中考训练题三
2020中考语文记叙文阅读专项考点系列训练题三(含答案 五篇)

2020中考语文记叙文阅读专项考点系列训练题三1.有关段落的作用;2分析句子含义。
(说明:试题中,其它考点可酌情作答训练)一、自行车之歌苏童①我父亲的那辆自行车是六十年代出产的永久牌,黑色车身,造型憨厚坚固。
从我记事到八十年代离家求学,我父亲一直骑着它早出晚归。
星期天的早晨,我总是能看见父亲在院子里用纱线擦拭他的自行车。
现在我是以感恩的心情想起了那辆自行车,因为它曾经维系着我的生命。
②童年多病,许多早晨和黄昏我坐在父亲的自行车上来往于去医院的路上。
曾经有一次我父亲用自行车带着我骑了二十里路,去乡村寻找一个握有家传秘方的赤脚医生。
我难以忘记这二十里路,大约十里是苏州城内的那种石子路、青石板路,另外十里就是乡村地带如海浪般起伏的泥路了。
我像一只小舢板一样在父亲身后颠簸,而我父亲就像一个熟悉水情的水手,也尽量让自行车的航行保持通畅。
③多少中国人对父亲的自行车怀有异样的亲情!多少孩子在星期天骑上父亲的自行车偷偷地出了门!去干什么?不干什么,就是去骑车!我记得我第一次骑车在苏州城漫游的经历。
我去了市中心的小广场,小广场四周有三家电影院,一家商场。
等我从商场出来,突然感到十分恐慌:我发现广场空地上早巳成一片自行车的海洋,每辆自行车看上去都像我们家的那一辆。
我拿着钥匙在自行车堆里走过来走过去,头脑中一片晕眩,我觉得许多半新不旧的“永久”自行车的坐垫和书包架上,都散发出我父亲和我自己身上的气息。
④1980年我中学毕业前夕,父亲给我买了一辆自行车。
他说:你假如考不上大学,这车就给你上班用。
但我考上了。
我父母又说:车放在家里,等你大学毕业了,回家工作后再用。
后来我大学毕业了,却没有回家乡工作。
于是我父母脸上流露出一种失望的表情,说:那就只好把车托运到南京去了,反正还是给你用。
⑤一个初秋的下午,我从南京西站的货仓里找到了从苏州托运来的那辆自行车。
车子的三角杠都用布条细致地包缠着,是为了避免装卸工的野蛮装卸弄坏了车子。
2020年中考生物专题训练三生物圈中的绿色植物(含答案)

专题训练三生物圈中的绿色植物一、选择题(请将各小题唯一正确的答案代码填在下面答案栏相应的空格内)1. 下列关于海带、葫芦藓、肾蕨的叙述,不正确的是()A.葫芦藓可作为空气污染的指示植物B. 海带有根和叶,没有茎C. 三种植物都能吸收二氧化碳,放出氧气D. 肾蕨有根、茎、叶的分化2. 地球上的生物是形形色色、多种多样的,有关下图四种植物的叙述错误的是( )A.水绵没有根、茎、叶的分化B.卷柏用孢子繁殖后代C.银杏有果实,属于被子植物D.月季有花、果实等器官3. 下列关于樱桃植株生长的叙述,正确的是()A.根吸收水分的主要部位是根尖的伸长区B.芽在发育时,营养组织的细胞分裂和分化,形成新的枝条C.茎加粗生长是茎的形成层细胞不断分裂和分化的结果D.植株生长需要施肥,主要是给植物提供有机物4. 清代诗人袁枚在《苔》中描写苔藓为“白日不到处,青春恰自来。
苔花如米小,也学牡丹开。
”下列有关苔藓和牡丹的叙述正确的是( )A.苔藓和牡丹都生活在阴暗潮湿的地方B.苔藓和牡丹都有根、茎、叶C.苔藓和牡丹都能进行光合作用D.苔藓和牡丹都能开花结果5. 被子植物的一生要经历生长、发育、繁殖、衰老和死亡的过程,下列叙述错误的是 ( )A. 雄蕊和雌蕊是花的主要结构B.种子的胚由胚芽、胚轴、胚根和胚乳构成C.根生长最快的部位是伸长区D.木本植物的茎能逐渐加粗,主要是因为茎中有形成层6. 玉米被誉为长寿食品,含有丰富的营养物质。
下列叙述正确的是( )A.玉米在开花期恰逢阴雨连绵,就会因传粉不足果穗缺粒减产B.玉米籽粒中的营养物质都是光合作用的产物C.玉米籽粒里的淀粉主要在胚芽内D.玉米果穗上有许多籽粒是因为其子房内有许多胚珠7. 2019年,位于北极圈附近的世界种子库已建成10年,其储存的种子样本已经超过100万份。
下列关于种子的储存和萌发叙述不正确的是 ( )A.较低的温度有利于种子的储存B.低氧条件下种子能储存较长时间C.只要有充足的水分种子就能萌发D.建立种子库利于保护生物多样性8. 菜豆种子萌发的过程如图所示,下列分析符合事实的是( )A.菜豆种子是由子房发育而来的B.菜豆种子萌发时,最先突破种皮的是胚芽C.菜豆种子在萌发过程中,提供营养物质的是胚乳D.菜豆种子萌发时,需要适宜的温度、一定的水分和充足的空气9.阳阳探究种子萌发是否需要光照,用如图9-3-1所示的实验装置,放入一粒小麦种子(具有休眠的特性),适宜温度下放在暗处,结果不萌发。
中考总复习专项训练题(三)(改错专练)

Jim was too frightened not to move.The snake 8.________
A B C D
6.You can sing in English,and so does he.
A B C D
7.Why not ask for help when you are with trouble?
A B C D
8.Ann didn't know how work out the problem in class.
the school,opened the door and went in the 7.________
classroom.That was nice and warm there 8.________
but Miss Jones was happy.But a small boy looked at her for a few 9.________
C D
25.How proudly they were when they heard the good news!
A B C D
26.It took the boy one and a half hour to fall asleep last night.
A B C D
A B C D
23.I hope my son to get on well with his classmates.
A B C D
24.—How did you come here this morning?
A B
—I came here by Mr Smith's car.
2023人教版中考英语总复习练习题--题型专项训练3 阅读理解

题型专项训练三阅读理解题型一判断正误型阅读理解A阅读下面短文,根据短文内容判断句子正误。
正确的写“A”,错误的写“B”。
We are collecting more news for our school English newspaper. Would you like to be reporters for it? Here are two pieces from the news page.2.Li Yu won the second prize in the 800-meter race yesterday.3.Yang Liu was the best runner last year.4.Mr.White will teach us English for two years at our school.5.We' 11 always remember Mr.White' s lively and interesting teaching.B根据文章内容,判断文后句子的正确(T)与错误(F)。
One day, little Roy was ill. So his mother took him to the clinic(诊所).A doctor examined him and said,“Well, boy, there is something wrong with you. I' m afraid you need to get injections(输液)twice a day. Then you will feel better soon. A nurse will give you the injection later.^Roy thought it would hurt so he was afraid.His mother wanted to comfort him,“Sweetie, don' t be nervous. I m here. If you' rc brave,r 11 take you to the zoo on weekends. I promise!” “Great! Mum, I love animalsl^said Roy.3 .Why do people choose to eat jiaozi on New Year' s Eve?4 .Do people need to follow set rules to make dumpling fillings?5 .How are dumpling wrappers made in some parts of Inner Mongolia?答案:题型一判断正误型阅读理解l.A 2.A 3.B 4.B 5.Al.T 2.T 3.F 4.F 5.F 题型二选择型阅读理解.every 200 kids1 .fit and healthy.how animals are raised and killed for food2 .more energy, water and land.have just a couple of vegetarian mealsLRiding bikes 2.bikes 3.low 4.easy and cheap 5.difficult/hard l.In ancient times. 2.It symbolizes wealth.1.1 n the hope of having a good future in the coming new year./Because they hope to have a good future in the coming new year.4 .No.5 .Dumpling wrappers are hand-pressed.1 .C 2.B 3.D 4.B 5.C1.C 2 .D 3.B 4.A 5.C3 .B 2.A 3.B 4.C 5.Dl.C 2.A 3.B 4.D 5.B题型三任务型阅读理解ABCDAJust then a young nurse came and said to him with a smile,“I am going to give you the injection now, Roy. Wheredo you want it? Left arm or right arm?”But Roy got scared again. He thought for a while and asked,"Nobody has let me choose that before. Must I choose now?”“Yes, Roy,"the nurse replied,"Where do you want it?”“Well,"Roy answered in a low voice,"I want it in your left arm, please.” l.Roy' s mother took him to the clinic because of his illness.2.The doctor told Roy he needed to get injections twice a day.3.Roy thought the doctor would hurt him so he was afraid.4.His mother promised to take him to the zoo on weekdays.5.Finally, the nurse gave the injection on her left arm.题型二选择型阅读理解AIn the 13th century, Marco Polo, the world known Italian traveller, saw many wonderful things in China. One of the things he discovered was money made of paper. People in the West did not have such kind of money until the 15th century. However, the Chinese began to use it in the 7th century.Paper was invented by a Chinese man called Cai Lun almost 2,000 years ago. But it was not made in Europe until the year 1 lOO.Four hundred years later, a German discovered that he could make the best paper from trees. After that countries rich in forests, such as Canada, Sweden, America, Finland became the most important ones in paper making.Paper can be used in many ways. The common uses include newspapers, magazines and books. But do you know that paper can be used for keeping warm? In Finland, the farmers wear paper boots to keep their feet warm in the snow. And even houses can be insulaled(使绝缘)from heat or cold with paper.However, we have to understand that paper still comes from trees now. If we keep on wasting so much paper, there will not be any trees left on the earth some day in the near future. Every day people throw away about 2,800 tons of paper in our city. It takes 17 trees to make one ton of paper. This means that we are cutting down nearly 48,000 trees every day. The fact is that it takes more than 10 years for a tree to grow.So we must start saving paper right now. We can use both sides of every piece of paper. We can make useful things out of used paper. We can use china cups instead of paper ones. When shopping, we can use fewer paper bags and reuse them if we have some.In short, we should keep a balance(平衡)between using paper and protecting trees, and do it now before it is too late.l.When did the Chinese begin to use paper money?A.In the 5th century.B.In the 6th century.C.In the 7th century.D.In the 15th century.2.Why did Canada become an important country in paper making?A.Because it was a large country.B.Because it had lots of forests.C.Because it was a very rich country.D.Because the inventor was from Canada.3.In Finland, paper is used for.A.making bedsB.reducing wasteC.making umbrellasD.keeping warm4. According to the passage, how many trees are needed to make one ton of paper?AJO.B.17.C.2,800.D.48,000.5.Paragraph 5 mainly talks about.A.how paper boots are madeB.how paper was inventedC.how we can save paperD.how we can make useful thingsBLong, long ago people made fires from lightning。
2024陕西中考数学二轮专题训练 题型三 简单计算题 (含答案)

2024陕西中考数学二轮专题训练题型三简单计算题类型一实数的运算【类型解读】实数的运算近7年在解答题考查6次,仅2020年未考查,分值均为5分,考查点涉及:①去绝对值符号;②二次根式运算;③0次幂;④分数的负整数指数幂;⑤立方根.考查形式:含3个考查点的加减混合运算.1.计算:20-|2-5|+(-2)2.2.计算:2×6+|3-2|-(-2022)0.3.计算:4×(-8)-|3-22|-(-13)-1.4.计算:-2×28+|7-1|+(-1)2022.5.计算:(-3)2×3-64-|-23|+(12)-2.6.计算:3×12-|2-6|-2tan45°.7.计算:-13×24+|22-2|-(-77)0+(-1)3.8.计算:13×(-327)-|1-3|+(-12)-3-2sin60°.类型二整式的化简(求值)1.计算:x (x +2)+(1+x )(1-x ).2.化简:(m+1)(m-3)-(m-2)2.3.化简:(x-3y)2-(x+2y)(x-2y).4.化简:(x-1)2-x(x-2)+(-x-3)(x-3).5.先化简,再求值:2x(1-x)-(x-3)(x+5),其中x=2.6.已知5x2-x-1=0,求代数式(3x+2)(3x-2)+x(x-2)的值.7.先化简,再求值:(x+2y)2+(x-2y)(x+2y)-2x(x+4y),其中x=2,y= 3.8.下面是小颖化简整式x(x+2y)-(x+1)2+2x的过程,仔细阅读后解答所提出的问题.解:原式=x2+2xy-(x2+2x+1)+2x第一步=x2+2xy-x2+2x+1+2x第二步=2xy+4x+1.第三步(1)小颖的化简过程从第________步开始出现错误,错误的原因是__________________________;(2)写出正确的解题过程.类型三分式的化简(求值)与解分式方程【类型解读】分式化简(求值)近10年考查6次,其中选择题1次(2017.5),解答题5次.其中分式化简考查5次,均为三项,形式包含:(A+B)÷C、(A-B)÷C;分式化简求值考查1次,形式为A-B,所给值为负数.解分式方程近10年考查5次,分值均为5分.考查形式:分式方程均为三项,其中两项为分式,另一项为常数1或-1.分式化简与解分式方程对比练习:针对分式化简与解分式方程过程中容易混淆的步骤,特设对比练习,让学生掌握基本步骤,明确解题方法,避免失分.对比练习①化简:12-x÷(2-2x2+x).解分式方程:12-x+2=2x2+x.解题过程对比练习②化简:(1-xx+1)÷1x2-1.解分式方程:1-xx+1=1x2-1.解题过程对比练习③化简:4x2-9÷(2x-3-1x+3).解分式方程:4x2-9-2x-3=1x+3.解题过程注意事项 1.分式化简时,分母始终存在,分 1.解分式方程时,第1步是利用等式式的每一项属于恒等变形;2.分式化简时,若遇到异分母分式相加或者相减,要进行通分,通分是将几个异分母的分式分别化成与原来的分式相等的同分母的分式;3.在化简的过程中,分子或分母能因式分解的先因式分解,以便看能否约去公因式的基本性质,去分母,因此分母不存在;2.解分式方程时,去分母是给方程两边同乘最简公分母,从而将分式方程化为整式方程;3.分式方程要检验,即检验所求的解是否是该方程的根考向一分式的化简(求值)1.化简:(1+1m-1)÷mm2-1.2.化简:a-ba+b-a2-2ab+b2a2-b2÷a-ba.3.化简:(x-2x+2-8x4-x2)÷x2+2xx-2.4.计算:x2-9x2+2x+1÷(x+3-x2x+1).5.已知A=2x-1,B=x+1x2-2x+1,C=x+13x-3,将它们组合成A-B÷C或(A-B)÷C的形式,请你从中任选一种组合形式,先化简,再求值,其中x=-3.考向二解分式方程1.解分式方程:xx+1=x3x+3+1.2.解分式方程:xx-3-6x=1.3.解分式方程:xx-2-1=4x2-4x+4.4.下面是小颖同学解分式方程的过程,请认真阅读并完成相应任务.解方程:x+2x-2-1=84-x2.解:(x+2)2-(x2-4)=-8,·················第一步x2+4x+4-x2-4=-8,····················第二步4x=0,···································第三步x=0,····································第四步所以原分式方程的解是x=0.················第五步任务一:①以上解分式方程的过程中,缺少的一步是________;②第________步开始出现错误,这一步错误的原因是________________________;任务二:请直接写出该分式方程的解;任务三:除纠正上述错误外,请你根据平时的学习经验,就解分式方程时还需要注意的事项给其他同学提一条建议.类型四一次方程(组)(常在一次函数的实际应用、二次函数综合题中涉及)1.解方程:x-32+x-13=4.2.=2y -y=6.3.x-y=-4-2y=-3.4.x-4(x+2y)=5+2y=1.5.2y=3-2+y3=-12.6.x+y=7=y-1的解也是关于x、y的方程ax+y=4的一个解,求a的值.7.x+2y=5①x+2y=-3②时的部分过程:x+2y=5①x+2y=-3②,①-②,得-2x=8,…(1)上述解法中,使用的方法是____________;(填“代入消元法”或“加减消元法”)(2)解方程组的基本思想是________;(3)请选择不同于题中的方法求解该方程组.类型五一元二次方程(常在二次函数综合题中涉及)1.解方程:(x+1)2-4=0.2.解方程:2x2+6x-3=0.3.解方程:x(x-7)=8(7-x).4.解方程:(x+1)(x-3)=1.5.若x=-1是关于x的一元二次方程(m-1)x2-x-2=0的一个根,求m的值及另一个根.6.已知关于x的一元二次方程x2-2x+1-k=0有两个不相等的实数根.(1)求k的取值范围;(2)请你给出一个k的值,并求出此时方程的根.7.已知关于x 的一元二次方程x 2-4mx +3m 2=0.(1)求证:该方程总有两个实数根;(2)若m >0,且该方程的两个实数根的差为2,求m 的值.类型六不等式(组)【类型解读】解不等式组近10年考查5次,其中解答题2次(近两年连续考查),选择题3次.1.-1≥2①x +3<13②.2.x <x +8(x +1)≤7x +10.3.x -1)≤1x -53.4.(x +1)≤7x +13-4<x -83.5.解不等式:3x +24≤x -13,并把解集在数轴上表示出来,同时写出它的最大整数解.第5题图6.6≤x+16,并把它的解集在数轴上表示出来.第6题图7.(1+x)>-1①1-x)>-2②的解答过程.解:由①,得2+x>-1,所以x>-3.由②,得1-x>2,所以-x>1,所以x>-1;所以原不等式组的解是x>-1.圆圆的解答过程是否有错误?如果有错误,写出正确的解答过程.参考答案类型一实数的运算1.解:原式=25-(5-2)+4=25-5+2+4=5+6.2.解:原式=2×6+(2-3)-1=23+2-3-1=3+1.3.解:原式=2×(-22)-(3-22)+3=-42-3+22+3=-2 2.4.解:原式=-2×27+(7-1)+1=-47+7-1+1=-37.5.解:原式=3×(-4)-23+4=-12-23+4=-8-2 3.6.解:原式=3×23-(6-2)-2=6-6+2-2=6- 6.7.解:原式=-13×24+(22-2)-1-1=-22+22-2-2=-4.8.解:原式=13×(-3)-(3-1)-8-2×32=-1-3+1-8-3=-23-8.类型二整式的化简(求值) 1.解:原式=x2+2x+1-x22.解:原式=m2+m-3m-3-(m2-4m+4)=m2-2m-3-m2+4m-4=2m-7.3.解:原式=x2-6xy+9y2-(x2-4y2)=x2-6xy+9y2-x2+4y2=-6xy+13y2.4.解:原式=x2-2x+1-x2+2x-(x+3)(x-3)=1-(x2-9)=1-x2+9=10-x2.5.解:原式=2x-2x2-(x2-3x+5x-15)=2x-2x2-x2+3x-5x+15=-3x2+15.当x=2时,原式=-3×22+15=3.6.解:原式=9x2-4+x2-2x=10x2-2x-4,∵5x2-x-1=0,∴5x2-x=1,∴原式=2(5x2-x)-4=-2.7.解:原式=x2+4xy+4y2+x2-4y2-(2x2+8xy)=x2+4xy+4y2+x2-4y2-2x2-8xy=-4xy.当x=2,y=3时,原式=-4×2×3=-4 6.8.解:(1)二;括号前是“-”号,去括号时里面的各项没有变号;(2)原式=x2+2xy-(x2+2x+1)+2x=x2+2xy-x2-2x-1+2x=2xy-1.类型三分式的化简(求值)与解分式方程解:原式=12-x ÷2(2+x )-2x 2+x=12-x ÷42+x=12-x ·2+x 4=2+x 8-4x.解:方程两边同乘(2+x )(2-x ),得2+x +2(2+x )(2-x )=2x (2-x ),2+x +8-2x 2=4x -2x 2,-3x =-10.解得x =103.检验:当x =103时,(2+x )(2-x )≠0,∴原分式方程的解是x =103.对比练习②解:原式=x +1-x x +1÷1(x +1)(x -1)=1x +1·(x +1)(x -1)=x -1.解:方程两边同乘(x +1)(x -1),得(x +1)(x -1)-x (x -1)=1,x 2-1-(x 2-x )=1,解得x =2.检验:当x =2时,(x +1)(x -1)≠0,∴原分式方程的解是x =2.对比练习③解:原式=4(x +3)(x -3)÷2(x +3)-(x -3)(x +3)(x -3)=4(x +3)(x -3)÷2x +6-x +3(x +3)(x -3)=4(x +3)(x -3)·(x +3)(x -3)x +9=4x +9.解:方程两边同乘(x +3)(x -3),得4-2(x +3)=x -3.4-(2x +6)=x -3.-3x =-1.解得x =13检验:当x =13时,(x +3)(x -3)≠0,∴原分式方程的解是x =13.考向一分式的化简(求值)1.解:原式=m -1+1m -1·(m +1)(m -1)m =m m -1·(m +1)(m -1)m=m +1.2.解:原式=a -b a +b -(a -b )2(a -b )(a +b )·a a -b=a -b a +b -a a +b=-b a +b.3.解:原式=(x -2x +2+8x x 2-4)÷x (x +2)x -2=x 2-4x +4+8x (x +2)(x -2)·(x -2)x (x +2)=x 2+4x +4(x +2)(x -2)·(x -2)x (x +2)=(x +2)2(x +2)(x -2)·(x -2)x (x +2)=1x.4.解:原式=(x +3)(x -3)(x +1)2÷x 2+x +3-x 2x +1=(x +3)(x -3)(x +1)2·x +1x +3=x -3x +1.5.解:A -B ÷C :2x -1-x +1x 2-2x +1÷x +13x -3原式=2x -1-x +1(x -1)2·3(x -1)x +1=2x -1-3x -1=-1x -1,当x =-3时,原式=-1-3-1=14;(A -B )÷C :(2x -1-x +1x 2-2x +1)÷x +13x -3原式=[2x -1-x +1(x -1)2]·3(x -1)x +1=[2x -2(x -1)2-x +1(x -1)2]·3(x -1)x +1=x -3(x -1)2·3(x -1)x +1=3x -9x 2-1,当x =-3时,原式=3×(-3)-9(-3)2-1=-94.考向二解分式方程1.解:方程两边同乘3(x +1),得3x =x +3x +3,解得x =-3.检验:当x =-3时,3(x +1)≠0,∴原分式方程的解为x =-3.2.解:方程两边同乘x (x -3),得x 2-6(x -3)=x (x -3).-3x =-18.解得x =6.检验:当x =6时,x (x -3)≠0,∴原分式方程的解为x =6.3.解:方程两边同乘(x -2)2,得x (x -2)-(x -2)2=4,2x=8.解得x=4.检验:当x=4时,(x-2)2≠0.∴原分式方程的解为x=4.4.解:任务一:①检验;②二,去括号时,括号前是“-”号,括号里面第二项没有变号;任务二:该分式方程的解为x=-4;【解法提示】x+2x-2-1=84-x2,(x+2)2-(x2-4)=-8,x2+4x+4-x2+4=-8,4x=-16,x=-4,检验:当x=-4时,x2-4≠0,∴原分式方程的解为x=-4.任务三:答案不唯一,如:去分母时,注意方程中的每项都要乘最简公分母;去括号时,注意正确运用去括号法则;解分式方程必须验根等.类型四一次方程(组)1.解:3(x-3)+2(x-1)=24,3x-9+2x-2=24,3x+2x=24+9+2,5x=35,x=7.∴原方程的解为x=7.2.解:=2y①-y=6②,把①代入②,得2y-y=6,解得y=6.把y=6代入①,得x=12.=12=6.3.解x-y=-4①-2y=-3②,①×2,得6x-2y=-8③,③-②,得5x=-5,解得x=-1,把x=-1代入①,得y=1.=-1=.4.解x-8y=5①+2y=1②,①+②得:-6y=6,解得y=-1,把y=-1代入②得:x-2=1,解得x=3,=3=-1.5.解:将原方程组整理,得:+2y=3①x-2y=1②,①+②,得4x=4,解得x=1,将x=1代入①,得1+2y=3,解得y=1,=1=1.6.解x+y=7=y-1②,把②代入①得:2(y-1)+y=7,解得y=3,代入①中,解得x=2,把x=2,y=3代入方程ax+y=4得,2a+3=4,解得a=12.7.解:(1)加减消元法;(2)消元;(3)由②得2y=-3-5x③.将③代入①得,3x+(-3-5x)=5,去括号,移项、合并同类项得-2x=8,解得x=-4,将x=-4代入①,得-12+2y=5,解得y=172,=-4=172.类型五一元二次方程1.解:(x+1)2=4,∴x+1=±2,解得x1=1,x2=-3.2.解:∵a=2,b=6,c=-3,∴b2-4ac=60>0,∴x=-b±b2-4ac2a=-6±602×2=-6±2154=-3±152.∴x1=-3+152,x2=-3-152.3.解:x(x-7)+8(x-7)=0,(x-7)(x+8)=0,解得x1=7,x2=-8.4.解:将方程整理为一般式为x2-2x-4=0,∵a=1,b=-2,c=-4,∴b2-4ac=(-2)2-4×1×(-4)=20>0,∴x=-b±b2-4ac2a=2±252=1±5,∴x1=1+5,x2=1-5.5.解:将x=-1代入原方程得m-1+1-2=0,解得m=2,当m=2时,原方程为x2-x-2=0,即(x+1)(x-2)=0,∴x1=-1,x2=2,∴方程的另一个根为x=2.6.解:(1)∵关于x的一元二次方程x2-2x+1-k=0有两个不相等的实数根.∴b2-4ac=(-2)2-4×1×(1-k)>0,∴4k>0,解得k>0;(2)由(1)知,实数k的取值范围为k>0,故取k=1,则x2-2x=0,即x(x-2)=0,解得x1=0,x2=2.7.(1)证明:∵b2-4ac=(-4m)2-4×1×3m2=4m2≥0,∴该方程总有两个实数根;(2)解:x2-4mx+3m2=0可化为(x-m)(x-3m)=0,解得x1=m,x2=3m.∵m>0,∴m<3m.∵该方程的两个实数根的差为2,∴x2-x1=3m-m=2m=2,解得m=1.类型六不等式(组) 1.解:解不等式①,得x≥3,解不等式②,得x<5,∴原不等式组的解集为3≤x<5.2.解x<x+8①(x+1)≤7x+10②,解不等式①,得x<4,解不等式②,得x≥-2,∴原不等式组的解集是-2≤x<4.3.解x-1)≤1①x-53②,解不等式①,得x≥1,解不等式②,得x<3.∴原不等式组的解集是1≤x<3.4.解(x +1)≤7x +13①-4<x -83②,解不等式①,得x ≥-3,解不等式②,得x <2.∴原不等式组的解集是-3≤x <2.5.解:去分母,得3(3x +2)≤4(x -1),去括号,得9x +6≤4x -4,移项、合并同类项,得5x ≤-10,解得x ≤-2.将不等式的解集在数轴上表示如解图,第5题解图∴不等式的最大整数解为x =-2.6.解6①≤x +16②,解不等式①,得x >-3,解不等式②,得x ≤2,∴这个不等式组的解集是-3<x ≤2.解集在数轴上表示如解图.第6题解图7.解:圆圆的解答过程有错误.正确的解答过程如下:由①,得2+2x >-1,∴2x >-3,∴x >-32,由②,得1-x <2,∴-x <1,∴x >-1.∴原不等式组的解集是x >-1.。
中考数学中档题突破 专项训练三 解含参数的不等式(组)(选填题)

1.关于 x 的方程 3x-2m=1 的解为正数,则 m 的取值范围是
1
1
A.m<-2 B.m>-2
1 C.m>2
1 D.m<2
Байду номын сангаас
( B)
x-a≥1, 2.已知关于 x 的不等式组x+5≤b 的解集是 3≤x≤4,则 a+b 的值为
( C)
A.5 B.8 C.11 D.9
14.对非负实数 x“四舍五入”到个位的值记为(x),即当 n 为非负整数
时,若 n-0.5≤x<n+0.5,则(x)=n.如(1.34)=1,(4.86)=5,若(0.5x
-1)=6,则实数 x 的取值范围是 113≤3≤x<x<15. 15
3.若关于 x 的不等式(m-1)x<m-1 的解集为 x>1,则 m 的取值范围是 ( B)
A.m>1 B.m<1 C.m≠1 D.m=1
x+2y=4k, 4.已知2x+y=2k+1的解满足 y-x<1,则 k 的取值范围是
1 A.k>1 B.k<-2
C.k>0 D.k<1
( D)
x+a≥0, 5.若不等式组5-3x>x-3有解,则 a 的取值范围是 A.a≤-2 B.a≥-2
数解,则实数 a 的取值范围是
( C)
A.7<a<8 B.7<a≤8
C.7≤a<8 D.7≤a≤8
2x+y=3, 8.★若 m 使得关于 x,y 的二元一次方程组mx-2y=7 有解,且使关于
x 的一元一次不等式组x-2 1-2x≤1,有且仅有 3 个整数解,那么所有满
4x+m≤2
足条件的整数 m 的值之和是
x+2y=3m+1, 12.(2020·铜仁模拟)已知关于 x,y 的二元一次方程组3x-y=2m+3, 且 x,y 满足 x+y>3,则 m 的取值范围是 mm>>11.
2020年中考物理试题专项训练——专题训练(三) 电功率之图象问题

专题训练(三)电功率之图象问题类型1I-U图象(一)定值电阻的I-U图象1.2020·常德用电器R1和R2上都标有“6 V”字样,它们的电流随电压变化关系如图ZT-3-1所示。
下列说法不正确的是()图ZT-3-1A.R1和R2的阻值不随温度的变化而变化B.R1∶R2=2∶1C.R1和R2并联在4 V电源上,通过的电流之比I1∶I2=2∶1D.R1和R2并联在4 V电源上,电路消耗的总功率为1.2 W2.2019·天津如图ZT-3-2甲所示的电路,电源电压保持不变,闭合开关S,滑动变阻器滑片P从a端移动到b端的整个过程中,电流表示数I与电压表示数U的关系图象如图乙所示。
则电阻R1的阻值为________Ω;当变阻器滑片P处于a端时,电阻R1消耗的电功率为________W。
图ZT-3-2(二)灯泡(非定值电阻)的I-U图象3.2020·青岛(多选)小明测量小灯泡的电功率,电路如图ZT-3-3甲所示,电源电压恒为6 V,小灯泡上标有“3.8 V”字样。
实验得到小灯泡的U-I图象如图乙所示。
下列分析正确的是()图ZT-3-3A.小灯泡的电阻约为12.7 ΩB.小灯泡的额定功率为1.14 WC.小灯泡正常发光时,滑动变阻器接入电路中的阻值为20 ΩD.小灯泡两端电压为2.0 V时,滑动变阻器消耗的电功率为0.88 W4.有两个电路元件A和B,流过元件A、B的电流与其两端电压的关系如图ZT-3-4甲所示。
把它们串联在电路中,如图乙所示,闭合开关S,这时电流表的示数为0.4 A,则电源电压和电路的总功率分别是()图ZT-3-4A.4.5 V 1.8 W B.2.5 V 1.0 WC.4.5 V 1.0 W D.2.0 V0.8 W5.甲、乙两灯的额定电压均为6 V,测得两灯的电流与电压关系图象如图ZT-3-5所示。
甲灯正常工作时的电阻是________Ω;当乙灯的实际功率是2.4 W时,它两端的实际电压是________V;当把甲、乙两灯串联接在7 V 的电源上时,电路消耗的总功率是________W。
2021-2022年中考物理复习真题训练试题第三章物态变化(含答案)

2021-2022年中考物理复习真题训练试题第三章物态变化(含答案)一、单选题1.(2021•福建)缺电地方的人们发明了一种陶制的罐中罐“冰箱”,内外罐之间填有沙子,如图,盛夏季节里,有利于给“冰箱”中食物降温的做法是()A.换用铁质材料制作内外罐B.经常给两罐间的沙子浇水C.把“冰箱”放在密闭房间内D.把“冰箱”放在湿热环境中2.(2021•通辽)下列物理现象及原因分析错误的是()A.寒冬河水结冰是升华现象B.抗疫值班医护人员眼罩的镜片常常模糊不清,是水蒸气液化形成的C.湿衣服被太阳晒干是汽化现象D.冬天玻璃上会出现冰花,这是凝华现象3.(2021•黔东南州)“二十四节气”是中华民族智慧的结晶,有关节气的谚语,下列分析正确的是()A.“惊蛰云不停,寒到五月中”,云的形成是升华现象,该过程需吸热B.“伏天三场雨,薄地长好麻”,雨的形成是液化现象,该过程需吸热C.“霜降有霜,米谷满仓”,霜的形成是凝华现象,该过程需放热D.“小寒冻土,大寒冻河”,河水结冰是凝固现象,该过程需吸热4.(2021•荆州)以下跟汽车有关的热现象中说法错误的是()A.冬天排气管冒出的“白气”,是空气液化形成的B.打开除雾功能,汽车玻璃上的“雾”很快消失,是汽化现象C.冬天,汽车水箱中加入适量酒精可以降低水的凝固点D.汽车空调制冷时,制冷剂汽化时吸热、液化时放热5.(2021•吉林)下列现象属于凝华的是()A.初春,冰雪消融B.盛夏,朝露晶莹C.晚秋,霜打枝头D.严冬,滴水成冰6.(2021•陕西)冷链储运中常用一种装有制冷装置的冷藏车,用于运输冷冻食品和疫苗药品等。
制冷装置通过液态制冷剂汽化将车的“热”搬运到外面,实现制冷。
下列说法正确的是()A.冷藏车厢体应选用导热性好的材料做成B.液态制冷剂在车厢内汽化吸热C.车厢内物品表面会有一层白霜,是凝固现象D.放入车厢内的水在凝固过程中温度降低7.(2021·济宁)淡水资源缺乏已是一个世界性的普遍现象,利用太阳能、海水等资源获得淡水具有重要的战略意义。
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中考专题复习资料英语(三)一. 单项选择从题中所给的四个选项中,选出一个最佳答案。
1. —How did he say yesterday?—He felt when things went against him.A. amazedB. frustratedC. interestedD. excited2. —What happened to you when the light went out?—I my way across the room and got the candle and matches.A. stayedB. stoodC. feltD. lost3. —Which team played better, Italy or Brazil?—Well, it’s hard to say. I think it’s all a ________ of opinion.A. questionB. matterC. troubleD. problem4. —We’ll study in different schools next term. Enjoy your time in the new school!—_______.A.I’ll take your adviceB. The same to youC. CongratulationsD. Me too5.—The winter holiday is on the way we’ll have more freedom.—I agree with you. But we should learn to ______ ourselves.A.manageB. spareC. preventD. avoid6. —Have you paid? What’s my share of the bill?—. It wasn’t very much.A. Don’t worry about it.B. None of you r business.C. It’s up to you.D. It’s my treat7.—It took real _____ to go back into the burning building.—So it did. The firefighter was brave enough.A.creativityB.powerC. courageD. fault8. —By the time we got to the cinema, the film for 10 minutes.—What a pity! You missed the most interesting part.A. had begunB. had been onC. have begunD. have been over9. —People today _____ posting wonderful articles and beautiful photos onto the micro message(微信) to share with friends.—Well. Internet makes our friendship stronger.A. pay attention toB. end upC. get used toD. look up to10. —What’s wrong with Bruce? He doesn’t look well.—He ________ his finger in the door.A. caughtB. threwC. keptD. set11. — Could you go shopping with me this afternoon?—Sorry. My money has ______ . I’m afraid I have to wait some timeA. run out ofB. run outC. used upD. given up12. — How much should I pay for the trip?—I’ve ______ your share of the expenses at $1000.A . come out B. set out C. worked out D. helped out13. —Could you help me repair the bike?—.A. You’re welcomeB. That’s all rightC. It’s my pleasureD. With pleasure14.—You are late today!—Sorry. I an old friend on the street just now and we talked a lot.A. came acrossB. came aboutC. came alongD. came up—9—15. —I wonder ________ there.—A man was caught when he was stealing a mobile phone.A. what happenedB. where did it happenC. what wowed happenD. where it happened二、完形填空阅读下面短文,掌握其大意,然后从各题所给的四个选项中,选出一个最佳答案“I’ve been writing a book, John. Do you think anyone would be interested in(1)it?”said theold lady.John took over the papers from her shaking hand and(2)her in chair, He rememberedHer rich(3)in the early days of the Old West. He looked through the papers.“It’s good, Grandma,”he said gently. Then realizing that she(4)hear him, he shouted into her ears, “l think it’s very Good. I’ll(5)it to a publisher.”Ten days later, he reported that the publisher had had time to read only a few(6).But he was so impressed that he had sent $100for an option(版权).(7)money would be given as an advance. Every month John (8)$100for her with a letter from the publisher telling about the progress of the book.One morning, three months after her 100th birthday Grandma didn’t get up, The doctor told her that she couldn’t(9)more than a few days. she was ready to go, but she first wanted her book to be in print. John promised that she could get it very soon.Grandma held on until the day the book came into her hands with the title and her name on the cover. Though she couldn’t see it, she could touch it. She proudly traced(探查)her name with her fingers, tears in her eyes. Two hours later, she died peacefully(10)holding her book.Her granddaughter took up the book and opened it. “Why, it’s just blank pages!”she cried in(11).John’s face turned(12).Then the girl understood. There never was a .book Grandma couldn’t hear the little bell when the typewriter came to the(13)of the line. She would keep on working, not(14)the whole sentences and sometimes the paragraphs were missing. John did not tell her,(15)he couldn’t take away her only hope .It was John himself who had written the letters and sold his car to pay the advance.1.A. buying B. publishing C. reading D. lending2.A. sat B. put C. placed D. seated3.A. sufferings B. experiences C. thoughts D. family4.A. couldn’t B. needn’t C. mustn’t D. doesn’t5.A. throw B. put C. send D. lift6.A. words B. sentences C. pages D. books7.A. Some B. Much C. Enough D. More8.A. brought B. took C. gave D. carried9.A.die B. stay C. last D. remain10.A. still B. yet C. always D. then11.A. anger B.joy C. surprise D. tears12.A. white B. pale C. gray D. pale13.A. middle B. last C. end D. beginning14.A. writing B. knowing C. thinking D. wanting15.A.when B. how C .for D. where三.阅读理解—10—A.A. an advertisement for a medicine.B. a scientific research about a medicineC. an introduction of a medicineD. a piece of news on a new kind of medicine2. What kind of patients must NOT take 666 POWDER FOR COLD?A. The patients who have got a fever.B. The patients who have got a high blood pressure.C. The patients who have got a cough.D. The patients who have got a sore throat.3. A bottle of 666 POWDER FOR COLD can last at least for a kid aged 10.A. one dayB. two daysC. three daysD. four days4. We should keep 666 POWDER FOR COLD in .A. a place with no sunlight in the kitchen C. a clean drawer in the parents’ bedroomB. a clean place near the window D. a dry place near a fireplace5. Which of the following is TRUE according to the passage?A. Patients can use 666 POWDER FOR COLD for more than eight days.B. If patients don’t feel well after taking, they need to drink more water and sleep.C. Patients should take 666 POWDER FOR COLD according to their weight.D. Patients can take the 666 POWDER FOR COLD in February, 2014.BI just returned from a trip to New Jersey. On the way back, I was stopped by a traffic accident.This accident covered a truck carrying a load of dangerous materials that were getting out. This meant that we weren’t going anywhere for several hours. At one point were five of us standing by my truck, complaining.Another truck with two elderly people inside stopped near us. The man, Joe, lowered his window and asked why no one was moving.Soon we were all talking with this couple. The lady, Anna, said that they had plenty of water and sodas in the cooler in their truck and offered everyone something to drink. While she was back there, she said that she also had plenty of food and asked if we would like a sandwich.After some urging from Joe, we agreed to a sandwich. While Anna was making the sandwiches, she was singing like a songbird, Being close to 70, I guessed, she had a sweet voice.When she finished making the sandwiches, I saw a Mississippi license plate on the truck. I asked what part of Mississippi they were from. Joe said Biloxi, Knowing that Biloxi had been damaged (损—11—坏) by hurricane Katrina (卡特里娜飓风), I asked if they had any damage. Joe said that they had lost almost everything. Everything they had was in the truck.All of us drivers tried unsuccessfully to pay them for their drinks and the sandwiches. Joe said that their son was living around Harrison-burg , Virginia and that they were going there. There was a home for sale and they were going to start all over there. Starting over at their age, we knew, would not be easy.These people lost everything except the pictures and some clothes. These wonderful people lost practically everything they owned and still would not accept any money for their food and drinks. Joe said that it was better to give than to receive.6. The author told us that the accident happened ______.A. On his way to New JerseyB. On the way from Virginja to New JerseyC. On his way returning from New JerseyD. On the way from New Jersey to Mississippi7. Who showed different attitude from others while waiting?A. The authorB. The policemenC. The driversD. The couple8. From the passage, we can infer ______.A. the couple would have a hard lifeB. the couple offered us some drink and breadC. the people from Biloxi had been away before hurricane KatrinaD. no one would be alive after the hurricane Katrina9. Which of the following is RIGHT?A. The driver of the first truck was drunk.B. The couple were always friendly to others.C. Anna was a cook and worked in a restaurant.D. The couple were rich and helped the poor people.10. The main idea of the passage is ______.A. we should learn from the coupleB. it is better to receive than to giveC. people in trouble should be full of hopeD. the wonderful people will not accept money 四阅读理解填词先阅读短文,在其后空白处写出各单词的正确形式,单词的第一个字母已给出Street fairs are very popular everywhere in the United States. Generally s 1 , each town will have at least one,and usually two street fairs every year. Street fairs mostly happen in the spring and the fall, and are a great d 2 of fun.The most important event at a street fair is the parade (游行). The high school marching band would lead it. They play marching music (进行曲) and walk t 3 the streets. The band is followed by many different types of people and cars.Firefighters would drive a few fire trucks in the parade, police officers would drive their police cars, and both would turn their alarms on. Sometimes, it becomes a game between them to see whose can be l 4 ! Other groups in the parade i 5 children from different clubs, Scottish people, people who can play the flute (长笛), people dressed up as cartoon characters...Basically, if you can think of a group, it will probably have a spot in the parade.Lastly, anyone else not in a group can join the parade at the end! The parade is not the only thing at the street fair. Along the s 6 of the streets, there are many booths (货摊) set up to sell things. Food for one—there is popcorn (爆米花), ice cram, soda, pizza, cotton candy... a 7 you can imagine is everywhere. Another is balloons; children love balloons. Street fairs are a great way to have fun with friends and meet new people, because there are also many games to play. One fun game that everyone loves is apple-bobbing (咬苹果). There is a big barrel (桶) f 8 with water, and in it are some apples. The point is to s 9 your head into the water and try to catch an apple with your teeth. When all the apples are g 10 , people sometimes use the water for water fights!—12—P—13—。