【附20套中考模拟试卷】广东省东莞市长安实验中学2019-2020学年中考化学模拟试卷含解析
【附15套中考模拟试卷】广东省东莞市长安中学2019-2020学年中考物理模拟试卷含解析
广东省东莞市长安中学2019-2020学年中考物理模拟试卷一、单选题（本大题共10小题，共30分）1．物块A静止在粗糙程度均匀的水平桌面上，如图甲所示，物块A受到水平拉力F作用，拉力F随时t 开始，每隔2s记录物块A的位置（用“·”表示物块A），如图间t的变化关系如图乙所示．小丽从0丙所示．下列说法正确的是A．0～2s内，物块所受摩擦力为6NB．8～l0s内，物块所受摩擦力小于9Ncm sC．l0～14s内，物块的平均速度为11/D．若18s时撤去F，物块将做匀速直线运动2．如图为自动垂直升降式车库的停车过程示意图．下列关于汽车匀速上升时的说法，正确的是（）A．动能增加，重力势能不变B．动能增加，重力势能增加C．动能不变，重力势能不变D．动能不变，重力势能增加3．如图，沿同一条直线向东运动的物体A、B，其运动相对同一参考点O的距离S随时间t变化的图象，以下说法正确的是（）①两物体由同一位置O点开始运动，但物体A比B迟3s才开始运动②t=0时刻，A在O点，B在距离O点5m处③从第3s开始，vA＞vB，5s末A、B相遇④5s内，A、B的平均速度相等A．只有①④正确B．只有③④正确C．只有①③正确D．只有②③正确4．如图是一种自动测定油箱内油面高度的装置，R是转动式滑动变阻器，它的金属滑片P是杠杆的一端，下列说法正确的是（）A．电路中R和R0是并联的B．油量表是由电流表改装而成的C．油位越高，流过R的电流越大D．油位越低，R两端的电压越小5．在水平桌面上，有两个完全相同的圆柱形容器甲和乙，内盛相等质量的同种液体．将体积相同、材料不同的两个小球A和B分别放入容器中，A球漂浮，B球悬浮，如图所示．两球在两容器中所受的浮力分别为F甲和F乙，两容器底部对桌面的压强分别为p甲和p乙,则下列关系中正确的是A．F甲＞F乙p甲＜p乙B．F甲＜F乙p甲＞p乙C．F甲＜F乙p甲＜p乙D．F甲＞F乙p甲＞p乙6．如图所示，电源电压不变，先闭合S1，再闭合S2，下列说法正确的是（）A．电压表、电流表示数均变小B．电压表示数变大，电路总功率变大C．电压表示数不变，总电阻变小，电流表示数变大D．电压表与电流表示数的比值变大7．如图所示，坐在甲火车中的小华在车窗里看到乙火车的车头，过一会儿，她又在车窗里看到乙火车的车尾．若两火车车头朝向一致，下列关于它们运动情况的判断，不可能的是A．甲火车停在轨道上，乙火车向前运动B．两列火车均向前运动，但甲火车运动较慢C．两列火车均向后倒车，但甲火车运动较慢D．甲火车向后倒车，乙火车停在轨道上8．下列事例中，利用大气压作用的是（）A．小王用吸管将饮料吸入口中B．医生用针筒把药水推入病人肌肉中C．小李用图钉把地图钉在墙上D．深水潜水员要穿特制的抗压潜水服9．如图是正常家庭电路的一部分。
人教版2019-2020学年九年级中考模拟化学试题(II)卷
人教版2019-2020学年九年级中考模拟化学试题（II）卷姓名:________ 班级:________ 成绩:________一、单选题1 . 下列说法正确的是（）A．盐酸能使紫色石蕊试液变蓝B．浓硫酸盛放在烧杯中较长一段时间，溶质质量分数会变大C．固体氢氧化钠露置于空气中保存D．打开浓盐酸的试剂瓶，瓶口会飘出白雾2 . 丙氨酸的化学式为C3H7O2N，其分子结构如图所示，关于丙氨酸的叙述不正确的是（）A．丙氨酸是由四种原子构成的B．丙氨酸是一种化合物C．丙氨酸分子中C、H、O、N四种原子的个数比为3：7：2：1D．丙氨酸中氮元素与氢元素的质量比为2：13 . 构建模型是化学学习常用的方法。
如图为某化学反应的微观模拟示意图，请判断下列说法，不正确的是（）A．物质丙的化学式为H2B．x的数值为2C．该反应中分子和原子的种类都发生了改变D．反应前后氧元素的化合价发生了改变4 . 掌握化学用语是学好化学的关键。
下列化学用语与所表述的意义相符合的是（）①Fe2+——铁离子；②2Ca2+——2个钙离子；③O2——2个氧原子；④——钠离子；⑤2H2O——2个水分子；⑥2H——2个氢元素；⑦——氮气中氮元素的化合价为零A．①⑤⑦B．②③④⑥C．①②⑤⑦D．②⑤⑦5 . 下列物质的性质和用途，对应关系不正确的是A B C D物质铁干冰小苏打盐酸性质导热性升华吸热能与酸反应能与活泼金属反应用途制作铁锅人工降雨治疗胃酸过多除铁锈A．A B．B C．C D．D6 . 下图是某保健品标签的部分内容，下列有关说法错误的是（）A．该保健品的主要功能是补钙B．锌属于人体需要的微量元素C．维生素 D 对钙的吸收没有任何帮助作用D．严重胃溃疡患者最好慎用该药品7 . 下列实验能用如图表示的是A．向一定质量的硫酸铜溶液中加入铁粉B．常温下，向饱和的澄清石灰水中加入氧化钙C．向一定质量的稀硫酸中加入锌片D．常温下，向饱和的硝酸钾溶液中加入硝酸钾8 . 下表对部分化学知识的归纳完全正确的一组是（）A健康常识人体缺铁元素会导致缺铁性贫血二氧化碳属于空气污染物B生活常识热水瓶中水垢可用食醋除去肥皂水可区分硬水和软水C防治污染废旧电池不必集中回收处理工业“三废”处理达标后排放D安全常识电器着火用水扑灭进入深井前做灯火实验A．A B．B C．C D．D9 . 硼是作物生长必需的微量营养元素，硼元素的相关信息如图所示。
2019-2020学年初中化学化学实验专项训练模拟测试(含答案) (41)
XX中学2019-2020年初中化学中考复习2019-2020学年初中化学化学实验专项训练模拟测试学校：__________ 姓名：__________ 班级：__________ 考号：__________一、选择题1．下列变化一定发生了化学变化的是（）A．冰雪融化B．食物腐烂C．金桂飘香D．尘土飞扬2．（08临沂）下列变化属于物理变化的是（）A．钢铁生锈B．高粱酿酒C．蜡烛受热熔化D．用“84”消毒液消毒3．（08乐山）下图所示的家庭小实验中，主要发生物理变化的是（）制取明矾晶体净水自制汽水将鸡蛋壳放入醋中A．B．C．D．4．（08扬州）2008年3月22日是第十六个“世界水日”。
今年“世界水日”的主题是“涉水卫生”。
下列涉水的变化中没有化学变化的是（）A．海水晒盐B．太阳能光解水制氢气C．饮用水生产D．肥皂水区分硬水和软水5．下列所示的变化中，属于化学变化的是（）A BC D6．下列变化中，属于化学变化的是（）A．冰雪融化B．矿石粉C．蜡烛燃烧D．干冰升华7．根据所学化学知识判断，下列说法缺乏科学依据的是（）A．盛放酒精、浓氨水的瓶子要塞紧瓶塞B．可用汽油洗涤衣服上的油污C．可用硫酸铜作饮用水的消毒剂D．石墨可作干电池的电极材料8．下列物质的用途主要与它的物理性质有关的是（）A．氧气用于炼钢B．干冰用于人工降雨C．一氧化碳用于炼铁D．天然气用作清洁燃料9．（08宜昌）下列变化属于化学变化的是（）A．冰棒融化B．木材燃烧C．湿衣服晾干D．灯泡发光10．五水合硫酸铜（俗称胆矾）是一种蓝色晶体，化学式是CuSO4·5H2O，胆矾受热时易失去结晶水，成为白色的无水CuSO4，在工业上精炼铜、镀铜等都要用胆矾。
上述对胆矾的描述中，没有涉及到的是（）A．物理性质B．用途C．制法D．化学性质11．家庭厨房中常发生下列变化，其中属于物理变化的是（）A．食物腐败B．水沸腾 C．天然气燃烧D．菜刀生锈12．下列离子能在PH = 12的水溶液中大量共存的是（）A．SO42-、NO3-、K+、H+B．Na+、Cl-、OH-、Al3+C．Cl-、NO3-、K+、Na+ D．Ag+、Cl-、CO32-、K+13．下列物质的用途主要利用其化学性质的是（）A．用氦气填充气球B．用石墨作电极C．用水银填充温度计D．用氧气供呼吸14．下列变化中，发生了物理变化的是（）A．蜡烛燃烧 B．气球充气过多爆炸C．粮食酿酒 D．铜在潮湿的空气中生成铜绿15．下列过程只发生物理变化的是（）A．光合作用 B．酒精挥发 C．用食醋除水垢 D．用灼烧法鉴别羊毛和合成纤维16．（6分）构建知识网络是一种重要的学习方法。
广东省东莞市2019-2020学年第三次中考模拟考试化学试卷含解析
广东省东莞市2019-2020学年第三次中考模拟考试化学试卷一、选择题（本题包括12个小题，每小题3分，共36分．每小题只有一个选项符合题意）1．下列过程中不涉及化学变化的是（）A．高粱酿酒B．燃放烟花C．干冰升华D．牛奶发酵【答案】C【解析】A、高粱酿酒过程中有新物质酒精生成，属于化学变化；B、燃放烟花过程中有新物质二氧化碳生成，属于化学变化；C、干冰升华过程中只是状态发生改变，没有新物质生成，属于物理变化；D、牛奶发酵过程中有新物质生成，属于化学变化。
故选C。
点睛：解答时要分析变化过程中是否有新物质生成，若没有新物质生成属于物理变化，若有新物质生成属于化学变化。
2．下图为钠的原子结构示意图。
下列说法不正确的是A．钠原子的质子数为11 B．图中n的值为10C．钠在反应中易失去电子D．钠元素位于第三周期【答案】B【解析】在原子结构示意图中，圆圈内的数字为质子数；弧线表示电子层，弧线上的数字为该层上的电子数。
原子的化学性质主要由最外层电子数决定，当最外层电子数小于4时，反应中易失去电子成为阳离子；当最外层电子数大于4时，反应中易得到电子成为阴离子；原子核外只有一个电子层且电子数为2，或者最外层电子数为8的结构为稳定结构，不易得失电子。
同一原子中，质子数=核外电子数，所以A．钠原子的质子数为11 ，正确；B．图中n的值为8；C．钠在反应中易失去电子；D．在元素周期表中，原子的电子层数等于其周期数，钠元素位于第三周期；选B3．如图是甲、乙两种固体物质在水中的溶解度曲线，M、N两点分别表示甲物质的两种溶液。
下列说法不正确的是A．在一定温度范围内甲的溶解度大于乙的溶解度B．将甲，乙的t2°C饱和溶液降温到t1°C，甲、乙溶液中溶质质量分数相同C．从N转化到M:先将N降温再加入适量固体甲D．从M转化到N:先将M升温再将其蒸发掉部分水【答案】D【解析】【详解】A、由图可知，温度是t1°C时，甲乙物质的溶解度相等，温度小于t1°C时，乙物质的溶解度大于甲物质的溶解度，温度大于t1°C时，甲物质的溶解度大于乙物质的溶解度，故正确；B、甲乙的溶解度都随温度的降低而降低，故将甲，乙的t2°C饱和溶液降温到t1°C时，甲乙都是饱和溶液，都有晶体析出，该温度下二者的溶解度相同，故饱和溶液的溶质的质量分数相等，故正确；C、M点的温度小于N点的温度，溶解度大于N点的溶解度，故从N转化到M:先将N降温再加入适量固体甲，故正确；D、由图可知，M到N的过程中，溶质的质量分数降低，故过程中不能蒸发水，应该加入水，故错误。
广东省东莞市长安中学2019-2020年八年级下数学第一次月考模拟试卷1附答案
八下数学第一次月考模拟卷1测试时间：90分钟 学生姓名：________ 测试分数：______/100一．选择题（每小题2分，共20分）1.要使二次根式x －3有意义，则x 的取值范围是( )A ．x ＝3B ．x ＞3C ．x ≤3D ．x ≥32.下列二次根式中，最简二次根式是（ ）A. B. C. D.3.n ）2的平方根是（ ） A. 14 B. 12 C. 14± D. 12±4.下列计算正确的是( )A ．53－23＝2B ．22×32＝62 C.3＋23＝3 D ．33÷3＝35.若12x <<，则3x -+的值为（ ）A. 24x -B. 2C. 42x -D. 2-6．下列选项中，不能用来证明勾股定理的是( )A. B. C. D.7.如图，△ABC 中，AC =3，BC = 5，AD ⊥BC 交BC 于点D ，AD =125，延长BC 至E 使得CE =BC ，将△ABC 沿AC 翻折得到△AFC ，连接EF ，则线段EF 的长为（ ）A. 6B. 8C. 325D.3238.把－()A. B. C. D.9．如图，两正方形彼此相邻且内接于半圆，若小正方形的面积为16cm2，则该半圆的半径为（）A. )cmB. 9cmC.D. cm10．如图，长方体的底面边长分别为2cm和3cm，高为6cm. 如果用一根细线从点A开始经过4个侧面缠绕一圈达到点B，那么所用细线最短需要（ （A. 11cm C. (8＋)cm D. (7＋二．填空题（每小题4分，共24分）11．实数a在数轴上的位置如图所示，化简|a－1|＋（a－2）2＝________.12．如果实数m满足（m－2）2＝m＋1，且0<m<3，那么m的值为________．13．一个直角三角形的两条直角边长为6和8，则它的斜边上的高是________．14．如图所示,一段楼梯,高BC是3 m,斜边AC是5 m,如果在楼梯上铺地毯,那么至少需要地毯________.15．如图，在东西走向的铁路上有A（B两站（视为直线上的两点）相距36千米，在A（B 的正北分别有C（D两个蔬菜基地，其中C到A站的距离为24千米，D到B站的距离为12千米，现要在铁路AB上建一个蔬菜加工厂E，使蔬菜基地C（D到E的距离相等，则E站应建在距A站_____千米的地方．16．已知16－x2－4－x2＝22，则16－x2＋4－x2＝________．三．解答题（7小题，每小题8分，共56分）17.计算下列各题： (1)(48＋20)－(12－5) (2)48÷3－215×30＋(22＋3)2；18.(6分)已知y ＝2x －3＋3－2x －4，计算x －y 2的值．19.先化简，再求值：⎝⎛⎭⎫6x y x ＋3y xy 3－⎝⎛⎭⎫4y x y ＋36xy ，其中x ＝2＋1，y ＝2－1.20.如图，在四边形ABCD 中，AB ＝BC ＝1，CD ，DA ＝1，且∠B ＝90°.求：(1)∠BAD 的度数；(2)四边形ABCD 的面积(结果保留根号)（21.如图是“赵爽弦图”，其中ABH V 、BCG V 、CDF V和DAE V 是四个全等的直角三角形，四边形ABCD 和EFGH 都是正方形，根据这个图形的面积关系，可以证明勾股定理.设AD c AE a DE b ===，，，取102c a b =-=，．()1正方形EFGH 的面积为______，四个直角三角形的面积和为______；()2求2()a b +的值．22.如图（甲、乙两船从港口A 同时出发（甲船以30海里/时的速度向北偏东35°的方向航行（乙船以40海里/时的速度向另一方向航行（2小时后（甲船到达C 岛（乙船到达B 岛（若C（B 两岛相距100海里（则乙船航行的方向是南偏东多少度？23.观察下列各式：①2－25＝85＝225；②3－310＝2710＝3310；③4－417＝6417＝4417.(1)根据你发现的规律填空：5－526＝________＝________；(2)猜想n－nn2＋1(n≥2，n为自然数)等于什么，并通过计算证实你的猜想．八年级下学期数学第一次月考模拟卷1参考答案一．选择题：1-5：D B D D B 6-10：D A A C B二．填空题：11. 1 12.21 13. 4.8 14. 7m 15. 12 16. 32 三．解答题： 17解：(1)原式＝43＋25－23＋5＝23＋3 5.(4分)(2)原式＝43÷3－215×30＋(22)2＋2×22×3＋(3)2＝4－26＋8＋46＋3＝15＋2 6.18.解：∵2x －3≥0，解得x ≥32.又∵3－2x ≥0，解得x ≤32，∴x ＝32.(3分)当x ＝32时，y ＝－4. ∴x －y 2＝32－(－4)2＝－29219.解：∵x ＝2＋1>0，y ＝2－1>0，∴原式＝(6xy ＋3xy )－(4xy ＋6xy )＝－xy ＝－（2＋1）（2－1）＝－1.20．（1）135°；（2解析：（1）∵AB=BC=1，且∠B=90°，∴∠BAC=45°，，而DA=1，∴CD 2=AD 2+AC 2，∴△ACD 是直角三角形，即∠DAC=90°，∴∠BAD=∠BAC+∠DAC=135°；（2）∵S 四边形ABCD =S △ABC +S △ACD ，而S△ABC=12AB×BC=12，S△ACD=12AD×，∴S四边形ABCD=S△ABC+S△ACD=12（）21．4；96解：（1）∵HE=a﹣b=2，∴S正方形EFGH=HE2=4．∵AD=c=10，∴S正方形ABCD=AD2=100，∴四个直角三角形的面积和=S正方形ABCD﹣S正方形EFGH=100﹣4=96．故答案为：4；96；（2）由（1）可知四个直角三角形的面积和为96，∴4×12ab=96，解得：2ab=96．∵a2+b2=c2=100，∴（a+b）2=a2+b2+2ab=100+96=196．22．乙船航行的方向为南偏东55°.解析：由题意可知，在△ABC中，AC＝30×2=60，AB＝40×2=80，BC＝100，∴AC2=3600，AB2=6400，BC2=10000，∴AC2＋AB2＝BC2，∴∠CAB＝90°，又∵∠EAD=180°，∠EAC=35°，∴∠DAB＝90°－∠CAE＝90°－35°＝55°，∴乙船航行的方向为南偏东55°.23.解：(1)125265526(2)猜想：n－nn2＋1＝nnn2＋1.(4分)验证如下：当n≥2，n为自然数时，n－nn2＋1＝n3＋n n2＋1－nn2＋1＝n3n2＋1＝nnn2＋1。
广东省东莞市2019-2020学年第三次中考模拟考试语文试卷含解析
广东省东莞市2019-2020学年第三次中考模拟考试语文试卷一、选择题1．结合语境选词填空,恰当的一项是( )每一次成功,都需要无数次失败的 ,没有任何一次成功是的，经历过点点滴滴大大小小的磕绊,成功会一步步走来。
A．磨练一气呵成除非才B．历练顺理成章只有才C．锤炼水到渠成既然就D．锻炼理所当然如果就2．下列文化常识中，正确的一项是( )A．“四书”指《大学》《春秋》《论语》《孟子》, “五经”指《诗》《书》《礼》《易》《中庸》。
B．《诗经》是我国最早的一部诗歌总集，收录了从东周到春秋时期的诗歌305篇。
C．及笄指女子15岁把头发簪起来，弱冠指男子20岁行成年礼束发戴冠，均表示已成年。
D．社是谷神，稷是土地神。
封建君主祭社稷，祈求丰年。
后把社稷作为国家的代称。
3．依次填入下列横线处的词语，最恰当的一项是（）关公崇拜起源于荆州，也寄寓着荆州人民对关羽的特殊感情。
关公是“义”的化身，在他身上，我们看到了守土报国的________，也看到了治军安民的________；看到了扶危济困的________，也看到了同生共死的________。
A．仁义侠义情义忠义B．忠义仁义侠义情义C．情义忠义仁义侠义D．侠义情义忠义仁义4．下列句子中没有语病的一项是( )A．为了避免今后再发生类似的事故，我们应当严格遵守交通规则。
B．非常雪白的墙壁，晃得人的眼睛都睁不开。
C．刘老师虽然年过六十，而且身体很健康。
D．21世纪需要有科学文化的一大批知识分子去建设祖国5．阅读下面的文字，完成下列小题。
读书足以怡．情，足以傅．彩，足以长才。
其怡情也，；其傅彩也，；其长才也，。
炼达之士虽能分别处．理细事或一一判别枝节，然纵观统筹，全局策划，则舍好学深思者莫属。
读书费时过多易惰，文采藻饰太盛则矫，全凭条文断事乃学究故态。
读书补天然之不足，经验又补读书之不足，盖天生才干犹如自然花草，读书然后知如何修剪移接；而书中所示，如不以经验范之，则又大而无当。
2024年广东省东莞市长安实验中学中考数学三模试卷(含详解)
2024年广东省东莞市长安实验中学中考数学三模试卷一.选择题（本大题10小题，每小题3分，共30分）1．（3分）4的平方根是（ ）A．±2B．﹣2C．2D．2．（3分）若|x+3|+（y﹣2）2＝0，那么x y的值为（ ）A．6B．﹣6C．9D．﹣93．（3分）已知单项式3x m+2y与x3y n﹣1是同类项，则m﹣n的值为（ ）A．1B．﹣1C．3D．﹣34．（3分）如图，数轴上表示﹣的点可能是（ ）A．点E B．点F C．点G D．点H5．（3分）已知方程x2﹣3x+1＝0的两根是x1，x2，则x1+x2+x1•x2的值是（ ）A．1B．2C．3D．46．（3分）不等式组的解集在数轴上表示正确的是（ ）A．B．C．D．7．（3分）从甲、乙、丙三名男生和A、B两名女生中随机选出一名学生参加问卷调查，则选出女生的可能性是（ ）A．B．C．D．8．（3分）如图是某平台销售的折叠椅子及其左视图，已知∠DAB＝60°，CD与地面AB平行，则∠CDE ＝（ ）A．60°B．75°C．110°D．120°9．（3分）如图，△ABC与△DEF位似，点O是它们的位似中心，其中OA＝AD，则△ABC与△DEF的面积之比是（ ）A．1：2B．1：4C．1：3D．1：910．（3分）如图，在直角坐标系中，正方形OABC的顶点O与原点重合，顶点A、C分别在x轴、y轴上，反比例函数y＝（k≠0，x＞0）的图象与正方形的两边AB、BC分别交于点E、F，FD⊥x轴，垂足为D，连接OE、OF、EF，FD与OE相交于点G．下列结论：①OF＝OE；②∠EOF＝60°；③四边形AEGD与△FOG面积相等；④EF＝CF+AE；⑤若∠EOF＝45°，EF＝4，则直线FE的函数解析式为y＝﹣x+4+2．其中正确结论的个数是（ ）A．2B．3C．4D．5二.填空题（本大题5小题，每小题3分，共15分）11．（3分）分解因式：a2﹣a＝ ．12．（3分）若代数式a+5b的值为3，则代数式7﹣a﹣5b的值为 ．13．（3分）若点A（﹣1，y1），B（3，y2）在抛物线y＝（x﹣2）2+k上，则y1，y2的大小关系为 （用“＞”连接）．14．（3分）如图，点O是正五边形ABCDE的中心，连接OC、OE、CE，则∠OCE的度数为 °．15．（3分）学了圆后，小亮突发奇想，想到用这种方法测量三角形的角度：将三角形纸片如图放置，使得顶点C在量角器的半圆上，纸片另外两边分别与量角器的半圆交于A，B两点．点A，B在量角器半圆上对应的读数分别是72°，14°，这样小明就能得到∠C的度数，请你帮忙算算∠C的度数是 ．三.解答题（一）（本大题2小题，每小题5分，共10分）16．（5分）解方程组：．17．（5分）如图，矩形ABCD．（1）尺规作图：作∠BAD的角平分线AE，交BC于点E（保留作图痕迹，不写作法）；（2）在（1）的条件下，连接DE，若AD＝3，AB＝2，写出DE长为 ．四、解答题（二）（本大题2小题，每小题7分，共14分）18．（7分）先化简，再求值：，其中x＝7．19．（7分）某学校学生的数学期末总评成绩由开学考试成绩、期中考试成绩、期末考试成绩三部分组成．小明与小红三项得分如表（单位：分）：姓名期末考试期中考试开学考试平均得分方差小明879093906小红898992①②（1）将表格中空缺的数据补充完整．（2）如果学校认为这三个项目的重要程度有所不同，而给予“期末考试”“期中考试”“开学考试”三个项目在期末总评成绩中所占的比例分别为50%，30%，20%，那么谁的最终成绩更高？请说明理由．五、解答题（三）（本大题3小题，每小题9分，共27分）20．（9分）如图，有长为30m 的篱笆，一面利用墙（墙的最大可用长度为10m ），围成中间隔有一道篱笆（平行于AB ）的矩形花圃．设花圃的一边AB 为x m ，面积为y m 2．（1）若要围成面积为63m 2的花圃，则AB 的长是多少？（2）求AB 为何值时，使花圃面积最大，并求出花圃的最大面积．21．（9分）【综合与实践】要测量学校旗杆CD 的高度，三个数学研究小组设计了不同的方案，测量方案与数据如表：课题测量学校旗杆的高度测量工具测量角度的仪器，皮尺，小镜子，直角三角形纸板等测量小组第一小组第二小组第三小组测量方案示意图说明利用镜子反射测量旗杆的高度，点O为镜子，眼睛B看到镜子中的旗杆顶端C．先测量观测台EA的高，再在观测点E处测得旗杆顶端C点的仰角∠CEF，旗杆底端D点的俯角∠DEF．（其中EF⊥CD于F）利用直角三角形纸板的直角边AE保持水平，并且边AE与点M在同一直线上，直角三角板的斜边AF与旗杆顶端C在同一直线上．测量数据AO＝1.5m，AD＝16.5m．EA＝2.2m，∠CEF＝60°，∠DEF＝30°．AE＝0.4m，EF＝0.2m，AB＝1.8m．（1）根据测量数据，无法计算学校旗杆的高度的小组有第 小组和第 小组；（2）请选择其中一个可计算的方案及运用其数据求学校旗杆的高度．22．（9分）如图，在等腰△ABC中，AB＝AC．点D是BC边上的动点，连结AD，将△ADC绕点A旋转至△AEB，使点C与点B重合，连结DE交AB于点F．作EG∥BC交AB于点G，连结CG，交AD于点H．（1）求证：∠1＝∠2；（2）求证：△AGH∽△AFD．六、解答题（四）（本大题2小题，每小题12分，共24分）23．（12分）如图，AB，CD是⊙O的两条直径，且AB⊥CD，点E是上一动点（不与点B，D重合），连接DE并延长交AB的延长线于点F，点P在AF上，且∠1＝∠2，连接AE，CE分别交OD，OB 于点M，N，连接AC，设⊙O的半径为10．（1）求证：PE是⊙O的切线；（2）当∠DCE＝15°时，求证：AM＝2ME；（3）在点E的移动过程中，判断CN•CE是否为定值，若是，求出该定值；若不是，请说明理由．24．（12分）如图，抛物线y＝ax2+bx+3与x轴交于A（﹣3，0），B（1，0）两点，与y轴交于点C．（1）求抛物线的解析式；（2）如图1，点P是直线AC上方抛物线上的动点，过点P作PE∥x轴交直线AC于点E，作PF∥y 轴交直线AC于点F，求E，F两点间距离的最大值；（3）如图2，连接BC，在抛物线上存在点Q，使∠QAC+∠OCB＝45°，请直接写出符合题意的点Q 坐标．参考答案与试题解析一.选择题（本大题10小题，每小题3分，共30分）1．（3分）4的平方根是（ ）A．±2B．﹣2C．2D．【解答】解：4的平方根是：±＝±2．故选：A．2．（3分）若|x+3|+（y﹣2）2＝0，那么x y的值为（ ）A．6B．﹣6C．9D．﹣9【解答】解：根据题意得，x+3＝0，y﹣2＝0，解得x＝﹣3，y＝2，∴x y＝（﹣3）2＝9．故选：C．3．（3分）已知单项式3x m+2y与x3y n﹣1是同类项，则m﹣n的值为（ ）A．1B．﹣1C．3D．﹣3【解答】解：若单项式3x m+2y与x3y n﹣1是同类项，则m+2＝3，n﹣1＝1，所以m＝1，n＝2，所以m﹣n＝1﹣2＝﹣1，故选：B．4．（3分）如图，数轴上表示﹣的点可能是（ ）A．点E B．点F C．点G D．点H 【解答】解：﹣≈﹣1.732．即在﹣1与﹣2之间，∴点E有可能为对应点．故选：A．5．（3分）已知方程x2﹣3x+1＝0的两根是x1，x2，则x1+x2+x1•x2的值是（ ）A．1B．2C．3D．4【解答】解：∵x2﹣3x+1＝0的两根是x1，x2，∴x1+x2＝3，x1•x2＝1，∴x1+x2+x1•x2＝3+1＝4．故选：D．6．（3分）不等式组的解集在数轴上表示正确的是（ ）A．B．C．D．【解答】解：解不等式3x﹣1≤2，得：x≤1，解不等式x+2＞0，得：x＞﹣2，则不等式组的解集为﹣2＜x≤1，故选：A．7．（3分）从甲、乙、丙三名男生和A、B两名女生中随机选出一名学生参加问卷调查，则选出女生的可能性是（ ）A．B．C．D．【解答】解：∵共有甲、乙、丙三名男生和A、B两名女生，∴随机选出一名学生参加问卷调查，则选出女生的可能性＝．故选：B．8．（3分）如图是某平台销售的折叠椅子及其左视图，已知∠DAB＝60°，CD与地面AB平行，则∠CDE ＝（ ）A．60°B．75°C．110°D．120°【解答】解：由题意知，CD∥AB，∴∠CDA＝∠DAB＝60°，∴∠CDE＝180°﹣∠CDA＝120°，故选：D．9．（3分）如图，△ABC与△DEF位似，点O是它们的位似中心，其中OA＝AD，则△ABC与△DEF的面积之比是（ ）A．1：2B．1：4C．1：3D．1：9【解答】解：∵OA＝AD，∴OA：OD＝1：2，∵△ABC与△DEF位似，∴△ABC∽△DEF，AB∥DE，∴△AOB∽△DOE，∴＝＝，∴△ABC与△DEF的面积之比为1：4，故选：B．10．（3分）如图，在直角坐标系中，正方形OABC的顶点O与原点重合，顶点A、C分别在x轴、y轴上，反比例函数y＝（k≠0，x＞0）的图象与正方形的两边AB、BC分别交于点E、F，FD⊥x轴，垂足为D，连接OE、OF、EF，FD与OE相交于点G．下列结论：①OF＝OE；②∠EOF＝60°；③四边形AEGD与△FOG面积相等；④EF＝CF+AE；⑤若∠EOF＝45°，EF＝4，则直线FE的函数解析式为y＝﹣x+4+2．其中正确结论的个数是（ ）A．2B．3C．4D．5【解答】解：①S△OCF＝S△AOE＝k，而OC＝OA，故CF＝AE，又∠OCF＝∠OAE＝90°，∴△OCF≌△OAE（SAS），∴OF＝OE；故①正确，符合题意；②由①知，OF＝OE，而EF不一定和OE或OF相等，即△EFO不一定是等边三角形，故∠EFO不一定等于60°，故②不一定正确，不符合题意；③四边形AEGD的面积＝S△AEO﹣S△ODG＝k﹣S△ODG，△FOG面积＝S△ODF﹣S△ODG＝k﹣S△ODG，故四边形AEGD与△FOG面积相等，故③正确，符合题意；④将△OAE绕点O旋转到OCE′时，即CE′＝AE，若∠EOF＝45°，则∠EOA+∠FOC＝45°，故∠FOE′＝∠E′OC+∠FOC＝45°＝∠EOF，而OE＝OE′，FO＝FO，∴△FOE′≌△FOE（SAS），∴EF＝E′F＝CF+CE′＝AE+CF，即当∠EOF＝45°时，才有EF＝CF+AE成立，故④错误，不符合题意；⑤若∠EOF＝45°，由④得EF＝CF+AE，由①知CF＝AE＝EF＝2，则BF＝BE，故△BEF为等腰直角三角形，则BE＝BF＝EF＝2，则OA＝AB＝AE+BE＝2+2，故点E的坐标为（2+2，2），∵△BEF为等腰直角三角形，故∠BFE＝45°，故设直线EF的表达式为：y＝﹣x+b，将点E的坐标代入上式并解得：b＝4+2，故直线FE的函数解析式为y＝﹣x+4+2，故⑤正确，符合题意，故正确的为①③⑤，故选：B．二.填空题（本大题5小题，每小题3分，共15分）11．（3分）分解因式：a2﹣a＝ a（a﹣1） ．【解答】解：a2﹣a＝a（a﹣1）．12．（3分）若代数式a+5b的值为3，则代数式7﹣a﹣5b的值为 4 ．【解答】解：由题意得，a+5b＝3，∴7﹣a﹣5b＝7﹣（a+5b）＝7﹣3＝4，故答案为：4．13．（3分）若点A（﹣1，y1），B（3，y2）在抛物线y＝（x﹣2）2+k上，则y1，y2的大小关系为 ＞ （用“＞”连接）．【解答】解：由抛物线的解析式可知，抛物线的开口向上，且对称轴为直线x＝2，所以抛物线上的点，离对称轴越远，其函数值越大．因为2﹣（﹣1）＝3，3﹣2＝1，且3＞1，所以y1＞y2．故答案为：＞．14．（3分）如图，点O是正五边形ABCDE的中心，连接OC、OE、CE，则∠OCE的度数为 18 °．【解答】解：如图，连接OD，∵点O是正五边形ABCDE的中心，∴∠COD＝∠DOE＝＝72°，在△COE中，OC＝OE，∠COE＝2∠COD＝144°，∴∠OCE＝＝18°．故答案为：18．15．（3分）学了圆后，小亮突发奇想，想到用这种方法测量三角形的角度：将三角形纸片如图放置，使得顶点C在量角器的半圆上，纸片另外两边分别与量角器的半圆交于A，B两点．点A，B在量角器半圆上对应的读数分别是72°，14°，这样小明就能得到∠C的度数，请你帮忙算算∠C的度数是 29° ．【解答】解：如图，设圆心为O，连接OA，OB，则∠AOB＝72°﹣14°＝58°，∴∠C＝∠AOB＝29°．故答案为：29°．三.解答题（一）（本大题2小题，每小题5分，共10分）16．（5分）解方程组：．【解答】解：，①×4+②得：11x＝22，解得：x＝2，把x＝2代入①得：4﹣y＝5，解得：y＝﹣1，则方程组的解为．17．（5分）如图，矩形ABCD．（1）尺规作图：作∠BAD的角平分线AE，交BC于点E（保留作图痕迹，不写作法）；（2）在（1）的条件下，连接DE，若AD＝3，AB＝2，写出DE长为 ．【解答】解：（1）如图所示；线段AE即为所求；（2）∵四边形ABCD是矩形，∴∠BAD＝90°，BC＝AD＝3，CD＝AB＝2，∵AE平分∠BAD，∴∠BAE＝∠DAE，∵AD∥BC，∴∠DAE＝∠AEB，∴∠BAE＝∠AEB，∴AB＝BE＝2，∴CE＝BC﹣BE＝1，∴DE＝＝＝，故答案为：．四、解答题（二）（本大题2小题，每小题7分，共14分）18．（7分）先化简，再求值：，其中x＝7．【解答】解：＝＝，当x＝7，原式＝＝2．19．（7分）某学校学生的数学期末总评成绩由开学考试成绩、期中考试成绩、期末考试成绩三部分组成．小明与小红三项得分如表（单位：分）：姓名期末考试期中考试开学考试平均得分方差小明879093906小红898992①②（1）将表格中空缺的数据补充完整．（2）如果学校认为这三个项目的重要程度有所不同，而给予“期末考试”“期中考试”“开学考试”三个项目在期末总评成绩中所占的比例分别为50%，30%，20%，那么谁的最终成绩更高？请说明理由．【解答】解：（1）由题意得，表格中①的值为：＝90；②的值为：[（89﹣90）2×2+（92﹣90）2]＝2；（2）小红的最终成绩更高，理由如下：小明的最终成绩为：87×50%+90×30%+93×20%＝89.1（分），小红的最终成绩为：89×50%+89×30%+92×20%＝89.6（分），因为89.6＞89.1，所以小红的最终成绩更高．五、解答题（三）（本大题3小题，每小题9分，共27分）20．（9分）如图，有长为30m的篱笆，一面利用墙（墙的最大可用长度为10m），围成中间隔有一道篱笆（平行于AB）的矩形花圃．设花圃的一边AB为x m，面积为y m2．（1）若要围成面积为63m2的花圃，则AB的长是多少？（2）求AB为何值时，使花圃面积最大，并求出花圃的最大面积．【解答】解：（1）x（30﹣3x）＝6330x﹣3x2＝633x2﹣30x+63＝0x2﹣10x+21＝0（x﹣3）（x﹣7）＝0．解得：x1＝3，x2＝7．当x＝3时，30﹣3x＝21＞10，不合题意，舍去；当x＝7时，30﹣3x＝9＜10，符合题意．答：若要围成面积为63m2的花圃，AB的长为7 m；（2）y＝x（30﹣3x）＝﹣3x2+30x＝﹣3（x2﹣10x+25）+75＝﹣3（x ﹣5）2+75．∵0＜30﹣3x ≤10，∴≤x ＜10．∴当x ＝时，y 最大．最大面积为：×（30﹣3×）＝（m 2）．答：AB 为m 时，花圃面积最大，花圃的最大面积为m 2．21．（9分）【综合与实践】要测量学校旗杆CD 的高度，三个数学研究小组设计了不同的方案，测量方案与数据如表：课题测量学校旗杆的高度测量工具测量角度的仪器，皮尺，小镜子，直角三角形纸板等测量小组第一小组第二小组第三小组测量方案示意图说明利用镜子反射测量旗杆的高度，点O 为镜子，眼睛B 看到镜子中的旗杆顶端C ．先测量观测台EA 的高，再在观测点E 处测得旗杆顶端C 点的仰角∠CEF ，旗利用直角三角形纸板的直角边AE 保持水平，并且边AE 与点M 在同一直线上，直角三角板的斜边AF杆底端D点的俯角∠DEF．（其中EF⊥CD于F）与旗杆顶端C在同一直线上．测量数据AO＝1.5m，AD＝16.5m．EA＝2.2m，∠CEF＝60°，∠DEF＝30°．AE＝0.4m，EF＝0.2m，AB＝1.8m．（1）根据测量数据，无法计算学校旗杆的高度的小组有第 一 小组和第 三 小组；（2）请选择其中一个可计算的方案及运用其数据求学校旗杆的高度．【解答】解：（1）第一，第三小组的数据无法算出大楼高度，理由：第一小组只测量了AO＝1.5m，AD＝16.5m，没有测量AB长度，所以第一小组的数据无法算出大楼高度，第三小组只测量了AE＝0.4m，EF＝0.2m，AB＝1.8m．没有测量线段EM或AM的长度，所以第三小组的数据无法算出大楼高度，故答案为：一，三；（2）第二小组的方案：在Rt△EFD中，∠EFD＝90°，∠DEF＝30°，DF＝AE＝2.2m，∴EF＝＝≈3.81（m），在Rt△EFC中，∠EFC＝90°，∠CEF＝60°，FC＝EF•tan∠CEF＝3.81×≈6.59（m），∴DC＝DF +FC≈8.8（m），答：学校旗杆的高度约为8.8m．22．（9分）如图，在等腰△ABC中，AB＝AC．点D是BC边上的动点，连结AD，将△ADC绕点A旋转至△AEB，使点C与点B重合，连结DE交AB于点F．作EG∥BC交AB于点G，连结CG，交AD于点H．（1）求证：∠1＝∠2；（2）求证：△AGH∽△AFD．【解答】证明：（1）∵EG∥BC，∴∠2＝∠ABC，∵AB＝AC，∴∠ACB＝∠ABC，由旋转的性质得到：∠1＝∠ACB，∴∠1＝∠2；（2）∵∠1＝∠2，∴EG＝EB，由旋转的性质得到：CD＝BE，∴EG＝CD，∵GE∥CD，∴四边形DCGE是平行四边形，∴GH∥FD，∴△AGH∽△AFD．六、解答题（四）（本大题2小题，每小题12分，共24分）23．（12分）如图，AB，CD是⊙O的两条直径，且AB⊥CD，点E是上一动点（不与点B，D重合），连接DE并延长交AB的延长线于点F，点P在AF上，且∠1＝∠2，连接AE，CE分别交OD，OB 于点M，N，连接AC，设⊙O的半径为10．（1）求证：PE是⊙O的切线；（2）当∠DCE＝15°时，求证：AM＝2ME；（3）在点E的移动过程中，判断CN•CE是否为定值，若是，求出该定值；若不是，请说明理由．【解答】（1）证明：连接OE，如图，∵CD为⊙O的直径，∴∠CED＝90°，∴∠OED+∠OEC＝90°，∵OC＝OE，∴∠2＝∠OCE，∴∠2+∠OED＝90°，∵∠1＝∠2，∴∠1+∠OED＝90°，∴∠OEP＝180°﹣∠OED﹣∠1＝180°﹣90°＝90°，∴OE⊥PE，∴OE为⊙O的半径，∴PE是⊙O的切线；（2）证明：∵∠DCE＝15°，∴∠DOE＝2∠2＝30°，∵AB⊥CD，∴∠AOD＝90°，∴∠AOE＝120°，∵OA＝OE，∴＝30°，∴，∠AMO＝90°﹣∠OAE＝60°，∵∠OMA＝∠DOE+∠OEM，∴∠OEM＝30°，∴∠OEM＝∠DOE＝30°，∴OM＝ME，∴AM＝2ME．（3）解：CN•CE是定值，为200，∵AB⊥CD，∴∠COB＝90°，∵∠CED＝90°，∴∠COB＝∠CED＝90°，∵∠OCE＝∠OCE，∴△CON∽△CED，∴，∴CN•CE＝CO•CD＝10×（2×10）＝200，∴CN•CE是定值，为200．24．（12分）如图，抛物线y＝ax2+bx+3与x轴交于A（﹣3，0），B（1，0）两点，与y轴交于点C．（1）求抛物线的解析式；（2）如图1，点P是直线AC上方抛物线上的动点，过点P作PE∥x轴交直线AC于点E，作PF∥y 轴交直线AC于点F，求E，F两点间距离的最大值；（3）如图2，连接BC，在抛物线上存在点Q，使∠QAC+∠OCB＝45°，请直接写出符合题意的点Q 坐标．【解答】解：（1）∵抛物线y＝ax2+bx+3与x轴交于A（﹣3，0），B（1，0）两点，∴，解得：，∴抛物线的解析式为y＝﹣x2﹣2x+3；（2）由抛物线的表达式知，点C（0，3），∴OC＝3，∵A（﹣3，0），∴OA＝3，∴OA＝OC，∴△CAO为等腰直角三角形，则∠ACO＝∠CAO＝45°，∵PE∥x轴，PF∥y轴，∴∠PFE＝∠ACO＝45°，∠PEF＝∠CAO＝45°，∴△PEF是等腰直角三角形，∴EF＝PF，由点A、C的坐标得：直线AC的表达式为：y＝x+3，设点P（x，﹣x2﹣2x+3），则点F（x，x+3），∴PF＝（﹣x2﹣2x+3）﹣（x+3）＝﹣x2﹣3x，∵﹣1＜0，故PF有最大值，当x＝﹣时，PF的最大值为：，则EF的最大值为：；（3）当点Q在AC下方时，如图，设AQ交y轴于点H，∵∠QAC+∠QAB＝45°，∠QAC+∠OCB＝45°，∴∠OCB＝∠QAB，∴tan∠OCB＝tan∠QAB，∴＝，即＝，∴OH＝1，则直线AH的表达式为：y＝（x+3），联立上式和抛物线的表达式得：﹣x2﹣2x+3＝（x+3），解得：x＝﹣3（舍去）或x＝，则点Q（，）；当点Q在AC上方时，如图，过点A作AM⊥x轴，使AM＝OA＝3，连接CM，在线段MC上截取MN＝1，连接AN，∵∠OAM+∠AOC＝90°+90°＝180°，∴AM∥OC，∵AM＝OC，∴四边形AOCM是平行四边形，∵∠AOC＝90°，∴四边形AOCM是矩形，则∠M＝90°＝∠BOC，∵MN＝OB＝1，∴△AMN≌△COB（SAS），∴∠MAN＝∠OCB，∵∠CAM＝90°﹣∠CAO＝45°，∴∠MAN+∠CAN＝45°，∵∠QAC+∠OCB＝45°，∴∠CAN＝∠QAC，∵A（﹣3，0），N（﹣2，3），∴直线AN的表达式为：y＝3（x+3），联立上式和抛物线的表达式得：﹣x2﹣2x+3＝3（x+3），解得：x＝﹣3（舍去）或﹣2，则点Q（﹣2，3）；综上，点Q的坐标为（，）或（﹣2，3）．。
2019-2020学年东莞市长安实验中学高三语文上学期期末考试试题及答案
2019-2020学年东莞市长安实验中学高三语文上学期期末考试试题及答案一、现代文阅读（36分）(一)现代文阅读I(9分)阅读下面的文字，完成下列小题。
两分硬币[日本]黑岛传治“妈妈，买根陀螺绳儿嘛。
”藤二缠起妈妈来了。
“问问爸爸，看叫买不。
”“说行哩。
”妈妈对所有的事情都很小气，一个原因是家里的日子难过。
尽管是答应给买了，还要把堆房翻腾一遍，看清楚是不是还有健吉玩旧的绳儿。
这沿河的小村庄的孩子们，都聚集到庙门前去，把新绳儿缠在新陀螺上使它转动起来，两个人一组撞陀螺，比输赢。
孩子们把这种玩法叫作“撞嘎嘎”。
缠好绳儿使劲一抽把陀螺撒出去，它就飞快地转动起来。
两个人一起撒，轮流让自己的陀螺去撞对方的，直到一方的陀螺停止转动，陀螺先停下来的就算输了。
“瞧，光俺一个人用这样又黑又旧的陀螺呢。
也给俺买个新的陀螺吧。
”藤二缠着妈妈。
“陀螺，不是有一个嘛，不买也行了。
”“这个，瞧，不都这么黑了吗？……人家都是新的！”“净说傻话，这个陀螺还不好！”健吉说，他深信自己从前用过的陀螺好，又舍不得拿钱给弟弟买陀螺。
“嗯。
”原来，藤二是哥哥说啥都相信的。
“这个陀螺好呀，不信跟他们比比看。
能够打败它的陀螺，谁也不会有的。
”说到这里，陀螺用旧的，算是说通了。
可一到跟妈妈两个人去买绳儿时，藤二又贪婪地摸弄起铺子里装在木盒中的涂得红红绿绿的新陀螺来了。
绳儿一共有几十条，都剪得一般长，其中只有一条比起别的来短那么一尺左右。
那是按尺码量着剪下来，最后剩了那么一条不足尺码的。
“多少钱一条哇？”“一条一角钱呀，那条短的就算您八分钱吧。
”“算八分钱……”“是啊。
”“那么，这条短的就好了。
”说着，妈妈拿出一角钱递给老板，被找回来两分钱硬币，就仿佛是赚了两分钱一样感到高兴。
直到妈妈催藤二回家，他还在玩弄那盒子里的新陀螺，看起来十分爱惜的样子。
然而，却也并没有硬逼着妈妈给他买，就跟着妈妈回来了。
邻村庙前的广场上，来了串乡的摔跤班子。
孩子们都结伴去看热闹。
2019-2020学年东莞市长安实验中学高三生物第二次联考试卷及答案
2019-2020学年东莞市长安实验中学高三生物第二次联考试卷及答案一、选择题：本题共15小题，每小题2分，共30分。
每小题只有一个选项符合题目要求。
1. 樱桃番茄(二倍体)的果实颜色多为红色，由3号染色体上的a基因控制。
研究人员在育种时发现一株结黄色果实的樱桃番茄，经分析确定这株番茄的3号染色体有三条，其他染色体正常，该植株的基因型为Aaa。
该植株进行减数分裂时，3号染色体中的任意两条发生配对并正常分离，第三条染色体随机移到细胞一极。
将该植株自交得F1。
下列相关叙述正确的是（）A.该植株可产生A、Aa、a、a四种配子，且数量比为1∶1∶1∶1B.F1中结黄色果实的植株中既有二倍体，也有三倍体和四倍体C.F1中结黄色果实的植株全是杂合子，结红色果实的植株全是纯合子D.若按体细胞染色体数目进行分类，则F1植株可分为3种类型2. 某兴趣小组对不同氧浓度下酵母菌的细胞呼吸方式及产物展开了研究，如图为测得的实验数据。
据图中信息推断，错误的是( )A.氧浓度为a时，酵母菌只进行无氧呼吸B.氧浓度为b和d时，酵母菌细胞呼吸方式不同C.氧浓度为c时，有2/5的葡萄糖用于有氧呼吸D.a、b、C、d四种氧浓度下，酵母菌都能产生[H]和ATP3. 腐乳和泡菜是我国独特的传统发酵食品，几百年来深受老百姓的喜爱。
腐乳是用豆腐发酵制成的，民间老法生产腐乳为自然发酵，现代腐乳生产多采用优良的毛霉菌种进行发酵。
现代化生产流程如图，请回答下列问题：（1）民间制作腐乳时毛霉来自__________。
（2）当豆腐上长出毛霉后，对豆腐要进行A处理，是指___________。
腐乳制作的后期要加入酒和多种香辛料配制的卤汤，其中酒的含量一般控制在12%左右，原因__________。
（3）泡菜制作过程中，乳酸发酵的过程即为乳酸菌进行__________的过程。
该过程发生在乳酸菌细胞的__________中。
（4）从开始制作到泡菜品质最佳这段时间内，泡菜液逐渐变酸，这段时间内泡菜坛中乳酸菌和其他杂菌的消长规律是__________，原因是___________。
2019-2020学年东莞市长安实验中学高三英语第三次联考试题及答案
2019-2020学年东莞市长安实验中学高三英语第三次联考试题及答案第一部分阅读（共两节，满分40分）第一节（共15小题；每小题2分，满分30分）阅读下列短文，从每题所给的A、B、C、D四个选项中选出最佳选项AThough online ordering is popular in the UK today，handson experience still attracts many buyers' attention.Oxford StreetLondon is a shoppers' paradise，and most visitors head for Oxford Street.Halfway along is Selfridges，one of the world's first department stores where the architecture and window dressing impress you even before you go in.There are at least four other major stores on this street，plus Europe's largest music shop.In December the atmosphere is especially festive because of the Christmaslights which are always lighted by a politician，a great sportsman，or a super star.Kensington High StreetA fashionable area for shopping is Kensington High Street.One of its department stores even has a roof garden—good for relaxing between purchases.There's also an organic food superstore.Borough MarketYou can't visit London without going to a supermarketOne of the oldest and best for food is probably Borough Market on the south bank of the Thames.Get off the underground at London Bridge and wander among fresh fish stalls，bakeries，and fruit and vegetable sellers.You can also buy specialities to take away，like cheeses，pork pies，mustard and chutney.More places for bargainsPortobello Road Market on a Saturday is your best choice for jewelry or collector's items.It's a shortwalk from the underground station at Notting Hill Gate and you never know what you will find.For clothes，Camden Market is the place.It gets a little crowded at the weekends，though.Convent Garden Market offers great experience for the simple pleasure of looking at jewelry and gifts.1.Oxford Street becomes special in December for ________.A.the wonderful window dressingB.the Europe's largest music shopC.the lights lighted by a famous personD.many bargains to choose from2.To enjoy food，you can goto ________.A.Camden MarketB.Borough MarketC.Kensington High StreetD.Portobello Road Market3.Where is this passage probably taken from?AA science book. B.A traveler's journal.C.A news report.D.A trip guide.BIsraeli Paintings—Israeli artist Menashe Kadishman will hold a personal show named "Flock of Sheep" from November 26 to December 20 at the China National Art Museum On show are 550 colourful oil paintings of sheep heads.His works have been on show inthe Metropolitan Museum in New York and Tate Gallery in London over the past 30 years.Time: 9: 00 a.m.—4: 00 p.m., November 26—December 20.Place: China National Art Museum, 1 Wusi Dajie, Dongcheng District, Beijing.Tel: 6401-2252Russian Ballet—The Kremlin Ballet from Russia will perform two immortal classical ballets—"Swan Lake" and "The Nutcracker"—at the Beijing Beizhan Theatre. Set up in 1990, the theatre has a number of first-class ballet dancers. Most of their performances are classical.Time: 7: 15 p.m., December 5 and 6 ("Swan Lake"); 7: 15 p.m., December 7 ("The Nutcracker")Place: Beizhan Theatre, Xiwai Dajie, Xicheng District, Beijing.Tel: 6605-3388Folk Concert—The Central Conservatory of Music will hold a folk concert in memory of the late musician Situ Huacheng.On the programme are many popular folks such as "Moon Night on the Bamboo Tower", "Celebrating Harvest", "Deep and Lasting Friendship", "Golden Snake Dances Wildly" and "Children's Holiday".Time: 7: 30 p.m., November 25.Place: Beijing Concert Hall, 1 Beixinhuajie, Xicheng District, Beijing.Tel: 6605-58124.If a child is very fond of dancing, his parents should take him to ________.A.China National Art MuseumB.Beizhan TheatreC.Beijing Concert HallD.1 Wusi Dajie5.Menashe Kadishman is well known for painting ________.A.deerB.birdsC.sheepD.flowers6.Which of the following is TRUE?A.The folk concert will last three days.B.The ballet "The Nutcracker" will be put on once.C.The Israeli paintings will be on show for a month.D.China National Art Museum lies in Xicheng District.7.If you dial the telephone number 6605-3388 on Dec. 8, you can ________.A.go to the folk concertB.visit the Art MuseumC.watch the balletD.none of the aboveCA smiling panda and a walking Chinese lantern will be the mascots of the 2022 Winter Olympics and Paralympics (残奥会）in Beijing .The mascots were known to the public on Sept.17, 2019 at a ceremony inBeijing. Beijing Mayor Chen Jining described them as adorable, unique , and exquisite (精致的）。
2019-2020学年东莞市长安实验中学高三英语第四次联考试卷及答案
2019-2020学年东莞市长安实验中学高三英语第四次联考试卷及答案第一部分阅读（共两节，满分40分）第一节（共15小题；每小题2分，满分30分）阅读下列短文，从每题所给的A、B、C、D四个选项中选出最佳选项AThe Fall 2020 Cookbooks Worth Your Time (and Money)Be My GuestFrom Priya Basil, this book is a self-reflection on how food and the act of serving it are used to express love and support. Basil reflects on some of her earliest memories of food and how it affected her upbringing and relationship with her parents. Now a parent herself, she centers food in her book's exploration of that change of identity.EastFrom Guardian columnist Meera Sodha comes a cookbook centered on vegetables. The book features recipes that cover a variety of Asian cuisines. Sodha showcases the diversity of vegetarian cooking with dishes like eggplant larb mushroom bao, Singapore noodles and so much more.I Cook in ColorA follow-up from her first cookbook My Two Souths, Asha Gomez focuses on the rainbow of vegetables to create desserts and cross-cultural dishes that associate cooking traditions of her mother's Keralite kitchen and Gomez's travel experiences.Time to EatIf you're a fan of The Great British Baking Show and Nadiya Hussain's Netflix series, you'll be just as excited for the American release of this book of time-saving tips for home cooks on a budget. It's a book to go to for inspiration that doesn't involve countless hours of sweating over a hot stove.1.What can we learn about the author ofBe My Guest?A.She had a bad relationship with her parents.B.She began to cook food in her early childhood.C.She considers food a means of expressing affection.D.She explores in the book how to be a grandparent.2.What do theEastandI Cook in Colorhave in common?A.They offer recipes about Asian cuisines.B.They center on cooking vegetables.C.They are the author's first cookbooks.D.They are based on the author's travel experiences.3.Which book can you refer toif you just have limited time for cooking?A.Be My Guest.B.East.C.I Cook in Color.D.Time to Eat.BJohn Montefiore's path to graduation from theUniversityofTorontowas a little unusual. He recently completed his bachelor's degree(学士学位) which he started in1995.Montefiore left university in 1996 and tried to tell himself that a degree wasn't necessary for personal success. But it remained unfinished businessuntil he made the decision to return in 2018 at the age 42. At that time, his job development stalled, so he made up his mind to go back to school in order to improve himself and work well in future.The second time around, Montefiore never missed a class and always sat in the front row. He found many courses invaluable and he received the Award of Excellence twice. He found support services played an important role in his successful return. He said, “I hadn't written a paper for years, so I found the college writing centre to be of great use. Before I handed in a paper, they would give me feedback, which was really great. The university has so much built in to help students succeed and I'm so thankful for that.” But he also met difficulties this time. As a student much older than others, he found it harder to make friends with classmates.However, no matter what had happened before, he finally got his bachelor's degree. He said, “After all these years, I had thought it wouldn't mean anything, but it means a lot. I totally understand the value of education now. It's not necessarily the value that other people see in it, but the value it gives me as a person, for my confidence and my self-esteem. It also helps me prepare well before I re-enter the workplace.”4. Why was Montefiore's graduation unusual?A. He had achieved personal success before.B. He understood the importance of a degree.C. He finished his degree at a much older age.D. He began his university study at a young age.5. What does the underlined word "stalled" in paragraph 2 probably mean?A. Stopped.B. Started.C. Survived.D. Succeeded.6. What can we learn about Montefiore from the third paragraph?A. He got good grades very easily.B. He took his study seriously this timeC. He was thankful for his classmates' helpD. He had difficulty using support services.7. What did Montefiore learn from his experience?A. Confidence is important in one's life.B. Others' opinions on education matter a lot.C. Higher education is a must for personal success.D. Education makes one feel better about himself.CSome of my earliest memories involve sitting with my dad in his study every evening when he came home from the office. I’d watch as he put his personal items away: his watch, wallet, comb and car keys would always occupy the same spot on the table every time.Dad’s comb was bought when he married Mum. Every evening, he would smile, hand me the comb and say: “Be a good girl and help Daddy clean it, OK?” I was more than happy to do it. This seems amundanetask, but it brought me such joy at that time. I would excitedly turn the tap on, then brush the comb with a used toothbrush as hard as I could. Satisfied that I’d done a good job, I would proudly return the comb to Dad. He would smile at me, and place the comb on top of his wallet.About two years later, Dad started his own business. I started primary school. That was when things started to change. Dad’s business wasn’t doing so well, and he didn’t come home as much as he used to. Over the years, I stopped waiting for him to come home.Today, I’ve graduated from college and Dad’s business are better now. Yet the uncomfortable silence between Dad and me continued. Two days before my birthday last year, Dad came home early and said to me, “Hey, would you like to help me clean my comb?” I looked at him a while, then took the comb and headed to the sink. It’s a new comb. I hadn’t noticed that he’d changed it. I brushed the comb, and it hit me then: why, as a child, helping my dad clean his comb was such a joy.I passed the clean comb back to Dad. This time, I noticed my day has aged. But his smile is still as heartwarming as before. Dad carefully places his comb on top of his wallet. After so many years, I guess some things never change. And for that, I’m glad.8. As a child, the author helped her dad clean his comb happily because ________.A. she was good at cleaning the combB. she thought that she should do that as a good girlC. her dad was home early to spend the evening with herD. the comb was important for her father and her mother9. Which of the following words can best replace the underlined wordmundanein paragraph two?A. importantB. excitingC. unnecessaryD. uninteresting10. When the author said, “It’s a new comb. I hadn’t noticed that he’d changed it.”, she felt ________.A. disappointedB. impatientC. tiredD. sorry11. What’s the best title of the passage?A. Evenings With Dad.B. How to Clean the Comb.C. My Memory with My Dad.D. I Love My Family Members.DIn the Pacific Northwest during winter, 5:15 am might as well be the dead of night. The alarm goes off and the onlylight is the red glow from my clock. My body says, “Go back to bed.” But I don’t. I know my running partner will be waiting in the street and I’m not going to stand her up. Then I walk onto the road, complaining about the cold and wishing I were back under my warm covers.If you’d have asked me a year ago if I could see myself running at 5:15 on a winter morning, I’d have laughed. Morning just wasn’t my thing and running in the morning was something I didn’t even consider. “I prefer to work out in the middle of the morning or in the afternoon,” I’d say to my friends who go to the gym before work.Then, last fall I reconnected with an old neighborhood friend. She’d been running in the morning and taken off forty pounds that year. When I looked in the mirror, I knew I could benefit from the same kind of weight loss. I asked if I could join her. I knew I needed to change something if I was going to get back in shape.The first two months were especially hard, because we ran twice a week at 5:15 am and I slept till 7:00 the other mornings. But as I’ve adjusted to the routine of running, I’ve discovered great joys that make it even more worthwhile than a little weight loss.While I haven’t lost forty pounds yet, it’s amazing how much more energy I have and how much stronger I feel. Because of the morning run, the rest of my day is more productive. I wouldn’t say I’ve become a morningperson, but I would say morning running is now my thing.12. What can we know about the author from paragraph 1?A. 5:15 is the ideal time for her to exercise.B. She prefers to run without any company.C. She takes the run with warm clothes on.D. She goes for a run in spite of the cold and early rise.13. What was the author’s attitude to morning running a year ago?A. Scared.B. Unfavorable.C. Supportive.D. Confused.14. What made the author begin to run in the morning?A. Her partner’s encouragement.B. Her friend’s suggestion.C. Realizing the benefits of running.D. Realizing the harm of being fat.15. What effect does morning runninghave on the author?A. She has become slim again.B. She has become more confident.C. She has become more energetic.D. She has become more exhausted.第二节（共5小题；每小题2分，满分10分）阅读下面短文，从短文后的选项中选出可以填入空白处的最佳选项。
2020年东莞市长安实验中学高三语文模拟试卷及答案解析
2020年东莞市长安实验中学高三语文模拟试卷及答案解析一、现代文阅读（36分）(一)现代文阅读I(9分)阅读下面的文字，完成下面小题。
汉字字序为什么从上至下汉字最初的行款应该是自由的，字序、行序并没有明确的规则。
如江苏吴县澄湖良渚古井出土的黑陶贯耳壶，腹部的4个字呈横斜状排列；而江苏高邮龙虬发现的刻文陶片，可以分为两组，4个字的那组应是竖排。
不过，这种自由式的行款在面临字数增多，或是有其他更高功能需求的记录时，不足就非常明显，新型的行款必然出现。
对新行款真正起关键作用的，应是新需求。
根据早期汉字的应用情况，我们不难猜测，它就是甲骨文占卜、竹简记录等活动。
所以，能对行款样式起主要作用的主要是两个方面：一是甲骨和竹简本身，二是活动性质的影响。
第一个方面的甲骨常被略去，因为甲骨本身对字序、行序没有多少约束；而竹简常受关注，学者们常从持简习惯、书写习惯等方面入手，认定竹简所起到的决定性作用。
然而，对于自上而下的字序，尤其是单简书写时，无论是“方便说”，或是“持简习惯说”，都略显牵强。
“方便说”认为，汉字字形便于竖写，所用的竹简宜于竖写，这是汉字书写的决定性条件。
但事实上，尚没有真正讲究书写顺序的初期汉字，是无所谓竖写横写的，这时候的书写是为字形服务，而非字形为书写服务。
而就竹简而言，客观上也没有明确的适宜横写或竖写，同样构不成竖写字序的决定性因素。
“持简习惯说”认为.古人应是席地而坐，左手持简，置于胸前，右手执笔而书。
正是持简的习惯性动作决定了字序的下行。
这个说法的前提条件是古人必须有竖向持简的习惯，而这其实是很难确定的。
正如北京大学教授李零所说：“我们最容易犯的错误，不是别的，就是‘以今人之心度古人之腹’。
”比如，甲骨是种不易写也不易刻的“不方便”材料，却被选为早期一个重要的书写载体，可见古人有时候对书写的目的更为重视，方便性反而是其次的。
这样，就剩下第二点，即活动本身。
它具有两个先天优势。
首先，地位优势。
2019-2020学年东莞市长安实验中学高三英语三模试卷及答案解析
2019-2020学年东莞市长安实验中学高三英语三模试卷及答案解析第一部分阅读（共两节，满分40分）第一节（共15小题；每小题2分，满分30分）阅读下列短文，从每题所给的A、B、C、D四个选项中选出最佳选项AUnique LighthousesAugust 7 is National Lighthouse Day. It's a day to celebrate the lights that guide us home and the historic importance of lighthouses and their keepers, who not only guided ships into harbor but also played key roles in naval battles across the globe. Check out these fantastic lighthouses across the globe as well as recommendations on the best places to stay near them.Cape Byron Lighthouse, Byron Bay, AustraliaThe Cape Byron Lighthouse in Byron Bay, Australia was built in the early 20th century to help protect the Australian coastline. Today, it's a beautiful location to watch the sunrise. Within walking distance is the Watermark, a perfect place to stay and get some much-needed rest and relaxation from daily life.Lighthouse of Chania, Crete, GreeceThe Lighthouse of Chania, Crete is one of the oldest surviving lighthouses in the world, dating back to the sixteenth century. Travelers can take a walk along its long pier (码头) during the sunset. Located near the pier to the lighthouse is a hotel from 1890, which offers beautiful views of the bay.Key West Lighthouse, Key West, Florida, USAThe Key West Lighthouse was built in 1825 to help guide ships entering the port. Travelers can enjoy climbing up the lighthouse to reach the wonderful sea views and can stay at the KimptonLighthouse Hotel, with easy access to the lighthouse and the Ernest Hemingway Home and Museum.Pigeon Point Lighthouse, Pescadero, California, USAThe Pigeon Point Lighthouse in Pescadero, California was built in1871 to help ships navigate (导航) the region's dangerous coastline. Today, the lighthouse is a state landmark, and the quarters where the lighthouse keepers lived have been turned into a hostel, making it a great home base to explore the outdoors, spot whales and watch the stars.1. Why is National Lighthouse Day celebrated?A. To show the hard life of lighthouse keepers.B. To instruct how to guide ships into harbor.C. To honor lighthouses and their keepers.D. To stress the importance of light.2. Of the following lighthouses, which is the oldest?A. Cape Byron Lighthouse.B. Lighthouse of Chania.C. Key West Lighthouse.D. Pigeon Point Lighthouse.3. What do the listed lighthouses have in common?A. They are all located in the USA.B. They have becometourist attractions.C. They offer accommodation to visitors.D. They are good spots to watch the sunrise.BIt is that time of year when people need to lock their cars. It’ s not because there are a lot of criminals running around stealing cars. Rather, it’ s because of the good-hearted neighbors who want to share their harvest. Especially with this year’s large crop, leaving a car unlocked in my neighborhood is an invitation for someone to stuff it full of zucchini(西葫芦).My sister-in-law, Sharon, recently had a good year for tomatoes. She and her family had eaten and canned so many that they began to feel their skin turn slightly red. That ’ s when she decided it was time to share herblessings.She started calling everyone she knew. When that failed, she began to ask everyone in the neighborhood like a politician, eventually finding a neighbor delighted to have the tomatoes. “ Feel free to take whatever you want,”Sharontold her. She felt happy that she could help someone and that the food didn’t go to waste.A few days later,Sharonanswered the door. There was the neighbor, holding some bread. The neighbor smiled pleasantly, “I want to thank you for all of the tomatoes, and I have to admit that I took a few other things and hope you wouldn’t mind.”Sharoncouldn’t think of anything else in her garden that had been worth harvesting and said so. “Oh, but you did,” the neighbor said. “You had some of the prettiest zucchini I’ve ever seen.”Sharonwas confused. Zucchini in her garden? They hadn’ t even planted any zucchini. But her neighbor insisted that there really were bright-green zucchini in her garden. The two of them walked together into the backyard. When the neighbor pointed at the long green vegetables,Sharonsmiled, “ Well, actually, those are cucumbers that we never harvested, because they got too big, soft and bitter for eating or canning.”The neighbor looked atSharon, shock written all over her face. Then she smiled, and held out the bread that she had shared all over the neighborhood, “I brought you a loaf of cucumber bread. I hope you like it.”4. Why does the author suggest that people in the neighborhood should lock their cars?A. They might be stolen by thieves.B. They might be moved away by the police.C. Their neighbors might fill them with their harvest.D. Their neighbors might throw rubbish in them.5. What does the underlined word “blessings” in the second paragraph mean?A. Tomatoes.B. God’s protection.C.Helpful things.D. Best wishes.6. What did the neighbor do inSharon’s garden?A. She harvested tomatoes only.B. She harvested zucchini by accident.C. She took some cucumbers mistakenly.D. She stole something withoutSharon’s permission.7. We can infer from the article that the neighbor’s bread would taste________.A. bitter but tastyB. strange and bitterC. hard and sourD. soft and sweetC“Heavy hearts, like heavy clouds in the sky, are best relieved by the letting of a little water, the French writer Antoine de Rivarol wrote. This love letter to the cleansing beauty of a good cry is a comforting thought at atime when the continuing stress of the COVID-19 has added heaviness to each of our lives.Scientifically, de Rivarol's poetic image doesn't, if you'll forgive the words used in the poem, hold water. There's limited research on crying, partly because of the difficulty of copying the behavior of real crying in a lab. But even within the previous studies, there's little evidence to suggest that crying provides a physiological cleansing of poisons in people's body.Psychologists believe the relief of a good cry connects with a different emotional process. “It seems that crying occurs just after the peak of the emotional experience, and crying is associated with this return to homeostasis: the process of maintaining a stable psychological state,” said Lauren Bylsma. He also said holding back tears can have negative physical consequences, including headaches and muscle tension. Such restriction canalso limit our experiences of joy, gratitude and other positive emotions if we avoid acknowledging our feelings.For me crying has been easier said than done during the COVID-19. Psychologists say it's normal to feel stopped up by the stresses of the past year. We should find opportunities to release and process our emotions.Watching a tear-jerking movie, having an emotional conversation with a close friend, and writing in a journal are healthy ways toelicita cry. Physical activity like light-footed walking or even dancing can also signal our bodies to release some emotional tightness. We can then open up to the flow of feelings that leave us feeling lighter and refreshed—like a clear sky after a soaking rain.8. What is the weakness of the studies ever clone on crying?A. They were clone in a laboratory setting.B. They cared little about different forms of crying.C. They were always concentrated on people's daily life.D. They showed little about the positive physical effect of crying.9. What is the function of crying according to Lauren Bylsma?A. Curing people of their diseases.B. Keeping emotionally balanced.C. Producing negative mental results.D. Expanding people's experience of joy.10. What does the underlined word “elicit” in the last paragraph mean?A. Produce.B. Postpone.C. Control.D. Repeat.11. What are people advised to do according to the text?A. Learn to hold back their tears wisely.B. Share their emotion with their colleagues.C. Have a good cry when necessary.D. Try to avoid admitting our feelings.DIn 1990, Hal Donaldson was 23 years old, fresh out of college and found himself in Calcutta, India, where he was asked to interview Mother Teresa.Donaldson says about the great woman famed for feeding the hungry, “She wasn't wearing shoes and her ankles were swollen. She sat down with me and was very polite.” After the interview, Mother Teresa asked him, “What are you doing to help the poor?” Donaldson admitted that he was young and wasn't focused on helping others. With a smile on her face, Mother Teresa said, “Everyone can do something.”Those words deeply struck Donaldson and forced him to face some hard truths about himself.Hal Donaldson grew up in the San Francisco Bay area. When he was 12 years old, his parents were hit by a drunk driver; his father died, and his mother was seriously injured. To make ends meet, they went on welfare. Donaldson says, “I had holes in my shoes and clothes. When you're teased at school for that, you just want to escape.”He managed to do just that. Donaldson got into college and turned his focus to making money for himself He says, “I was just trying to find my way out of insignificance. However, it's easy to overlook others along the way. I was the guy that would see a homeless person and cross the street, so I didn'thave to confront (面对) him. My focus was on climbing to the top instead of helping those trying to climb with me.”Donaldson returned home from India with a different thought. He traveled to eight cities in America and stayed on the streets and listened tostories of the homeless. “My heart broke,” he says. “I knew I could no longer just live for myself.”Inspired by Mother Teresa's words and the stories he'd heard across America. Donaldson loaded a pick-up truck with $300 worth of groceries and handed them out to anyone who needed help. In 1994, Donaldson created the nonprofit organization, Convoy for Hope, which works with communities across America and around the world. Their work focuses on feeding children, women's empowerment, helping farmers and disaster services.12. What did 23-year-old Hal Donaldson do in India?A. He attended an interview for a college.B. He fed the hungry with Mother Teresa.C. He interviewed Mother Teresa.D. He did something to help the poor.13. What can we learn about Hal Donaldson from paragraph 4?A. He was born with disability.B. He led a hard life as a child.C. He was well treated at school.D. He survived as a parentless boy.14. How does Hal Donaldson describe himself in college?A. Self-centered.B. Sympathetic.C. Popular.D. Casual.15. How did Hal Donaldson change after he returned home from India?A. He preferred traveling to volunteering.B. He suddenly fell in love with journalism.C. He turned his focus to living for himself.D. He gradually devoted himself to helping others.第二节（共5小题；每小题2分，满分10分）阅读下面短文，从短文后的选项中选出可以填入空白处的最佳选项。
2019-2020学年东莞市长安实验中学高三生物一模试卷及答案
2019-2020学年东莞市长安实验中学高三生物一模试卷及答案一、选择题：本题共15小题，每小题2分，共30分。
每小题只有一个选项符合题目要求。
1. 广州南沙区拥有面积达200多公顷的湿地，是多种候鸟南下过冬的重要栖息地，被誉为广州的“南肾”。
由于近年来多项大型石油化工项目落户南沙，引起环保专家对南沙自然环境的关注。
下列有关叙述中正确的是（）A.湿地的破坏不会影响该生态系统生物多样性的间接价值B.负反馈调节是湿地生态系统自我调节能力的基础C.南沙湿地群落的物种丰富度会保持不变D.南沙开发应追求经济发展第一，不用考虑对环境的影响2. 构成糖类的元素是（）A. C、H、O、NB. C、H、OC. C、H、O、N、PD. C、H、O、N、P、S3. 人类某遗传病受两对等位基因控制，已知基因A、a位于常染色体上，基因B、b位于X染色体上，且基因A、B同时存在时个体表现正常，其佘情况下均表现为患病。
下图是某家系中该病的遗传系谱图，已知1号个体为纯合子，理论上4号和5号个体生育的男孩或女孩中，正常的概率均为1/4,下列相关叙述错误的是A.2号的基因型是AaX B X bB.5号的基因型是aaX B X bC.3号与2号基因型相同的概率是1/4D.1号和2号再生一个患病男孩的概率是1/24. 赫尔希和蔡斯的T2噬菌体侵染大肠杆菌实验证实了DNA是遗传物质，下列关于该实验的叙述正确的是（）A. 实验需分别用含32P和35S的培养基培养噬菌体B. 搅拌目的是使大肠杆菌破裂，释放出子代噬菌体C.35S标记噬菌体的组别，搅拌不充分可致沉淀物的放射性增强D.32P标记噬菌体的组别，放射性同位素主要分布在上清液中5. 已知水稻的高杆和矮杆、抗病和感病分别受一对基因控制，两对基因分别位于两对同源染色体上。
孝感市科研人员用高杆抗病水稻和矮秤感病水稻杂交，后代全为高杆抗病。
再利用该高杆抗病水稻，通过不同的育种方法培育出矮杆抗病水稻。
2019-2020学年东莞市长安实验中学高三英语三模试题及答案
2019-2020学年东莞市长安实验中学高三英语三模试题及答案第一部分阅读（共两节，满分40分）第一节（共15小题；每小题2分，满分30分）阅读下列短文，从每题所给的A、B、C、D四个选项中选出最佳选项ADuring ancient times, children didn’t have smartphones, iPad or computers to entertain themselves. Instead, they came up with interesting games to play.★Stone ballsDuring the Qing Dynasty, kicking a stone ball around was a popular sport in the northern part of China, and it was often played in the winter to protect kids from the cold. Stones were carved into small balls and kicked along with feet. In 1999, the sport was included in the 6th National Ethnic Group Traditional Sports Meeting held in Beijing.★Flying kitesKites have quite a long history. The earliest kites were made of wood, instead of paper. Nowadays, the four most famous kites are the Beijing kite, Tianjin kite , Weifang kite and Nantong kite, of which each has distinctive features. The kite which resembles a swallow is a well-known Beijing style.★Hide-and-seekHide-and-seek is a traditional game for children, popular around the nation. There are two ways to play: covering a child’s eyes while other kids run around to tease(戏弄) him or, more commonly, participants hide and one child must try to find them.★Playing diabolosA diabolo is always made of wood or bamboo and has empty space in the center. By juggling(边抛边接) the diabolo on the rope, the high-speed spinning diabolos will make a sound like a whistle. Playing diabolos is an interesting folk game, especially popular in North China. Playing diabolos was also included in the first group of national intangible cultural heritage(非物质文化遗产).1.Why did ancient children often play stone balls in the winter?A.To practice their feet.B.To warm themselves.C.To train their skills.D.To relax themselves.2.Which kites are swallow-shaped?A.Weifang kites.B.Tianjin kites.C.Beijing kites.D.Nantong kites.3.Why does playing diabolos make a sound?A.Because the diabolo’s center is empty.B.Because the high-speed spinning diabolo is light.C.Because the diabolo is equipped with a whistle.D.Because ropes’ surface moves against the diabolo’s.BOn World Oceans Day, which falls on June 8, the US National Geographic Society announced it would recognize the Southern Ocean in Antarctica, bringing the global total to five.Unlike the Arctic, Atlantic, Indian and PacificOceans—which are defined by the continents that bound them—the Southern Ocean is instead characterized by the Antarctic Circumpolar Current（南极洋流）. According to the National Geographic, the Southern Ocean includes most of the waters surrounding Antarcticaout to 60 degrees south latitude（纬度）."Encircled by the powerfully swift ACC, it is the only ocean to touch three others and to completely embrace a continent rather than being embraced by them," Sylvia Earle, a marine biologist and oceanographer, told the Daily Mail.Those familiar with the Southern Ocean know it's unlike any other. "Anyone who has been there will struggle to explain what's so charming about it, but they'll all agree that the glaciers are bluer, the air colder, the mountains more awful and the landscapes morecaptivatingthan anywhere else you can go," Seth Sykora-Bodie, a marine scientist at the National Oceanic and Atmospheric Administration, told National Geographic.National Geographic hopes their revised maps will bring public awareness to the region, thereby encouraging Southern Ocean conservation—but its significance is beyond that."We think it's really important from an educational standpoint, as well as from a map-labeling standpoint, to bring attention to the Southern Ocean as a fifth ocean," Alex Tait, National Geographic Society geographer, told The Post. "So when students learn about parts of the ocean world, they learn it's an interconnected ocean, and they learn there are these regions called oceans that are really important, and there's a distinct one in the icy waters around Antarctica."4. Why is the Southern Ocean different from other oceans?A. It has never been explored before.B. It surrounds the Antarctic all around.C. It is enclosed by the fast-flowing ACC.D. It has ecologically distinct environment.5. What does the underlined word "captivating" in paragraph 4 probably mean?A. Strange.B. Unusual.C. Attractive.D. Informal.6. What does the National Geographic think of the Southern Ocean?A. It will be instructive for students.B. It will promote tourism development.C. It will encourage public to treasure water.D. It will draw scientists to study in the Antarctic.7. What is the best title for the text?A. World Oceans DayB. Revised Antarctic MapsC. Adding a New OceanD. New Discovery under the SeaCBefore moving to Stokholm, I did my research on Sweden and was confident about my move. However, I quickly realized on my first day that so much of what I learnedwas so very wrong. There are many things that a Google search cannot show about Sweden.The first is fika. A fika is taking a break from whatever you are doing to enjoy a coffee with friends. Swedes value community highly so it makes sense that they would like to set aside time each day to reconnect with others. Fika is a great time to meet new people as well as catch up with friends.I grew up in the American South where everyone is very friendly. I found that little things like not being asked my life story at the coffee shop by the waiter upset me. However, Swedish people are not rude. Instead, they practice being logom, which means “just enough”.The winters can be very dark and cold, so the Swedish people do not take any sunny day for granted. Since the weather has been fine, I have found myself walking a lot around Stockholm. Often it is easiest to get from place to place by walking, which allows you to see so much of the city and enjoy the fresh air. Though it has been very tiring to get used to, it also has made me feel better about all of the kardemummabullar that I have been eating!I think it is important for students who want to study abroad to know that it is hard to move to countries no matter how “similar” you may think they may be. You have to jump in with both feet and be patient with yourselfas well as others. As long as you keep an open mind and are willing to learn, you will have a great experience.8. What do we know about fika?A. It is a waste of time.B. It is a way to balance life and work.C. It is all about drinking coffee.D. It is a Swedish social tradition.9. What does the author think of Swedish people?A. They are friendly.B. They seem a bit cold.C. They appear really rude.D. They are interested in other's life.10. Why does the author like walking?A. It is fun and not very tiring.B. It is good exercise on cold days.C It allows her to enjoy sunny days. D. It gives her the chance to eat the local food.11. What's the author's advice for students going abroad?A. Be confident.B. Be careful.C. Be open- minded.D. Be hard- working.DIn the U. S., speaking more than one language fluently is not very common except in Los Angeles, California.The city has one of the largest population in the U. S. of young people between the ages of 18 and 34. This generation is often called millennials (新千年一代). More than half of millennials in Los Angeles are bilingual (双语的), which means they speak more than one language.Maria Elena Burgos is cooking a Mexican breakfast. She says making Mexican food is just one of the many traditions in her home. Another is speaking Spanish to her children.“We want them to be bilingual. We want to keep the Spanish somewhere in their learning too, not only at home.”When Ms Burgos first came to the United States from Mexico, she learned English. She knew her children would learn English quickly. So she wanted them to speak Spanish at home and study the language at school.She says being bilingual will give them more opportunities in the future. Knowing Spanish also means the children can talk with their s in Mexico.“When we had our children, one of the decisions we as parents made was to name them with a name that was easily pronounced in English and Spanish.”Elizabeth wants to know her family’s culture.” “The culture-to go back to our roots because that’s part of who we are.”Monica wants to pass on the culture to her children“It’s nice to know our culture and then to be able to pass it onto our children and grand-children and everyone to let them know where we come from.”And, Monica says she does not speak only English and Spanish. She has even learned some Korean in school.12. Which of the following is a tradition of Maria?A. Cooking breakfast for her s.B. Talking with her children in Spanish.C. Talking with her s in Spanish.D. Forcing her children to speak Spanish.13. What can be inferred from Monica’s words?A. She doesn’t care where she comes from.B. She looks forward to learning Spanish.C. Everyone should know his own culture.D. She doesn’t like American culture.14. Which of the following is mentioned about children speaking more languages?A. It can give children more chances in the future.B. It can make children feel proud before their friends.C. It can give the children a chance to go to a good college.D. It can let children go to the places where they want to go.15. What’s the main purpose of this passage?A. To entertain the readers with a funny story.B. To inform the readers of a shocking experiment result.C. To encourage more persons to learn a second language.D. To tell a truth that many people in Los Angeles are bilingual.第二节（共5小题；每小题2分，满分10分）阅读下面短文，从短文后的选项中选出可以填入空白处的最佳选项。
广东省东莞市长安中学2019-2020学年七年级下数学第一次月考模拟卷(含答案)
广东省东莞市长安中学2019-2020七下数学第一次月考模拟卷测试时间：90分钟学生姓名：___________ 测试分数：______/100 一．选择题（每小题2分，共20分）1. 下列有理数大小关系判定正确的是（）A. B. C. D.2．过点P作线段AB的垂线段的画法正确的是( )3．如图，直线AB、CD相交于点O，射线OM平分∠AOC，ON⊥OM，若∠AOM ＝35°，则∠CON的度数为( )A．35°B．45°C．55°D．65°4．直线l上有A、B、C三点，直线l外有一点P，若P A＝5cm，PB＝3cm，PC ＝2cm，那么点P到直线l的距离( )A．等于2cm B．小于2cmC．小于或等于2cm D．在于或等于2cm，而小于3cm5. 的算术平方根是（）A. 11B.C.D.6.如图所示，点E在AC的延长线上，下列条件中能判断AB∥CD的是（）A. ∠3=∠AB. ∠1=∠2C. ∠D=∠DCED. ∠D+∠ACD=180°7.设的整数部分为，小整数部分为，则的值为（）．A. B. C. D.8.如图是某公园里一处矩形风景欣赏区ABCD，长AB=50米，宽BC=25米，为方便游人观赏，公园特意修建了如图所示的小路（图中非阴影部分），小路的宽均为1米，那小明沿着小路的中间，从出口A到出口B所走的路线（图中虚线）长为（）A.100米B. 99米C. 98米D. 74米9.下列哪个图形是由如图平移得到的（）A. B. C. D.10.观察下列计算过程：因为112=121，所以，因为1112=12321，所以……，由此猜想=（）A. 111 111 111B. 11 111 111C. 1 111 111D. 111 111二．填空题（每小题3分，共15分）11. 若x与2x－6是同一个正数m的两个不同的平方根，则x＝____，m＝______.12. 16的算术平方根是_______，－8的立方根是_______．13.如图，下列条件中：①∠B+∠BCD=180°；②∠1=∠2；③∠3=∠4；④∠B=∠5；则一定能判定AB∥CD的条件有（填写所有正确的序号）．14.如图，将一张长方形纸片ABCD折叠成如图所示的形状，∠EGC=26°，则∠DFG=．15.将一副直角三角尺ABC和CDE按如图方式放置，其中直角顶点C重合，∠D=45°，∠A=30°．若DE∥BC，则∠1的大小为度．三．解答题（8小题，16-22每小题8分，第23小题9分，共56分）16. 计算：(1)（－1）2+－－︱－5︱（2）17.如图所示，数轴的正半轴上有A、B、C三点，表示1的对应点分别为A、B，点B到点A的距离与点C到点O的距离相等，设点C所表示的数为x．（1）请你写出数x的值；（2）求（x）2的立方根．18.如图，已知AB∥CD，AD∥BC，AC＝15cm，BC＝12cm，BE⊥AC于点E，BE＝10cm.求AD和BC之间的距离．19.已知的平方根是，y+19的立方根是3，求的平方根．20.若x、y都是实数，且y+8，求x+3y的立方根．21.已知：如图，∠CDG=∠B，AD⊥BC于点D，EF⊥BC于点F，试判断∠1与∠2的关系，并说明理由．22.. 已知：如图，∠A=∠ADE，∠C=∠E．（1）若∠EDC=3∠C，求∠C的度数．（2）求证：BE∥CD．23. 如图，直线EF、CD相交于点O，OA⊥OB，且OC平分∠AOF.(1)若∠AOE＝40°，求∠BOD的度数；(2)若∠AOE＝α，求∠BOE的度数；(用含α的代数式表示)(3)从(1)(2)的结果中能看出∠AOE和∠BOD有何关系？广东省东莞市长安中学2019-2020七下数学第一次月考模拟卷答案一．选择题：1-5：D D C C C 6-10：B D C C A 二．填空题：11.(1). 2 (2). 4 12. (1). 4 (2). －2 13. ①③④． 14.77° 15. 105 三．解答题： 16. (1)0；（2）417.【解答】解：（1）∵点A 、B 分别表示1，∴AB ﹣1，即x ﹣1； （2）∵x =2﹣1，∴原式==，∴1的立方根为1．18. 解：过点A 作BC 的垂线，交BC 于P 点，三角形ABC 的面积为12×AC ×BE ＝12×15×10＝75(cm 2)，又因为三角形ABC 的面积为12×BC ×AP ＝12×12×AP ＝75，所以AP ＝12.5cm .因此AD 和BC 之间的距离为12.5cm .19.【答案】±10．学#科#网...学#科#网...学#科#网...学#科#网...学#科#网... 试题解析：∵x ﹣2的平方根是±2，2x +y +7的立方根是3， ∴x ﹣2=4，2x +y +7=27，解得x =6，y =8， ∴==100，∴的平方根是±10．20.【解答】解：∵y+8，∴3030xx-≥⎧⎨-≥⎩解得：x=3，将x=3代入，得到y=8，∴x+3y=3+3×8=27，即x+3y的立方根为3．21.【答案】∠1=∠2，理由详见解析.【解析】试题分析：即可判定DG∥BA，根据平行线的性质得到，又因为AD∥EF，，即可得到∠1与∠2的关系.试题解析：∠1=∠2，理由：∴DG∥BA（同位角相等，两直线平行），（两直线平行，内错角相等），（已知），∴AD∥EF（在同一平面内，垂直于同一直线的两条直线平行），（两直线平行，同位角相等），（等量代换）．22.【答案】(1) ∠C=45°；（2）详见解析.【解析】试题分析：可以判定AC∥DE，根据平行线的性质得到又即可求出的度数.根据AC∥DE，得到又根据等量代换得到根据平行线的判定即可判定BE∥CD．试题解析：（1）∴AC∥DE，又 即 （2）∵AC ∥DE ， 又∴BE ∥CD ．23.(1) 解：∵∠AOE ＋∠AOF ＝180°(互为补角)，∠AOE ＝40°，∴∠AOF ＝140°；又∵OC 平分∠AOF ，∴∠FOC ＝12∠AOF ＝70°，∴∠EOD ＝∠FOC ＝70°.而∠BOE ＝∠AOB －∠AOE ＝50°，∴∠BOD ＝∠EOD －∠BOE ＝20°；(2) 解：∵∠AOE ＋∠AOF ＝180°(互为补角)，∠AOE ＝α，∴∠AOF ＝180°－α；又∵OC 平分∠AOF ，∴∠FOC ＝90°－12α，∴∠EOD ＝∠FOC ＝90°－12α(对顶角相等)；而∠BOE ＝∠AOB －∠AOE ＝90°－α，∴∠BOD ＝∠EOD －∠BOE ＝12α； (3) 解：从(1)(2)的结果中能看出∠AOE ＝2∠BOD。
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广东省东莞市长安实验中学2019-2020学年中考化学模拟试卷一、选择题（本题包括12个小题，每小题3分，共36分．每小题只有一个选项符合题意）1．以人为本，关注健康是人类永恒的主题。
下列叙述错误的是（）A．处于生长发育期的青少年应该适当多补充蛋白质B．人体如果摄入过多的油脂后，容易引发肥胖C．人体内如果缺乏维生素A，可能会患坏血病D．青少年长期偏食、挑食不利于身体健康2．分离、提纯是化学实验的重要环节，下列实验设计不能达到实验目的的是( )选项实验目的实验设计A 除去CO中的少量H2O和CO2先通过浓硫酸，再通过氢氧化钠溶液B 除去NaCl固体中的少量Na2CO3先加足量水溶解，再加适量稀盐酸，蒸发结晶C 除去KNO3溶液中的少量K2SO4加入适量的Ba(NO3)2溶液，过滤D 除去铜粉中混有的少量铁粉用磁铁吸引A．A B．B C．C D．D3．有三瓶无色、无味的气体x、y、z，它们分别是甲烷、氢气、一氧化碳中的一种，分别点燃三种气体，用干燥的冷烧杯罩在火焰上方，只有y和z火焰上方的烧杯内壁有水滴出现，燃烧后分别向烧杯中注入澄清的石灰水，振荡，只有x和y的烧杯内石灰水变浑浊。
则x、y、z分别是A．CH4H2CO B．CH4CO H2C．CO CH4H2D．H2CH4CO4．下列问题的研究中，未利用对比实验思想方法的是（）A．研究空气中氧气含量B．研究分子运动C．研究燃烧的条件D．研究二氧化碳与水的反应A．用洗洁精清洗油腻的餐具B．用汽油清洗油污C．用自来水清洗手上的泥土D．用食醋清除水垢6．“三效催化转换器”可将汽车尾气中的有毒气体处理为无毒气体，下图为该反应的微观示意图。
下列有关说法中，正确的是（）。
A．该反应属于置换反应B．反应前后分子和原子的种类及个数均不变C．反应物均为氧化物D．参加反应的和质量之比为1∶17．在一密闭容器内加入甲、乙、丙、丁四种物质，在一定条件下发生化学反应，反应前后各物质的质量变化见下表。
下列说法中不正确的是（）物质甲乙丙丁反应前物质质量/g 8 32 5 4反应后物质质量/g 16 4 x 24A．该反应为分解反应B．丙可能为该反应的催化剂C．甲、乙两种物质间参加反应的质量比为1:4D．乙、丁两种物质间反应的质量比为7:58．如图是某化学反应前后的微观示意图，下列说法不正确的是A．该反应属于分解反应B．生成的甲、乙分子个数比是1:4C．该反应前后原子个数不变D．该反应的生成物都是单质9．化学已经渗透到社会发展的各个方面，在①环境保护；②能源开发利用；③新材料研制；④生命过程探索等领域中，与化学科学发展密切相关的是A．只有①②③B．只有②③④C．只有①②④D．①②③④10．将稀硫酸加入CuO和Fe粉的混合物中进行反应，当反应停止后，滤出不溶物，并向滤液中投入一枚铁钉，片刻后取出铁钉，发现无任何变化．根据上述现象确定下哪个结论是正确的C．滤液中一定含有FeSO4，但不一定含有CuSO4D．滤液中一定含有FeSO4，一定不含有CuSO4 11．超市出售的“84消毒液”的主要成分是次氯酸钠（NaClO），次氯酸钠中氯元素的化合价为A．+5 B．+1 C．+3 D．-112．元素观是化学的重要观念之一。
下列有关元素的说法中错误的是( )A．元素是具有相同核电荷数的一类原子的总称B．元素周期表，元素的原子序数与该元素原子核电荷数在数值上相同C．同种元素的原子核内质子数与中子数一定相等D．在物质发生化学变化时，原子的种类不变，元素也不会改变二、填空题（本题包括4个小题，每小题7分，共28分）13．如右图所示装置可用于收集氧气，请回答下列问题.(1)用向上排空气法收集氧气，则氧气应从____端导管通入，空气由____排出.若要检查已收集满氧气，可将带火星的木条放在____端导管口处；(2)若用排水法收集氧气，可使集气瓶中装满水，氧气从____端导管通入，水从____端导管排出. 14．水是生命之源，“珍惜水、节约水、保护水”是每个公民的义务和责任。
水体污染来源之一是_____。
可用_____检验地下水是硬水还是软水。
利用氢氧化钠溶液的_____性制叶脉书签。
图A中，①t1℃时，将甲、乙的饱和溶液升温至t2℃，溶液中溶质的质量分数为：甲_____乙（填“＞”“＜”或“＝”）②t1℃时，将30g乙物质加入50g水中，充分溶解后溶液的质量为_____g2019年3月，我国朴玲玉研究员和天津大学马智教授团队成功利用可见光和锐钛矿氧化钛催化剂（TiO2/Pt）将水分解，原理如图B所示，写出该反应的化学方程式_____，此反应在实践中的优点之一是_____。
15．目前，我国火力发电量占全国总发电量的80%以上．请回答问题：火力发电以煤做燃料，使水变成水蒸气，推动涡轮运动，从而为我们的生产和生活提供电能，此过程中发生的全部能量转化是_____．烧煤时，通常会向炉灶内鼓入空气，并将煤磨成煤粉，这样做有利于节能减排，理由是①_____，但还存在应选择_____（填字母）．A 铝合金B 玻璃C 塑料液化石油气是家庭常用的气体燃料，利用加压后压缩到钢瓶中．当打开减压阀时，压强①_____，气体逸出，液化石油气的主要成分是丙烷、丁烷等，已知“烷”这类物质的化学式规律是：C n H2n+2，例如：甲烷，n的取值为1，甲烷的化学式为CH4，乙烷，n的取值为2，其化学式C2H6，以此类推，请写出丁烷的化学式②_____．16．写出下列物质的用途（各写一条即可）：盐酸的用途：_____；氢氧化钠的用途：_____；氯化钠的用途：_____；氧气的用途：_____；石墨的用途：_____；稀有气体的用途：_____。
三、实验题（本题包括2个小题，每小题7分，共14分）17．学校实验室开放日，某化学兴趣小组的同学在老师的指导下，进行了“自选仪器设计实验”的活动。
实验室准备的仪器如图所示，请回答下列问题：仪器F的名称是_____，取用固体粉末必须用到的仪器是_____（填序号）；若不考虑夹持装置：①用高锰酸钾制氧气，发生装置应选用的仪器是_____ （填序号），②如果用过氧化氢溶液和二氧化锰制氧气，发生装置应选用的仪器是_____（填序号），其反应的化学方程式为_____，这套发生装置还可以用来制取_____气体，该气体的检验方法是_____；连接好气体发生装置后，必须先进行的操作是_____，然后才能制取气体，如果用向上排空气法收集氧气时，其验满的方法是_____。
18．铝、铁、铜是人类广泛使用的三种金属，与我们的生活息息相关。
下图是某同学验证三种金属的化学性质时完成的部分实验。
开始实验后B、D中都有明显的现象，而A、C中却没有明显的现象。
分析回答下列问题：实验时B中发生反应的化学方程式为______。
D中的实验现象为______。
开始实验时A、C中没有明显现象的原因分别是_____。
四、计算题（本题包括1个小题，共12分）加入质量分数为10%的Na2SO4溶液，反应生成BaSO4沉淀的质量与所加入的Na2SO4溶液的质量关系如图所示．试回答下列问题：完全反应后生成BaSO4沉淀__________g；A点时，溶液的溶质有___________；恰好完全反应时消耗Na2SO4溶液的质量是多少克？________恰好完全反应时所得溶液中溶质的质量分数是多少？_____________参考答案一、选择题（本题包括12个小题，每小题3分，共36分．每小题只有一个选项符合题意）1．C【解析】A、处于生长发育期的青少年应该适当多补充蛋白质，正确；B、人体如果摄入过多的油脂后，容易引发肥胖，正确；C、人体内如果缺乏维生素A，可能会患夜盲症，错误；D、青少年长期偏食、挑食不利于身体健康，正确。
故选C。
2．A【解析】试题分析：除杂质的要求是：要把杂质除去，但不能除去了需要的物质更不能带入新的杂质。
A中应先通氢氧化钠溶液把二氧化碳除去，再把混合气体通过浓硫酸把水蒸汽除去，A错误；B中稀盐酸与碳酸钠反应生成的是氯化钠、水和二氧化碳，在蒸发可将水除去，正确；C中硝酸钡与硫酸钾反应生成的是硫酸钡沉淀和硝酸钾，过滤可将硫酸钡沉淀除去，正确；磁铁能将铁粉吸引除去，正确。
故选A。
考点：除杂质3．C【解析】【详解】甲烷中含有碳、氢两种元素，燃烧产物是二氧化碳和水；氢气只有氢元素组成，燃烧产物是水；一氧化碳一氧化碳，在y、z火焰上方的烧杯内壁上有水珠出现，且y杯内的石灰水变浑浊，说明y为甲烷，z杯内壁上有水珠，注入的澄清石灰水没有变化，说明只生成了水，为氢气，所以x、y、z分别是CO、CH4、H1．故选C．【点评】解答本题首先要熟悉气体的性质，并能利用其性质对它进行检验、鉴别，对于可燃性的气体往往是通过检验其燃烧产物对它们进行鉴别．4．A【解析】【详解】A、研究空气中氧气含量是利用白磷燃烧，消耗空气中氧气，使瓶内气体压强减小，水在外界大气压的作用下进入集气瓶内，所以根本不存在对照实验，故A正确；B、烧杯A中的酚酞试液和烧杯B中的酚酞试液属于对照试验，烧杯A置于放有浓氨水的烧杯附近；烧杯B置于空气中，在空气中没变色，说明空气不能使酚酞试液变红，烧杯A中变红说明氨分子在不断运动，进入烧杯A中，使酚酞试液变红，说明了分子在不断运动，所以利用了对比实验的原理，故B错；C、铜片上的白磷与铜片上的红磷属于对照实验，都与氧气接触，都属于可燃物，变量是着火点不同，白磷着火点低，红磷着火点高，热水能达到白磷的着火点，达不到红磷的着火点，从而证明可燃物燃烧温度必须达到可燃物的着火点，所以属于对比实验，故C错；D、纸花都是用石蕊溶液染成，都与二氧化碳接触，变量是一瓶内纸花中有水，一瓶内纸花中没有水，由实验可知没有水的纸花没变色，含有水的纸花变成红色，说明二氧化碳与水反应生成了一种酸，酸使石蕊试纸变成红色，所以属于对比实验，故D错。
故选A5．A【解析】【详解】A、洗洁精是洗涤剂，有乳化作用，能将大的油滴分散成细小的油滴随水冲走，故选项是利用乳化作用。
B、用汽油洗去油污是利用汽油能溶解油污来达到目的，利用的是溶解原理，故选项不是利用乳化作用。
C、用自来水清洗手上的泥土，是利用水流把手上的泥土冲走，故选项不是利用乳化作用。
D、用食醋洗去热水瓶中的水垢是因为水垢的主要成分碳酸钙能和食醋反应，从而把水垢除去，故选项不是利用乳化作用。
故选：A。
6．C【解析】A、由微观示意图可知，反应物中没有单质参加反应，故不可能是置换反应，错误；B、在化学变化中，分子的种类一定发生变化，错误；C、由图可知，反应物是一氧化碳和一氧化氮，它们由两种元素组成，且一种元素是氧元素，故都是氧化物，正确；D、有图可知，2个一氧化氮分子与2个一氧化碳分子反应生成了1个氮气分子和2个二氧化碳分子，故参加反应的一氧化碳和一氧化氮分子个数比为1∶1，质量之比不可能为1∶1，错误。