北京市2020年顺义一模及答案

顺义区2020届初三第一次统一练习化学试卷考 生须 知1.本试卷共6页，共两部分，22道小题，满分45分。

考试时间与生物合计90分钟。

2 .在试卷和答题卡上准确填写学校名称、姓名和准考证号。

3 .试题答案一律填涂或书写在答题卡上，在试卷上作答无效。

4 .在答题卡上，选择题用2B 铅笔作答，其他试题用黑色字迹签字笔作答。

可能用到的相对原子质量：N 14 C 12 O 16第一部分 选择题（共12分）（每小题只有一个选项符合题意。

共12道小题，每小题1分）1 .下列变化属于物理变化的是A .食物腐烂B .汽油挥发C .钢铁生锈D .粮食酿酒2 .下列物质在氧气中燃烧，火星四射、生成黑色固体的是A .木炭B .铁丝C .蜡烛D .红磷3 .下列金属的金属活动性最强的是A . CuB . FeC . AlD . Ag4 . 一种铈原子的原子核内有58个质子和82个中子，该原子的核外电子数为8.下列燃料，不属于化石燃料的是A . 58B . 24C . 82D . 1405 .关于右图所示的电解水实验，下列说法正确的是A .试管1中是氧气B .得出水由氢气和氧气组成的结论C .试管1和试管2中气体的质量比为2： 1D .用带火星的木条检验试管2中的气体能复燃 6 .下列符号能表示2个氢分子的是A . 2H 2B . H 2C . 2HD . 2H +7 .下列实验操作正确的是B .滴加液体C .加热液体D .检查气密性A .石油B .煤C .氢气D .天然气20℃时，向2只盛有100g 水的烧杯中，分别加入30g 两种固体，充分溶解。

11 .上述溶液为饱和溶液的是A .①B .②C .③D .④12 .下列说法正确的是A .①所得溶液中溶质与溶剂质量比为3： 10B .②所得溶液中溶质的质量分数为30%C .①和③的溶质质量分数相等D .③和④的溶质质量分数相等第二部分 非选择题(共33分，每空1分)【生活现象解释】13 .解释下列生活现象: (1)干冰常用于人工降雨，利用了干冰 的性质。

顺义区2020届初三第一次统一练习物理试卷学校姓名准考证号一、单项选择题（下列各小题均有四个选项，其中只有一个选项符合题意。

共30分，每小题2分）1．下列学习用具中，通常情况下属于导体的是A．塑料笔杆B．布质笔袋C．橡皮D．钢尺2．图1所示的光现象中，由于光的反射形成的是3．下列物理量和其国际单位对应正确的是A．功——瓦特B．质量——千克C．电阻——伏特D．电流——库伦4．下列用电器中，利用电流热效应工作的是A．电暖气B．洗衣机C．电视机D．微波炉5．下列实例中，为了增大摩擦的是A．在旅行箱下端装有底轮B．在冰壶比赛中运动员用力刷冰C．汽车轮胎上制有较深的花纹D．磁浮列车运行时使车身与轨道间形成间隙6．图2所示的四个物态变化的实例中，属于液化的是考生须知1．本试卷分为试题卷和答题卡两部分。

请把答案和解题过程写在答题卡上，其中写在试题卷上的答案无效。

2．本试卷满分90分，考试时间90分钟。

3．在答题卡密封线内准确填写学校、姓名和准考证号。

4．考试结束，将答题卡交回。

皮影在幕布上的影子桥在水面形成倒影图1放大镜把字放大勺柄在水面处折断A B C D图2A B C D初春，湖面上冰化成水盛夏，草叶上形成露珠严冬，树枝上形成雾凇深秋，枫叶上形成霜7．图3所示的实例中，目的是为了减小压强的是8．在下列实例中，用做功的方式来改变物体内能的是A ．热水倒入茶杯，茶杯的温度升高B ．将冰冻食物放在水中解冻，水变凉C ．刚煮熟的鸡蛋放在冷水中，鸡蛋的温度降低D ．寒冷的冬天，双手互搓，手的温度升高9．关于安全用电，下列做法中正确的是A ．更换灯泡时先断开电源开关B ．用湿布擦拭正在工作的电视机C ．家用电器电线绝缘皮破损了仍继续使用D ．在高压线下放风筝10．运动会上，某同学参加了跳远比赛项目。

他用力蹬地，腾空一跃，如图4甲所示。

若用“ ”表示该同学，不计空气阻力，分析他腾空时的受力情况，图4乙中正确的是11．图5中所示的电源正负极、电流方向和通电螺线管N 极三者的关系正确的是12．如图6所示电路，闭合开关S 后，小灯泡L 1、L 2均发光， 则下列说法正确的是A ．通过两灯的电流相等B ．通过灯L 2的电流小于通过电源的电流C ．灯L 1和灯L 2两端的电压一定相等D ．灯L 1的电压与电源电压相等图7 R Q气敏元件 S VAG F G G F A B C D甲 乙图4A B C D图3 滑雪板的面积较大安全锤的锤头做得很尖盲道上凸起的圆点吸管一端做成尖形图6L 1L 2S+图5IN 极 I I N 极BCDI13．某化工厂为了检测车间中的某种有害气体浓度，设计了一种检测仪，其简化电路如图7所示。

顺义区2020届初三第一次统一练习一、选择题（本题共16分，每小题2分）第1-8题均有四个选项，符合题意的选项只有．．一个．1．港珠澳大桥被英国《卫报》誉为“新世界七大奇迹”之一，它是世界总体跨度最长的跨海大桥，全长55000米．数字55000用科学记数法表示为（A）45.510⨯（B）45510⨯（C）55.510⨯（D）60.5510⨯2．下列有关医疗和倡导卫生的图标中，是轴对称图形的是（A）（B）（C）（D）3．将一副三角板和一个直尺按如图所示的位置摆放，则1∠的度数为（A）60︒（B）65︒（C）75︒（D）85︒4．在数轴上，点A表示数a，将点A向右平移4个单位长度得到点B，点B表示数b．若a b=，则a的值为（A）3-（B）2-（C）1-（D）15．箱子内装有除颜色外均相同的28个白球及2个红球，小芬打算从箱子内摸球，以毎次摸到一球后记下颜色将球再放回的方式摸28次球．若箱子内每个球被摸到的机会相等，且前27次中摸到白球26次及红球1次，则第28次摸球时，小芬摸到红球的概率是（A）12（B）114（C）115（D）127 6．已知直线l及直线l外一点P．如图，（1）在直线l上取一点A，连接PA；（2）作PA的垂直平分线MN，分别交直线l，PA于点B，O；NMBQOA lP1（3）以O 为圆心，OB 长为半径画弧，交直线MN 于另一点Q ； （4）作直线PQ ．根据以上作图过程及所作图形，下列结论中错误的是 （A ）△OPQ ≌△OAB （B ）PQ ∥AB（C ）12AP BQ =（D ）若PQ=PA ，则60APQ ∠=︒7．用三个不等式a b >，c d >，a c b d +>+中的两个不等式作为题设，余下的一个不等式作为结论组成一个命题，组成真命题的个数为（A ）0 （B ）1 （C ）2 （D ）38．小明、小聪参加了100m 跑的5期集训，每期集训结束时进行测试，根据他们的集训时间、测试成绩绘制成如下两个统计图．图1 图2 根据图中信息，有下面四个推断： ①这5期的集训共有56天；②小明5次测试的平均成绩是11.68秒；③从集训时间看，集训时间不是越多越好，集训时间过长，可能造成劳累，导致成绩下滑； ④从测试成绩看，两人的最好成绩都是在第4期出现，建议集训时间定为14天． 所有合理推断的序号是（A ）①③ （B ）②④（C ）②③ （D ）①④二、填空题（本题共16分，每小题2分）926x -x 的取值范围是 ．10．如图，在量角器的圆心O 处下挂一铅锤，制作了一个简易测倾仪，从量角器的点A 处观测，当量角器的0刻度线AB 对准旗杆顶端时，铅垂线对应的度数是50°，则此时观测旗杆顶端的仰角度数是________________.10题图 11题图11．在如图所示的几何体中，主视图、左视图和俯视图完全相同的几何体是 ．（写出所有正确答案的序号）12．化简分式22231x y x y x y x y ⎛⎫--÷ ⎪+--⎝⎭的结果为 ． 13．如图，将一矩形纸片ABCD 沿着虚线EF 剪成两个全等．．的四边形纸片．根据图中标示的长度与角度，求出剪得的四边形纸片中较短的边AE 的长是 ．14．已知点(2,3)A -关于x 轴的对称点A '在反比例函数ky x=的图象上，则实数k 的值为 ．①从扇形图中分析出最受学生欢迎的种类 ②去图书馆收集学生借阅图书的记录 ③绘制扇形图来表示各个种类所占的百分比 ④整理借阅图书记录并绘制频数分布表 正确统计步骤的顺序是 ．16．如图，在正方形ABCD 中，4AB =，E 、F 是对角线AC 上的两个动点，且2EF =，P 是正方形四边上的任意一点．若PEF ∆是等边三角形，符合条件的P 点共有 个，此时AE 的长为 ．三、解答题（本题共68分，第17-21题，每小题5分，第22-23题6分，第24题5分，第25-26题，每小题6分，第27-28题，每小题7分） 解答应写出文字说明、演算步骤或证明过程． 17．计算：()15tan 30203--+︒--．18．解方程组：2313x y x y +=⎧⎨-=⎩19．已知：关于x 的方程()2220xm x m +--=．（1）求证：方程总有实数根；（2）若方程有一根小于2，求m 的取值范围．20．如图，AM ∥BC ，且AC 平分∠BAM ．（1）用尺规作∠ABC 的平分线BD 交AM 于点D ，连接CD ．（只保留作图痕迹，不写作法）（2）求证：四边形ABCD 是菱形．21．小宜跟几位同学在某快餐厅吃饭，如图为此快餐厅的菜单．若他们所点的餐食总共为10份盖饭，x 杯饮料，y 份凉拌菜．（1）他们点了份套餐， 份套餐， 份； （2）若x =6，且A 、B 、C 套餐均至少点了1份，则最多有 种点餐方案．22．如图，在□ABCD 中，∠B =45°，点C 恰好在以AB 为直径的⊙O 上．（1）求证：CD 是⊙O 的切线； （2）连接BD ，若AB =8，求BD 的长．23．2019年11月，胡润研究院携手知识产权与科创云平台汇桔，联合发布《IP 助燃AI新纪元—2019中国人工智能产业知识产权发展白皮书》，白皮书公布了2019中国人工智能企业知识产权竞争力百强榜，对500余家中国人工智能主流企业进行定量评估（满分100分），前三名分别为：华为、腾讯、百度．对得分由高到低的前41家企业的有关数据进行收集、整理、描述和分析．下面给出了部分信息：a ．得分的频数分布直方图（数据分成8组：60≤x ＜65，65≤x ＜70，70≤x ＜75， 75≤x ＜80，80≤x ＜85，85≤x ＜90，90≤x ＜95，95≤x ≤100，）；MCBADb．知识产权竞争力得分在70≤x ＜75这一组的是： 70.3 71.6 72.1 72.5 74.1c ．41家企业注册所在城市分布图（不完整）如下：（结果保留一位小数）北京53.7% 深圳7家 上海m 家杭州2家 广州2家 苏州1家 合肥1家 南京1家d ．汉王科技股份有限公司的知识产权竞争力得分是70.3 .（以上数据来源于《IP 助燃AI 新纪元—2019中国人工智能产业知识产权发展白皮书》） 根据以上信息，回答下列问题：（1）汉王科技股份有限公司的知识产权竞争力得分排名是第 ；（2）百度在人工智能领域取得诸多成果，尤其在智能家居、自动驾驶与服务于企业的智能云领域，百度都已进行前瞻布局，请你估计百度在本次排行榜中的得分大概是； （3）在41家企业注册所在城市分布图中，m = ，请用阴影标出代表上海的区域； （4）下列推断合理的是．（只填序号）①前41家企业的知识产权竞争力得分的中位数应在65≤x ＜70这一组中，众数在 65≤x ＜70这一组的可能性最大；②前41家企业分布于我国8个城市. 人工智能产业的发展聚集于经济、科技、教育相对发达的城市，一线城市中，北京的优势尤其突出，贡献榜单过半的企业，充分体现北京在人工智能领域的产业集群优势.24．如图，D 是直径AB 上一定点，E ，F 分别是AD ，BD 的中点， P 是»AB 上一动点，连接PA ，BAPE，PF．已知AB＝6cm，设A，P两点间的距离为x cm，P，E两点间的距离为y1cm，P，F两点间的距离为y2cm．小腾根据学习函数的经验，分别对函数y1，y2随自变量x的变化而变化的规律进行了探究．下面是小腾的探究过程，请补充完整：(2)在同一平面直角坐标系xOy中，描出补全后的表中各组数值所对应的点(x，y1)，(x，y2)，并画出函数y1，y2的图象；(3)结合函数图象，解决问题：当△PEF为等腰三角形时，AP的长度约为cm．25. 已知：在平面直角坐标系xOy中，函数n=(n≠0，x>0) 的图象过点A(3，2)，与yx=+交于点C，直线l与y轴交于点B(0,-1)．直线l：y kx b（1）求n 、b 的值；（2）横、纵坐标都是整数的点叫做整点．记函数ny x(n ≠ 0，x>0) 的图象在点A ，C 之间的部分与线段BA ，BC 围成的区域（不含边界）为W ．①当直线l 过点（2，0）时，直接写出区域W 内的整点个数，并写出区域W 内的整点的坐标；②若区域W 内的整点不少于．．．5．个，结合函数图象，求k 的取值范围．26．在平面直角坐标系x O y 中，二次函数y =ax 2+bx +c 的图象经过点A （0，-4）和B （-2，2）.（1）求c 的值，并用含a 的式子表示b ；（2）当-2<x <0时，若二次函数满足y 随x 的增大而减小，求a 的取值范围；（3）直线AB 上有一点C （m ，5），将点C 向右平移4个单位长度，得到点D ，若抛物线与线段CD 只有一个公共点，求a 的取值范围．27．已知，如图，△ABC 是等边三角形.（1）如图1，将线段AC 绕点A 逆时针旋转90°，得到AD ，连接BD ，∠BAC 的平分线交BD 于点E ，连接CE . ①求∠AED 的度数；②用等式表示线段AE 、CE 、BD 之间的数量关系（直接写出结果）.（2）如图2，将线段AC 绕点A 顺时针旋转90°，得到AD ，连接BD ，∠BAC 的平分线交DB 的延长线于点E ，连接CE . ①依题意补全图2；②用等式表示线段AE 、CE 、BD 之间的数量关系，并证明.图2图1ABCEDCBA28．已知：点P 为图形M 上任意一点，点Q 为图形N 上任意一点，若点P 与点Q 之间的距离PQ始终满足PQ >0，则称图形M 与图形N 相离．（1）已知点A （1，2）、B （0，-5）、C （2，-1）、D （3，4）．①与直线y =3x -5相离的点是 ；②若直线y =3x +b 与△ABC 相离，求b 的取值范围； （2）设直线33+=x y 、直线33+-=x y 及直线y =-2围成的图形为W ，⊙T 的半径为1，圆心T 的坐标为（t ，0），直接写出⊙T 与图形W 相离的t 的取值范围．顺义区2020届初三数学第一次统一练习参考答案9．x≥3；10．40°；11．①③；12．1；13．3；14．6；15．②④③①；16．4，1或1．三、解答题（共12道小题，共68分）17．解：原式-……………………………………4分= …………………………………………………………5分18．解一：233x yx y+=⎧⎨-=⎩②×3得3x-1分①+③得510x=………………………………………2分∴2x=．……………………………………………………3分把2x=代入②得1y=-………………………………………4分∴原方程组的解是21xy=⎧⎨=-⎩……………………………………5分解二：由②得：3x y=+③………………………………………1分把③代入①得2(3)31y y++=……………………………2分解得1y=-……………………………………………3分把1y=-代入②得2x=…………………………………4分∴原方程组的解是21xy=⎧⎨=-⎩……………………………………5分19．解：（1）证明：()22224(2)41244(2)b ac m m m m m-=--⨯⋅-=++=+，…1分∵2(2)0m+≥，∴方程总有实数根．……………………………………………………2分（2）解：∵2(2)2m mx-±+==，∴12222m mx-++==，2222m mx m---==-．………4分∵方程有一根小于2，∴-m<2．∴m>-2．…………………………………………………………5分20．解：（1）作图如图1所示．…………1分（2）证明：∵AC平分∠BAM，∴∠1=∠2．……………2分MB∵AM ∥BC ， ∴∠2=∠3． ∴∠1=∠3．∴AB =BC ．……………… 3分 同理可证：AB =AD ． ∴AD =BC ． 又∵AD ∥BC ，∴四边形ABCD 是平行四边形．……………………………… 4分∵AB =BC ，∴□ABCD 是菱形．…………………………………………… 5分 21．解：（1）他们点了（10-y ）份A 套餐，（10-x ）份B 套餐，（x+y -10）份C 套餐（均用含x 或y 的代数式表示）；…………………………3分（2）若x =6，且A 、B 、C 套餐均至少点了1份，则最多有 5种点餐方案． …………………………………………………………………………5分22．(1)证明：连接OC ，∵OB=OC ，∠B=45°， ∴∠BCO =∠B=45°．∴∠BOC =90°．…………………… 1分 ∵四边形ABCD 是平行四边形， ∴AB ∥DC ．∴∠OCD=∠BOC =90°．…………2分 ∵OC 是，∴CD 是⊙O 的切线．……………… 3分(2)解：连接AC ，交BD 于点E ．∵AB 是直径，AB =8， ∴∠ACB =90°．∴BC AC ==．…………4分 ∵四边形ABCD 是平行四边形，∴12CE AC ==∴BE ===．………………………………5分∴2BD BE ==6分23．解：（1）汉王科技股份有限公司的知识产权竞争力得分排名是第16；…… 1分（在90≤x ＜95范围内都对） 2分（3）在41家企业注册所在城市分布图中，m = 5 ，…………………… 3分在下图中用阴影标出代表上海的区域：D上海………………4分（4）推断合理的是①②．…………………………………………………6分24．解：（1）表中的所填数值是1.9；……………………………………………1分（2）…………………………2分（3）结合函数图象，解决问题：当△PEF为等腰三角形时，AP的长度约为 3.5，3.8，4.6 cm．………………………………………………………………………………5分25．解：（1）∵点A（3，2）在函数n=的图象上，yx∴n=6．………………………………………………………………1分=+上，∵点B（0，-1）在直线l：y kx b∴b=-1．………………………………………………………………2分（2）①区域W内的整点个数为 1 ，……………………………………3分区域W内的整点的坐标为（3，1）；……………………………4分②（ⅰ）当直线l在BA下方时，若直线l与x轴交于点（3，0），结合图象，区域W内有4个整点，此时：3k-1=0，∴1k=．3当直线l与x轴的交点在（3，0）右侧时，区域W内整点个数不少于5个，．∴0<k<13（ⅱ）当直线l在BA上方时，若直线l过点（1，4），结合图象，区域W内有4 个整点，此时k-1= 4，解得k= 5．结合图象，可得k> 5时，区域W内整点个数不少于5个，图1综上，k 的取值范围是0<k <13或k > 5．…………………………………6分 26．解：（1）把点A （0，-4）和B （-2，2）分别代入y =ax 2+bx +c 中，得c =-4，…………………………………………………………………1分4a -2b +c =2．∴b=2a -3．……………………………………………………………2分（2）当a <0时，依题意抛物线的对称轴需满足232a a --≤-2． 解得32-≤a<0． 当a >0时，依题意抛物线的对称轴需满足232a a --≥0． 解得 0< a ≤32． ∴a （3）可求直线AB ∴C （-3，5） ①当a >0 (如图1)的下方．∴a +2a -3-4<5解得a <4． ∴0<a <4．②当a <0∴244ac ba -=解得3a =-+综上，a27．（1）解：①∵△ABC ∴AB=AC ，∠∵AE 平分∠∴∠BAE =12∠由旋转可知：∴AB=AD ，∠∴∠ABD =∠D ∴∠AED =∠ABD +∠BAE =45°．……………………………………2分654321FCBA 图3E D②用等式表示线段AE 、CE 、BD之间的数量关系为2BD CE =+． ………………………………………………………………………3分 （2）解：①依题意补全图2．……………………………………………………4分②用等式表示线段AE 、CE 、BD之间的数量关系为2BD CE =-．………………………………………………………………………5分 证明：过点A 作AF ⊥AE ，交ED 的延长线于点F （如图3）．∵△ABC 是等边三角形， ∴AB=AC ，∠BAC =60°． ∵AE 平分∠BAC ，∴∠1=12∠BAC = 30°．由旋转可知：AD=AC ，∠CAD =90°． ∴AB=AD ，∠2=∠CAD -∠BAC =30°． ∴∠3=∠4=75°． ∴∠5=∠4-∠1=45°． ∵AF ⊥AE ， ∴∠F =45°=∠5． ∴AF=AE ． ∴AE ．∵∠6=∠EAF -∠1-∠2=30°， ∴∠6=∠1=30°．又∵∠F =∠5=45°，AD=AB ， ∴△ADF ≌△ABE ． ∴DF=BE ．∵AB=AC ，AE 平分∠BAC ， ∴AE 垂直平分BC ． ∴CE=BE ． ∵BD =EF -DF -BE ，DE 图2ABC∴BD AE-2CE．……………………………………………7分28．解：（1）①与直线y=3x-5相离的点是A、C；……………………………2分②当直线y=3x+b过点A（1，2）时，3+ b=2．∴b=-1．当直线y=3x+b过点C（2，-1）时，6+ b=-1．∴b=-7．∴b的取值范围是b>-1或b<-7．……………………………………4分（2）t的取值范围是：t<或t或t. ……………………7分。

2020年北京顺义国际学校高三英语一模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AI once taught in a small private school. Each morning at nine o’clock all the students, ranging in age from three to seven years old, gathered in the Great Room for a warm-up in preparation for the day.One morning the headmistress made an announcement to all the children gathered,“Today we begin a great experiment of the mind.” She held up two ivy(常春藤) plants, each potted in an identical container. She continued, “Do they look the same?”All the children nodded. So did I, for, in this way, I was alsoa child.“We will give the plants the same amount of light, the same amount of water, but not the same amount of attention,” She said. “Together we are going to see what will happen when we put one plant in the kitchen away from our attention and the other plant right here in this room. Each day for the next month, we shall sing to our plant in the Great Room and tell it how much we love it, and how beautiful it is. We will use our good minds to think good thoughts about it.”Four weeks later my eyes were as wide and disbelieving as the children’s. The kitchen plant was leggy and sick-looking, and it hadn’t grown at all. But the Great Room plant, which had been sung to and surrounded by positive thoughts and words, had increased threefold in size with dark leaves that were filled with energy.In order to prove the experiment, the kitchen ivy was brought to the Great Room to join the other ivy. Within three weeks, the second plant had caught up with the first ivy. Within four weeks, they could not be distinguished, one from the other.I took this lesson to heart and made it my own.1. Why did the headmistress do the experiment?A. She wanted to teach me a lesson.B. She expected the students to learn to grow plants.C. She meant to prove the impact of good minds on growth.D. She intended to show students how to save a sick-looking plant.2. What happened to the ivy in the kitchen at last?A. It stopped growing and died.B. It was leggy and sick with dark leaves.C. It looked almost the same as the other one.D. It grew better than the one in the Great Room.3. What can be a suitable title for the passage?A. Life Means GrowthB. Things Grow with LoveC. Equality Makes a DifferenceD. Positive Thoughts Really CountBWhat acts of kindness will make us the happiest, and who tends to benefit the most? A newly-published review of decades of kindness research provides some answers.In this paper, researchers analyzed the results from 126 research articles looking at almost 200, 000 participants from around the world. The studies they chose measured well-being in various ways, including both mental and physical health. Some were experiments, where people did a kindness practice to observe its effects, while others just surveyed people about how kind and happy they were.As expected, people who were kind tended to have higher well-being. Lead researcher Bryant Hui wasastoundedthat the relationship wasn't stronger than it was, but he was still encouraged by the results.One thing Hui and his colleagues found was that people who performed random, informal acts of kindness, like bringing a meal to a sad friend, tended to be happier than people who performed more formal acts of kindness, like volunteering in a soup kitchen.The researchers also found that people who were kind tended to be higher in "eudaimonic happiness"(a sense of meaning and purpose in life) more than "hedonic happiness"(a sense of pleasure and comfort). Perhaps this makes sense, given that being kind takes effort, which reduces comfort but could make people feel better about themselves and their abilities, which would provide a sense of meaning.Being kind came with greater eudaimonic happiness for women than for men, too. According to Hui, this could be because, in many cultures, women are expected to be kinder than men; so, they may have more to gain from it. And younger participants experienced more happiness when they were kind than older participants, perhaps for developmental reasons, he says.Hui isn't sure why acting kind might have these different effects on different groups, but he points to theories put forth by researcher Elizabeth Midlarsky: Being kind may make us feel better about ourselves as a person orabout the meaning of our lives, help us forget our own troubles and stresses, or help us be more socially-connected with others.4. What does the data in the second paragraph intend to show?A. The recent paper is worthy of being read.B. The recent paper gives convincing results.C. Kindness is always a hot topic of research.D. Kindness is closely linked to one's well-being.5. What does the underlined word "astounded" in paragraph 3 mean?A. Afraid.B. Certain.C. Excited.D. Surprised.6. Which of the following acts of kindness can make one feel happier according to paragraph 4?A. Volunteering in a hospital.B. Cleaning a community.C. Returning a lost item to its owner.D. Collecting donations for the poor.7. What do the researchers find from the paper?A. Being kind has different effects on different groups.B. Eudaimonic happiness makes people feel comfort.C. The younger experienced more happiness than the older.D. Female participants are kinder than male ones.CWe all know that a healthy lifemeans getting both plenty of exercise and enough good-quality sleep, but reality often gets in the way. The new research indicates that doing enough exercise could make up for some of the unhealthy impacts of bad sleep. While the health benefits of exercise and sleep are nothing new, it's the relationship between them that is interesting in this particular study — it could even give doctors another option to suggest for patients dealing with sleep problems.“We found those who had both the poorest sleep quality and who exercised the least were most at risk of death from heart disease, stroke, and cancer,” says epidemiologist Bo-Huei Huang, from the University of Sydney in Australia.Participants were grouped into three levels of physical activity (high, medium or low) and were also given a sleep quality score from 0-5 based on the amount of shut-eye they got, how late they stayed up, insomnia, snoring and daytime sleepiness.Those with the highest risk of dying from cancer or heart disease during the study period were those with the worst quality sleep and who didn't meet the WHO recommended guidelines for exercise. That risk went down for people with poor quality sleep but who did meet the exercise guidelines.In the case of all forms of cancer, for example, those at the unhealthiest end of the sleep and exercise scale had a 45 percent higher risk of dying from cancer than those with good sleep scores who kept physically active. However, that risk just about disappeared for those who didn't score well on sleep but did score well on physical activity.For now it's not clear why more exercise might make up for poor sleep, as far as our health goes. It could be that the increased activity iscounteractinginflammation (炎症), or reducing irregularities in glucose metabolism, suggest the researchers.“Considering that physical activity is perhaps more modifiable than sleep, our study offers people more health incentives to be physically active.” says population health researcher Emmanuel Stamatakis, from the University of Sydney.8. This research is of particular interest in that ________.A. it’s in this study that exercise is known to be beneficial to sleep.B. this study offers people more health treatments to be physical active.C. it could enable doctors to cure patients of their sleeping condition.D. the relationship between exercise and sleep is updated in this study.9. Which of the following statements istrueaccording to the passage?A. Those who had the poorest sleep quality were most at risk of death from heart disease.B. Those scoring lowest on sleep and exercise scale were more likely to die from cancer.C. There’s no risk of cancer for those who didn't sleep well but did score well on physical activity.D. It's evident that in terms of health more exercise could make up for poor sleep.10. What does the underlined word in Paragraph 6 mean?A. interactingB. increasingC. preventingD. causing11. Where can this passage most probably be taken from?A. A research findings reportB. A medical examination reportC. A poor sleep study reportD. A physical activity study reportDIn Colombia a group, named WebConserva, is carrying out a project in the San Lucas Mountains with the help of coffee growers.The San Lucas area is one of the most unexplored places in Colombia, which is home to many thousands of species of animals and plants. Yet gold mining and coca farming have dealt a blow to its ecosystem. To limitadditional development in the San Lucas area, the group helps coffee growers by linking them with processors from around the country.Colombia has more different kinds of living things than any other country except neighboring Brazil. In 2016, the Colombian government signed a peace deal with the Revolutionary Armed Forces of Colombia ending years of civil war. As a result, more land became accessible for use, with deforestation(毁林) coming along. Government information shows that in 2017, almost 220,000 hectares of forest were destroyed compared to around 124,000 hectares in 2015.To date, the project includes 10 families who farm 400 hectares of coffee plants, which costs about $77,000 dollars a year. WebConserva hopes that, in time, 200 families will be included. At that level, 20,000 hectares of untouched forest could be protected. In San Lucas, the families promise not to cut down trees to expand their crops or to hunt wild animals from the forests. In return, they receive $ 250 to $ 300 per 125 kilograms of coffee, an enviable amount there. Arcadio Barajas is among those taking part. His new coffee plantation(种植园) makes a barrier between cattle farms and forests where wild animals like the jaguar live and hunt. In this way, he doesn't have to kill wild animals to protect his cattle.Barajas said that pulling down the forest to plant coca and killing wildlife were against his will. Now he feels that growing coffee lets him be astewardof the land. "I'm taking care of the environment, the forest and the animals," he said.12. Why does WebConserva set up the project?A. To help local farmers make money.B. To expand areas of coffee growing.C. To link processors with coffee growers.D. To conserve biodiversity in the Mountains.13. What happened after Colombia’s civil war was over?A. Colombia helped many needy families.B. Colombia lost lots of areas of forests.C. Colombia started to save damaged forests.D. Colombia became more peaceful than Brazil.14. Which is probably a function of Barajas's coffee plantation?A. A method of protecting cattle and wildlife.B. A substitute for hunting of wild animals.C. A barrier between man and wild animals.D. A shelter for cattle against human hunters.15. What does the underlined word "steward" mean in the last paragraph?A. Farmer.B. Master.C. Guardian.D. Explorer.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届北京市顺义区第一中学高三英语一模试卷及参考答案第一部分阅读（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AMy wife Hilary andI were on the beach, with three of our children, taking pictures of shore birds near our home in Alaska when we saw a bear. The bear was thin and small, moving aimlessly.Just a few minutes later, I heard my daughter shouting, “Dad! The bear is right behind us!" An aggressive bear will usually rush forward to frighten away its enemy but would suddenly stop at the last minute. This one was silent and its ears pinned back the sign of an animal that is going in for the kill. And it was a cold April day. Thebear behaved abnormally, probably because of hunger.I held my camera tripod(三脚架)in both hands to form a barrier as the bear rushed into me. Its huge head was level with my chest and shoulders, and the tripod stuck across its mouth. It bit down and I found myself supporting its weight. I knew 1 would not be able to hold it for long.Even so, this was a fight I had to win: I was all that stood between the bear and my family, who would stand little chance of running faster than a brown bear.The bear hit at the camera, cutting it off the tripod. I raised my left arm to protect my face; the beast held tightly on the tripod and pressed it into my side. My arm could not move, and I sensed that my bones were going to break.Drawing back my free hand, I struck the bear as hard as I could for five to six times. The bear opened its mouth and I grasped its fur, trying to push it away. I was actually wrestling with the bear at this point. Then, as suddenly as it had begun, the fight ended. The bear moved back towards-the forest,before returning for another attack the first time I felt panic.Obviously satisfied that we caused no further threat, the bear moved off, destroying a fence as it went. My arm was injured, but the outcome for us could hardly have been better. I'm proud that my family remained clear-headed when panic could have led to a very different outcome.1. How did the writer feel when faced with the brown bear?A. Fearful but confident.B. Nervous but brave.C. Upset but determined.D. Awful but hopeful.2. The bear finally went away after itA. got injuredB. felt safeC. found some foodD. took away the camera3. What does the author want to tell us?A. We should keep calm when troubles comeB. We should rise to the challenge when faced with difficulties.C. We should not risk ourselves in some dangerous areas.D. We should learn to take advantage of anything at hand when in trouble.BWith their tiny brains and excellent ability to memorize nectar locations, honeybees are a favorite model organism for studying learning and memory. Such research has indicated that to form long-term memories—ones that last a day or more—the insects need to repeat a training experience at least three times. By contrast, short-and mid-term memories that last seconds to minutes and minutes to hours, respectively, need only a single learning experience.Exceptions to this rule have been observed, however. For example, in some studies, bees formed long-lasting memories after a single learning event. Such results are often regarded as circumstantial anomalies, says Martin Giurfa of the University of Toulouse. But the anomalous findings, together with research showing that fruit flies and ants can form long-term memories after single experiences, aroused Giurfa’s curiosity. Was it possible that honeybees could reliably do the same? Giurfa reasoned that the ability to form long-term memories might depend on the particular type of bee and the experience. Within a honeybee colony, there are nurses, who clean the hive and feed the young; guards, who patrol and protect the hive; and foragers, who search for nectar.While previous studies have tested bees as a whole, Ciurfa and his colleagues focused on foragers, tasking them with remembering an experience relevant to their role: an odor associated with a sugary reward.The researchers observed that a single exposure to a reward-paired odor was enough for most forager bees to remember that specific odor the following day. Many foragers could even remember the odor three day later.The results do not mean that all prior research was wrong, says André Fiala of the University of Göttingen. “People have done the experiments in a different way.” Still, the new results do show that “the commonly held belief that one needs multiple training trials to achieve long-term memory is not always true,” he says, and this “really advances the field.”4. What does the author want to tell us through Paragraph 1?A. A model for memory research.B. The classification of memories.C. New research on learning and memory.D. Previous findings on memory formation.5. Which factor might influence a bee’s memory of an experience, according to Giurfa’s research?A. Whether the bee's role is related.B. Whether the bee is introduced or native.C. How often the bee repeats the experience.D. How long the bee is exposed to the reward.6. What is Andre Fiala’s attitude towards the new results?A. Doubtful.B. Favorable.C. Intolerant.D. Unclear.7. Which of the following is a suitable title for the text?A. Learning and Memory: How Honeybees RememberB. Honeybee Memory: Honeybee Knows What to DoC. Honeybees Remember after Just One LessonD. Honeybees Use Memory for CommunicationCMore than 10,000 people were made homeless in Ternang when the Sungai Mas overflowed its banks yesterday after six days of continuous heavy rain.The wooden bridge across the river has been washed away. The town is cut off by flood waters. At the fifth mile, Jalan Tengkn, the water is two meters deep. It is closed to all traffic. Flooding first happened at mid-afternoon yesterday along the river banks. People trying to get to higher ground were just in time to escape the destroying of the flood. Most of the flood victims(受害者) had to leave all their things behind.The National Flood Relief(救济) Center was reported to give its help and by early evening the whole town was moved out, helped by the army, police, Red Cross Society and volunteers(志愿者).The flood victims are now housed in different simple relief centers in the nearby town of Ternang. “Everything possible is being done to help the unlucky people,” a government spokesman said, “In fact, money, food and clothing have begun to come in from public organizations and helpful people. A Disaster Relief Fund(救灾基金会) will be started as soon as possible.”According to the latest reports it is still raining heavily at Ternang. The whole town is expected to be wholly covered by the water. So far no deaths have been reported.8. This passage is probably taken from______.A. a storybookB. a textbookC. a magazineD. a newspaper9. It seems that the flood happened just because ______.A. the banks were too lowB. the wooden bridge is solid (坚固)C. the river was too narrowD. they had had wet days for some time10.From the passage we know that ______.A. though the town was flooded, you could still go there by busB. as soon as the water flowed over the banks, people began to go to higher landsC. the government and the whole society are taking great care of the flood victimsD. the flood hasn't brought a large loss to the town as nobody died in the flood11. What is the best title for this passage?A. A Big FloodB. Ternang Is destroyedC. Over 10,000 People Are HomelessD. Rescue Team ArrivedDElizabeth Bishop is considered one of the best American poets of the 20th century. She was born in Worcester, Massachusetts in 1911. Her dad died when she was just a baby and her mom never recovered from the loss. She went to live with her grandparents in Nova Scotia, Canada when she was five. Eventually Bishop attended Vassar College, where she began to write poetry.At Vassar she discovered Marianne Moore's poetry and met Ms Moore and began their life-long friendship. She later met poet Robert Lowell. She wrote tons and tons of letters to both of them, which is good for us because we would otherwise know very little of her personal life.Bishop published her first book of poetry in 1946 and wrote until her death in 1979. She would spend years working on a single poem. Her poems are not the result of hasty scribbling (匆忙乱写) on paper while eating breakfast. She would look through drafts of poems again and again and improve them until they were as close to perfect as she could get them.Reading Elizabeth Bishop is like being transported to the very place, the very moment she's writing about. She leads us to a microscope so we can see every smallest part of the scene. It seems that she's always asking us to notice more, and more until the poem is so clear in our minds that it's almost painful—like a light that's too bright.12. What do we know about Bishop's early life?A. She was mainly brought up by her grandparents.B. She spent her childhood mainly in Worcester.C. She was always encouraged by her parents.D. She started to write poems at five.13. Why are Bishop's letters to Moore and Lowell important?A. They have a deep influence on other poets.B. They offer much information about her life.C. They help us study Moore and Lowell's poetry.D. They prove she had friendships with famous poets.14. What can we say about Bishop's poetic creation?A. She liked to write in the morning.B. She could write poems at high speed.C. She tried her best to achieve perfection.D. She published hundreds of books of poetry.15. Which word can be used to best describe the style of Bishop’s poems?A. Enthusiastic.B. Romantic.C. Humorous.D. Exact.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年北京顺义国际学校高三英语一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AJuanito Estrella has been a housekeeping manager on the US-based large passenger ship Carnival Spirit for 18 months and feels he has found the suitable position in his career(职业). He has always wanted to travel. “I guess I am a really restless spirit.I like traveling, so when the chance came, I jumped at it,” he says.The chance came in the form of a newspaper advertisement for work on cruise ships（游船）. At the time Estrella was the housekeeping manager at a Melbourne hotel. He applied and, after two interviews, a medical check and police clearance, the job was his.Estrella is responsible(负责的)for the cleanliness of the ship, making sure that 160 crew work properly. “I enjoy it because there is no other work-you wake up each day in a different place anda different culture. It’s exciting when you go to the next country and you don’t understand the language,” he says.Estrella likes being busy and getting to know people from all over the world. The 1,000 crew come from 94 countries, and Estrella has learnt Spanish and a little Croatian.But there is adownside. “You cannot get really drunk...because you have safety responsibilities to yourself and others,” he says. “You don’t really think about home.You start to think about home only when you get closer to your vacation and wonder what you’ll be doing.”Life on the ship is anything but cruising. Estrella and his fellows work at least 10 hours a day, seven days a week. He warns the job is not for everybody. “You have to love being busy and be prepared to work every day-and to give up drinking too much alcohol.” In his spare time, if the ship sails into a port, Estrella explores it, otherwise he works out in the crew’s gym, goes on the internet or calls home.1.Which of the following is true?A.He has been a housekeeping manager for 18 months.B.He doesn’t drink wine now.C.He cannot speak a foreign language.D.He used to be a housekeeping manager.2.The underlined word“downside”in paragraph 5 probably means ________ .A.disappointmentB.disadvantageC.failureD.loss3.In the last paragraph, the writer thinks that life on the ship is ________.A.not a tiring journey at allB.just an interesting voyageC.far from a voyage for pleasureD.more than a pleasant travel by seaBJoshua Nelson, 18, fromMissouri, is graduating fromSt. CharlesWestHigh Schoolthis week and will be attendingSoutheastMissouriStatein the fall. He had saved upmoney to pay for his tuition, but when he received the college's President's Scholarship, he decided to take his savings and donate it to other students in need.“It comes from my family education and faith," Nelson said. "I've always lived by strong principles as far as being a cheerful giver andhaving an open handwhen it comes to giving back so I feel like that really motivated me.”SEMO's President's Scholarship is the school’s most celebrated, and is only awarded to five top students annually. Nelsonsaid he sat down and outlined how a scholarship could work to help future students who need financial assistance for college. Originally the plan was to give away $ 1,000 the one time, but then he met up with his counselor (顾问), Yolanda Curry, to work outa game plan.“I wasn't expecting it at all!” Curry said. "He told me he had a great idea and wanted to share it with me. I could tell he was really excited.Nelson, in association with his high school, set up the Joshua Nelson Leaders In Action Scholarship fund. Each year, $1,000 will be awarded to a senior. The money will come from donations, of which there have been $16,000 so far — for a total of $17,435 at last count, according to the school. With the money already in the fund, there's enough to give out a scholarship each year for over a decade. The first scholarship was awarded on June 1 to Darrell Montalvo-Luna. As the first recipient, his scholarship was $2,000.“Joshua has the heart of a servant leader. He leads by example and he's genuinely excited when good things happen for other people," Curry said. "He's an encouragement — he's good at building others up and does what he can to help encourage and motivate those around.4. What did Nelson's initial donation come from?A. His scholarship.B. His savings.C. His pocket money.D. His wages.5. What does the underlined phrase "having an open hand" in paragraph 2 mean?A. Ambitious.B. Courageous.C. Generous.D. Cautious.6. How did Curry feel when hearing Nelson's idea?A. Shocked.B. Confused.C. Excited.D. Delighted.7. What can be inferred about the Joshua Nelson Leaders In Action Scholarship fund?A. It never supports high school students.B. It was set up more than ten years ago.C. It was founded by Nelson and Curry.D. It is going very smoothly.CWe are in lack of enough sleep, according to Arianna Huffington, the co-founder and editor-in-chief of The Huffington Post. And thishas great consequences on our health, our job performance, our relationships and our happiness. What is needed, she ly declares, is nothing short of a sleep revolution. Only by renewing our relationship with sleep can we take back control of our lives.In her bestseller Thrive, Arianna wrote about our need to redefine success through wellbeing, wisdom, wonder, and giving. Her discussion of the importance of sleep as a gateway to this more fulfilling way of living struck such a powerful chord (弦) that she realized the mystery and transformative power of sleep called for a fuller investigation (调查).The result is a scientifically sweeping and personal exploration of sleep from all angles, from the history of sleep, to the role of dreams in our lives, to the consequences of sleep deprivation (剥夺), and the new golden age of sleep science that is showing the vital role sleep plays in our every waking moment and every aspect of our health — from weight gain, diabetes, and heart disease to cancer and Alzheimer’s.In The Sleep Revolution, Arianna shows how our cultural removal of sleep as time wasted damages our health and our decision-making and our work lives and shortens our personal lives. She explores all the latest science on what exactly is going on while we sleep and dream. She decides the dangerous sleeping pill industry, and all the ways of our addiction to technology disturb our sleep. She also offers a range of recommendations and tips from leading scientists on how we can get better and more restorative sleep.In today’s fast-paced, always-connected and sleep-deprived world, our need for a good night’s sleep is more important than ever. The Sleep Revolution both sounds the alarm on our worldwide sleep crisis and provides a detailed road map to the great sleep awakening that can help transform our lives, our communities, and ourworld.8. What is the first paragraph mainly about?A. The importance of sleep.B. The necessity of improving sleep.C. The way to improve our sleep.D. The effect of sleep on health.9. What can be inferred about Arianna’s attitude to success?A. She thinks good sleep is more important.B. She doesn’t think much of becoming successful.C. She thinks it wrong to sacrifice health to success.D. She is concerned about the nature of success.10. What can be said about Arianna’s investigation?A. It is really of great value.B. It is scientific and historical.C. It costs Arianna’s sleep in practice.D. It covers all necessary aspects scientifically,11. What influence does TheSleep Revolution have on society?A. It helps to slow down the pace of modern life.B. It warns people against taking sleeping pills.C. It warns the harm of inadequate sleep of people.D. It helps to stress the value of sleep to success.DWhen Alex Linwas 11 years old, he read an alarming article in the newspaper, which said that people were burying old computers in backyards, throwing TVs into streams, and dumping (丢弃) cell phones in the garbage. This was dangerous because e-waste contains harmful chemicals that can leak into the environment, getting into crops, animals, water supplies and people.Alex was really worried and decided to make it next project for WIN-the Westerly Innovations Network. Alex and six of his friends had formed this organization to help solve community problems two years before.But what could they do about this project with e-waste? The team spent several weeks gathering information about the harmful chemicals in e-waste and their effects on humans. They learned how to dispose(处置) of e-waste properly and how it could be recycled. Then, they sent out a Survey and found only one in eight know what e-waste was, let alone how to properly dispose of it.Alex and his friends went into action. They advertised in the local newspaper and distributed notices to students, asking residents to bring their unwanted electronics to the school parking lot. The drive lasted two days, and they collected over 9, 500 kilograms of e-waste. The next step was to set up a long-term e-waste drop-off center for the town. After some research, they’d learned that reusing is the best way to deal with electronic devices and it is seven times more efficient than recycling. So, they began learning to retrofit (翻新) computers themselves and distributed them to students who didn’t have their own. In this way, they could help students in the area and protect the environment at the same time.For a lasting solution to e-waste, the drop-off center wasn’t enough. Lawswould have to be passed. In 2016, WIN helped push for an e-waste bill in their town, which required companies that manufactured or sold electronics to take back e-waste. The bill clearly forbids the dumping of e-waste. Because of the work of WIN, more and more people, like Alex and his team, are getting the message about safe disposal of e-waste. As Alex says, “Today’s technology should not become tomorrow’s harmful garbage.”12. What was Alex’s worry after he read the article?A. The littering of e-waste.B. The recycling of plastic.C. The change of environment.D. At 11 p.m. on Monday.13. What did Alex do to start the project?A. Set up WIN.B. Collect information.C. Ask friends for help.D. The overuse of old computer.14. Which can best describe the way Alex and his team did their work?A. Traditional.B. Competitive.C. Scientific.D. Convenient.15. What message does the story convey?A. There is no end to perfection.B. success comes through failure.C. Every positive attitude has a reward.D. young people can make a big difference.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年北京市顺义区中考数学一模试卷一、选择题（本大题共8小题，共16.0分）1.港珠澳大桥全长约为55000米，将数据55000科学记数法表示为()A. 0.55×105B. 5.5×104C. 55×103D. 550×1022.下面四个手机应用软件图标中是轴对称图形的是()A. B. C. D.3.直角三角板和直尺如图所示放置，若∠1=36°，则∠2的度数为()A. 34°B. 44°C. 54°D. 64°4.如图，数轴上点A表示数a，则|a−1|是()A. 1B. 2C. 3D. −25.一个布袋内只装有1个黑球和2个白球，这些球除颜色外其余都相同，随机摸出一个球后放回并搅匀，再随机摸出一个球，则两次摸出的球都是黑球的概率是()A. 49B. 13C. 16D. 196.如图，在△ABC中，AD平分∠BAC，按如下步骤作图：①分别以点A、D为圆心，以大于12AD的长为半径在AD两侧作弧，交于两点M、N；②连接MN分别交AB、AC于点E、F；③连接DE、DF，则下列说法中正确的是()A. DF平分∠ADCB. AF=3CFC. AE=AFD. DA=DB7.给出下列命题：①若−3a>2a，则a<0；②若a<b，则a−c<b−c；③若a>b，则ac2>bc2；④若ab>c，则b>c，其中正确命题的序号是()aA. ①②B. ①③C. ③④D. ②④8.下面的统计图反映了我国最近十年间核电发电量的增长情况．根据统计图提供的信息，下列推断合理的是()A. 2011年我国的核电发电量占总发电量的比值约为1.5％B. 2006年我国的总发电量约为25000亿千瓦时C. 2013年我国的核电发电量占总发电量的比值是2006年的2倍D. 我国的核电发电量从2008年开始突破1000亿千瓦时二、填空题（本大题共8小题，共16.0分）9.要使式子√2−x有意义，则x的取值范围是______ ．10.如图，小明在操场上距离旗杆18米的C处，用测角仪测得旗杆AB的顶端A的仰角为30°，已知测角仪CD的高为1.4米，那么旗杆AB的高为______米(保留三个有效数字)．11.在如图所示的几何体中，其三视图中有矩形的是______.(写出所有正确答案的序号)12.化简：(1m −1n)÷m−nn______．13.如图，矩形ABCD的对角线AC=8cm，∠AOD=120°，则AB的长为______cm．14.已知点P(a,b)在反比例函数y=2x 的图象上，若点P关于y轴对称的点在反比例函数y=kx的图象上，则k的值为______．15.2019年是中华人民共和国成立70周年，天安门广场举行了盛大的国庆阅兵式和群众游行活动．其中，群众游行队伍以“同心共筑中国梦”为主题，包含有“建国创业”“改革开放”“伟大复兴”三个部分，某同学要统计本班学生最喜欢哪个部分，制作扇形统计图．以下是打乱了的统计步骤：①绘制扇形统计图；②收集三个部分本班学生喜欢的人数；③计算扇形统计图中三个部分所占的百分比；其中正确的统计顺序是______．16.如图，四边形ABCD为正方形，△BPC为等边三角形，连接PD、BD，则∠BDP=________．三、解答题（本大题共12小题，共188.0分）17. 计算：3tan60°−(13)−2−√12+|2−√3|.18. 解二元一次方程组：{x +y =52x −y =419. 已知方程x 2−6x +c =0．(1)当此方程有两个不相等的实数根时，求c 的取值范围；(2)若3+√7是方程的一个根，求方程的另一个根及c 的值．20.如图，在△ABC中，∠BAC=90°，AD⊥BC，垂足为D．(1)求作∠ABC的平分线，分别交AD，AC于P，Q两点;(要求：尺规作图，保留作图痕迹，不写作法)(2)在(1)的基础上，过点P画PE//AC交BC边于E，联结EQ，则四边形APEQ是什么特殊四边形⋅证明你的结论．21.某校组织35名团员去某学习基地学习，准备用400元钱为每个人购买一份中餐．已知中餐有两种，12元一份和10元一份，根据以上内容，回答下列问题：(1)若全部购买12元一份的中餐，则400元钱够不够？(2)最多能买多少份12元一份的中餐？22.如图，⊙O过A，B两点，∠AOB=90°，E为OA上，C是OA延长线上一点，直线BE交⊙O于点D，连接CD，已知CD=CE．(1)求证：CD是⊙O的切线；(2)若OB=8，OE=2，求CD长．23.随着社会的发展，中学生上学带手机的现象越来越受到社会的关注，为此某校随机抽取了部分同学对其所持手机的态度进行了问卷调查(将对所持手机的态度分为四种类型：A非常赞同、B 赞同、C无所谓、D不赞同，所随机抽取的学生必须在四种类型中选择一种)，现将调查结果制成了如图所示的两幅不完整统计图．请结合两幅统计图，解答下列问题：(1)请补全条形统计图和扇形统计图；(2)抽取的同学中，对所持手机的态度的众数是__________；(3)若该校有3000名学生，请你估计该校学生对持“赞同”和“非常赞同”两种态度的人数之和．24.如图，在△ABC中，∠C=60°，BC=3厘米，AC=4厘米，点P从点B出发，沿B→C→A以每秒1厘米的速度匀速运动到点A.设点P的运动时间为x秒，B、P两点间的距离为y厘米．小新根据学习函数的经验，对函数y随自变量x的变化而变化的规律进行了探究．下面是小新的探究过程，请补充完整：(1)通过取点、画图、测量，得到了x与y的几组值，如下表：x(s)01234567y(cm)0 1.0 2.0 3.0 2.7 2.7m 3.6经测量m的值是______(保留一位小数)．(2)建立平面直角坐标系，描出表格中所有各对对应值为坐标的点，画出该函数的图象；(3)结合画出的函数图象，解决问题：在曲线部分的最低点时，在△ABC中画出点P所在的位置．25.如图，在平面直角坐标系xOy中，直线l：y=kx−1(k≠0)与函数(x>0)的图象交于点A(3,2)．y=mx(1)求k，m的值；(2)将直线l沿y轴向上平移t个单位后，与y轴交于点C，与函数y=m(x>0)的图象交于点D．x①当t=2时，求线段CD的长；②若√2≤CD≤2√2，结合函数图象，直接写出t的取值范围．26.在平面直角坐标系xOy中，已知抛物线y=x2+bx+c经过(−1,m2+2m+1)，(0,m2+2m+2)两点，其中m为常数．(1)求b的值，并用含m的代数式表示c；(2)若抛物线y=x2+bx+c与x轴有公共点，求m的值；(3)设(a,y1)，(a+2,y2)是抛物线y=x2+bx+c上两点，请比较y2−y1与0的大小，并说明理由．27.操作发现：(1)如图1，△ABC为等边三角形，点D为AB边上的一点，∠DCE=30∘，将线段CD绕点C顺时针旋转60∘得到线段CF，连接AF、EF，请直接写出下列结果：①∠EAF的度数为_________；②DE与EF之间的数量关系_________；类比探究：(2)如图2，△ABC为等腰直角三角形，∠ACB=90∘，点D为AB边上的一点，∠DCE=45∘，将线段CD绕点C顺时针旋转90∘得到线段CF，连接AF、EF．①求∠EAF的度数，并说明理由；②线段AE，ED，DB之间的数量关系？并说明理由．28.对于平面直角坐标系xOy中的点P，给出如下定义：记点P到x轴的距离为d1，到y轴的距离为d2，若d1≥d2，则称d1为点P的最大距离；若d1<d2，则称d2为点P的最大距离．例如：点P(−3,4)到到x轴的距离为4，到y轴的距离为3，因为3<4，所以点P的最大距离为4．(1)①点A(2,−5)的最大距离为______；②若点B(a,2)的最大距离为5，则a的值为______；(2)若点C在直线y=−x−2上，且点C的最大距离为5，求点C的坐标；(3)若⊙O上存在点M，使点M的最大距离为5，直接写出⊙O的半径r的取值范围．【答案与解析】1.答案：B解析：[分析]科学记数法的表示形式为a×10n的形式，其中1≤|a|<10，n为整数．确定n的值时，要看把原数变成a时，小数点移动了多少位，n的绝对值与小数点移动的位数相同．当原数绝对值>10时，n是正数；当原数的绝对值<1时，n是负数．[详解]55000用科学记数法可表示为：5.5×104，故答案选：B．[点睛]本题考查的知识点是科学记数法—表示较大的数，解题的关键是熟练的掌握科学记数法—表示较大的数．2.答案：D解析：【试题解析】本题考查的是轴对称图形的概念．轴对称图形的关键是寻找对称轴，图形两部分折叠后可重合．根据轴对称图形的概念解答．解：A.不是轴对称图形，故此选项错误；B.不是轴对称图形，故此选项错误；C.不是轴对称图形，故此选项错误；D.是轴对称图形，故符合题意．故选D．3.答案：C解析：解：作直线AB//a，∵a//b∴AB//a//b，∵AB//a，∴∠1=∠3，∵AB//b，∴∠2=∠4，∵∠3+∠4=90°，∴∠1+∠2=90°，∵∠1=36°，∴∠2=90°−36°=54°，故选：C．首先作平行线，然后根据平行线的性质可得到∠1+∠2=90°，据此求出∠2的度数．本题考查了平行线的性质，解题的关键是掌握两直线平行，同位角相等．4.答案：C解析：解：根据数轴得：a=−2，∴|a−1|=|−2−1|=|−3|=3，故选：C．根据数轴上A点的位置得出a表示的数，利用绝对值的意义计算．此题考查了数轴，以及绝对值，熟练掌握绝对值的意义是解本题的关键．5.答案：D解析：解：列表得：∵共9种等可能的结果，两次都是黑色的情况有1种，∴两次摸出的球都是黑球的概率为1，9故选D．列表将所有等可能的结果列举出来，利用概率公式求解即可．本题考查了列表法与树状图法的知识，解决本题时采用了两个独立事件同时发生的概率等于两个独立事件单独发生的概率的积，难度不大．6.答案：C解析：解：由作法得MN垂直平分AD，即EF⊥AD，∵AD平分∠BAC，∴AE=AF．故选：C．利用基本作图得MN垂直平分AD，由于AD平分∠BAC，利用等腰三角形的判定方法即可得到AE= AF．本题考查了作图−基本作图：熟练掌握基本作图(作一条线段等于已知线段；作一个角等于已知角；作已知线段的垂直平分线；作已知角的角平分线；过一点作已知直线的垂线)是解题的关键．7.答案：A解析：解：①若−3a>2a，则a<0，是真命题；②若a<b，则a−c<b−c，是真命题；③当a>b，c=0时，ac2=bc2，∴a>b，则ac2>bc2，是假命题；④ab>c，a<0时，b<c，a∴ab>c，则b>c，是假命题；a∴正确命题有①②．故选A．根据不等式的基本性质判断即可．本题考查了命题的真假判断、不等式的性质，正确的命题叫真命题，错误的命题叫做假命题．判断命题的真假关键是要熟悉课本中的性质定理．判定命题是假命题时，可举反例．8.答案：B解析：本题考查的是条形统计图，折线统计图有关知识，根据条形统计图，折线统计图的数据进行解答即可．解：A.错误，2011年我国的核电发电量占总发电量的比值大于1.5％，小于2.0%，B.正确，2006年我国的总发电量约为500÷2.0%=25000亿千瓦时，C.错误，2013年我国的核电发电量占总发电量的比值与2006年相比显然不到2倍，D.错误，我国的核电发电量从2008年开始未达到1000亿千瓦时．故选B．9.答案：x≤2解析：本题考查的是算术平方根的性质．根据被开方数大于等于0列式计算即可得解．解：根据题意得，2−x≥0，解得x≤2．故答案为：x≤2．10.答案：11.8解析：解：过点D作DE⊥AB，垂足为E．在直角△ADE中，有AE=DE×tan30°=6√3，那么旗杆AB的高为AE+EB=6√3+1.4=11.8(m)．运用三角函数定义求解．本题要求学生借助仰角构造直角三角形，并结合三角函数解直角三角形．11.答案：①②解析：解：长方体主视图，左视图，俯视图都是矩形，圆柱体的主视图是矩形，左视图是矩形，俯视图是圆，圆锥的主视图、左视图是等腰三角形，俯视图是带有圆心的圆，故答案为：①②．主视图、左视图、俯视图是分别从物体正面、左面和上面看，所得到的图形，据此作答．本题主要考查三视图的知识，熟练掌握常见几何体的三视图是解题的关键．12.答案：=−1m解析：[分析]本题主要考查分式的混合运算，解题的关键是掌握分式混合运算顺序和运算法则．先计算括号内异分母分式的减法，再计算除法即可得．[解答]解：原式=n−mmn ÷m−nn=−(m−n)mn·nm−n=−1m，故答案为=−1m．·13.答案：4解析：解：∵∠AOD=120°，∴∠AOB=60°，∵四边形ABCD是矩形，×8=4cm，BO=OD，∴AC=BD，AO=OC=12∴AO=BO=4cm，∴△ABO是等边三角形，∴AB=AO=4cm，故答案为：4根据矩形的性质求出AO=BO=4cm，求出△AOB是等边三角形，即可求出AB．本题考查了矩形的性质和等边三角形的性质和判定，能根据矩形的性质求出AO=BO是解此题的关键．14.答案：−2解析：【试题解析】的图象上，解：∵点P(a,b)在反比例函数y=2x∴ab=2，∵点P关于y轴对称的点的坐标是(−a,b)，∴k=−ab=−2．故答案为：−2．本题主要考查了反比例函数图象上点的坐标的特征，在解题时要能灵活应用反比例函数图象上点的坐标的特征求出k的值是解决本题的关键．先根据已知条件，求出ab的值，再根据点P关于y轴对称并且点P关于y轴对称的点在反比例函数y=k的图象上即可求出点k的值．x15.答案：②③①解析：解：正确的统计顺序是：②收集三个部分本班学生喜欢的人数；③计算扇形统计图中三个部分所占的百分比；①绘制扇形统计图；故答案为：②③①．根据扇形统计图的制作步骤求解可得．本题主要考查扇形统计图，扇形统计图是用整个圆表示总数用圆内各个扇形的大小表示各部分数量占总数的百分数．通过扇形统计图可以很清楚地表示出各部分数量同总数之间的关系．用整个圆的面积表示总数(单位1)，用圆的扇形面积表示各部分占总数的百分数．16.答案：30°解析：本题考查了等边三角形的性质，等腰三角形的性质，正方形的性质的应用，能求出∠CDB和∠CDP的度数是解此题的关键，注意：等边三角形的三边都相等．根据等边三角形的性质和正方形的性质得出BC=DC=CP，∠DCB=90°，∠PCB=60°，求出∠DCP=30°，∠CDB=∠CBD=45°，∠CDP=∠CPD=75°，即可求出答案．解：∵四边形ABCD为正方形，△BPC为等边三角形，∴BC=DC=CP，∠DCB=90°，∠PCB=60°，∴∠DCP=90°−60°=30°，∠CDB=∠CBD=45°，×(180°−30°)=75°，∠CDP=∠CPD=12∴∠BDP=∠CDP−∠CDB=75°−45°=30°，故答案为30°．17.答案：解：原式=3×√3−9−2√3+2−√3=−7．解析：直接利用负指数幂的性质以及绝对值的性质、特殊角的三角函数值分别化简得出答案． 此题主要考查了实数运算，正确化简各数是解题关键．18.答案：解：{x +y =5 ①2x −y =4 ②， ①+②，得：3x =9，∴x =3，把x =3代入①，得：y =2，∴此方程组的解为{x =3y =2．解析：此题考查了二元一次方程组的解法．解题关键是掌握运用加减消元法解二元一次方程组．解题时，先由①+②消去y ，求出x 的解，再把x 的值代入方程②，求出y 的解，即可得出方程组的解．19.答案：解：(1)∵关于x 的一元二次方程x 2−6x +c =0有两个不相等的实数根，∴b 2−4ac =36−4c >0，解得：c <9．(2)∵x =3+√7是此方程的一个根，∴代入方程得：16+6√7−6(3+√7)+c =0，解得：c =2，∴原方程为：x 2−6x +2=0，解得：x 1=3+√7，x 2=3−√7，方程的另一个根为3−√7．解析：此题主要考查了一元二次方程的解以及根的判别式，利用方程根与判别式的关系得出方程与不等式是解题关键．(1)利用方程根与判别式的关系，得出根的判别式符号直接解不等式得出即可；(2)将x=3+√7代入，进而求出c的值，进而得出方程的解．20.答案：解：(1)BQ就是所求的∠ABC的平分线，P、Q就是所求作的点．；(2)证明：四边形APEQ是菱形，∵∠BAD+∠CAD=∠CAD+∠ACD=90°，∴∠BAD=∠ACD，∵PE//AC，∴∠PED=∠ACD，∴∠BAD=∠PED，又∵BP平分∠ABC，∴∠ABP=∠EBP，又BP=BP，∴△ABP≌△EBP，∴PE=AP，∵∠AQP=90°−∠ABQ，∠APQ=∠BPD=90°−∠CBQ，∴∠AQP=∠APQ，∴AP=AQ，∴AQ=PE，又AQ//PE，∴四边形APEQ是平行四边形，∵PE=AP，∴四边形APEQ是菱形．解析：本题考查的是作图−作一个角的平分线和菱形的判定，涉及的知识点有：三角形的性质与判定定理，直角三角形的性质，菱形的判定等，熟知角平分线的作法和菱形的判定定理是解答此题的关键．(1)根据角平分线尺规作图作出BQ即可；(2)由已知条件推出∠BAD=∠ACD，因为PE//AC，所以∠PED=∠ACD，又BP平分∠ABC，推出△ABP≌△EBP，从而得出AP=PE，再证明AP=AQ，即可证明四边形APEQ是菱形．21.答案：解：(1)不够，因为35×12=420>400，∴全买12元一份的中餐，400元不够．(2)设12元一份的中餐能买x份，则10元一份的能买(35−x)份，由题意可得：12x+10(35−x)⩽400，解得：x⩽25，故最多能买25份12元一份的中餐．解析：本题考查的是解一元一次不等式应用有关知识．(1)先计算出全部购买12元一份的中餐所需要的费用，然后再与400比较即可解答；(2)设12元一份的中餐能买x份，则10元一份的能买(35−x)份，根据题意列出不等式即可解答．22.答案：解：(1)如图，连接OD，∵OD=OB，∴∠OBD=∠ODB，∵∠AOB=90°，∴∠BEO+∠OBE=90°，∵∠CED=∠BEO，∴∠CED+∠ODB=90°，∵CD=CE，∴∠CDE=∠CED，∴∠CDE+∠ODB=90°，∴∠CDO=90°，∴OD⊥CD，OD是⊙O的半径，∴CD是⊙O的切线；(2)在Rt△COD中，OD=OB=8，OE=2，∴OC=CE+2=CD+2，根据勾股定理，得OC2=OD2+CD2，即(CD+2)2=82+CD2解得CD=15．答：CD长为15．解析：本题考查了切线的判定与性质、勾股定理，解决本题的关键是掌握切线的判定与性质．(1)连接OD，根据OD=OB，CD=CE，可证明∠CDO=90°，即可证明CD是⊙O的切线；(2)根据勾股定理，得OC2=OD2+CD2，(CD+2)2=82+CD2，即可求出CD的长．23.答案：解：(1)∵5÷10%=50，∴在这次问卷调查中一共随机调查了50名学生；×100%=30%，补全条形统计图“无所谓”的学生人数为：50−10−20−5=15，百分比为1550和扇形统计图如下：(2)B“赞同”；(3)3000×(40%+20%)=1800人，答：估计该校学生对持“赞同”和“非常赞同”两种态度的人数之和为1800人．解析：本题考查了作样本估计总体，扇形统计图和条形统计图及众数.读懂统计图，从不同的统计图中得到必要的信息是解决问题的关键．条形统计图能清楚地表示出每个项目的数据；扇形统计图直接反映部分占总体的百分比大小．(1)根据D类5个点调查人数的10%求出调查的人数，即可补全条形统计图和扇形统计图；(2)根据众数的定义，出现次数最多的是B类；(3)用学校总人数乘以调查人数中持“赞同”和“非常赞同”两种态度所占的比．解：(1)见答案；(2))抽取的同学中，对所持手机的态度的众数是B“赞同”，故答案为B赞同；(3)见答案．24.答案：(1)3.0(2)描点、连线，画出图象，如图1所示．(3)在曲线部分的最低点时，BP⊥AC，如图2所示．解析：(1)经过测量可找出BP的长(利用等边三角形的判定定理可得出：当t=6时，△BCP为等边三角形)；解：(1)经测量，当t=6时，BP=3.0．(当t=6时，CP=6−BC=3，∴BC=CP．∵∠C=60°，∴当t=6时，△BCP为等边三角形．)故答案为：3.0．(2)描点、连线，画出函数图象；(3)由点到直线之间垂线段最短，可得出：在曲线部分的最低点时，BP⊥AC，依此即可画出图形．本题考查了动点问题的函数图象、等边三角形的判定、函数图象及垂直．25.答案：解：(1)将点A(3,2)的坐标分别代入y=kx−1和y=m中，得x2=3k−1，2=m，3∴k=2，m=3×2=6；(2)①∵直线y=kx−1与y轴交于点C(0,−1)，∴当t=2时，C(0,1)．中，整理得，x(x+1)=6，此时直线解析式为y=x+1，代入函数y=6x解得x1=−3(舍去)，x2=2，∴D(2,3)，∴CD=2√2．②当CD=√2时，点C的坐标为(0,6)，∴2≤t≤6．，即可求出k、m的值；解析：(1)将点A分别代入y=kx−1(k≠0)与函数y=mx(2)①求出当t=2时直线解析式，代入函数y=6中，整理得，x(x+1)=6，解方程求出点D的坐x标，即可求出CD的长；②观察图象解答即可．本题考查了一次函数与反比例函数的交点问题，待定系数法求解析式，利用函数图象性质解决问题是本题的关键．26.答案：解：(1)∵抛物线y=x2+bx+c经过(−1,m2+2m+1)，(0,m2+2m+2)两点，∴{1−b+c=m2+2m+1，c=m2+2m+2∴{b=2c=m2+2m+2，即：b=2，c=m2+2m+2，(2)由(1)得y=x2+2x+m2+2m+2，令y=0，得x2+2x+m2+2m+2=0，∵抛物线与x轴有公共点，∴△=4−4(m2+2m+2)≥0，∴(m+1)2≤0，∵(m+1)2≥0，∴m+1=0，∴m=−1；(3)由(1)得，y=x2+2x+m2+2m+2，∵(a,y1)，(a+2,y2)是抛物线的图象上的两点，∴y1=a2+2a+m2+2m+2，y2=(a+2)2+2(a+2)+m2+2m+2，∴y2−y1=[(a+2)2+2(a+2)+m2+2m+2]−[a2+2a+m2+2m+2]=4(a+2)当a+2≥0，即a≥−2时，y2−y1≥0，当a+2<0，即a<−2时，y2−y1<0．解析：此题是二次函数综合题，主要考查了抛物线与x轴的交点，比较代数式的大小．(1)由抛物线上两点代入抛物线解析式中即可求出b和c；(2)令y=0，抛物线和x轴有公共点，即△≥0，和非负数确定出m的值，(3)将两点代入抛物线解析式中，表示出y1，y2，求出y2−y1分情况讨论即可27.答案：解：操作发现：①∵△ABC是等边三角形，∴AC=BC，∠BAC=∠B=60°，由旋转知，CD=CF，∠DCF=60°，∴∠ACF=∠BCD，∴△ACF≌△BCD(SAS)，∴∠CAF=∠B=60°，∴∠EAF=∠BAC+∠CAF=120°；②DE=EF；理由如下：∵∠DCF=60°，∠DCE=30°，∴∠FCE=60°−30°=30°，∴∠DCE=∠FCE，又∵CD=CF，CE=CE∴△DCE≌△FCE(SAS)，∴DE=EF；(2)①∵△ABC是等腰直角三角形，∠ACB=90°，∴AC=BC，∠BAC=∠B=45°，由旋转知，CD=CF，∠DCF=90°，∴∠ACF=∠BCD，又∵AC=BC，CF=CD，∴△ACF≌△BCD(SAS)，∴∠CAF=∠B=45°，AF=DB，∴∠EAF=∠BAC+∠CAF=90°；②AE2+DB2=DE2，理由如下：∵∠DCF=90°，∠DCE=45°，∴∠FCE=90°−45°=45°，∴∠DCE=∠FCE，∵CD=CF，CE=CE∴△DCE≌△FCE(SAS)，∴DE=EF，在Rt△AEF中，AE2+AF2=EF2，又∵AF=DB，∴AE2+DB2=DE2.解析：解析：本题是几何变换综合题目，考查了旋转的性质、等边三角形的性质、全等三角形的判定与性质、等腰直角三角形的判定与性质、勾股定理；本题综合性强，有一定难度，证明三角形全等是解决问题的关键．操作发现：①由等边三角形的性质得出AC=BC，∠BAC=∠B=60°，求出∠ACF=∠BCD，证明△ACF≌△BCD，得出∠CAF=∠B=60°，求出∠EAF=∠BAC+∠CAF=120°；②证出∠DCE=∠FCE，由SAS证明△DCE≌△FCE，得出DE=EF即可；(2)①由等腰直角三角形的性质得出AC=BC，∠BAC=∠B=45°，证出∠ACF=∠BCD，由SAS证明△ACF≌△BCD，得出∠CAF=∠B=45°，AF=DB，求出∠EAF=∠BAC+∠CAF=90°；②证出∠DCE=∠FCE，由SAS证明△DCE≌△FCE，得出DE=EF；在Rt△AEF中，由勾股定理得出AE2+AF2=EF2，即可得出结论．28.答案：解：(1)5，±5；(2)设点C的坐标(x,y)，∵点C的“最大距离”为5，∴x=±5或y=±5，当x=5时，y=−7，当x=−5时，y=3，当y=5时，x=−7，当y=−5时，x=3，∴点C(−5,3)或(3,−5)．(3)如图，观察图象可知：当⊙O于直线x=5，直线x=−5，直线y=5，直线y=−5有交点时，⊙O上存在点M，使点M的最大距离为5，∴5≤r≤5√2．解析：解：(1)①∵点A(2,−5)到x轴的距离为5，到y轴的距离为2，∵2<5，∴点A的“最大距离”为5．②∵点B(a,2)的“最大距离”为5，∴a=±5；故答案为5，±5．(2)见答案；(3)见答案(1)①直接根据“最大距离”的定义，其最小距离为“最大距离”；②点B(a,2)到x轴的距离为2，且其“最大距离”为5，所以a=±5；(2)根据点C的“最大距离”为5，可得x=±5或y=±5，代入可得结果；(3)如图，观察图象可知：当⊙O于直线x=5，直线x=−5，直线y=5，直线y=−5有交点时，⊙O 上存在点M，使点M的最大距离为5，本题考查一次函数综合题、“最大距离”的定义、圆的有关知识，解题的关键是理解题意，灵活运用所学知识解决问题，学会利用特殊位置解决数学问题，属于中考压轴题．。

顺义区2020届初三第一次统一练习化学试卷考生须知1．本试卷共6页，共两部分，22道小题，满分45分。

考试时间与生物合计90分钟。

2．在试卷和答题卡上准确填写学校名称、姓名和准考证号。

3．试题答案一律填涂或书写在答题卡上，在试卷上作答无效。

4．在答题卡上，选择题用2B铅笔作答，其他试题用黑色字迹签字笔作答。

可能用到的相对原子质量：N 14 C 12 O 16第一部分选择题（共12分）（每小题只有一个选项符合题意。

共12道小题，每小题1分）1．下列变化属于物理变化的是A．食物腐烂B．汽油挥发C．钢铁生锈D．粮食酿酒2．下列物质在氧气中燃烧，火星四射、生成黑色固体的是A．木炭B．铁丝C．蜡烛D．红磷3．下列金属的金属活动性最强的是A．Cu B．Fe C．Al D．Ag4．一种铈原子的原子核内有58个质子和82个中子，该原子的核外电子数为A．58 B．24 C．82 D．1405．关于右图所示的电解水实验，下列说法正确的是A．试管1中是氧气B．得出水由氢气和氧气组成的结论C．试管1和试管2中气体的质量比为2：1D．用带火星的木条检验试管2中的气体能复燃6．下列符号能表示2个氢分子的是A．2H2B．H2 C．2H D．2H+7．下列实验操作正确的是A．取用固体B．滴加液体C．加热液体D．检查气密性8．下列燃料，不属于化石燃料的是A．石油B．煤C．氢气D．天然气9．关于下列物质的用途，说法不正确．．．的是A．氧气用于急救病人B．氯化钠用于调味品C．浓硫酸用于食品干燥剂D．熟石灰用于改良酸性土壤10．向下列物质中加入稀盐酸，无明显现象的是A．Fe2O3粉末B．滴有酚酞的NaOH溶液C．Ag D．NaHCO3溶液下表是Na11~12题。

温度Na2CO3NaCl20℃21.8g 36.0g30℃39.7g 36.3g20℃时，向2只盛有100g水的烧杯中，分别加入30g两种固体，充分溶解。

11．上述溶液为饱和溶液的是A．①B．②C．③D．④12．下列说法正确的是A．①所得溶液中溶质与溶剂质量比为3：10B．②所得溶液中溶质的质量分数为30%C．①和③的溶质质量分数相等D．③和④的溶质质量分数相等第二部分非选择题（共33分，每空1分）【生活现象解释】13.解释下列生活现象：（1）干冰常用于人工降雨，利用了干冰________的性质。

1顺义区2020届高三第二次统练数学试卷一、选择题共10小题，每小题4分，共40分。

在每题列出的四个选项中，选出符合题目要求的一项。

（1）已知集合{}32A x x =-<<，{}3,2,0=--B ，那么A B =I （A ）{}2-（B ）{}0（C ）{}2,0-（D ）{}2,0,2-（2）在复平面内，复数()i 1i z =+对应的点位于 （A ）第一象限（B ）第二象限（C ）第三象限（D ）第四象限（3）下列函数中，既是偶函数，又在()0,+∞上单调递减的是（A ）2y x =- （B ）2y x =- （C ）cos y x =（D ）12xy =（）（4）抛物线2=4y x 上的点与其焦点的最短距离为（A ）4 （B ）2 （C ）1（D ）12（5）若角α的终边经过点(1,2)P -，则sin α的值为（A （B （C ）（D ） （6）某三棱锥的三视图如图所示，则该三棱锥的体积是2（A ）6 （B ）8 （C ）12 （D ）24（7）若α为任意角，则满足cos()cos 4π+⋅=k αα的一个k 值为（A ）2（B ）4（C ）6（D ）8（8）已知,,a b c ∈R ，在下列条件中，使得a b <成立的一个充分而不必要条件是（A ）33a b < （B ）22ac bc <（C ）11a b> （D ）22a b <（9）设{}n a 是各项均为正数的等比数列，n S 为其前n 项和.已知1316a a ⋅=, 314S =,若存在0n 使得012,n a a a ⋅⋅⋅，，的乘积最大，则0n 的一个可能值是 （A ）4（B ）5（C ）6（D ）7（10）已知()f x ＝21|1|,02,0x x x x x -+<⎧⎨-≥⎩，若实数[]2,0m ∈-，则()(1)f x f --在区间[],2m m +上的最大值的取值范围是（A ）[]1,4（B ）[]2,4（C ）[]1,3（D ）[]1,2数学 第3页（共6页）第二部分(非选择题 共110分)二、填空题共5小题，每小题5分，共25分。

答案和解析1.【答案】A【解析】解：根据质量数和电荷数守恒， 24He+ 714N→ 817O+ 11X，X表示的是质子，故A正确，BCD错误。

故选：A。

根据质量数和电荷数守恒求出x的电荷数和质量数，即可判断x是否表示电子、质子、还是中子。

本题比较简单，考查了核反应方程中的质量数和电荷数守恒的应用。

2.【答案】B【解析】解：A、内能是物体内所有分子的分子动能和分子势能的总和，故A错误；B、温度是分子平均动能的标志，标志着物体内大量分子热运动的剧烈程度，故B正确；C、气体压强不仅与分子的平均动能有关，还与分子的密集程度有关，故C错误；D、气体膨胀对外做功且温度降低，温度是分子平均动能的标志，温度降低，则分子的平均动能变小，故D错误。

故选：B。

温度是分子平均动能的标志。

内能是所有分子的分子动能和分子势能的总和。

气体压强与温度、体积有关。

此题解答的关键是掌握温度的含义和气体压强的微观意义，并能运用来分析实际问题。

温度是分子平均动能的标志，温度越高，分子平均动能越大。

3.【答案】A【解析】解：A、矢量是既有大小、又有方向的物理量，速度、磁感应强度和冲量均为矢量，故A 正确。

B、I=UR 不是电流定义式，速度公式v=△x△t采用比值定义法，故B错误。

C、根据F=kx知k的单位是N⋅m，其基本单位表达是kg⋅s−2；故C错误。

D、点电荷采用的物理方法是理想化模型，故D错误。

故选：A。

速度、磁感应强度和冲量都是矢量。

速度公式v=△x△t采用比值定义法。

根据F=kx确定k的单位。

点电荷是一种理想化的物理模型。

解决本题的关键要理解并掌握物理基本知识。

要注意物理量定义式与决定式的区别，不能混淆。

4.【答案】C【解析】【分析】根据整体法求出AB共同的加速度，将加速度分解为水平方向和竖直方向，隔离对B分析，求出A、B之间的支持力和摩擦力，从而即可求解。

解决本题的关键能够正确地进行受力分析，运用牛顿第二定律进行求解，注意整体法和隔离的运用。

2020年北京市顺义区高考地理一模试卷一、单选题（本大题共22小题，共44.0分）1.如图为北京某手机用户查看天气预报时的手机截屏。

读图，回答1～4题。

图示期间（）A. 地球接近公转轨道远日点B. 时值我国立冬到小雪之间C. 太阳直射点向赤道移动D. 南极大陆极昼范围扩大2.如图为北京某手机用户查看天气预报时的手机截屏。

读图，回答1～4题。

图示期间，北京（）A. 天安门升旗时间提早B. 6点后日出东北方向C. 昼长变化幅度比哈尔滨大D. 正午太阳高度角比拉萨小3.如图为北京某手机用户查看天气预报时的手机截屏。

读图，回答1～4题。

图中11月29日比12月1日气温日较差小，主要原因是11月29日（）A. 地面吸收的太阳辐射多B. 大气对太阳辐射削弱多C. 受南风影响白天气温高D. 夜晚大气逆辐射作用弱4.如图为北京某手机用户查看天气预报时的手机截屏。

读图，回答1～4题。

图示期间，北京空气质量较好，主要原因是（）①空气对流运动旺盛，净化空气②降雪利于污染物的沉降③晴天较多，排放的污染物减少④刮风利于污染物的扩散A. ①③B. ①④C. ②③D. ②④5.如图为北京时间某日11时亚洲局部海平面气压分布图（单位：百帕）。

读图，回答5～7题。

据图推断，此时（）A. ①地可能出现强降水天气B. ②地风向为西北风C. ③地受高压控制气流上升D. ④地可见海上日出6.如图为北京时间某日11时亚洲局部海平面气压分布图（单位：百帕）。

读图，回答5～7题。

与北京相比（）A. ①地气压高B. ②地风速大C. ③地云量多D. ④地气温低7.如图为北京时间某日11时亚洲局部海平面气压分布图（单位：百帕）。

读图，回答5～7题。

如图所示季节（）A. 我国塔里木河进入丰水期B. 地中海沿岸温和多雨C. 印度盛行西南风，降水多D. 南非热带草原一片枯黄8.读图，回答8、9题。

图中（）A. ①处的物质主要来源于地核B. 形成①、②处岩石的地质作用相同C. 断层发生在岩层③形成之后D. ④处溶洞景观由岩层断裂下陷造成9.读图，回答8、9题。

2020年北京市顺义区高考物理一模试卷解析版
一、本部分共14小题，每小题3分，共42分．在每小题列出的四个选项中，选出最符合题
1．（3分）关于分子动理论，下列说法正确的是（）
A．气体扩散的快慢与温度无关
B．分子间同时存在着引力和斥力
C．布朗运动是液体分子的无规则运动
D．分子间的引力总是随分子间距增大而增大
【解答】解：A、扩散的快慢与温度有关，温度越高，扩散越快，故A错误；
B、分子间同时存在相互作用的引力和斥力，故B正确；
C、布朗运动是悬浮在液体中固体小颗粒的无规则运动，它不是液体分子的运动，它间接
体现了液体分子在永不停息地做不规则运动，故C错误；
D、分子间同时存在引力和斥力，引力和斥力均随着分子间距离的增大而减小，故D错
误。

故选：B。

2．（3分）下列说法中正确的是（）
A．天然放射现象的发现，揭示了原了核是由质子和中子组成的
B．汤姆孙通过对阴极射线的研究提出了原了核具有复杂的结构
C．氢原子的能级理论是玻尔在卢瑟福核式结构模型的基础上提出来的
D．卢瑟福的α粒子散射实验揭示了原子只能处于一系列不连续的能量状态中
【解答】解：A、天然放射现象揭示了原子核有复杂结构，故A错误；
B、汤姆孙通过对阴极射线的研究发现了电子，说明原子具有复杂的结构，故B错误；
C、玻尔的原子结构理论是在卢瑟福核式结构学说基础上引进了量子理论提出来的，故C
正确；
D、卢瑟福的α粒子散射实验揭示了原子具有核式结构，故D错误。

故选：C。

3．（3分）如图所示，P是一束含有两种单色光的光线，沿图示方向射向半圆形玻璃砖的圆心O，折射后分成a、b两束光线，则下列说法中正确的是（）
第1 页共18 页。

2020年北京市顺义区高考物理一模试卷一、单选题（本大题共6小题，共24.0分）1.频闪照相是每隔相等时间曝光一次的照相方法，在同一张相片上记录运动物体在不同时刻的位置．如图所示是小球在竖直方向运动过程中拍摄的频闪照片，相机的频闪周期为T，利用刻度尺测量相片上2、3、4、5与1位置之间的距离分别为x1、x2、x3、x4.以下说法正确的是()A. 小球一定处于下落状态B. 小球在2位置的速度大小为x22TC. 小球的加速度大小为x2−2x1T2D. 频闪照相法可用于验证机械能守恒定律2.如图电路，闭合电键S，电源电动势为E，内阻为r，待电路中的电流稳定后，减小变阻器R的阻值．则下列说法中正确的是()A. 电流表的示数减小B. 电压表的示数减小C. 电阻R2两端的电压减小D. 路端电压增大3.氢原子光谱在可见光部分只有四条谱线，一条红色、一条蓝色、两条紫色，它们分别是从n=3、4、5、6能级向n=2能级跃迁时产生的，则()A. 红色光谱是氢原子从n=3能级向n=2能级跃迁时产生的B. 蓝色光谱是氢原子从n=6能级或n=5能级向n=2能级跃迁时产生的C. 如果原子从n=6能级向n=l能级跃迁，则产生的是红外线D. 如果原子从n=6能级向n=l能级跃迁所产生的光子不能使某金属发生光电效应，则原子从n=6能级向n=2能级跃迁时可能使该金属发生光电效应．4.“洞察号”火星探测器在火星表面着陆前开始减速，加速度是地球表面重月加速度的12倍，已，由这些数据可推知洞察号减速时加速知火星平径约为地球半径的半火星质量约为地球质量的19度大约等于火屋表面加速度的()A. 3倍B. 9倍C. 27倍D. 81倍5.如图所示，M为一固定的带电球，丝线一端连接带电小球N，另一端悬挂在P位置，N球静止时丝线偏离竖直方向一定角度，M球的电荷量大于N球的电荷量，则()A. 两球都带正电荷B. 两球都带负电荷C. M球受到的静电力大于N球受到的静电力D. 若只增加M球的电荷量，则丝线偏离竖直方向的角度增加6.2018年12月8日2时23分我国自行研制的“嫦娥四号”无人探测器发射成功，开启人类首次月球背面软着陆探测之旅。

2020年北京市顺义区中考物理一模试卷一、单选题（本大题共15小题，共30.0分）1.下列用品中，通常情况下属于导体的是()A. 金属勺B. 塑料盆C. 玻璃杯D. 干木棒2.下列如图所示现象中，由于光的反射形成的是()A. 太阳光经过凸透镜形成光斑B. 手影的形成C. 水中铅笔看起来变弯折D. 塔在水中形成倒影3.关于物理量的符号和单位，下列对应错误的是()A. 速度v--m/sB. 功率P--J(N⋅m)C. 压强p--Pa(N/m2)D. 密度ρ--kg/m34.在如图的家用电器中，主要是利用电流热效应工作的是()A. 空气净化器B. 电冰箱C. 音响设备D. 电饭锅5.寒冷的冬天，小敏在卫生间泡热水澡，下列对有关现在的描述或解释，错误的是()A. 澡前，能用镜子看清自己的脸，这是光的反射造成的B. 在热水中浸泡时，皮肤血管逐渐舒张，以调节体温的相对恒定C. 搓背用的洗澡巾表面粗糙是为了增大摩擦D. 澡后，镜子表面变得模糊不清，这是汽化现象6.下列物态变化事例中，属于液化的是()A. 湿衣服晒后不久变干B. 灯丝用久了变细C. 清晨树叶上的露珠D. 冬天窗户上的霜7.下列四图中为了减小压强的是()A. 冰鞋上装有冰刀B. 飞镖的箭头很尖C. 载重车装有许多车轮D. 压路机的碾子质量很大8.下列事例中，属于用做功的方式改变物体内能的是()A. 酒精涂在手上会觉得凉B. 冬天在太阳光的照射下，人感到暖和C. 锯木头时，锯条会发烫D. 烧红的铁块置于空气中，温度逐渐降低9.下列做法中，正确的是()A. 有金厲外壳的家用电器在使用时．其外壳一定要接地B. 电器失火时，先用泡沫灭火器灭火，再进行检修C. 空气开关跳闸时．应立即使空气开关复位，再进行检修D. 遇到有人触电时．先直接将人拉开进行抢救，后切断电源10.如图中画出了物体A、B所受拉力F1与F2的示意图，由图可知()A. F1>F2B. F1=F2C. F1<F2D. 无法判断F1和F2的大小11.如图所示，标出了四个通电螺线管的N极和S极，其中正确的是()A. B.C. D.12.两只小灯泡L1和L2串联在电路中时，可以确定两灯的()A. 亮度不同B. 电压相等C. 电流相等D. 功率相等13.图示电路中，电源电压保持不变。

2020年北京市顺义区⾼三⼀模地理（含答案）2020北京顺义⾼三⼀模地理第⼀部分本部分共15题，每题3分,共45分。

在每题列出的四个选项中，选出最符合题⽬要求的⼀项。

2019年10⽉15⽇,中国⾸艘⾃主建造的极地科学考察破冰船“雪龙2”号从深圳出发，⾸次前往南极执⾏科考任务。

图1为我国南极考察站分布图。

读图，回答第1-3题。

1.中⼭站A.纬度⾼于泰⼭站B.位于西半球C.位于长城站西南D.濒临印度洋2.昆仑站到南极点的直线距离最接近A. 1100千⽶B. 3300千⽶C. 6600 千⽶D. 8800千⽶3.考察船出发时A.适逢中国霜降节⽓B.巴西⾼原草⽊枯黄C.长城站6点后⽇出东南且昼长夜短D.中⼭站⽐昆仑站正午太阳⾼度⾓⼤图2为某⽇6时北半球局部海平西⽓压分布图(单位:百帕)，读图，回答第4、5题，4.图中A.①⽐③⽓温⾼B.①⽐④云量多C.②⽐③风速⼤D.②⽐④⽓压低5.据图推断A.①地受⾼⽓压控制，炎热⼲燥B.低压天⽓系统中，⑤地的强度最强C.黄海海域天⽓晴朗，风⼤浪⾼D.北京位于冷锋锋前，出现⼤风降⽔图3为⾮洲局部⽓温、降⽔登分布图，读图，回答第6、7题。

6.甲地A.⽓温⽐同纬度内陆地区⾼B.沿岸洋流⾃低纬流向⾼纬C.出现独特的热带⾬林景观D.附近海域的渔业资源丰富7.⼄地降⽔丰富，主要原因有①沿岸有暖流经过，增温增湿②夏季东南季风影响，⽔汽丰富③地处热带，空⽓对流运动旺盛④位于迎风海岸，受到地形抬升A.①③B. ①④C. ②③D. ②④图4为我国江南地区某河流上游河段的单侧断⾯⽰意图，甲地河流沉积物颗粒⽐⼄地⼤。

读图，回答第8、9题。

8.图中A.甲地河流沉积物的⾯积不断扩⼤B.甲形成时期河流流速⽐⼄形成时期慢C.⼄地河流沉积物的⾯积不断缩⼩D.河流沉积物的形成时期甲地早于⼄地9.该河⾕A.南岸为阳坡，因流⽔堆积作⽤形成B.地处平原地区，沿岸⼈⼝聚落密布C.夏秋季节为洪⽔期，河流流速较快D.平⽔期流⽔侵蚀强，沿岸杨柳成荫读图5，回答第10、11题10.图中A.①的城市等级最⾼B.②的服务业最综合C.③对外联系最频繁D.④⼈⼝的数量最⼤11.下列表述正确的是A.城市等级只依据⾏政级别⾼低来确定B.⾼等级城市提供的就业岗位相对不多C.低等级城市服务业均由⾼等级城市提供D.⾼等级城市的交通需求⽐低等级城市⾼紫鹊界梯⽥位于湖南省西北部的娄底市新化县，是全球重要农业⽂化遗产、世界灌溉⼯程遗产。

2020年北京市顺义区中考英语一模试卷知识运用(共14分)一.单项填空。

(共6分, 每小题0.5分)从下面各题所给的A、B、C、D四个选项中，选择可以填入空白处的最佳选项。

1.My mother is a nurse.______ is very kind.A.heB. SheC. TheyD. It2.David is going to buy a T-shirt for his father ______ Father’s Day.A.atB. inC. onD. for3.--- ______ do your parents usually go to work, Jack?--- By bus.A.WhenB. WhereC. WhyD. How4.--- Peter, would you like to go shopping with me?--- I’d like to, ______ I have to finish my homework first.A.orB. andC. soD. but5.--- Dad, ______ you make a kite for me?--- Of course I can.A.canB. mustC. shouldD. need6.--- Which season do you like ______, spring or autumn?--- Spring.A.wellB. betterC. bestD. the best7.--- What do you usually do on weekends?--- I usually ______ my grandparents.A.visitB. visitedC. will visitD. am visiting8.--- Where is Lily, Mum?--- She ______ the flowers in the garden.A.waterB. watersC. is wateringD. has watered9.We ______ online classes on February 17 because of COVID-19.A.hadB. haveC. will haveD. are having10.--- Do you know Mr. Smith?--- Yes. I ______ him since 2017.A.knowB. knewC. have knownD. will know11.The environment in my hometown is improving because many trees ______ every year.A.plantB. are plantedC. plantedD. were planted12.--- Excuse me, could you tell me ______?--- Sure. Go down the street, and you can find it at the second crossing.A. where is the supermarketB. where was the supermarketC. where the supermarket isD. where the supermarket was二.完型填空。