ability to deal with the problems," Ren added.In an interview several years ago,Ren Zhengfei said,“I started Huawei with only £4000 at the beginning,but now it has become a 100 billion company. The experience was not as romantic as you imagine.Facing the law of the US,Huawei is growing. Huawei's smartphone sales around the world rose 50 percent compared with a year earlier in the first three months of2019. At the same time,sales from both Samsung and Apple fell. So far Huawei has grown into the world's largest telecommunication equipment supplier(供应商), selling in 170 countries. It may beat Samsung as the largest smartphone maker in the near future.6. How many kinds of smartphones are mentioned in total in this passage?A. One.B. Two.C. Three.D. Four.7. Which of the following sentences is TRUE according to the passage?A. Huawei collected the information for the Chinese government.B. Ren Zhengfei started Huawei with only L4000 in1987.C. Huawei has beaten Samsung.a South-Korea phone maker so far.D. Huawei has developed its business smoothly.8. What does the underlined word "romantic”in Paragraph 4 mean in Chinese?A.浪漫的B.现实的C.成功的D.麻烦的9. The last paragraph mainly tells us.A. Huawei has become one of the most famous phone companies.B. Huawei has become the largest maker of smart phones in the world.C. Huawei has got into some systems of the US.D. Huawei is full of hope and must succeed in the future .三、阅读表达（共5小题，每小题2分，满分10分）阅读下面的短文，并根据短文后的要求答题。
2021年中考总复习25分钟限时规范训练(含答案)限时训练26 用药与急救 健康地生活
不要因为长期埋头科学，而失去对生活、对美、对待诗意的感受能力。
——达尔文2021年中考总复习25分钟限时规范训练（含答案）姓名：班级：限时训练26用药与急救健康地生活(时间25分钟分值19分)一、选择题(每小题1分，共10分)1．在拨打“120”急救电话时，你必须讲清楚的三点是（A）A．你的地址电话病人症状B．你的单位地址病人症状C．天气情况地址病人症状D．身份证号发病原因发病症状2．东汉时期的张仲景在《金匮要略》中记载：“救自缢死……一人以手按据胸上，数动之。
”其方法与现今的________急救措施相似（D）A．人工呼吸B．按压止血C．开放气道D．胸外心脏按压3．对非处方药的说法不正确的是（D）A．非处方药不需要凭医师处方即可购买B．标有“OTC”的药品是非处方药C．在使用非处方药前要仔细阅读使用说明D．非处方药对人体没有毒副作用4．“珍爱生命，健康生活”是一个永恒的主题。
下列说法错误的是（D）A．远离烟、酒，拒绝毒品B．经常玩手机、熬夜上网，都属于不健康的生活方式C．每天锻炼一小时，幸福生活一辈子D．清华大学在学生中开展的“刷卡”锻炼活动，能提高学生对所有疾病的免疫力5．连花清瘟胶囊对治疗新型冠状病毒肺炎有一定的辅助作用。
下列有关药品说明书的理解正确的是（A）A.属于非处方药B．可治疗风寒感冒C．首次服用药量可加倍D．中成药无毒副作用，可以长期服用6．生活中，正确的急救方法往往能在危急时刻挽留生命。
以下各种急救的做法中正确的是（A）A．对心跳骤停者进行胸外心脏按压B．动脉出血在远心端止血，并拨打“120”C．运动时发现人骨折后立即把患者移动到阴凉处休息D．高楼发生火灾，赶快从窗户跳下7．某同学为夏令营设计的一份意外处理预案，不合理的是（C）A．表皮轻微擦伤涂碘伏B．表皮轻微烫伤立即局部冷却，再消毒处理C．腹泻则大剂量服用消炎药D．流浪狗咬伤反复冲洗伤口，并及时就医8．吸烟有害健康，室内公共场所禁止吸烟。
九年级英语限时训练(附参考答案)
九年级英语限时训练（附参考答案）（满分35分时间25分钟）一、单词拼写（共5小题；每小题2分，满分10分）根据句意和首字母或汉语提示，将单词的正确形式完整地写在答题纸相应的位置上。
1. If it rains tomorrow, you could go to the museum i___________.2. Do you know who is the g___________ writer since Shakespeare in the English language?3. How much time do you spend ___________（练习）English every day?4. Could you tell me where I can c___________ a bus going downtown?5. If possible, a___________（避免）stopping under trees, light posts, or power lines.二、完形填空（共10小题；每小题1分，满分10分）阅读下面短文，掌握其大意，然后从每题所给的A、B、C、D四个选项中，选出能填入短文相应空白处的最佳选项，并在答题卡上将该项涂黑。
Many people have to work at the weekends．Some people do not mind．Other people think it’s 6 ．One man thinks that working at the weekends can be 7 ．He is George Smith．Mr．Smith works in an office, in Brighton, England．One Saturday, May 24, 1996, he went to the office to do some work．After he 8 the lift, it stopped between floors．Mr．Smith could not get out of the lift．He began to shout, but 9 heard him．Then Mr．Smith remembered that it was a holiday in England．No one was going to come to work 10 Tuesday．There was 11 for Mr．Smith to do．He had to wait until one of his workmates came to work and found him．With nothing do 12 , Mr．Smith was very hungry and had to sleep most of the time．Early on Tuesday morning, one of his workmates came to work and found the lift was not 13 ．When the lift was opened, Mr．Smith came out, cold, weak, and tired．He had been in the lift for 14 hours!Now Mr．Smith says, “I only use lifts if they have 15 in them．”6. A.glad B.terrible C.good eful7. A.dangerous B.happy C.angry D.free8. A.got off B.got into C.got out of D.got to9. A.someone B.everyone C.no one D.either10. A.on B.to C.from D.until11. A.nothing B.something C.anything D.everything12. A.read or write B.eat or drink C.cook D.know the time13. A.there B.closed C.working D.here14. A.nearly 24 B.abut 40 C.more than 60 D.over 9415.A.pans B.beds C.exits D.telephones三、阅读表达共6小题；71-73小题，每小题2分；74-76小题，每小题3分，满分15分）阅读下面的短文，并根据短文后的要求答题。
宁德市高级中学2015届高考化学选择题专项限时训练系列套题
宁德市高级中学2015届高考化学选择题专项限时训练系列套题25专题13 有机化学A【说明】每组选择题共7题，每题只有1个选项符合题意，每题6分，共计42分6．（2011福建高考）下列关于有机化合物的认识不正确．．．的是A．油脂在空气中完全燃烧转化为水和二氧化碳B．蔗糖、麦芽糖的分子式都是C12H22O11，二者互为同分异构体C．在水溶液里，乙酸分子中的—CH3可以电离出H＋D．在浓硫酸存在下，苯与浓硝酸共热生成硝基苯的反应属于取代反应7．（2012·福建高考）下列关于有机物的叙述正确的是A．乙醇不能发生取代反应B．C4H10有三种同分异构体C．氨基酸、淀粉均属于高分子化合物D．乙烯和甲烷可用溴的四氯化碳溶液鉴别8.(2013年福建理综,7,6分)下列关于有机化合物的说法正确的是A.乙酸和乙酸乙酯可用Na2CO3溶液加以区别B.戊烷(C5H12)有两种同分异构体C.乙烯、聚氯乙烯和苯分子中均含有碳碳双键D.糖类、油脂和蛋白质均可发生水解反应9.(2014年福建理综)下列关于乙醇的说法不正确的是A.可用纤维素的水解产物制取B.可由乙烯通过加成反应制取C.与乙醛互为同分异构体D.通过取代反应可制取乙酸乙酯10.(2014年浙江理综)下列说法正确的是A.乳酸薄荷醇酯()仅能发生水解、氧化、消去反应B.乙醛和丙烯醛()不是同系物,它们与氢气充分反应后的产物也不是同系物C.淀粉和纤维素在酸催化下完全水解后的产物都是葡萄糖D.CH 3COOCH2CH3与CH3CH2COOCH3互为同分异构体,1H NMR谱显示两者均有三种不同的氢原子且三种氢原子的比例相同,故不能用1H NMR来鉴别11.(2014年山东理综)苹果酸的结构简式为,下列说法正确的是A.苹果酸中能发生酯化反应的官能团有2种B.1 mol苹果酸可与3 mol NaOH发生中和反应C.1 mol苹果酸与足量金属Na反应生成1 mol H2D.与苹果酸互为同分异构体12.(2013年山东理综)化学与生产和生活密切相关,下列说法正确的是A.聚乙烯塑料的老化是因为发生了加成反应B.煤经过气化和液化等物理变化可转化为清洁燃料C.合成纤维、人造纤维及碳纤维都属于有机高分子材料D.利用粮食酿酒经历了淀粉→葡萄糖→乙醇的化学变化过程宁德市高级中学2015届高考化学选择题专项限时训练系列套题26专题13 有机化学B【说明】每组选择题共7题，每题只有1个选项符合题意，每题6分，共计42分6.(2014年北京理综)下列说法正确的是A.室温下,在水中的溶解度:丙三醇>苯酚>1氯丁烷B.用核磁共振氢谱不能区分HCOOCH3和HCOOCH2CH3C.用Na2CO3溶液不能区分CH3COOH和CH3COOCH2CH3D.油脂在酸性或碱性条件下均可发生水解反应,且产物相同7.(2013年新课标全国理综Ⅰ)香叶醇是合成玫瑰香油的主要原料,其结构简式如图所示。
【江西专用】2014届高考语文二轮复习高频考点训练(25)及答案解析
高频考点训练(二十五)时间：25分钟分值：100分每日必练 15分钟限时训练1．(2013·江苏省徐州市考前模拟)下列词语中加点的字，每对读音都相同的一组是( )A．仓猝．/憔悴．一摞．/落．脚点契．合/雕栏玉砌．B．弓弦．/船舷．坼．裂/开小差．强．迫/强．词夺理C．怂．恿/悚．然干涸．/和．稀泥秕．谷/如丧考妣．D．危殆．/怠．慢皎．洁/广角．镜蒹葭．/汗流浃．背解析A．cù/cuì，luò/luò，qì/qì。
B.xián/xián，châ/chāi，qiǎng/qiǎng。
C.sǒng/sǒng，hã/huò，bǐ/bǐ。
D.dài/dài，jiǎo/jiǎo，jiā/jiā。
答案 D2．(2013·江西省临川一中最后一次模拟)下列各组词语中没有错别字的一项是( ) A．编纂兰天蔚然成风诙谐幽默B．瞭望重叠杳无音信颗粒归仓C．赝品痉孪心劳力拙知书达礼D．弦律蛰伏人参鹿茸舐犊情深解析A．“兰天”改为“蓝天”。
C.“痉孪”改为“痉挛”。
“知书达礼”改为“知书达理”。
D.“弦律”改为“旋律”。
答案 B3．(2013·云南省部分名校第二次统一考试)下列各句中，加点的成语使用不恰当的一项是( )A．北京时间2月25日上午，第八十五届奥斯卡金像奖颁奖典礼在洛杉矶杜比剧院落幕，李安凭借《少年派的奇幻漂流》再次获得最佳导演的称号，全场沸腾，人言啧啧．．．．，李安再次被媒体关注。
B．王珞丹是个胸无城府．．．．的年轻演员，从她出道到现在，她得到了许多光环，可是她的出言无忌，却给她惹来了很多麻烦。
C．春节期间，笼罩京津冀等地区的雾霾还没散去，多地地下水污染又激起轩然大波．．．．。
D．有关钓鱼岛争端不断升级，中国海监船继续在钓鱼岛领海内巡航，日方采取措施，主动出击，日舰机近距离跟踪干扰，媒体有关钓鱼岛问题会擦枪走火．．．．的议论不断。
高三英语二轮复习阅读理解限时强化练习25(含答案版)
新高考高中阅读强化限时训练25阅读理解+七选五（含参考答案）限时：35分钟满分：50分阅读（共两节，满分50 分）第一节（共15 小题；每小题2.5 分，满分37.5 分）AThe time may soon come when we say goodbye to most of the world’s languages. Today humans express themselves in over 6,000 different languages. But that is quickly changing. Many scientists say that over half of these languages will disappear within the next 50 years. After 100 years, the languages used in the world will not be more than 20.Why? It is because people from different cultures live and work together much more often than before. This brings changes. The languages of the world’s main culture are replacing the languages of the smaller cultures. Most international trade takes place in world languages such as English. People respect their own cultures and traditions, but when it comes to getting a job, knowing a world language is often necessary. It may mean the difference between success and failure.Technology works on the change of languages in an even more amazing way. Modern media such as radio and television give young people in developing countries much knowledge about the world. But this knowledge doesn’t come in words from the mouths of their parents or the elders in their neighborhood. It usually comes in the language of a different culture.People in different cultures think it good for them to share a popular language. They can quickly share ideas and work together. Knowing the same language means easier communication and is a basis for trust.Is the death of a small local language such a terrible thing? The answer is maybe. Many cultures may have words for many useful things we know nothing about. If their languages die, their valuable wisdom may be lost forever. The future of the world’s language depends on our actions now. Will we protect endangered languages or allow them to quietly disappear?Time will have the last word.( ) 1. Scientists say that within 50 years, perhaps, there will be only _______languages in the world.A. 4,000B. over 3,000C. around 3,000D. no more than20( ) 2. In “the languages of the world’s main culture s are replacing the languages of the smaller cultures.” the verb “replace” means “_______”.A. to put something back into a correct placeB. to use a second thing in place of the first thingC. to find good place for somethingD. to decide how important something is( ) 3. The passage says that if all the people in the world knew a major world language, _______.A. radio and television would all use the languageB. it would be easier for them to share their ideasC. lesson s at schools would be taught in the languageD. people would respect their own culture more参考答案：CBBBHave you wondered why different animals or pests have their particular colours? Colours in them seem to be used mainly to protect themselves.Birds, especially seagulls are very fond of locusts (飞蝗), but birds can’t easily catch locusts because locusts change their colours together with the change of the colour of crops. When crops are green, locusts look green. But when crops are ripe, locusts take on exactly the same brown colour as crops have. Some other pests with different colours from plants are usually easily found and eaten by their enemies. So they have to hide themselves in terror for lives and appear only at night.If you study the animal life in any part of the world, you will find the main use of colouring is to protect them. Bears, wolves and other beasts move quietly through forests. They are usually invisible to the eyes of hunters, because they have the colour much like the barks of trees.An even more strange act remains to be noticed. A kind of fish living in seas can send out a kind of very black liquid when it faces danger. While the liquid is over, its enemies cannot find it, and it quickly swims away. Thus, it has existed up to now though it is not powerful at all.( ) 4. Locusts are pests but they aren’t easily wiped out by their enemies because _______.A. they are powerful enoughB. they are dangerous to their enemiesC. they take on the same colours as cropsD. they fly very fast( ) 5. The pests that have different colours from plants usually appear at night because _______.A. their enemies can easily find them and eat themB. they have the habit of coming out in darknessC. it’s easy for them to destroy plants in darknessD. birds take their rests when night comes( ) 6. What does the underlined word “invisible” in Paragraph 3 mean?A. Can’t be seen.B. Can be seen.C. Can’t move.D. Can’t change.( ) 7. A certain fish living in seas has lived through millions of years because_______.A. it is the most powerful in the seaB. no other fishes can swim as fast as it canC. it can send out a kind of liquid which makes its enemies unable to find itD. the liquid it sends out can kill its enemies参考答案：CAACCCaptain James Cook was a great explorer. Before he started exploring, maps of the Pacific Ocean were almost empty. He visited hundreds of islands across the Pacific Ocean and put them in the correct places on the map. He made maps of the coastlines of Australia and New Zealand. James Cook was born in England in 1728. His parents were poor farm workers. When James was 18, he found a job on a coastal ship. He worked on the ship until he was 27 years old, and then he joined the navy. He fought in Canada in a war against France, and he mapped some of the eastern coasts of Canada. In 1768 King George made him Captain of a ship and sent him to the Pacific. He was gone for nearly three years. When he returned, he was regarded as a national hero.He started his third voyage in 1776. On this trip he visited Hawaii. He was the first European to set foot on this beautiful island. Then he mapped the western coastof North America. After that he returned to Hawaii. Unfortunately there was some trouble between the Hawaiians and the white men and they started fighting. In the end Captain was killed in a clash with the local.( ) 8. In which order did James Cook do the following things?a. Fought against France.b. Made maps of some of the eastern coast of Canada.c. Mapped the coast lines of Australia and New Zealand.d. Mapped the coast of North America.e. Was made Captain of a ship.f. Work on a coastal ship.A. f a b e d cB. f a b d e cC. f a b e c dD. a b e c f d( ) 9. He started exploring when _______.A. he worked on a coastal shipB. he was 18 years oldC. he was sent to the PacificD. he served in the navy( ) 10. Which of the following is NOT true?A. He made the first maps of the Pacific Ocean.B. He went on three long important voyages in his life.C. He was the first English man to reach Hawaii.D. He was respected by his people.( ) 11. He was considered a national hero because of _______.A. his experience in CanadaB. his being the first European to visit HawaiiC. his heroic deathD. his devotion to exploration on the Pacific Ocean参考答案：CDADDWhen you search Google or use Amazon, you might assume the results you see are the same as those viewed by your friends, family and other Internet users. But you’d be wrong. Websites and social networks track your location and search history and make assumptions about your age, race, sex and political views. They then show ads they believe to be the most relevant, in order to maximize clicks, but personalizewhich results you see by eliminating what they think is irrelevant.This is sold to the public as positive, making each web session relevant and interesting, yet it is leading researchers to fear this could widen divides between the North and South, rich and poor, and young and old. For example, in terms of wealth, if users are only ever shown particular products and job advertisements based on how much they earn or where they live, these users will never be given the opportunities to increase their wealth, or how much they spend on items.Princeton University has created bots（自动程序）, each with their own fake profiles. These bots have different fake ages and sexes, earn different levels of money, are virtually(虚拟地) based in various locations around the world and have different interests. By using these bots to scan and research the web, the researchers hope to create a picture of not only what each of them sees, but also what sites they are missing out on.According to lead researcher, Arvind Narayanan, “Our goal is a web privacy census（普查）which will be a comprehensive map of who are collecting what information, what they are inferring from it, and who they are sharing it with. It is an important step in our final goal of figuring out how users are treated based on that information.”Personalization also has its benefits. Shopping sites such as Amazon and eBay can scan a user’s search and purchase history to offer suggestions. This can help find similar, cheaper items or items that are more suited to their needs at a glance. It’s also possible to disable personalized ads and results. Google’s search engine lets you switch off personalization, for example.Researchers from the Universitat Pompeu Fabra in Barcelona and Yahoo felt the issue was so potentially damaging, and they have also created a way to “burst the filter(过滤) bubble”. They believe that just because people have opposing views on certain topics it doesn’t mean they won’t share interests with others.( ) 12. The underlined word “eliminating” in Paragraph 1 probably means“_______”.A. decoratingB. removingC. personalizingD. protecting( ) 13. Princeton University created bots to ______.A. explain why different websites are personalizedB. offer users some advice on how to protect privacyC. assess how personalization is affecting Internet usersD. stress the advantages and disadvantages of personalization of websites( ) 14. Which of the following websites have done something to cut off personalization?A. Google and YahooB. eBay and GoogleC. Amazon and eBayD. Amazon and Yahoo( ) 15. What is this passage mainly about?A. Different websites are doing something to offer quality service.B. Personalized ads and search results could be creating different web pages.C. Personalization of different sites will lead to users’ privacy being violated.D. Personalization of shopping sites makes online shopping more convenient.参考答案：BCAB第二节（共5 小题；每小题2.5 分，满分12.5 分）What makes one person more intelligent than another? What makes one person a genius, like the brilliant Albert Einstein, and another person a fool? Are people born intelligent or stupid, or is intelligence the result of where and how you live? 16 We know, however, that just being born with a good mind is not enough. In some ways, the mind is like a leg or an arm muscle. 17 Mental exercise is particularly important for young children. Many child psychologists think that parents should play with their children more often and give them problems to think about. 18 If, on the other hand, children are left alone a great deal with nothing to do, they are more likely to become dull and unintelligent.19 According to some psychologists, if parents are always tellinga child that he or she is a fool or an idiot, then the child is more likely to keep doing silly and foolish things. So it is probably better for parents to say very positive things to their children, such as “That was a very clever thing you did.” or“20 ”A. A healthy body contributes to one's intelligence.B. Parents should also be careful about what they say to young children.C. What people want to express is like this.D. The children are then more likely to grow up bright and intelligent.E. It needs exercise.F. You are such a smart child.G. These are very old questions and the answers to them are still not clear.参考答案：GEDBF。
衡水中学2010高考物理考前40天选择题限时练(25)
2010年高考选择题限时训练25一、选择题：1．下列说法中不正确．．．的是 A ．根据速度定义式t x v ∆∆=，当t ∆非常非常小时，tx ∆∆就可以表示物体在t 时刻的瞬时速度，该定义应用了极限思想方法。
B ．在探究加速度、力和质量三者之间关系时，先保持质量不变研究加速度与力的关系，再保持力不变研究加速度与质量的关系，该实验应用了控制变量法。
C ．在推导匀变速运动位移公式时，把整个运动过程划分成很多小段，每一小段近似看作匀速直线运动，然后把各小段的位移相加，这里采用了微元法。
D ．在不需要考虑物体本身的大小和形状时，用质点来代替物体的方法叫假设法。
2．在08北京奥运会中，牙买加选手博尔特是公认的世界飞人，在男子100m 决赛和男子200m 决赛中分别以9.69s 和19.30s 的成绩破两项世界纪录，获得两枚金牌。
关于他在这两次决赛中的运动情况，下列说法正确的是A ．200m 决赛中的位移是100m 决赛的两倍B ．200m 决赛中的平均速度约为10.36m/sC ．100m 决赛中的平均速度约为10.32m/sD ．100m 决赛中的最大速度约为20.64m/s3．无极变速可以在变速范围内任意连续地变换速度，性能优于传统的档位变速器，很多种高档汽车都应用无极变速。
如图所示是截锥式无极变速模型示意图，两个锥轮之间有一个滚动轮，主动轮、滚动轮、从动轮之间靠着彼此之间的摩擦力带动。
当位于主动轮和从动轮之间的滚动轮从左向右移动时，从动轮转速增加。
当滚动轮位于主动轮直径D 1、从动轮直径D 2的位置时，主动轮转速n 1、从动轮转速n 2的关系是A ．2121D D n n =B ．2112D D n n = C ．222112D D n n = D ．2112D D n n = 4．如图，甲、乙两图为与匀强磁场垂直放置的两个金属框架，乙图除了一个电阻为零、自感系数为L 的线圈外，其他部分与甲图都相同，导体AB 以相同的加速度向右做匀加速直线运动。
九年级英语限时训练(附参考答案)
九年级英语限时训练（附参考答案）（满分45分时间25分钟）一、听力（共10小题；每小题1分，满分10分）（一）录音中有五个句子，每个句子听一遍，然后从每小题A、B、C中选出适合每个句子的答语。
（5分）1. A. Qingdao. B. Xi'an. C. Kunming.2. A. At 6:00 p. m. B. At 11:00 p. m. C. At 6:00 a. m.3. A. At home. B. A dictionary. C. When he was ten.4. A. Sorry, I don't. B. Certainly, I could. C. OK, here you are.5. A. Don't do it. B. Me neither. C. Good idea.（二）在录音中你将听到一段短文及五个问题。
根据短文内容及问题选择正确答案。
短文及问题听两遍。
（5分）6.A. 13 years old. B. 14 years old. C. 15 years old.7. A. She likes reading and running.B. She likes painting and jogging.C. She likes dancing and singing.8. A. She thinks it is interesting. B. She thinks it is difficult. C. She thinks it is easy.9. A. She is a math teacher. B. She is a policewoman. C. She is a doctor for children.10. A. Jane works hard at math.B. Jane's aunt asked her to do more exercises.C. Jane got the right answer of the math problem.二、完形填空（共10小题；每小题1分，满分10分）阅读下面短文，掌握其大意，然后从每题所给的A、B、C三个选项中，选出能填入短文相应空白处的最佳选项，并在答题卡上将该项涂黑。
无锡新领航教育特供(课程标准卷地区专用)2013高英语二轮复习 专题限时训练 25
小升初 中高考 高二会考 艺考生文化课 一对一辅导 /wxxlhjy QQ:1571710901 无锡新领航教育特供专题限时训练(四十三) [记叙文型短文改错(二)](限时：每篇8分钟)(一)One day Tom and I were walking down the street while we saw an old man fall off his bike.He was badly hurt. Many people crowded around us. Someone suggested carrying the old man to the roadside, so Tom disagreed. He has learned first aid. He said that they ought to leave him where he was and checked him first. At that time the old man wasn't breathing. Tom asked me to call in the First Aid Center at once and he began to start the old man's breathing, us e the mouthtomouth way. Within five minutes, the old man began to move little and doctors also arrived. They said that we had done was correct. I have learned from this experience that a knowledge of first aid can make a really difference.(二)I just come back from Britain last week. I was luckily enough to be one of the student from different countries to visit the UK from Feb.16 to 28.We paid a visit to many places, like London, Oxford or the Lake District. I learned much about British culture and history in London, where was my favorite. I also liked Oxford, in which I saw much more old buildings. The Lake District was beautiful, but it was pity that it rained heavily when they were there. The most excited thing for me in the Britain was that I made a lot of friends there.(三)On Saturday afternoon, Li Hua and Wang Ping, members from “Green Eyes”， was having an environmental protection activity near the riverside when they catch sight of a bird on the ground. They picked it out and found it wounded. Thinking it should die without timely help, they took it home. Under their treatment and care, the lucky birds got recovered soon. When time came for them to fly the bird back to nature, they felt a bit of pity but very delightful. I think it's worthwhile for him to do such a thing. Here I call on the public to show respects for the nature. Only by changing the way which we treat the environment can we get along well with it.(四)It was my 18th birthday yesterday. As the age is special for our teenagers, so my parents held a birthday party for me at home. With my parents and some of my good friends attend my birthday party, I really had unforgettable experience. We sang songs, dancing and played games together. We all enjoyed ourselves very much. During the party, my parent told me that from then on I was no longer a child and an adult. They also said I should be more independent and responsibly. Hearing their words, I was greatly encouraged. It was just in that moment when I felt I was a grownup.。
高中英语真题-专题限时训练二十八) [故事型阅读理解]
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高中英语真题:专题限时训练(二十八) [故事型阅读理解](限时：25分钟)(一)With the tears streaming down her face, she put her two hands to her lips, and kissed them to him; then clasped(紧握) them on her breast，as if she laid his ruined head there.“You are not the jailer's daughter？”She sighed, “No.”“Who are you？”Not yet trusting the tones of her voice, she sat down on the ben ch beside him.He drew back but she laid her hand upon his arm .A strange thrill struck him when she did so, and visibly passed over his frame; he laid the knife down softly，as he sat staring at her.Her golden hair，which she wore in long curls，had been hurriedly pushed aside，and fell down over her neck.Advancing his hand by little and littl e，he took it up and looked at it.In the middle of the action he wentastray，and，with another deep sigh，fell to work at his shoemaking.But not for long.Releasing his arm，she laid her hand upon his shoulder.After looking doubtfully at it ，two or three times，as if to be sure that it was really there，he laid down his work，put his hand to his neck，and took off a blackened string with a scrap of folded rag attach ed to it.He opened this，carefully，on his knee，and it contained a very little quantity of hair：not more than one or two long golden hairs，which he had，in some old day，wound on upon his finger.He took her hair into his hand again，and looked closely at it.“It is the same.How can it be! When was it! How was it！”As the concentrating expression returned to his forehead，he seemed to become conscious that it was in hers too.He turn ed her full to the light，and looked at her.“She had laid her head upon my shoulder，that night when I was summoned(传唤)out—she had a fear of my going，though I had none—and when I was brought to the North Tower they found these up on my sleeve.‘You will leave me them? They can never help meto escape in the body，though they may in the spirit.’ Those were the words I said.I re member them very well.”He formed this speech with his lips many times before he could utter it.But when he did find spoken words for it，they came to him coherently(连贯地)，though slowly.“How was this? Was it you？”1．The underlined word“it”in the passage refers to“________”．A．her hair B．her handC．his arm D．his shoulder2．The passage is most probably taken from________.A．a chant B．a dramaC．a novel D．an essay3．From the passage，we can infer that________.A．the lady was the jailer's friendB．the man lived a peaceful lifeC．they hadn't seen each other for yearsD．they made a happy conversation4．The old man took the lady's hair into his hand again becaus e________.A．the hair reminded him of his daughterB．he found the hair of high qualityC．the lady had almost the same hair as he didD．the lady's hair worried him so much5．The writer attracts the readers by________.A．describing the changes of the relationshipB．giving a vivid description of detailsC．using funny and humorous languageD．presenting unpredictable consequence(二)A man sat at a metro station in Washington D．C. and started t o play the violin; it was a cold January morning. He played six pieces for about 45 minutes. During that time, since it was rush hour, 1,100 people went through the station, most of them on th eir way to work.Three minutes went by, and a middleaged man noticed there w as musician playing. He slowed his pace, and stopped for a few seconds, and then hurried up to meet his schedule.A minute later, the violinist received his first dollar tip: a woman threw the money in the money box without stopping, and contin ued to walk.A few minutes later, someone leaned against the wall to listen t o him, but the man looked at his watch and started to walk again. Clearly he was late for work.The one who paid the most attention was a 3yearold boy. His m other tagged him along, hurried, but the kid stopped to look at t he violinist. Finally, the mother pushed hard, and the child conti nued to walk, turning his head all the time. This action was repe ated by several other children. All the parents, without exceptio n, forced them to move on.In the 45 minutes the musician played, only 6 people stopped a nd stayed for a while. About 20 gave him money, but continued to walk their normal pace. He collected 32$. When he finished p laying and silence took over, no one noticed it. No one applaud ed, nor was there any recognition.No one knew this, but the violinist was Joshua Bell, one of the most talented musicians in the world. He had just played one of the most beautiful pieces ever written, on a violin worth 3.5 milli on dollars.Two days before his playing in the subway, Joshua Bell sold ou t at a theatre in where the seats averaged 100$.This is a real story. Joshua Bell's playing in the metro station w as organized by the Washington Post as part of a social experi ment.The outlines were in a common environment at an inappropriat e hour. Do we enjoy beauty? Do we stop to appreciate it? Do we recognize the talent in an unexpected situation?One of the possible conclusions from this experience could be: If we do not have a moment to stop and listen to one of the best musicians in the world playing the best music ever written, how many other things are we missing?6．Few people stopped to listen to Joshua Bell playing becaus e________.A．people were in a hurryB．they were not interested in musicC．it was too cold in the subwayD．the performance was not good enough7．When children stopped to look at the violinist, their parents _ _______.A．would give him some moneyB．would stop to enjoy the musicC．would applaud for the performanceD．would urge them to continue walking8．Joshua Bell played in the metro station in order to ________. A．make more moneyB．practise his skills in playing musicC．made an advertisement for his concertD．find out people's reaction under such a circumstance 9．The purpose of the passage is to ________.A．set us to think about our lifeB．show us how to play musicC．tell us the importance of musicD．report a subway performance(三)My father was 44 and knew he wasn't going to make it to 45. H e wrote me a letter and hoped that something in it would help m e for the rest of my life.Since the day I was 12 and first read his letter, some of his wor ds have lived in my heart. One part always stands out.“Right no w, you are pretending to be a time killer. But I know that one da y, you will do something great that will set you among the very best.”Knowing that my dad believed in me gave me permission to believe in myself.“You will do something great.”He didn't kno w what that would be, and neither did I, but at times in my life w hen I've felt proud of myself, I remember his words and wish he were here so I could ask，“Is this what you were talking about, Dad? Should I keep going ？”A long way from 12 now, I realize he would have been proud when I made any progress. Lately, though, I've come to believe h e'd want me to move on to what comes next: to be proud of and believe in somebody else. It's time to start writing my own letter s to my children. Our children look to us with the same unansw ered question we had. Our kids don't hold back because they're afraid to fail. They're only afraid of failing us. They don't worry about being disappointed. Their fear—as mine was until my father's letter—is of being a disappointment.Give your children permission to succeed. They're waiting for y ou to believe in them. I always knew my parents loved me. But t rust me. That belief will be more complete, that love will be mor e real, and their belief in themselves will be greater if you write t he words on their hearts，“Don't worry; you'll do something g reat.”Not having that blessin g from their parents may be the only thing holding them back. 10．We learn from the text that the author________.A．lost his father when he was youngB．worked hard before he read his father's letterC．asked his father permission to believe in himselfD．knew exactly what great thing his father wanted him to do 11．What does the author tell us in the 3rd paragraph?A．Children need their parents' letters.B．Children are afraid to be disappointed.C．His children's fear of failure held them back.D．His father's letter removed his fear of failing his parents. 12．Which of the following is TRUE of the author?A．He got no access to success.B．He wrote back to his father at 12.C．He was sure his parents loved him.D．He once asked his father about the letter.13．The main purpose of the text is to ________.A．describe children's thinkingB．answer some questions children haveC．stress the importance of communicationD．advise parents to encourage their children专题限时训练(二十八) [故事型阅读理解](限时：25分钟)(一)With the tears streaming down her face, she put her two hands to her lips, and kissed them to hi m; then clasped(紧握) them on her breast，as if she laid his ruined head there.“You are not the jailer's daughter？”She sighed, “No.”“Who are you？”Not yet trusting the tones of her voice, she sat down on the bench beside him.He drew back but she laid her hand upon his arm.A strange thrill struck him when she did so, and visibly passed over his frame; he laid the knife down softly，as he sat staring at her.Her golden hair，which she wore in long curls，had been hurriedly pushed aside，and fell down over her neck.Advancing his hand by little and little，he took it up and looked at it.In the middle of the action he went astray，and，with another deep sigh，fell to work at his shoemaking.But not for long.Releasing his arm，she laid her hand upon his shoulder.After looking doubtfully at it，two or three times，as if to be sure that it was really there，he laid down his work，put his hand to his neck，and took off a blackened string with a scrap of folded rag attached to it.He opened this，carefully，on his knee，and it contained a very little quantity of hair：not more than one or two long golden hairs，which he had，in some old day，wound on upon his finger.He took her hair into his hand again，and looked closely at it.“It is the same.How can it be! When was it! How was it！”As the concentrating expression returned to his forehead，he seemed to become conscious that it was in hers too.He turned her full to the light，and looked at her.“She had laid her head upon my shoulder，that night when I was summoned(传唤)out—she had a fear of my going，though I had none—and when I was brought to the North Tower they found these upon my sleeve.‘You will leave me them? They can never help me to escape in the body，though they may in the spirit.’ Those were the words I said.I remember them very well.”He formed this speech with his lips many times before he could utter it.But when he did find spo ken words for it，they came to him coherently(连贯地)，though slowly.“How was this? Was it you？”1．The underlined word“it”in the passage refers to“________”．A．her hair B．her handC．his arm D．his shoulder2．The passage is most probably taken from________.A．a chant B．a dramaC．a novel D．an essay3．From the passage，we can infer that________.A．the lady was the jailer's friendB．the man lived a peaceful lifeC．they hadn't seen each other for yearsD．they made a happy conversation4．The old man took the lady's hair into his hand again because________.A．the hair reminded him of his daughterB．he found the hair of high qualityC．the lady had almost the same hair as he didD．the lady's hair worried him so much5．The writer attracts the readers by________.A．describing the changes of the relationshipB．giving a vivid description of detailsC．using funny and humorous languageD．presenting unpredictable consequence(二)A man sat at a metro station in Washington D．C. and started to play the violin; it was a cold Ja nuary morning. He played six pieces for about 45 minutes. During that time, since it was rush h our, 1,100 people went through the station, most of them on their way to work.Three minutes went by, and a middleaged man noticed there was musician playing. He slowed his pace, and stopped for a few seconds, and then hurried up to meet his schedule.A minute later, the violinist received his first dollar tip: a woman threw the money in the money b ox without stopping, and continued to walk.A few minutes later, someone leaned against the wall to listen to him, but the man looked at his watch and started to walk again. Clearly he was late for work.The one who paid the most attention was a 3yearold boy. His mother tagged him along, hurried,but the kid stopped to look at the violinist. Finally, the mother pushed hard, and the child contin ued to walk, turning his head all the time. This action was repeated by several other children. All the parents, without exception, forced them to move on.In the 45 minutes the musician played, only 6 people stopped and stayed for a while. About 20 gave him money, but continued to walk their normal pace. He collected 32$. When he finished p laying and silence took over, no one noticed it. No one applauded, nor was there any recognitio n.No one knew this, but the violinist was Joshua Bell, one of the most talented musicians in the w orld. He had just played one of the most beautiful pieces ever written, on a violin worth 3.5 millio n dollars.Two days before his playing in the subway, Joshua Bell sold out at a theatre in where the seats averaged 100$.This is a real story. Joshua Bell's playing in the metro station was organized by the Washington Post as part of a social experiment.The outlines were in a common environment at an inappropriate hour. Do we enjoy beauty? Do we stop to appreciate it? Do we recognize the talent in an unexpected situation?One of the possible conclusions from this experience could be: If we do not have a moment to s top and listen to one of the best musicians in the world playing the best music ever written, how many other things are we missing?6．Few people stopped to listen to Joshua Bell playing because________.A．people were in a hurryB．they were not interested in musicC．it was too cold in the subwayD．the performance was not good enough7．When children stopped to look at the violinist, their parents ________.A．would give him some moneyB．would stop to enjoy the musicC．would applaud for the performanceD．would urge them to continue walking8．Joshua Bell played in the metro station in order to ________.A．make more moneyB．practise his skills in playing musicC．made an advertisement for his concertD．find out people's reaction under such a circumstance9．The purpose of the passage is to ________.A．set us to think about our lifeB．show us how to play musicC．tell us the importance of musicD．report a subway performance(三)My father was 44 and knew he wasn't going to make it to 45. He wrote me a letter and hoped th at something in it would help me for the rest of my life.Since the day I was 12 and first read his letter, some of his words have lived in my heart. One p art always stands out.“Right now, you are pretending to be a time killer. But I know that one day , you will do something great that will set you among the very best.”Knowing that my dad believ ed in me gave me permission to believe in myself.“You will do something great.”He didn't know what that would be, and neither did I, but at times in my life when I've felt proud of myself, I rem ember his words and wish he were here so I could ask，“Is this what you were talking about, Dad? Should I keep going？”A long way from 12 now, I realize he would have been proud when I made any progress. Lately, though, I've come to believe he'd want me to move on to what comes next: to be proud of and believe in somebody else. It's time to start writing my own letters to my children. Our children lo ok to us with the same unanswered question we had. Our kids don't hold back because they're afraid to fail. They're only afraid of failing us. They don't worry about being disappointed. Their f ear—as mine was until my father's letter—is of being a disappointment.Give your children permission to succeed. They're waiting for you to believe in them. I always k new my parents loved me. But trust me. That belief will be more complete, that love will be mor e real, and their belief in themselves will be greater if you write the words on their hearts，“Don't worry; you'll do something great.”Not having that blessing from their parents may be the only thing holding them back.10．We learn from the text that the author________.A．lost his father when he was youngB．worked hard before he read his father's letterC．asked his father permission to believe in himself D．knew exactly what great thing his father wanted him to do 11．What does the author tell us in the 3rd paragraph? A．Children need their parents' letters.B．Children are afraid to be disappointed.C．His children's fear of failure held them back.D．His father's letter removed his fear of failing his parents. 12．Which of the following is TRUE of the author?A．He got no access to success.B．He wrote back to his father at 12.C．He was sure his parents loved him.D．He once asked his father about the letter.13．The main purpose of the text is to ________. A．describe children's thinkingB．answer some questions children haveC．stress the importance of communicationD．advise parents to encourage their children。
2013学生暑期作业7月25日
高二数学复习限时训练（25）1、复数13i z =+，21i z =-，则复数12z z 在复平面内对应的点位于第_______象限． 2、“1x >”是“2x x >”的 条件．3、一个靶子上有10个同心圆，半径依次为1、2、……、10，击中由内至外的区域的成绩依次为10、9、……、1环，则不考虑技术因素，射击一次,在有成绩的情况下成绩为10环的概率为 .4、△ABC 中，︒=∠==30,1,3B AC AB ，则△ABC 的面积等于_________．5、函数2()ln(1)f x x x =+-的零点所在的区间是（n ,n ＋1），则正整数n =______． 6、在∆ABC 中，AB=BC ，187cos -=B ，若以A 、B 为焦点的椭圆经过点C ，则该椭圆的离心率e = 7、若等比数列{a n }满足：354321=++++a a a a a ，122524232221=++++a a a a a ，则54321a a a a a +-+-的值是________________．8、若不等式n a n n1)1(2)1(+-+<-对于任意正整数n 恒成立，则实数a 的取值范围是____ 9、有如下结论：“圆222r y x =+上一点),(00y x P 处的切线方程为200r y y y x =+”，类比也有结论：“椭圆),()0(1002222y x P b a b y a x 上一点>>=+处的切线方程为12020=+by y a x x ”，过椭圆C ：1422=+y x 的右准线l 上任意一点M 引椭圆C 的两条切线，切点为 A 、B. （1）求证：直线AB 恒过一定点；（2）当点M 在的纵坐标为1时，求△ABM 的面积。
2021年中考总复习25分钟限时规范训练(含答案)限时训练3 生物的生存依赖一定的环境
2021年中考总复习25分钟限时规范训练（含答案）姓名：班级：限时训练3生物的生存依赖一定的环境(时间25分钟分值25分)一、选择题(每小题1分，共15分)1．生物有许多区别于非生物的特征。
下列属于生物的是（A）A．地衣B．机器人C．钟乳石D．煮熟的鸡蛋2．《齐民要术》是我国古代的农业百科全书，对世界农业科学史产生了重要的影响。
其中对菜地的管理有“有草锄之”的论述。
种菜要锄草，因为杂草与蔬菜之间的关系是（A）A．竞争B．合作C．寄生D．共生3．“万物生长靠太阳”这句话体现出的生物与环境之间的关系是(C)A．生物适应环境B．生物影响环境C．环境影响生物D.生物与环境相互影响4．下列诗句中最能体现出光对植物生长影响的是AA．春色满园关不住，一枝红杏出墙来B．人间四月芳菲尽，山寺桃花始盛开C．竹外桃花三两枝，春江水暖鸭先知D．停车坐爱枫林晚，霜叶红于二月花5．“烟雨湿阑干，杏花惊蛰寒”，惊蛰节气前后气温转暖，雨水增多，杏花开放，惊雷惊醒了蛰伏于泥土中冬眠的昆虫。
这说明AA．环境影响生物B．环境适应生物C．生物影响环境D．生物适应环境6．下列选项中体现了生物适应环境的是AA．仙人球的叶变成刺状，以减少水分的散失B．千里之堤，溃于蚁穴C．过度放牧，破坏草场D．大树底下好乘凉7．地衣生活在岩石表面，可以从岩石中得到所需的营养物质；地衣又能够分泌地衣酸，对岩石有腐蚀作用。
这一事实说明(D)A．生物能适应环境B．生物不能适应环境，也不能影响环境C．生物能影响环境D．生物既能适应环境，又能影响环境8．生命世代相续，生生不息。
下列诗词中没有体现生殖现象的是BA．几处早莺争暖树，谁家新燕啄春泥B．碧玉妆成一树高，万条垂下绿丝绦C．穿花蛱蝶深深见，点水蜻蜓款款飞D．日出江花红胜火，春来江水绿如蓝9．下列所描述的生命现象与其实例不符的是CA．生物的生命活动需要营养——螳螂捕蝉，黄雀在后B．生物能对外界刺激作出反应——朵朵葵花向太阳C．生物能排出体内的代谢废物——蜻蜓点水D．生物能生长繁殖——离离原上草，一岁一枯荣10．谚语、俗语和古诗词中蕴含着一些生物学原理。
动能和动能定理2 训练题(含答案)
高一物理限时训练25（动能和动能定理）审定：高一物理组1．一质量为2kg 的滑块，以4m/s 的速度在光滑水平面上向左滑行，从某一时刻起，在滑块上作用一向右的水平力.经过一段时间，滑块的速度方向变为向右，大小为4m/s.在这段时间里水平力做的功为( )A.0B.8JC.16JD.32J2．如下图所示，物体由静止开始分别沿不同斜面由顶端A 滑至底端B ，两次下滑的路径分别为图中的Ⅰ和Ⅱ，两次物体与斜面间动摩擦因数相同，且不计路径Ⅱ中转折处的能量损失，则到达B 点时的动能( )A.第一次小B.第二次小C.两次一样大D.无法确定3．物体在水平恒力作用下，在水平面上由静止开始运动，当位移为S 时撤去F ，物体继续前进3S 后停止运动，若路面情况相同，则物体的摩擦力和最大动能是（ ） A. Fs E F f k 4,3== B. Fs E F f k ==,3 C. 3,4Fs E F f k == D. Fs E F f k 43,4== 4．如图所示，一物体由A 点以初速度v 0下滑到底端B ，它与挡板B 做无动能损失的碰撞后又滑回到A 点，其速度正好为零，设A 、B 两点高度差为h ，则它与挡板碰撞前的速度大小为( )A . 4220v gh +B . gh 2C . 2220v gh +D . 202v gh +5． 静止在光滑水平面上的物体，在水平恒力F 作用下，经过时间t ，获得动能为k E .若作用力的大小改为2F ，而获得的动能仍为E k ，则力2F 作用时间应为( ) A.4t B.22t C.2t D. 2t6．质量不等但有相同动能的两物体，在动摩擦因数相同的水平地面上滑行直到停止，则( )A.质量大的物体滑行距离小B.它们滑行的距离一样大C.质量大的物体滑行时间短D.它们克服摩擦力所做的功一样多7．一子弹原来的速度是v 0 ，打穿一木块后的速度是40v ，设木块对子弹的阻力是恒定的，则：①那么子弹射入木块的一半深度时，它的速度是多少？②要打穿两块这样的木块子弹至少应具有多大的速度？8．答案【①01827v v =；②02430v v =】。
初二第二次物理限时训练(含答案)
初二第二次限时训练物理试卷一、选择题（每小题3分，共36分）1．古典名著《三国演义》中，猛将张飞单枪立马在长坂坡当阳桥头，一声大喝，吓退十万曹操大军．这个典故形容张飞声音（）A．频率高B．音色差C．音调高D．响度大2．如下图所示，在下面几幅交通标志牌中，属于环境保护的是（）A．B．C．D．3．下列关于温度的描述中符合实际的是（）A．发高烧时人体温度可达40℃B．冰箱冷冻室的温度为10℃C．饺子煮熟即将出锅时温度为50℃D．加冰的橙汁饮料温度为﹣20℃4．做匀速直线运动的甲、乙两物体，它们的速度之比为2：3，通过的路程之比为3：1，则它们所用的时间之比为（）A．1：2 B．2：1 C．9：2 D．2：95．月亮、太阳、点燃的火把、镜子，其中都属于光源的一组是（）A．太阳和月亮B．月亮和镜子C．太阳和镜子D．太阳和点燃的火把6．如图所示，一束光斜射到平面镜上，其中反射角是（）A．∠1 B．∠2 C．∠3 D．∠47．白天我们能从不同方向看到桌子等物体，这是因为（）A．这些物体都是发光的B．眼睛发出的光射到这些物体上C．射到这些物体上的光发生了镜面反射D．射到这些物体上的光发生了漫反射8．使用拉伸了的软塑料尺测物体的长度，测量的结果将（）A．比真实值偏大B．比真实值偏小C．不受影响D．和真实值完全一样9．在物理课堂或生活中，我们曾经体验过以下声现象，其中能够说明声音产生的原因是（）A．放在密闭玻璃罩里的手机正在响铃，把罩内的空气抽走后，铃声变小B．在一根长钢管的一端敲击一下，从另一端可以听到两次敲击声C．将正在发声的音叉接触平静水面，会在水面上激起水波D．通常我们根据音色辨别不同人说话的声音10．下列关于声现象的说法中，正确的是（）A．我们听到的上课铃声是由铃的振动产生的B．登上月球的阿姆斯特朗可与他的同伴进行面对面的直接谈话C．安装在步行街路口的“噪声监测装置”可以防止噪声的产生D．地震专家通过耳朵直接接听地壳运动产生的次声波来预测地震的发生11．电影院的墙壁上都被装成坑坑凹凹的，俗称燕子泥，其目的是（）A．减弱回声B．防止声音振坏墙壁C．增大声音的频率D．增强响度12．在下列物态变化的过程中，放出热量的是（）A．初春，河面上的冰雪消融成水B．秋天，雨后的早晨出现大雾C．夏天，教室里洒水后空气变得凉爽D．冬天，晾晒的衣服渐渐变干二、填空题（每空1分，共21分）13．（3分）一只2B铅笔的长度约为20 ，一位初二的学生脉搏跳动10次的时间约为0.2 ．（填上合适的单位）．一张纸的厚度约为70 ．14．（2分）小明测量小球的直径，记录的数字分别是：2.41cm、2.43cm、2.40cm、2.42cm，这个球的直径是，他选择的刻度尺的分度值是．15．（2分）一个体温计的示数为38℃，如果没有甩，就用它给一个体温为36.5℃的人测体温，测量结果是，如果给一个体温为39℃的人测体温，测量结果是．16．（1分）2010年3月28日王家岭煤矿发生透水事故，救援工作迅速展开．4月2日下午，事故矿井下发现有生命迹象，原来是被困人员通过敲击钻杆，发出“当当”的求救信号，这是因为传声效果比气体好．17．（2分）如果一物体做匀速直线运动，4s内通过20m的路程，那么它前2s内的速度是m/s，2min后它通过的路程是m．18．（3分）李白诗句“不敢高声语，恐惊天上人”中的“高”是指声音的．女同学说话声音“尖细”，是指女同学声音的高，这是因为女同学说话时声带振动比较的缘故．19．（3分）乘电梯上升的站着的乘客相对地面是，相对电梯厢是．如图在空中加油时，加油机与受油机是相对（“运动”或“静止”）．20．（2分）暑假里，天气热极了，小红在家里写作业，汗流不止．抬头看了看挂在墙上的寒暑表，发现示数为32℃．她打开电风扇立刻感到凉快多了，这是因为的缘故．这时她看了看寒暑表，会发现示数（填“升高”、“不变”或“降低”）．21．（2分）人工降雨是利用干冰吸热，使云层中水蒸气成小冰晶或液化成小水珠，使云中的小水滴逐渐增大，从而形成降雨（两空选填物态变化的种类）．22．（1分）汽车在长100km的公路上行驶，前50km的速度为20m/s，后50km的速度为10m/s，汽车在这100km公路上的平均速度为m/s．三、解答题（共2小题，满分6分）23．在图中根据光路作出平面镜放置的位置（注意标明法线）．24．在图中画出反射光线并标出反射角．四、填空题（共3小题，满分16分）25．（5分）如图所示，探究声音的传播实验中（1）在玻璃钟罩内放一个正在发声音乐闹铃，钟罩底部插上玻璃管的软木塞，此时你听到音乐．（填“能”或“不能”）（2）用抽气设备抽钟罩内空气，在抽气的过程中，你听到音乐声将会．（3）如果把钟罩内空气完全抽出我们听到声音．（填“能”或“不能”）但有时还是能听到铃声．请你分析原因可能是：．（4）该实验表明声音不能在中传播．26．（7分）如图所示是探究“平面镜成像的特点”的情景：竖立的薄透明玻璃板下方放一张白纸，再准备A、B两支大小、外形完全一样的蜡烛，然后把点燃的蜡烛A立在玻璃板前，又把蜡烛B放在玻璃板后面，以A蜡烛为成像物体．[来源:学科网ZXXK]（1）该实验采用透明薄玻璃板代替日常使用的平面镜的目的是：．（2）该实验选择两个相同的蜡烛A和B，是为了比较像与物的关系．（3）在寻找蜡烛像的位置时，眼睛应该在蜡烛（选填“A”或“B”）侧观察．（4）将蜡烛B在玻璃板后的纸面上来回移动，发现无法让它与蜡烛A的像完全重合（如图甲）．你分析出现这种情况的原因可能是．（5）解决以上问题后，蜡烛B与蜡烛A的像能够完全重合，此时若将蜡烛A靠近玻璃板时，则像将（选填“靠近”或“远离”）玻璃板移动，像的大小（选填“变大”、“变小”或“不变”）．（6）图乙是某小组的同学经过三次实验，这样做的目的是：．27．（3分）小军同学在4块相同的玻璃板上各滴一滴相同数量的水，进行如图所示的实验探究，得出水蒸发快慢与水的温度、水的表面积和水面上方空气流动快慢有关．（1）通过A、B两图的对比，可以得出水蒸发快慢与有关．（2）通过两图的对比，可以得出水蒸发快慢与水的温度有关．（3）小军同学猜想水蒸发快慢还可能与水的多少有关，于是继续进行了如下探究：在相同环境下的两块相同的玻璃板上分别滴上一滴和两滴水（如图），观察并比较两图中哪块玻璃板上的水先蒸发完．从实验设计环节看，你认为他存在的主要问题是．五．综合应用题（5分）28．一列火车以20m/s的速度在平直的铁轨上匀速行驶，鸣笛后2s内收到前方障碍物反射回来的声音，此时司机立即刹车．问刹车处司机距障碍物多远？初二第二次限时训练物理试卷一、选择题1~5 D C A C D 6~10 B D B C A 11~!2 A B二、填空题13．cm；min；μm．14．2.42cm、1毫米．15．38℃，39℃．16．固体．17．5；600．18．响度，音调，快．19．运动；静止；静止．20．蒸发吸热；不变．21．升华；凝华．22．13.3．三、解答题23．24．四、填空题25．（1）能；（2）减小；（3）不能；A．空气没有被全抽出．B．底座的固体传声．（4）真空．26．（1）确定A蜡烛像的位置；（2）大小；（3）A；（4）玻璃板没有竖直放置；（5）靠近；不变；（6）防止实验的偶然性，使实验结论具有普遍性．点评：理解实验中选择两个相同的蜡烛、刻度尺、透明玻璃板的原因，把透明玻璃板竖直放在水平桌面的原因等．27．（1）液体的表面积；（2）A、C；（3）没有控制液体的质量相同．五．综合应用题（4分）28．解答：解：在t=2s的时间内，汽车行驶的距离：s1=v1t=20m/s×2s=40m，声音传播的距离：s2=v2t=340m/s×2s=680m，设司机鸣笛时汽车到山崖的距离为s，则：2s=s1+s2，∴s===360m，刹车处司机距障碍物的距离：s3=s﹣s1=360m﹣40m=320m．答：刹车处司机距障碍物的距离为320m．。
限时训练怎样做才更有效？
限时训练怎样做才更有效？
限时训练怎样做才更有效？
-----100天⾏动之第7天
⼯欲善其事，必先利其器。
有学习的愿望和⾏动，还要有有效的学习⽅法，才能事半功倍。
限时训练是学习中常见的很有效的⽅法。
限时训练的基本思想来源于把平时的练习当做考试，⽬标就是在规定的时间内达到⾼效的学习效果或检验。
什么情况下进⾏限时训练呢？教师可以在上课刚开始的时候或者下课前最后的时候，这时候的限时训练，边缘时间得到很有效的利⽤。
学⽣可以针对⾃⼰学习任务，随时可以进⾏专项的训练。
⽐如⼀套卷⼦的选择题在10钟内完成，看得分率，或者最后三道⼤题在25分钟完成等。
只要有限时的意识，效率就会变⾼。
点塔七层，不如暗处⼀灯。
限时训练如果能结合专题训练，针对性更强，效果会更好。
我记得⼥⼉⾼三英语学习中，改错题就是利⽤每天午睡前的10分钟，进⾏专项限时训练，这样限时专项训练⼤约进⾏了三周，改错题得率已经有明显上升。
限时训练时间可以很短，⽐如5~10分钟，也可以是⼀个番茄时间25分钟，不易过长，如达40分钟，那就是⼀次考试了。
总之。
限时训练要限时（10分钟）、专项（针对性）、持续（每次时间不长，每天都要进⾏），达到重点突破的效果。
限时训练虽然有不少好处，⽐如增强学习的效率、锻炼考试的⼼态等，当然也有⼀定的局限性，不宜处处限时训练。
⽐如做题时，如果限时训练，⼤家就会以的⾼分为⽬的，有些题⽬较难，因需要深⼊思考、需要时间⽽放弃，这样往往不能深度学习。
2023-2024学年八年级上学期人教版数学阶段限时训练卷(第11~13章)(含解析)
2023-2024学年八年级上学期人教版数学阶段限时训练卷（第11~13章）一．选择题（共10小题，满分30分，每小题3分）1．（3分）下面有4个汽车标致图案，其中不是轴对称图形的是（）A．B．C．D．2．（3分）下列每组数据分别是三根小木棒的长度，用这些木棒能摆成三角形的是（）A．5cm，5cm，11cm B．13cm，12cm，20cmC．8cm，7cm，15cm D．3cm，4cm，8cm3．（3分）如图，工人师傅门时，常用木条EF固定长方形门框，使其不变形，这样做的根据是（）A．三角形的稳定性B．两点确定一条直线C．两点之间，线段最短D．四边形的不稳定性4．（3分）下列条件不能得到等边三角形的是（）A．有两个内角是60°的三角形B．三个外角都相等的三角形C．有两个角相等的等腰三角形D．有一个角是60°的等腰三角形5．（3分）如图，AB∥CD，∠AFE＝135°，∠D＝80°，则∠E等于（）A．55°B．45°C．80°D．50°6．（3分）如图，已知AC∥BD，∠A＝∠C，则下列结论不一定成立的是（）A．∠B＝∠D B．OA＝OCC．OA＝OD D．AD＝BC7．（3分）如图，已知MB＝ND，∠MBA＝∠NDC，下列条件中不能判定△ABM≌△CDN的是（）A．∠M＝∠N B．AM∥CNC．AB＝CD D．AM＝CN8．（3分）等腰三角形一腰上的高与另一腰的夹角为60°，则等腰三角形的底角度数为（）A．15°B．30°C．15°或75°D．30°或150°9．（3分）如图所示，在Rt△ACB中，∠C＝90°，AD平分∠BAC，若BC＝16，BD＝10，则点D到AB的距离是（）A．9B．8C．7D．610．（3分）如图，BE、CF是△ABC的角平分线，∠A＝50°，BE、CF相交于D，则∠BDC的度数是（）A．115°B．110°C．100°D．90°二．填空题（共7小题，满分28分，每小题4分）11．（4分）点P（2，﹣3）关于y轴对称的点的坐标是．12．（4分）已知在△ABC中，∠A＝40°，∠B﹣∠C＝40°，则∠C＝．13．（4分）已知a，b是等腰三角形的两边长，且a，b满足（a+b﹣13）2＝0，则此等腰三角形的周长为．14．（4分）如图，在△ABC中，AB＝AC，点D在AC上，且BD＝BC＝AD，则∠ABD＝．15．（4分）如图Rt△ABC中，∠A＝30°，AB+BC＝12cm，则AB＝cm．16．（4分）一艘海轮位于灯塔P的南偏东70°方向的M处，它以每小时40海里的速度向正北方向航行，2小时后到达位于灯塔P的北偏东40°的N处，则N处与灯塔P的距离为．17．（4分）如图，等边△ABC中，E是AC边的中点，AD是BC边上的中线，P是AD上的动点，若AD＝6，则EP+CP的最小值为．三．解答题（共8小题，满分62分）18．（6分）如图，AE＝CF，AD＝CB，DF＝BE，求证：△ADF≌△CBE．19．（6分）一个多边形的内角和比它的外角和的2倍还大180度，求这个多边形的边数．20．（6分）如图，已知AC＝AE，∠B＝∠D，∠1＝∠2，求证：AB＝AD．21．（8分）如图，△ABC的周长为20，其中AB＝8，（1）用直尺和圆规作AB的垂直平分线DE交AC于点E，垂足为D，连接EB；（保留作图痕迹，不要求写画法）（2）在（1）作出AB的垂直平分线DE后，求△CBE的周长．22．（8分）如图，在平面直角坐标系中，A（﹣3，2），B（﹣4，﹣3），C（﹣1，﹣1）．（1）在图中作出与△ABC关于y轴对称的△A1B1C1（要求点A与A1，点B与点B1，点C和点C1相对应）；写出点A1，B1，C1的坐标（直接写答案）：A1；B1；C1；（2）请直接写出△A1B1C1的面积是．23．（8分）如图，在△ABC中，已知AB＝AC，BD平分∠ABC，AE为BC边的中线，AE、BD相交于点D，其中∠ADB＝125°，求∠BAC的度数．24．（10分）如图，△ABC中，AB＝AC，D、E、F分别为AB、BC、AC上的点，且BD＝CE，∠DEF＝∠B．（1）求证：∠BDE＝∠CEF；（2）当∠A＝60°时，求证：△DEF为等边三角形．25．（10分）（1）如图①，把△ABC纸片沿DE折叠，使点A落在四边形BCED的内部点A′的位置，试说明2∠A＝∠1+∠2；（2）如图②，若把△ABC纸片沿DE折叠，使点A落在四边形BCED的外部点A′的位置，此时∠A与∠1、∠2之间的等量关系是（无需说明理由）；（3）如图③，若把四边形ABCD沿EF折叠，使点A、D落在四边形BCFE的内部点A′、D′的位置，请你探索此时∠A、∠D、∠1与∠2之间的数量关系，写出你发现的结论并说明理由．2023-2024学年八年级上学期人教版数学阶段限时训练卷（第11~13章）参考答案与试题解析一．选择题（共10小题，满分30分，每小题3分）1．【解答】解：A．是轴对称图形，故此选项不合题意；B．是轴对称图形，故此选项不合题意；C．是轴对称图形，故此选项不合题意；D．不是轴对称图形，故此选项符合题意；故选：D．2．【解答】解：A、5+5＜11，不能组成三角形，故此选项错误；B、13+12＞20，能组成三角形，故此选项正确；C、8+7＝15，不能组成三角形，故此选项错误．D、3+4＜8，不能够组成三角形，故此选项错误；故选：B．3．【解答】解：用木条EF固定长方形门框，得到了△AEF，使其不变形，这样做的根据是三角形的稳定性，故选：A．4．【解答】解：A、两个内角为60°，因为三角形的内角和为180°，可知另一个内角也为60°，故该三角形为等边三角形；故本选项不符合题意；B、三个外角相等说明该三角形中三个内角相等，故该三角形为等边三角形；故本选项不符合题意；C、等腰三角形的两个底角是相等的，故不能确定该三角形是等边三角形．故本选项符合题意；D、有一个角是60°的等腰三角形是等边三角形，故本选项不符合题意；故选：C．5．【解答】解：∵AB∥CD，∠AFE＝135°，∴∠DGF＝∠AFE＝135°，∴∠DGE＝180°﹣∠DGF＝45°，∵∠D＝80°，∴∠E＝180°﹣∠D﹣∠DGE＝55°，故选：A．6．【解答】解：A、∵AC∥BD，∴∠A＝∠D，∠C＝∠B，∵∠A＝∠C，∴∠B＝∠D，正确，故本选项不符合题意；B、∵∠A＝∠C，∴OA＝OC，正确，故本选项不符合题意；C、根据已知不能推出OA＝OD，错误，故本选项符合题意；D、∵∠A＝∠C，∠B＝∠D，∴OA＝OC，OD＝OB，∴OA+OD＝OC+OB，即AD＝BC，正确，故本选项不符合题意；故选：C．7．【解答】解：A、∠M＝∠N，符合ASA，能判定△ABM≌△CDN，故A选项不符合题意；B、AM∥CN，得出∠MAB＝∠NCD，符合AAS，能判定△ABM≌△CDN，故B选项不符合题意．C、AB＝CD，符合SAS，能判定△ABM≌△CDN，故C选项不符合题意；D、根据条件AM＝CN，MB＝ND，∠MBA＝∠NDC，不能判定△ABM≌△CDN，故D选项符合题意；故选：D．8．【解答】解：在等腰△ABC中，AB＝AC，BD为腰AC上的高，∠ABD＝40°，当BD在△ABC内部时，如图1，∵BD为高，∴∠ADB＝90°，∴∠BAD＝90°﹣46°＝30°，∵AB＝AC，∴∠ABC＝∠ACB（180°﹣30°）＝75°；当BD在△ABC外部时，如图2，∵BD为高，∴∠ADB＝90°，∴∠BAD＝90°﹣60°＝30°，∵AB＝AC，∴∠ABC＝∠ACB，而∠BAD＝∠ABC+∠ACB，∴∠ACB∠BAD＝15°，综上所述，这个等腰三角形底角的度数为75°或15°．故选：C．9．【解答】解：∵BC＝16，BD＝10∴CD＝6由角平分线的性质，得点D到AB的距离等于CD＝6．故选：D．10．【解答】解：∵∠A＝50°，∴∠ABC+∠ACB＝180°﹣50°＝130°，∵BE、CF是△ABC的角平分线，∴∠EBC∠ABC，∠FCB∠ACB，∴∠EBC+∠FCB（∠ABC+∠ACB）＝65°，∴∠BDC＝180°﹣65°＝115°，故选：A．二．填空题（共7小题，满分28分，每小题4分）11．【解答】解：点P（2，﹣3）关于y轴对称的点的坐标为：（﹣2，﹣3）．故答案为：（﹣2，﹣3）．12．【解答】解：∵在△ABC中，∠A＝40°，∴∠B+∠C＝140°①，∵∠B﹣∠C＝40°②，∴①﹣②得，2∠C＝100°，解得∠C＝50°．故答案为：50°．13．【解答】解：∵（a+b﹣13）2＝0，∴a﹣b+3＝0，a+b﹣13＝0，∴a＝5，b＝8，∵a，b是等腰三角形的两边长，∴等腰三角形的三边长为5，5，8或5，8，8，∴5+5+8＝18或5+8+8＝21，∴等腰三角形的周长为18或21，故答案为：18或21．14．【解答】解：设∠ABD＝x，∵BC＝AD，∴∠A＝∠ABD＝x，∵BD＝BC，∴∠C＝∠BDC，根据三角形的外角性质，∠BDC＝∠A+∠ABD＝2x，∵AB＝AC，∴∠ABC＝∠C＝2x，在△ABC中，∠A+∠ABC+∠＝180°，即x+2x+2x＝180°，解得x＝36°，即∠ABD＝36°．故答案为：36°．15．【解答】解：∵Rt△ABC中，∠A＝30°，∴BC AB．设BC＝xcm，则有AB＝2xcm∴x+2x＝12，∴x＝4，∴AB＝8cm．故答案为：8．16．【解答】解：如图∠NPM＝180°﹣70°﹣40°＝70°，∵向北的方向线是平行的，∴∠M＝70°，∴∠NPM＝∠M，∴NP＝MN＝40海里×2＝80海里，故答案为：80海里．17．【解答】解：作点E关于AD的对称点F，连接CF，∵△ABC是等边三角形，AD是BC边上的中线，∴AD⊥BC，∴AD是BC的垂直平分线，∴点E关于AD的对应点为点F，∴CF就是EP+CP的最小值．∵△ABC是等边三角形，E是AC边的中点，∴F是AB的中点，∴CF是△ABC的中线，∴CF＝AD＝6，即EP+CP的最小值为6，故答案为6．三．解答题（共8小题，满分62分）18．【解答】证明：∵AE＝CF，∴AE﹣EF＝CF﹣EF，∴AF＝CE．在△ADF和△CBE中，∴△ADF≌△CBE（SSS）．19．【解答】解：设这个多边形的边数为n，由题意得，（n﹣2）•180°＝2×360°+180°，解得n＝7，答：这个多边形的边数是7．20．【解答】证明：∵∠1＝∠2，∴∠1+∠CAD＝∠2+∠CAD，∴∠BAC＝∠DAE，在△ADF和△CBE中，，∴△ADF≌△CBE（AAS），∴AB＝AD．21．【解答】解：（1）如图，BE为所作；（2）∵DE是AB的垂直平分线，∴EA＝EB，∴EB+EC＝EA+EC＝AC，∵△ABC的周长为20，∴AC+BC＝20﹣AB＝20﹣8＝12，∴△CBE的周长＝BE+EC+BC＝AE+EC+BC＝AC+BC＝12．22．【解答】解：（1）如图所示，△A1B1C1即为所求；故答案为：（3，2），（4，﹣3），（1，﹣1）；（2）如图所示，S△ABC＝S梯形BCDE﹣S△ACD﹣S△ABE3×（5+3）2×31×5＝12﹣2.5﹣3＝6.5．故答案为：6.523．【解答】解：∵AB＝AC，AE为BC边的中线，∴AE⊥BC，∴∠AEB＝90°，又∵∠ADB＝125°，∴∠DBE＝∠ADB﹣∠AEB＝35°，∵BD平分∠ABC，∴∠ABC＝2∠DBE＝70°，∵AB＝AC，∴∠C＝∠ABC＝70°，∴∠BAC＝180°﹣∠ABC﹣∠C＝40°．24．【解答】证明：（1）∵∠DEC是△BDE的一个外角，∴∠B+∠BDE＝∠DEF+∠CEF，∵∠DEF＝∠B，∴∠BDE＝∠CEF；（2）由（1）可知∠BDE＝∠CEF，∵AB＝AC，∠A＝60°∴∠B＝∠C＝60°，∴∠DEF＝60°，在△BDE和△CEF中∴△BDE≌△CEF（ASA），∴DE＝EF，∴△DEF为等边三角形．25．【解答】解：（1）如图，根据翻折的性质，∠3（180﹣∠1），∠4（180﹣∠2），∵∠A+∠3+∠4＝180°，∴∠A（180﹣∠1）（180﹣∠2）＝180°，整理得，2∠A＝∠1+∠2；（2）根据翻折的性质，∠3（180﹣∠1），∠4（180+∠2），∵∠A+∠3+∠4＝180°，∴∠A（180﹣∠1）（180+∠2）＝180°，整理得，2∠A＝∠1﹣∠2；（3）根据翻折的性质，∠3（180﹣∠1），∠4（180﹣∠2），∵∠A+∠D+∠3+∠4＝360°，∴∠A+∠D（180﹣∠1）（180﹣∠2）＝360°，整理得，2（∠A+∠D）＝∠1+∠2+360°．。
2015年中考英语考点限时训练：考点+25
考点跟踪突破25形容词和副词1．This tree is __A__ than that one.(2014，永州)A．taller B．tall C．the tallest2．—How do you feel about the movie？(2014，遂宁)—Wonderful！I've never seen a __B__ one before.A．good B．better C．best3．It is __C__ to do things well than do big things poorly.(2014，成都)A．worse B．funnier C．better4．There are many beautiful flowers in the world，but in parents' eyes，their children are the __C__ of all.(2014，衡阳)A．as beautiful as B．more beautifulC．most beautiful5．This movie wasn't __A__．He fell asleep half way through it.(2014，阜康)A．interesting enough B．enough interestingC．interested enough D．enough interested6．—I think English is as __D__ as maths.—I agree with you.(2014，南充)A．more interesting B．most interestingC．the most interesting D．interesting7．—Do you think yesterday's math problem was difficult?—Yes，I could __B__ work it out.(2014，黔南)A．easily B．hardly C．finally D．nearly8．—Where shall we eat tonight?—Let's call Harry.He __D__ knows the best places to go.(2014，河南)A．only B．nearly C．seldom D．always9．Grace is pretty healthy because she __D__ exercises and eats a lot of vegetables.(2014，杭州)A．never B．hardly C．sometimes D．often10．Tomorrow is Anna's birthday.Her mother is going to make a __A__ meal for her.(2014，杭州)A．big B．common C．quick D．simple11．—How __A__ Li Ming writes！(2014，黔东南)—Yes，he is the ________ in our class.A．carefully；most careful B．careful；most carefulC．carefully；careful D．careful；careful12．Some of the tired students keep their eyes __C__ in breaks.(2014，平凉)A．opened B．close C．closed D．open13．Many students say that if there were no examinations they should have __D__ at school.(2014，平凉)A．the happiest time B．a more happier timeC．much happiest time D．a much happier time14．—We've no money and the last bus has gone.Any __B__ ideas?—Oh，Tom'll drive home from work at this time.Ask him for a ride？(2014，武汉)A．funny B．bright C．opposite D．correct15．Steve isn't as __C__ as Kelly.He often makes mistakes in his writing.(2014，衢州)A．careless B．tidyC．careful D．difficult16．My grandfather is over 80，but he is still in good health and stays __D__．(2014，嘉兴)A．safe B．warm C．awake D．active17．—Do you like eating fish，Wang Han？(2014，嘉兴)—Of course.Nothing can be __C__，I think.A．delicious B．beautifulC．more delicious D．more beautiful18．__C__ you study，________ grades you'll get.(2014，贺州)A．The hard；the good B．Harder；betterC．The harder；the better D．The hardest；the best19．Take care when you are driving，__B__ in a summer storm like this.(2014，广东)A．immediately B．especiallyC．probably D．recently20．—The song Where did the time go？tells us that our parents grow old without being noticed.—We should stay with them as __A__ as possible.(2014，山西)A．often B．soon C．little21．The cakes taste __A__，and they sell ________.I will buy some.(2014，绥化)A．good；well B．well；well C．well；good22．We are so glad to see Meizhou is developing __A__ these years than it did before.(2014，梅州)A．more quickly B．the more quicklyC．most quickly D．the most quickly23．—Which season do you like __B__，winter or summer?—Summer.(2014，北京)A．well B．betterC．best D．the best24．—He was chosen to be a volunteer of the Olympic Games.(2014，鄂州)—Great！No one speaks English __D__ him.A．as beautiful as B．as badly asC．worse than D．better than25．I hear they are going to London，but I don't know __C__ they will stay there.(2014，呼和浩特)A．how soon B．how oftenC．how long D．how fast26．—Excuse me，would you please speak a little more __D__？(2014，滨州)—Sorry，I thought you could follow me.A．sadly B．quickly C．politely D．slowly27．To my surprise，my brother can speak English __B__．(2014，威海)A．lively B．perfectlyC．badly D．friendly28．—Why do people there __A__ use umbrellas in the sun？(2014，福州)—Because they would rather enjoy the sunshine.A．hardly B．often C．always29．Mr Black used to be busy.But now he's retired and __C__，so he has plenty of time to exercise.(2014，连云港)A．hard B．calmC．free D．nervous30．Lucy is a(n) __D__ student，she answers the teacher's questions ________ in her class.(2014，陕西)A．more active；more activelyB．active；more activelyC．more active；the most activelyD．active；the most actively31．We'd better not eat too much __C__ food because it's not only bad for our teeth，but also makes us fat easily.A．tasty B．delicious C．sweet D．cheap32．—These days I have always felt stressed.—You can ask Mrs Lee for help.It's __D__ for her to solve your problem.A．necessary B．usefulC．important D．possible33．—Are you __A__，Mike?—Yes，Mom.Could you please get me some water?A．thirsty B．tired C．hungry D．sick34．I think my hometown is becoming __C__．A．more beautiful and more beautifulB．more and more cleanerC．more and more beautifulD．clean and clean35．—Is there __A__ about this place?—Yes.All the houses here are green.A．anything special B．special anythingC．nothing special D．special nothing36．The experiment was __C__ easier than we had expected.A．more B．much moreC．much D．more much37．All the children are talking and laughing in the living room，so it is __B__．A．small B．noisy C．quiet D．big38．Canada is larger than __B__ country in North America.A．any B．any otherC．other D．other any39．John was so sleepy that he could hardly keep his eyes __D__．A．opening B．be opened C．to open D．open40．—Jack，do you think time is money?—Yes，but I think it is __C__ money.A．no important as B．not important asC．more important than D．much important than41．It takes a long time to by train，it's __D__ by boat.A．quick B．the quickestC．much quick D．quicker42．—It's one of the __A__ things in the world to stay with friends.—I agree with you.It always makes us comfortable.A．happiest B．worstC．busiest D．hardest43．—__A__ is your sister now?—She is much better.A．How B．What C．Where D．Who44．She always finish her homework on time.She __B__ leaves it till tomorrow. A．always B．neverC．usually D．sometimes45．—Hi，Bob！I can't find my history book.Have you seen it __D__？—Sorry，I haven't.A．somewhere B．everywhereC．nowhere D．anywhere46．The bag of rice is __A__ heavy for the little boy to carry.Let's go and help him. A．so B．such C．even D．just47．How __D__ the girls are playing！I really want to join them.A．happy B．happier C．happiest D．happily48．—Our teacher wants us to be __B__ when we talk with the foreigners.—Yes，we should believe in ourselves.A．comfortable B．confidentC．unusual D．energetic49．—Can I help you?—Well，I'm afraid the box is __D__ heavy for you，but thank you all the same.A．so B．much C．very D．too50．—Terra，you shouldn't be so __C__，you always leaves your things here and there. —Sorry，mom.I'll put them away soon.A．terrified B．cheerfulC．careless D．frightened。
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2.如果命题 p : x 1 y 2 0 ，命题 q : x 1 y 2 0 ，那么命题 p 是命题 q 的（ ）.
A.充分不必要条件 C.充要条件
B.必要不充分条件 D.既不充分也不必要条件
π
3.要得到函数
y
cos
2x
3
的图像只需将
y
cos 2x
的图像（
）.
π
A.向右平移 个单位长度
.
D1 C1
A1
B1
Q
D A
C B
2
A. 5
B. 2 5
C. 4
D. 2 3
x2 2x, x0
6.函数 f x
的零点个数为 （ ）.
1 ln x, x 0
A. 4
B. 3
C. 2
D.1
7.已知函数 y f x 是在闭区间0, 2 上单调递增的偶函数，设 a f 2 ,b f 0 , c f 1 ，则
（ ）.
1
A. b c a
B. a b c
C. a c b
D. c b a
8. 在 R 上定义运算 a b a 1 b ．若不等式 x y x y 1 对于任意实数 x 恒成立，则实数 y
的取值范围是（ ）.
A. 0, 2
B. 1,1
C.
3 2
,
1 2
D.
1 3
2
,
2
二、填空题：本大题共 6 小题，每小题 5 分，共 30 分. 把答案填在题中的横线上.
11.若双曲线
a2
y2
b2
1a 0,b 0 与抛物线 y2
2 bx 有一个交点为
3
3,
2 ,则此双曲线的离心率
为___________．
b
c
21
12. 在 △ABC 中， a,b, c 分别为角 A, B,C 的对边，若
，且 cos A ,b ，则 a 的
cos B cos C
32
值为___________．
13.在△ABC 中， BD 2CD ，若 AD AB AC ，则 4 ___________．
14. 在正方体 ABCD A1B1C1D1 中，点 Q 是 CC1 的中点，点 F 是侧面 BCC1B1 内的动点且 A1F∥平面
AD1Q ，则 A1F 与平面 BCC1B1 所成角的正切值的取值范围为
3
π
B.向左平移 个单位长度
3
π
C.向右平移 个单位长度
6
π
D.向左平移 个单位长度
6
4.某程序框图如图所示，程序运行后，输出 s 的结果是（ ）.
开始
i=1 ,s=0
否 i <20 ?
是
i=i+2
输出s
s=s+i
结束
A.143
2 的直线与圆 x2 y2 6x 2 y 1 0 交于 A, B 两点，则 AB 的最小值是（ ）.
限时训练（二十五）
一、选择题：本大题共 8 小题，每小题 5 分，共 40 分. 在每小题给出的四个选项中，只有一项是符合 题目要求的.
1.已知 a i1 i b ，其中 i 为虚数单位，则实数 a,b 的值分别为（ ）.
A. a 1,b 1
B. a 1,b 2
C. a 1,b 1
D. a 1,b 2
9.已知集合 A x x2 5x 6 0 , B x x2 2x 8 0 ，则 A B ___________．
x 3y 30 10.若变量 x，y 满足约束条件 2x y 3 0 ，则 z x y 的最大值为____________.
x y 1 0
x2