江苏省无锡市天一实验学校、江阴初级中学、太湖格致中学2020届九年级下学期期中(一模)英语试题含答案

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江苏省无锡市天一实验学校、江阴初级中学、太湖格致中学2020届九年级下学期期中(一模)英语试题含答案

2019-2020学年第二学期期中考试初三英语试卷（考试时间：100分钟满分：90分）第I卷（客观题共50分）一、单项填空在A、B、C、D四个选择中，选出可以填入空白处的最佳选项，并在答题卡上将该项涂黑。

（本大题共14小题，每小题1分，共14分）1. --Have you heard of Li Wenliang , doctor in Wuhan Central Hospital?-- Yes, it's said that he was one of first men to remind people of the coronavirus.A. a; theB. the; aC. a; aD. / ; the2. --Joan is not so quick, but she has a good habit of working hard, it is like a hidden .A. competitionB. treasureC. traditionD. influence3. --The frozen yogurt tastes like ice cream but has of the fat.--It suits my mother, she is on a diet.A. anyB. neitherC. someD. none4. –Where was Mr John at that time?- -Em, we found the robot. Something was wrong with it.A. him fixingB. he fixedC. that he fixedD. he fixing5.--May I speak to Mr. Green?--Sorry, the wrong number. Please to 114 and check the number.A. go throughB. look throughC. run throughD. put through6. Many scientists believe human beings will face more serious problems ______they take action to change the way they live.A. butB. thoughC. unlessD. until7. --This task is really beyond me.-- Well. if you_______ solve it, you won’t get paid.A. needn’tB. can’tC. shouldn’tD. mustn’t8. We found him __________ with. He’s quite an easy-going guy.A. easily to workB. easily workingC. easy to workD. easy working9. --Look at Ann. How pale she looks!--Well, she never eats ________ and that’s why she is not healthy.A. rapidlyB. smoothlyC. completelyD. properly10.--Do you know in Tokyo?--It will be put off, but the date hasn't been decided yet.A. when will the 32nd Olympic Games take placeB. when the 32nd Olympic Games will be heldC. when will the 32nd Olympic Games be heldD. when the 32nd Olympic Games will be taken place11.--I hear that we may have to be at school on Saturday this term!--What?! I've never heard of idea before.A. a crazierB. the crazierC. a craziestD. the craziest12. --It's said that Chris achieved high grades in the exam.-- That's no surprise .He is______________, you know.A. a dark horseB. a green handC. an early birdD. a wet blanket13. --May I go to the cinema with Tom tomorrow, mom?--Of course, if your homework _______ by then.A. will be finishedB. finishC. will finishD. is finished14. --The music is too loud. Could you turn it down, please?--_______________.A. Really? Thank you for telling meB. Sorry , I didn't noticeC. Well, I'm glad to hear thatD. It's my pleasure二、完形填空先通读下面的短文，掌握其大意，然后在每小题所给的四个选项中，选出可以填入空白处的最佳选项,并在答题卡上将该项涂黑。

江苏省无锡市天一实验学校、江阴初级中学、太湖格致中学2020届九年级下学期期中(一模)数学试题含答案

无锡市天一实验学校2020年春学期初三中考第一次适应性考试数学试卷（考试时间：120分钟试卷分值：130分）一、选择题（本大题共10小题，每小题3分，共30分．在每小题所给出的四个选项中，只有一项是正确的，请把正确的选项填涂在答卷相应的位置．）1．﹣4的相反数（▲）A．14B．4C．﹣4D．±42．下列图形中，是轴对称图形但不是中心对称图形的是（▲）A．B．C．D．3．下列各式中，计算正确的是（▲）A．8a﹣3b＝5ab B．（a2）3＝a5C．a8÷a4＝a2D．a2•a＝a34．如图是由5个相同的正方体搭成的几何体，其左视图是（▲）A．B．C．D．5．在四边形ABCD中，O是对角线的交点，能判定这个四边形是正方形的条件是（▲）A．AC＝BD，AB∥CD，AB＝CD B．AD∥BC，∠A＝∠CC．AO＝BO＝CO＝DO，AC⊥BD D．AO＝CO，BO＝DO，AB＝BC6．在某次测试后，班里有两位同学议论他们小组的数学成绩，小明说：“我们组考87分的人最多”，小华说：“我们组7位同学成绩排在最中间的恰好也是87分”．上面两位同学的话能反映出的统计量是（▲）A．众数和平均数B．平均数和中位数C．众数和中位数D．众数和方差7．如图，AB是⊙O的直径，DB、DE分别切⊙O于点B、C，若∠ACE＝25°，则∠D的度数是（▲）A．50°B．55°C．60°D．65°（第7题）8．如图1，在矩形ABCD 中，动点P 从点B 出发，沿BC ﹣CD ﹣DA 运动至点A 停止．设点P 运动的路程为x ，△ABP 的面积为y ，若y 关于x 的函数图象如图2所示，则y 的最大值是（ ▲ ） A ．55 B ．30C ．16D ．15（第8题） (第9题)9. 如图，在Rt △ABC 中，∠C ＝90°，AC ＝3，BC ＝4，点D 是AB 的中点，点P 是直线BC 上一点，将△BDP 沿DP 所在的直线翻折后，点B 落在B 1处，若B 1D ⊥BC ，则点P 与点B 之间的距离为（ ▲ ） A ．1B ．54C ．1或 3D ．54或5 10．已知直线y ＝﹣x +7a +1与直线y ＝2x ﹣2a +4同时经过点P ，点Q 是以M （0，﹣1）为圆心，MO为半径的圆上的一个动点，则线段PQ 的最小值为（ ▲ ） A ．103B ．163C ．85D ．185二、填空题（本大题共8小题，每小题2分，共16分．不需要写出解答过程，只需把答案直接填写在答卷相应的横线上．） 11．分解因式：a 3﹣4a ＝ ▲． 12．函数1xy x =- 的自变量x 的取值范围是 ▲ ． 13．每到四月许多地方杨絮、柳絮如雪花般漫天飞舞，人们不堪其扰，据测定，杨絮纤维的直径约为0.0000105m ，该数值用科学记数法表示为 ▲ ．14．圆锥的底面半径为14cm ，母线长为21cm ，则该圆锥的侧面展开图的圆心角为 ▲ 度．(第15题) (第16题)15．一次函数y 1＝mx +n 与y 2＝﹣x +a 的图象如图所示，则0＜mx +n ＜﹣x +a 的解集为▲ ． 16．如图，在矩形ABCD 中，AB ＝2DA ，以点A 为圆心，AB 为半径的圆弧交DC 于点E ，交AD 的延长线于点F ，设DA ＝2，图中阴影部分的面积为 ▲ ．17．如图，四边形ABCD 的顶点都在坐标轴上，若AB ∥CD ，△AOB 与△COD 面积分别为8和18，若双曲线ky x=恰好经过BC 的中点E ，则k 的值为 ▲ ． 18．如图，在边长为1的菱形ABCD 中，∠ABC ＝60°，将△ABD 沿射线BD 的方向平移得到△A 'B 'D '，分别连接A 'C ，A 'D ，B 'C ，则A 'C +B 'C 的最小值为 ▲ ．(第17题) (第18题)三、解答题（本大题共10小题，共84分．请在答卷相应的区域内作答，解答时应写出文字说明、证明过程或演算步骤．） 19．（本题满分8分）（1）计算：°04cos30+2 12（1 -）- （2）化简：23)(3)(3)x y x y x y --+-（20．（本题满分8分）（1）解方程：112xx x-=-（2）解不等式组：572(1)1023x xxx-<+⎧⎪+⎨>⎪⎩21．（本题满分8分）如图，在△ABC中，CD是AB边上的中线，E是CD的中点，过点C作AB 的平行线交AE的延长线于点F，连接BF．（1）求证：CF＝AD；（2）若CA＝CB，试判断四边形CDBF的形状，并说明理由．22．（本题满分8分）某高中学校为使高一新生入校后及时穿上合身的校服，现提前对某校九年级（1）班学生即将所穿校服型号情况进行摸底调查，并根据调查结果绘制如图两个不完整的统计图（校服型号以身高作为标准，共分为6种型号）．根据以上信息，解答下列问题：（1）该班共有多少名学生？（2）在条形统计图中，请把空缺部分补充完整；在扇形统计图中，请计算185型校服所对应的扇形圆心角的大小；（3）求该班学生所穿校服型号的众数和中位数．如果该高中学校准备招收2000名高一新生，则估计需要准备多少套180型号的校服？23．（本题满分6分）三辆汽车经过某收费站下高速时，在2个收费通道A，B中，可随机选择其中的一个通过．（1）一辆汽车经过此收费站时，选择A通道通过的概率是；（2）求三辆汽车经过此收费站时，至少有两辆汽车选择B通道通过的概率．（请用画树状图的方法写出分析过程，并求出结果）.24．（本题满分8分）如图，四边形ABCD是菱形，请仅用无刻度的直尺按要求画图．（不写画法，保留作图痕迹）．（1）在图1中，画出∠A的平分线；（2）在图2中，AE⊥CD，过点C画出AD边上的高CF；（3）在图3中，AE⊥CD，过点C画出AB边上的高CG．25．（本题满分8分）如图，△ABC 的点A ，C 在⊙O 上，⊙O 与AB 相交于点D ，连接CD ，∠A ＝30°，DC．（1）求圆心O 到弦DC 的距离；（2）若∠ACB +∠ADC ＝180°，求证：BC 是⊙O 的切线.26．（本题满分8分）“扬州漆器”名扬天下，某网店专门销售某种品牌的漆器笔筒，成本为30元/件，每天销售y （件）与销售单价x （元）之间存在一次函数关系，如图所示．（1）求y 与x 之间的函数关系式；（2）如果规定每天漆器笔筒的销售量不低于240件，当销售单价为多少元时，每天获取的利润最大，最大利润是多少？（3）该网店店主热心公益事业，决定从每天的销售利润中捐出150元给希望工程，为了保证捐款后每天剩余利润不低于3600元，试确定该漆器笔筒销售单价的范围．图1图2D图327．（本题满分11分）如图①，一次函数122y x =-的图象交x 轴于点A ，交y 轴于点B ，二次函数212y x bx c =-++的图象经过A 、B 两点，与x 轴交于另一点C ．（1）求二次函数的关系式及点C 的坐标；（2）如图②，若点P 是直线AB 上方的抛物线上一点，过点P 作PD ∥x 轴交AB 于点D ，PE ∥y轴交AB 于点E ，求PD +PE 的最大值；（3）如图③，若点M 在抛物线的对称轴上，且∠AMB ＝∠ACB ，求出所有满足条件的点M 的坐标．28．（本题满分11分）如图，矩形ABCD中，AB＝6，AD＝8．动点E，F同时分别从点A，B出发，分别沿着射线AD和射线BD的方向均以每秒1个单位的速度运动，连接EF，以EF为直径作⊙O交射线BD于点M，设运动的时间为t．（1）当点E在线段AD上时，用关于t的代数式表示DE，DM．（2）在整个运动过程中，①连结CM，当t为何值时，△CDM为等腰三角形．②圆心O处在矩形ABCD内（包括边界）时，求t的取值范围，并直接写出在此范围内圆心运动的路径长．初三中考第一次适应性考试数学答案及评分标准一、选择题三、解答题19．（本题满分8分）（1）原式=-（3分）（2）原式=2222969x xy y x y -+-+ （2分）=1 （4分） =226y xy - （4分）20．（本题满分8分）（1）2x =- （3分）（2）由（1）3x < ，由（2）2x < （2分）检验（4分） ∴ 2x < （4分）21.（本题满分8分）（1）证明：∵CF ∥AB ，∴∠CFE＝∠DAE，∠FCE＝∠ADE，∵E为CD的中点，∴CE＝DE，……………………1分在△ECF和△EDA中，，∴△ECF≌△EDA（AAS），……………………3分∴CF＝AD；……………………4分（2）解：四边形CDBF为矩形，理由如下：……………………5分∵CD是AB边上的中线，∴AD＝BD，∵CF＝AD，∴CF＝BD；∵CF＝BD，CF∥BD，∴四边形CDBF为平行四边形，……………………7分∵CA＝CB，CD为AB边上的中线，∴CD⊥AB，即∠BDC＝90°，∴四边形CDBF为矩形，……………………8分22.（本题满分8分）解：（1）15÷30%＝50（名）即该班共有50名学生；……………………1分（2）穿175型校服的学生有10名：50×20%＝10（名），185型的学生人数为：50﹣3﹣15﹣15﹣10﹣5＝50﹣48＝2（名），图略 185型校服所对应的扇形圆心角为：×360°＝14.4°； ……………………4分（3）众数是165和170；中位数是170，600套． ……………………8分23.（本题满分6分）解：（1）12……………………1分（2）画树状图得：……………………4分∵共有8种等可能的情况，其中至少有两辆汽车选择B 通道通过的有4种情况， ∴至少有两辆汽车选择B 通道通过的概率为＝． ……………………6分24．（本题满分8分）（2分）；连接BD(2分)画出CF(1分)；画出点O(1分) 画出EG(1分) 画出CG(1分)25．（本题满分8分）解：（1）连接OD ，OC ，过O 作OE ⊥OC 于E ，FEA图1图2∵∠A＝30°，∴∠DOC＝60°，∵OD＝OC，CD＝，∴△OCD是等边三角形，……………………2分∴OD＝OC＝CD＝，∵OE⊥DC，∴DE＝，∠DEO＝90°，∠DOE＝30°，∴OE＝DE＝，∴圆心O到弦DC的距离为：；……………………4分（2）①由（1）得，△ODC是等边三角形，∴∠OCD＝60°，∵∠ACB+∠ADC＝180°，∠CDB+∠ADC＝180°，∴∠ACB＝∠CDB，∵∠B＝∠B，∴△ACB∽△CDB，……………………6分∴∠A＝∠BCD＝30°，∴∠OCB＝90°，∴BC是⊙O的切线；……………………8分26．（本题满分8分）解：（1）设y＝kx+b，∵直线y＝kx+b经过点（40，300），（55，150），∴，解得：．故y与x之间的函数关系式为：y＝﹣10x+700，……………………2分（2）由题意，得﹣10x+700≥240，解得x≤46，∴30＜x≤46，……………………3分设利润为w＝（x﹣30）•y＝（x﹣30）（﹣10x+700），w＝﹣10x2+1000x﹣21000＝﹣10（x﹣50）2+4000，……………………5分∵﹣10＜0，∴x＜50时，w随x的增大而增大，∴x＝46时，w最大＝﹣10（46﹣50）2+4000＝3840，……………………6分答：当销售单价为46元时，每天获取的利润最大，最大利润是3840元；（3）w﹣150＝﹣10x2+1000x﹣21000﹣150＝3600，﹣10（x﹣50）2＝﹣250，x1＝55，x2＝45，由图象得：当45≤x≤55时，捐款后每天剩余利润不低于3600元．……………8分27．（本题满分11分）解：（1）二次函数的关系式为y＝﹣x2+x﹣2；……………2分当y＝0时，﹣x2+x﹣2＝0，解得x1＝1，x2＝4，则C（1，0）；……………3分（2）设P（m，﹣m2+m﹣2），则E（m，m﹣2）．∴PD+PE＝3PE＝3×[﹣m2+m﹣2﹣（m﹣2）]＝﹣m2+6m＝﹣（m﹣2）2+6；∵0＜m＜4，∴当m＝2时，PD+PE有最大值6；……………7分（3）当点M在直线AB上方时，则点M在△ABC的外接圆上，如图1．∵△ABC的外接圆O1的圆心在对称轴上，设圆心O1的坐标为（，﹣t），∵O1B＝O1A，∴（）2+（﹣t+2）2＝（﹣4）2+t2，解得t＝2．∴圆心O1的坐标为（，﹣2）．∴O1A＝＝，即⊙O1的半径半径为．此时M点坐标为（，）；……………9分当点M在在直线AB下方时，作O1关于AB的对称点O2，如图2．∵AO1＝O1B＝，∴∠O1AB＝∠O1BA．∵O1B∥x轴，∴∠O1BA＝∠OAB．∴∠O1AB＝∠OAB，O2在x轴上，∴点O2的坐标为（，0）．∴O2D＝1，∴DM＝＝．此时点M的坐标为（，）．……………11分综上所述，点M的坐标为（，）或（，）．28．（本题满分11分）解：（1）（1）．ED＝8﹣t，MD＝．……………3分（2）①t＝；t＝；t＝﹣1（舍去）；t＝．综上所述，当t＝或t＝或t＝时，△DCM为等腰三角形．……………7分② 0≤t≤．……………9分圆心运动的路径长为8103……………11分。

江苏省无锡地区2020年中考一模英语试卷精选汇编：动词填空专题

动词填空专题江苏省无锡市锡北片2020届九年级一模英语试题五、动词填空（本大题共6分，每小题1分）46. Not only my brother but also I____________(expect) to be an artist two years ago by our parents.47. The thief ____________(steal) 500 pounds from the shop.48. Now more and more people have realized the importance of ____________(save) water.49. -When did Yang Ying say?-She said they ____________ (have) a school trip the next weekend.50.Mom makes me eat an apple every day ____________ (keep) the doctor away.51.You ____________ (not be) really happy unless you are satisfied with what you have.52.五、动词填空（本大题共6分，每小题1分）46. was expected 47. stole 48. saving49. would have 50. to keep 51. will not be/won’t be江苏省无锡市惠山区2020届九年级一模英语试题六、动词填空用括号内所给动词的适当形式填空，并将答案写在答题卡标有题号的横线处（本大题共6小题，每小题1分，共6分）66. The old man exercises every day __________(improve) his health.67. The firemen _____________(control) the fire, so all of you are out of danger now.68. The secret of life is whenever an excellent chance _____________ (appear), take it.69. At present, the number of people with COVID-19 in the USA _________ (increase) rapidly.70. If Steve finishes the job in time, he ____________ (allow) to have three weeks off.71. The three boy students Miss White paid special attention to __________ (make) great progress at last.六、动词填空（本大题共6分，每小题1分）66. to improve 67. have controlled 68. appears 69. is increasing70. will be allowed 71. made江苏省无锡市天一实验学校、江阴初级中学、太湖格致中学2020届九年级一模英语试题五、动词填空用括号内所给动词的适当形式填空，并将答案写在答题卡对应题号的横线上。

江苏省无锡市天一实验学校届九年级数学下学期第三次模拟试题(精选资料)

第9题图第8题图无锡市天一实验学校九年级三模数学试卷一、选择题：（本大题共10小题，每题3分，共30分．）1、下列图形中，既是轴对称图形，又是中心对称图形的是（ ▲ ） A ．正三角形 B ．平行四边形 C ．矩形 D ．等腰梯形2、计算32)2(b a -的结果是（ ▲ ）A ．366b a - B ．b a 28- C ．362b a - D ．368b a -3、若a b 3a b 7+=-=，，则22a b -的值为（ ▲ ） A ．－21 B ．21 C ．-10 D ．104（ ▲ ） A．12 D ．185、已知直角三角形ABC 的一条直角边AB=4cm ，另一条直角边BC=3 cm ，则以A B 为轴旋转一周，所得到的圆锥的侧面积是（ ▲ ）A ．230cm πB ．215cm πC ．212cm πD ．220cm π6、在某校“我的中国梦”演讲比赛中，有15名学生参加决赛，他们决赛的最终成绩各不相同。

其中的一名学生想要知道自己能否进入前8名，不仅要了解自己的成绩，还要了解这15名学生成绩的（ ▲ ）.A ．众数B ．方差C ．平均数D ．中位数7、若二次函数2()1y x m =--．当x ≤ 3时，y 随x 的增大而减小，则m 的取值范围是A ．m = 3B ．m >3C ．m ≥ 3D ．m ≤ 3 （ ▲ ）8、如图1所示，将一个正四棱锥（底面为正方形，四条侧棱相等）的其中四条边剪开，得到图2，则被剪开的四条边有可能是（ ▲ ）A ．PA ，PB ，AD ，BC B ．PD ，DC ，BC ，AB C ．PA ，AD ，PC ，BC D ．PA ，PB ，PC ，AD 9、如图，在直角坐标系中放置一个边长为2的正方形ABCD ，将正方形ABCD 沿x 轴的正方向无滑动的在x 轴上滚动，当点A 第三次回到x 轴上时，点A 运动的路线与x 轴围成的图形的面积和为（ ▲ ）A ．ππ+2B ．22+πC ．ππ323+D ．66+π10．如图，在△ABC 中，∠C =90°，AC =4，BC =2，点A 、C 分别在x 轴、y 轴上，当点A 在x 轴上运动时，点C 随之在y 轴上运动．在运动过程中，点B 到原点的最大距离是( ▲ ) A ．6 B ．2 6 C ．2 5 D ．22＋2第15题第18题第17题二、填空（本大题共8小题，每题2分，共16分） 11、函数xy -=11中自变量x 的取值范围是 ▲ ．12、我国因环境污染造成的巨大经济损失每年高达680000000元，这个数用科学记数法表示为 ▲ 元．13、已知点A （x 1，y 1）、B （x 1―3，y 2）在直线y ＝―2x ＋3上，则y 1 ▲ y 2 （用“＞”、“＜”或“＝”填空）14、若关于x 的二次方程032=+++a ax x 有两个相等的实数根，则实数a = ▲ 15、如图，点A 在双曲线x y 3=上，点B 在双曲线xy 5=上，且AB∥x 轴，C 、D 在x 轴上，若四边形ABCD 为平行四边形，则它的面积为 ▲16、如图，方格纸中有三个格点A 、B 、C ，则点A 到BC 的距离为＝ ▲ ．17、如图，正方形ABCD 的边长为1，中心为点O ，有一边长大小不定的正六边形EFGHIJ 绕点O 可任意旋转，在旋转过程中，这个正六边形始终在正方形ABCD 内（包括正方形的边），当这个六边形的边长最大时，AE 的最小值为_ _▲__18、如图所示，圆圈内分别标有1，2，…，12，这12个数字，电子跳蚤每跳一步，可以从一个圆圈逆时针跳到相邻的圆圈，若电子跳蚤所在圆圈的数字为n ，则电子跳蚤连续跳（3n-2）步作为一次跳跃，例如：电子跳蚤从标有数字1的圆圈需跳12-13=⨯步到标有数字2的圆圈内，完成一次跳跃，第二次则要连续跳42-23=⨯步到达标有数字6的圆圈，…依此规律，若电子跳蚤从①开始，第2016次电子跳蚤能跳到的圆圈内所标的数字为___▲__三、解答题（本大题共10小题，共84分） 19、（每小题5分，共10分）①解不等式组⎪⎩⎪⎨⎧+<≥+325,5)5.1(2m m m ，并将解集在数轴上表示出来 .②先化简，再求代数式的值:a a a a a -÷⎪⎭⎫⎝⎛+--+112122，其中13-=a .20、（本题满分6分）如图，线段AB 绕点O 顺时针旋转一定的角度得到线段A 1B 1．（1）请用直尺和圆规作出旋转中心O （不写作法，保留作图痕迹）；（2）连接OA 、OA 1、OB 、OB 1，如果∠AO A 1＝∠BOB 1＝α；OA ＝OA 1＝a ；OB ＝OB 1＝b ．则线段AB 扫过的面积是 ▲ ． 111210987654321B21、（本题满分6分）如图，E，F是四边形ABCD的对角线AC上两点，AF=CE，DF=BE，DF∥BE．求证：AB=CD22、（本题满分8分）在读书月活动中，学校准备购买一批课外读物．为使课外读物满足同学们的需求，学校就“我最喜爱的课外读物”从文学、艺术、科普和其他四个类别进行了抽样调查（每位同学只选一类），如图是根据调查结果绘制的两幅不完整的统计图．请你根据统计图提供的信息，解答下列问题：（1）本次调查中，一共调查了▲名同学；（2）条形统计图中，m= ▲，n= ▲；（3）扇形统计图中，艺术类读物所在扇形的圆心角是▲度；（4）学校计划购买课外读物5000册，请根据样本数据，估计学校购买其他类读物多少册比较合理？23、（本题满分7分）现有4根小木棒，长度分别为：2、3、3、5（单位：cm），从中任意取出3根，请用画树状图或例举法求它们能首尾顺次相接搭成三角形的概率．24、(本题满分8分)如图，某大楼的顶部树有一块广告牌CD，小李在山坡的坡脚A处测得广告牌底部D的仰角为60°．沿坡面AB向上走到B处测得广告牌顶部C的仰角为45°，已知山坡AB的坡度i=1：，AB=8米，AE=10米．（i=1：是指坡面的铅直高度BH与水平宽度AH的比）（1）求点B距水平面AE的高度BH；（2）求广告牌CD的高度．（测角器的高度忽略不计，结果精确到0.1米．）25、(本题满分9分)某景区门票价格80元/人，为吸引游客，对门票价格进行动态管理，非节假日打a折，节假日期间，10人以下（包括10人）不打折，10人以上超过10人的部分打b折，设游客为x人，门票费用为y元，非节假日门票费用y1（元）及节假日门票费用y2（元）与游客x（人）之间的函数关系如图所示．（1）a=___▲____，b=___▲_____（2）直接写出y1、y2与x之间的函数关系式；（3）导游小王4月15日（非节假日）带A旅游团，5月1日带B旅游团到该景区旅游，两团共计50人，两次共付门票费用3040元，求A、B两个旅游团各多少人？26．(本题满分10分)已知点O是四边形ABCD内一点，AB=BC，OD=OC，∠ABC=∠DOC=α．（1）如图1，α=60°，探究线段AD与OB的数量关系，并加以证明；（2）如图2，α=120°，探究线段AD与OB的数量关系，并说明理由；（3）结合上面的活动经验探究，请直接写出如图3中线段AD与OB的数量关系为▲（直接写出答案）27．(本题满分10分) 在平面直角坐标系xOy中，定义直线y=ax+b为抛物线y=ax2+bx的特征直线，C（a，b）为其特征点．设抛物线y=ax2+bx与其特征直线交于A、B两点（点A在点B的左侧）．（1）当点A的坐标为（0，0），点B的坐标为（1，3）时，特征点C的坐标为___▲___；28、(本题满分10分)如图，在平面直角坐标系中，O 为坐标原点，直线6+-=x y 交y 轴于点A ，交x 轴于点B ，点C 、B 关于原点对称，点P 在射线AB 上运动，连结CP 与y 轴交于点D ，连结BD ．过P 、D 、B 三点作⊙Q 与y 轴的另一个交点为E ，延长DQ 交⊙Q 于点F ，连结EF ，BF ．（1）求A 、B 、C 三点的坐标；（2）当点P 在线段AB （不包括A ，B 两点）上时．求证：DE=EF ；（3）请你探究：点P 在运动过程中，是否存在以B ，D ，F 为顶点的直角三角形，满足两条直角边之比为2：1？如果存在，求出此时点P 的坐标：如果不存在，请说明理由．。

江苏省无锡市2020-2021学年下学期九年级英语期中试卷分类汇编：阅读理解

江苏省无锡市2020-2021学年下学期九年级英语期中试卷分类汇编阅读理解江苏省无锡市2020—2021学年九年级下学期期中考试英语试卷三、阅读理解阅读下面的短文，然后根据短文内容，在每小题所给的四个选项中选出最佳选项。

（本大题共13小题，每小题2分，共26分）AEvery school has notice boards. Let’s see what is on the school boards of a middle school.Class AnnouncementTesting Dates:The Chinese test is on May 12The math test is on May 13.After-school Programs:The programs will be open from 3:00 p.m. to 6:00 p.m. every day.3:00-4:30 Doing homework4:30-6:00 Joining in ActivitiesParents Meeting:The parents meeting is at 8:00 a.m. on Friday, May 19 in the meeting hall.School PolicyFighting, saying rude words and all other bad behaviors are not allowed.Do not throw rocks or sticks on the school ground.Hand in a note if your child will be absent for the day.Parents need to check in at the school gate when entering the school.How to Keep Yourself Safe from Novel Coronavirus1. Wear masks outdoors.Make sure to wear it properly by tightening up the nose clip and pulling the bottom of it over your chin so that your nose and mouth are both covered.2. Cover your coughs and sneezes with napkins.Cover your mouth and nose with a napkin when you cough or sneeze, or you can cough or sneeze into your sleeve, but avoid covering with your hands directly.3. Wash your hands properly.25. From the school notice boards, we can know .A. students are not allowed to behave badlyB. parents meeting will be held in the gymC. after-school programs last two hours every dayD. parents need to hand in notes when entering the school26. To keep yourself safe fr om novel coronavirus, you’d better .A. pull the top of the mask over the mouthB. cover with your hands when coughingC. wash your hands with running water onlyD. do sports regularly to strengthen yourself27. Who are these notices most probably written to?A. Doctors and nurses.B. Parents and students.C. The school headmaster.D. Visitors to the school.BSeven years ago, Joyce Akinpe moved to Australia to start a new life, finding an exciting job in Sydney. After the outbreak (爆发) of COVID-19, she suddenly lost her job.Seeing that there were many others like herself in trouble from the outbreak, Akinpe and her two roommates, Michele Gomez and Maureen Lee, brainstormed ideas for how to help their local community. They came up with a street pantry（储藏柜）. Gomez said the idea was very simple, “Take what you need and leave what you can.”With the help of Gomez’s father, they built the Blessing Box – a street pantry, with shelves and hanging baskets and two doors made from old furniture.It sits just at the back of the three girls’ home, so they can look after it. They put some information notices into their neighbors’ mailboxes, and the Blessing Box was quickly filled with the donations (捐赠)from the community, “It is the community’s str ong support that keeps the project alive,” Akinpe said.We now have hundreds of people visiting our box every day. It might only a hours for the box to be full and next hour it might become empty again. “We are now helping others to carry outsimilar proj ects in their own communities, too”, Gomez said.Lee said things in the box were mostly convenience foods, as well as some necessary life things such as spaghetti and toilet paper. “Few people take everything at once. They think there are other people who need them more.” Lee added.There were many people rushing there for donations. The three girls needed to sanitize (消毒）all the donations and make sure all food packages were not broken. Gomez said that they had no time for rest, but what they did was well worth.28. Paragraph 2 mainly talks about ________.A. the way to build the Blessing BoxB. the help from the local communityC. the purpose of building a street pantryD. the trouble from the outbreak of COVID-1929. Put the following sentences in the right order according to the passage.a. The three girls thought up a good idea.b. The three girls received and sanitized the donations.c. The three girls put information notices into their neighbors’ mailboxes.d. The three girls buil t the Blessing Box with the help of Gomez’s father.A. c—a—b—dB. c—b—a—d.C. a—b—-d—cD. a—d—c—b30. Few people take everything they need at once because __________.A. they would like to use their own thingsB. they think other people need these things moreC. there aren’t enough donations in the Blessing BoxD. it's not safe to use the things from the Blessing BoxCHow much time do you spend looking at your smartphone, tablet or computer every day? These electronic devices help us m many ways, but they may also cause health problems.Too much screen time can cause eyestrain which leaves your eyes feeling dry and sore and could also affect your eyesight. To help your eyes stay healthy, follow the “20-20-20” rule: every 20 minutes, look at something 20 feet away for 20 seconds.Your eyes aren't the only parts of your body that could become worse from using electronic devices. People who write a lot of text messages can develop an injury called texting thumb". Therepeated movement of typing with thumbs can cause thumb and wrist pain and lead to the loss of grip strength （握力受损）.To avoid this, do this exercise: put a rubber band around the tips of your five fingers and open your hand to stretch the rubber band. Repeat this a few times.Scientific research suggests that electronic devices can also hurt your mind. One of the biggest problems is that using these devices can affect your sleep patterns. Doctors say the screen light stop you from feeling sleepy. So they advise people not to use electronic devices for at least one hour before trying to sleep.Another serious danger is Internet addiction （瘾）. Many people turn to the Internet to ease feelings of stress, sadness, and loneliness. Over time, they might start to depend on the Internet and feel worried if they're not connected To stop yourself from falling into this kind of trap, limit the amount of time you spend on line.To use your smartphone or computer safely, just make sure you follow these health tips. Also, remember that there is more to life than looking at an electronic screen.31. The first 20 of the "20-20-20"rule in the passage suggests________________.A. how long the break lastsB. how often you have the breakC. how far you look at objects from youD. how long you need to take a break32. Which picture best shows the rubber and exercise according to the passage?33. The underlined word "they" in Paragraph 5 refers to _________________.A. computer games or InternetB. feelings of stress, sadness and lonelinessC. several serious mind problemsD. people who have Internet addiction34. What's the passage mainly about?A. Electronic devices can hurt both your body and mind.B. Looking at screen for too long can cause sore eyes.C. Typing a lot can develop "texting thumb".D. The more you depend on the Internet, the less worried you might be.DThe woman was very frightened. What could she do? She dialed 999. The emergency calloperator Robert Naylor answered the call immediately."Please help me! It's in my bathroom! It's moving!" the woman cried. "What is it that's moving?" Robert answered calmly."A spider!" the woman shouted back at him.Robert believes that a significant number of the calls are not emergencies. The actual number across the country is close to 75%.Firstly, there are "silent calls". The emergency number is dialed, but when an operator answers, no one speaks. Often it's a small child or even a pet who has been playing with her phone and has accidentally rung the emergency number.Then there are "joke calls", often from teenagers. An operator answers the phone and the caller immediately hangs up. Robert believes these are declining, as there are far fewer public payphones these days. "People are less interested to make a call when they are doing it from their own mobile phone and they know we have their number!"The police always follow up both types of calls. It's a huge waste of money, the average (平均的) cost of responding to a silent or joke call is around ￡250.The great numbers of the none-emergency calls are like those from the woman above. A situation like this isn't an emergency. But this example is far from the worst. What do you think of the following?● A teenager girl in America called the police because her parents had decorated her room and she didn't like the color.● A mother in Italy rang the emergency services when her 16-year-old son refused to get out of the bed.● A Bra zilian teenage boy rang and asked the police to remove a video of him from YouTube. In the video, the boy was falling off his bike.There are many other examples, and most of these are from adults. These calls waste more than time and money. "If someone makes a joke call and the police manage to find them, then they can expect a fine of up to ￡5,000, and even a prison sentence (监禁)," warns Robert. "But for peoplewhose emergency aren't really serious, we simply try to deal with their calls as quickly as possible," he continues. "The person often quickly realizes their situation isn't really an emergency and ends up apologizing (道歉) for calling us. But if someone refuses to listen, then we have to hang up. Someone with a real emergency is probably waiting to speak to us."35. What does the underlined word "declining" probably mean?A. Getting serious.B. Turning worse.C. Getting useless.D. Becoming less.36. Why are there so many none-emergency calls?A. Operators give excellent service.B. Callers do not take any responsibilities.C. Dealing with none-emergency costs little.D. Many don't consider it an improper behavior.37. Which of the following is the best title for this passage?A. Emergency services.B. Is it an emergency?C. Different kinds of emergency calls.D. Who is to be responsible?答案：ADB CDB BBDA DDB江苏省江阴市青阳片2020-2021学年九年级下学期期中考试英语试题三、阅读理解（本大题共13 小题，每小题 2 分，共26 分）AIt's believed that people reach their mental peak (顶峰) in their 20s. However, this isn’t completely true. According to a recent study by scientists from the Massachusetts Institute of Technology in the US, people are best at doing different things at different ages. They studied many people aged 10 to 90 years old, who were asked to take part in different memory tests.25. At what age can people reach the peak of their attention?A. 2.B. 18.C. 43.D. 50.26. Which fact does the passage provide?A. The younger people are, the better memory they have.B. The study is based on some research on people of all ages.C. People in their 40s can understand others’ feelings best.D. Different people are good at different things at the same age.27. This passage is probably a(n)_____________________.A. novelB. report.C. advertisement.D. notice. BNEW DICOVERIES are popular among our students and let’s take a close look at what they are. 28._____________. To young children, a year might seem to last forever. But older people might say that it flies by. Why is that? According to US scientists, young people’s brains process information at a faster speed than older people. They take in more information and do more things in a day. Therefore, they feel like each day lasts longer. However, older people’s brains degrade (退化) as they age. They take in less information and thus see a day pass more quickly.A robot A sks for hugsLovot is a special robot from Japan. It cangive people comfort and warmth. It looks likea mix of a penguin ( 企鹅), an owl, and ateddy bear. Lovot has a camera on its head. Itcan remember about 1,000 faces. Wheelsunder Lovot’s body help the robot movearound. The fun thing about Lovot isreal-human. It can ask for a hug by openingits arms and waving to you, just like a baby.T A king 10,000 steps A d A yYou may have heard that walking 10,000 steps a day is good for your health. But is that true? In fact, there is no official recommendation to walk this much, US scientists said. It was an idea from an advertisement for Japanese pedometers (计步器) in the 1960s. Scientists suggest that people can have 150 minutes of moderate activity a week, such as quick walking. As a result walking about 7,000 to 8,000 steps a day is a good choice.28. Which may be suitable for 28 ?A. Time makes old people less wiseB. People of different ages see time differentlyC. Time has something to do with people’s ageD. Time flies faster to the young compared to the old29. Based on the paper, which of these is a fact?A. Lovot is good at remembering people’s faces .B. Each day lasts longer to the old people.C. Walking 10,000 steps a day is good for healthD. Robots are completely the same as the humans.30. According to the reading, which fits best in the “Cause” box below?A. Walking 10,000 steps a day may hurt your bones.B. Quick walking is the best form of exercise.C. Advertisements say the more exercise the better.D. Scientists think 150 minutes of moderate activity a week good for health.COne day, Bassanio came to visit Antonio. This was not unusual because they were good friends. But the visit was more important than usual for Bassanio. He already owed Antonio a lot of money, but now he wanted to borrow some more.“I have been spending more money than I earn,” began Bassanio. “I already owe you a lo t of Cause__________Effec t (结果) Walking about 7,000 to 8,000 steps a day is a good choicemoney. I will tell you how I am going to get enough money to pay back all the money I owe.”“Yes, tell me,” said Antonio. “If I can help you, I will.”“When I was a boy at school,” began Bassanio, “I sometimes lost a ball when I was playing. When that happened, I would throw another ball in exactly the same way and watch it carefully. I would often find the two balls together. You might think of your money that way. The money you gave me is the first ball. It is lost, and I Know it’s my fault. But if you gave me some more money, it could be like that second ball and help you get all the money back. I will give back the money you give me now as well as the money that I have already lost.”Antonio invited him to continue.Bassanio told him about a rich young lady in Belmont. Her name was Portia. Her father died and left her a lot of money. She was beautiful as well as rich, and she was not married. Many men came from all over the world to court her, but nobody had succeeded. Bassanio had met Portia before, and he knew that she liked him. He told Antonio that if he had enough money he would soon make her his wife.“She is rich and young and beautiful. Her hair is like gold, and her face is always sunny and happy. She is always smiling. Antonio! She is beautiful. She likes me. I am certain she would marry me, marry me!” he explained.Antonio laughed. “You are my friend, Bassanio,” he comforted. “and I will help you. You know that all my ships are at sea just now, so I do not have much money to give you. However, you can go into town and try to borrow the money. Tell the moneylenders that Antonio will guarantee the money is paid back to them. Don't worry!”31. How would Bassanio pay back Antonio’s money?A. He would use Antonio's money as “the first ball”.B. H e would use Antonio's money as “the second ball”.C. He would return the money with the help of relatives.D. He would borrow some money from the moneylenders.32. What does the underlined word “ guarantee” mean in the last paragraph?A. make sureB. worry aboutC. carry outD. work out33. What can you infer (推断) from the passage?A. Portia would refuse to meet Bassanio.B. Antonio didn't lend the money to Bassanio.C. Bassanio would go to Belmont and court Portia.D. Bassanio would pay all the money back to Antonio.DLearning to control our greatest fearsAlmost everyone is afraid of something, whether that’s snakes, heights, or public speaking.Fearing something is natural and common, and can even be helpful to frighten ourselves sometimes. In fact, fear can keep our bodies alert (警觉的) so we can act quickly to protect ourselves in the event of danger.But for some people, fear develops into a “phobia”, which is a strong and unreasonable fear of something. For example, most of us feel a little scared when looking down from a tall building . But people with terrible acrophobia — a fear of heights — may not only feel dizzy (头晕的) when faced with a great height, they may also even turn down a great job just because the company’s office is on a high floor of a building.Indeed, phobias can prevent some of us from living a normal life. According to Katherina Hauner, a researcher at Northwestern University in the US, people who are terribly scared of spiders might stay away from their home for days if they knew a spider was there.However, since it’s thought that fear comes from personal experiences or memories, some scientists believe it’s possible to “rewrite” these unpleasant memories, helping people get through their phobias.In a study by Hauner and other scientists, people with arachnophobia — a fear of spiders —were asked to first touch a spider with a paintbrush. Once they saw it wasn’t really dangerous, they then tried touching it while wearing a glove. Finally, they were able to hold it with their hands directly.Certain medicine has also been found to be helpful. Back in 2015, researchers at the University of Hiroshima in Japan injected (注射) a special medicine into a fish —which was afraid of light — to turn off the fear centre in its brain. From then on, the fish no longer feared light.While the search for ways to deal with phobias is making great progress, there’s still the question of whether getting rid of ( 去除) fear is a good idea or not. In fact, Dave Smithson ofthe charity Anxiety UK thinks it’s a bad idea. “It’s fear that prevents us from doing crazy things,” he said. “There’s a name for people who don’t have fear of consequences: psychopaths (精神变态者).”34. The main point of the article is to _________________.A. show us what kind of role fear plays in our livesB. discuss if it is good to try to get rid of fearC. tell us about fear and phobiaD. discuss scientific studies about fear35. How does the writer make the meaning of “phobia” clear?A. By making comparisons (比较).B. By giving examples.C. By giving statistics (数据).D. By giving lively descriptions (描述).36. Which of the following shows the progress scientists have made in finding ways to deal with phobias?A. They can use phobias to keep our bodies alert.B. They can now reduce the pain that is connected with the phobia.C. New medicine can shut off fear centers in animal brains whenever needed.D. They have succeeded in helping some people pay no attention to the bad memories connected with their phobia.37. Which of the following would Dave Smithson probably agree with?A. There is nothing to fear except fear itself.B. We should not let fear influence our decisions.C. Fear is not a completely bad thing.D. Without fear, everyone would be brave.答案：25. C 26. C 27. B 28. B 29. A 30. D 31. B 32. A 33. B 34. C 35. B 36. D 37. C江苏省江阴市要塞片2020-2021学年九年级下学期期中考试英语试题四、阅读理解（共13 小题, 每小题 2 分, 满分26 分）阅读下面的短文, 然后根据短文内容, 在每小题所给的四个选项中选出最佳选项。

无锡市天一学校九年级数学下册期中试卷(含答案解析)

无锡市天一学校九年级数学下册期中试卷(含答案解析)无锡市天一学校2021九年级数学下册期中试卷(含答案解析)一、选择题〔本大题共10小题，每题3分，共30分．在每题所给出的四个选项中，只要一项为哪一项正确的，请用2B 铅笔把答题卡上相应的选项标号涂黑〕1．以下各数中，属于在理数的是〔▲〕A． B． C． D．2．计算a2?a4的结果是〔▲〕A．a8 B．a6 C．2a6 D．2a83．2021年3月份，无锡市某周的日最高气温统计如下表：那么这七天中日最高气温的众数和中位数区分是〔▲〕A．4，4 B．5，4 C．4，3 D．4，4.54．左图是由八个相反的小正方体组合而成的几何体，那么其仰望图是〔▲〕5．如图，在四边形ABCD中，E、F、G、H区分是AB、BD、CD、AC的中点，要使四边形EFGH是菱形，那么四边形ABCD 只需求满足一个条件，是〔▲〕A．四边形ABCD是梯形 B．四边形ABCD是菱形C．对角线AC＝BD D．AD＝BC6．如图，OP平分∠MON，PA⊥ON于点A，点Q是射线OM上一个动点，假定PA＝3，那么PQ的最小值为〔▲〕A． B．2 C．3 D．27．如图，在平面直角坐标系中，过格点A、B、C作一圆弧，点B与以下格点的连线中，可以与该圆弧相切的是〔▲〕A．点(0，3) B．点(2，3) C点(5，1) D．点(6，1) 8.如图1,在△ABC中，∠ACB=90°，∠CAB=30°, △ABD是等边三角形，E是AB的中点，连结CE并延伸交AD于F，如图2，现将四边形ACBD折叠,使D与C重合，HK为折痕，那么sin∠ACH的值为〔▲〕A． B． C． D．9．假定不等式对恒成立，那么x的取值范围是〔▲〕A. B. C. D.10. 如图，用四个螺丝将四条不可弯曲的木条围成一个木框，不计螺丝大小，其中相邻两螺丝的距离依次为2、3、4、6，且相邻两木条的夹角均可调整．假定调整木条的夹角时不破坏此木框，那么恣意两个螺丝间的距离的最大值为〔▲〕A．6 B．7 C．8 D．10二、填空题〔本大题共8小题，每题2分，共16分．不需写出解答进程，只需把答案直接填写在答题卡上相应的位置处〕11．函数y＝中自变量x的取值范围是____▲____．12．因式分解：2m2－8m＋8＝____▲____．13．如图，AB、CD是水平放置的轮盘〔仰望图〕上两条相互垂直的直径，一个小钢球在轮盘上自在滚动，该小钢球最终停在阴影区域的概率为____▲____．14．如图，在四边形ABCD中，∠A＋∠B＝200°，∠ADC、ABCD的平分线相交于点O，那么∠COD的度数是____▲____．15．如图，一个扇形铁皮OAB，OA＝60 cm，∠AOB＝120°，小明将OA、OB合拢制成了一个圆锥形烟囱帽〔接缝疏忽不计〕，那么烟囱帽的底面圆的半径为____▲____．16．将量角器按如下图的方式放置在三角形纸片上，使点C 在半圆圆心上，点B在半圆上，边AB、AC区分交半圆于点E、F，点B、E、F对应的读数区分为160°、70°、50°，那么∠A的度数为____▲____．17.正方形ABCD、BEFG和矩形DGHI的位置如图，其中G、F 两点区分在BC、EH上。

江苏省无锡市太湖格致中学、江阴初级中学2020届九年级6月跟踪性测试物理试题(可编辑PDF版,无答案)

R3
A
B
R1
R2
第 11 题图
第 12 题图
图 12．如图所示电路，电源电压为 12V 且保持不变。闭合开关 S，当滑片 P 置于变阻器的中点时，电压表的示数为 4V；当滑片 P 置于变阻器的 b 端时，定值电阻 R 在 10s 内产生的热量为 60J。则下列结果正确的是（） A．电路中的最小电流为 1.5A B．R 先后两次消耗的电功率之比为 8﹕9 C．R1 先后两次消耗的电功率之比为 4﹕3 D．滑片 P 在中点时，9s 内滑动变阻器 R 消耗的电能为 60J
A．若 K 是小孔并将光屏向右移动少许，光屏上的像将变模糊
B．若 K 是凸透镜，则它的焦距满足 f＞15cm
C．仅需水平移动 S、K 或 P 中的一个，即可判断 K 是否为小孔
D．若 K 是凸透镜并移至 35.0cm 刻度线处，光屏上将得到清晰的放大像
6．下列给出的现象中，物体运动状态没有发生改变的是（）
源，它属于＿＿＿＿＿（选填“可再生”或“不可再生”）能源。
14.烧水时水开后壶嘴周围有“白气”，且____(选填“a”或“b”)处较浓，这是
（填物态变化名称）现象．用温度计测量冰箱冷藏室的温度，往往在温度计的玻璃泡上裹
一小团湿棉花，这样做的好处是：
。
第 14 题图
第 15 题图
15.如图，让一束太阳光通过挡光板的狭缝照射到三棱镜的一个侧面上，慢慢转动三
A．苹果从树上落下
B．汽车匀速转弯
C．人造卫星绕地球匀速转动
D．货物被起重机吊起匀速上升
7．为了探究滑动摩擦力,小明同学利用牙刷做实验,当用力匀速拖动牙刷时,刷毛发
生了如图所示的弯曲,对这一实验的分析错误的是(

江苏省无锡市江阴市长泾片2020届九年级下学期数学期中考试试卷及参考答案

（1）求证：△ABD≌△ACE；（2）若∠1＝25°，∠2＝30°，求∠3的度数. 22. 如图，在3 3的正方形网格中，点A、B、C、D、E、F都是格点.
（1）从A、D、E、F四点中任意取一点，以所取点及B、C为顶点画三角形，那么所画三角形是等腰三角形的概率是. （2）从A、D、E、F四点中任意取两点，以所取两点及B、C为顶点画四边形，求所画四边形是平行四边形的概率.（请用“画树状图”或“列表”等方式写出分析过程） 23. 某校为了解七、八年级学生对“防溺水”安全知识的掌握情况，从七、八年级各随机抽取50名学生进行测试，并对成绩（百分制）进行整理、描述和分析.部分信息如下： a.七年级成绩频数分2）将线段AC绕点A旋转60°得到线段AC'，若点C'在抛物线的对称轴上，求出此时抛物线的函数解析式. 28. 如图，在Rt△ABC中，∠ACB＝90°，AC、BC的长为方程x2﹣14x+a＝0的两根，且AC﹣BC＝2，D为AB的中点.
（1）求a的值. （2）动点P从点A出发，以每秒2个单位的速度，沿A→D→C的路线向点C运动；动点Q从点B出发，以每秒3个单位的速度，沿B→C的路线向点C运动，且点Q每运动1秒，就停止2秒，然后再运动1秒…若点P、Q同时出发，当其中有一点到达终点时整个运动随之结束.设运动时间为t秒. ①在整个运动过程中，设△PCQ的面积为S，试求S与t之间的函数关系式；并指出自变量t的取值范围； ②是否存在这样的t，使得△PCQ为直角三角形？若存在，请直接写出所有符合条件的t的值. 参考答案
并说明理由；
（4）该校七年级学生有400人，假设全部参加此次测试，请估计七年级成绩超过平均数76.9分的人数. 24. 如图，在⊙O中，C，D分别为半径OB，弦AB的中点，连接CD并延长，交过点A的切线于点E.

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2019-2020学年第二学期期中考试
初三英语试卷
（考试时间：100分钟满分：90分）
第I卷（客观题共50分）
一、单项填空在A、B、C、D四个选择中，选出可以填入空白处的最佳选项，并在答题卡上将该
项涂黑。