小题满分练(十)
2013数学高考试题天天练(10)

高考试题天天练(十)湖南17.(本小题满分12分)在A B C ∆中,角,,A B C 所对的边分别为,,a b c ,且满足sin cos c A a C =.(I )求角C 的大小;(II cos()4A B π-+的最大值,并求取得最大值时角,A B 的大小.湖北19(本小题满分13分)已知数列{}n a 的前n 项和为n S ,且满足:()()*110,,,1n n a a a a rS n N r R r +=≠=∈∈≠- (Ⅰ)求数列{}n a 的通项公式(Ⅱ)若存在*k N ∈,使得12,,k k k S S S ++成等差数列,试判断:对于任意的*m N ∈,且2m ≥,12,,m m m a a a ++是否成等差数列,并证明你的结论。
湖北18(本小题满分12分)如图,已知正三棱柱111ABC A B C -的各棱长是4,E 是BC 的中点,动点F 在侧棱1C C 上,且不与点C 重合 (Ⅰ)当CF=1时,求证:1EF A C ⊥;(Ⅱ)设二面角C-AF-E 的大小为θ,求tan θ的最小值。
高考试题天天练(十)答案17.解析:(I )由正弦定理得sin sin sin cos .C A A C =因为0,A π<<所以sin 0.sin cos .cos 0,tan 1,4A C C C C C π>=≠==从而又所以则(II )由(I )知3.4B A π=-于是cos()cos()4cos 2sin().63110,,,,46612623A B A A A A A A A A A ππππππππππ-+=--=+=+<<∴<+<+==从而当即时2sin()6A π+取最大值2.综上所述,cos()4A B π-+的最大值为2,此时5,.312A B ππ==19(本小题满分13分)解:(Ⅰ)由已知1n n a rS +=可得21n n a rS ++=,两式相减可得()2111n n n n n a a r S S ra ++++-=-=,即()211n n a r a ++=+,又21a ra ra ==,所以当r=0时,数列{}n a 为a,0,0……,0,……; 当0,1r r ≠≠-时,由已知0a ≠,所以()20,n a n N ≠∈, 于是由211n n n a a ra +++-=,可得211n n a r a ++=+,所以23,,,,n a a a 成等比数列,当2n ≥时,()21n n a r r a -=+。
部编版五年级下册语文第1单元《古诗词三首》同步拓展练习题 有答案

部编版五年级下册语文第1单元《古诗词三首》同步拓展练习题一.选择题(共1小题,满分5.5分,每小题5.5分)1.(5.5分)给加点的字词选择正确的解释。
稚子..金盆脱晓冰。
()A.幼稚的孩子。
B.幼小的孩子。
C.顽皮的孩子。
二.填空题(共11小题,满分60.5分,每小题5.5分)2.(5.5分)《四时田园杂兴》作者:年代:这是其中的一首,描写农村生活中的一个场景。
3.(5.5分)《渔歌子》作者:年代:这首词描写了江南水乡春汛时期的情景。
有鲜明的山光水色,有渔翁的形象,是一幅用诗写的山水画。
4.(5.5分)《乡村四月》诗人:;朝代:;整首诗突出了乡村四月的劳动。
整首诗就像一幅色彩鲜明的图画,不仅表现了诗人对乡村风光的与赞美,也表现出他对劳动人民的,对劳动生活的赞美之情。
5.(5.5分)根据拼音写词语。
cán sāng zhòu yèyún tián chéng jìbái lùdǒu lì6.(5.5分)拼一拼,写一写。
zhòu夜耕yún sāng树短dí拂xiǎo gòng耕织7.(5.5分)给下面的字注音。
耘陂腔铮衔磬浸漪8.(5.5分)查资料,抄写一首自己喜欢的其他田园诗。
9.(5.5分)选择正确的读音,填在横线上。
(1)昼.出耘田夜绩麻。
(zhòu zòu)(2)彩丝穿取当银钲.。
(zēng zhēng)(3)草满池塘水满陂.。
(bēi pō)10.(5.5分)根据意思写出诗句。
那小牧童横骑在牛背上,缓缓地回家去,他拿着一支短笛,随口吹着,也没有固定的曲调。
11.(5.5分)给划线字选择合适的解释。
绩:A.把麻搓成丝或绳B.功业、成果(1)昼出耘田夜绩麻(2)成绩傍:A.靠近B.临近(3)傍晚(4)也傍桑阴学种瓜川:A河流B.平地(5)绿遍山原白满川(6)川流不息12.(5.5分)形近字组词。
2025版新教材高考英语复习特训卷课下天天练十50分阅读提分练

课下每天练(十) 50分阅读提分练姓名________ 班级________ 考号________ 时间:40分钟阅读(共两节,满分50分)第一节(共15小题;每小题2.5分,满分37.5分)阅读下列短文,从每题所给的A、B、C和D四个选项中,选出最佳选项。
A[2024·福建省高三诊断性练习]Today's modern travelers are journeying further to explore Europe off the beaten track, and bringing home new skills and experience. Here are 4 ideas for an unusual holiday in Europe.Volunteer in TransylvaniaTransylvania is a top choice for an unusual European city break, with wonderfully preserved medieval (中世纪的) towns and castles that inspired the famous novel Dracula. In addition, you can take your unusual holiday experience even further by volunteering in Eastern Europe's largest bear reserve and working with bears.Teach skiing in AustriaAustria is one of Europe's top skiing destinations. If you're looking for a more unusual way to spend a winter holiday, why not consider training to be a ski instructor there? You'll gain a qualification that is recognized worldwide, and this programme includes a guaranteed paid instructor job at a ski resort (旅游胜地) once you have finished your training.Go diving in SpainFor a European holiday with a difference, take part in a plastic cleanup project based in Barcelona, help to empty plastic waste in the Mediterranean Sea and make a difference as you travel. This volunteer project combines diving with collecting plastic or other waste from the water, alongside giving you the chance to explore the city.Explore Tuscany on horsebackTuscany, one of the best places in Europe to explore on horseback, has witnesseda sharp increase in travelers. There are various activities that combine sightseeing with basic horse riding lessons and you can stay in Renaissance villas (文艺复兴风格的别墅) and farmhouses. You don't need to have any experience for horse riding holidays, and they are a brilliant alternative to your typical guided tour.1.What does the author suggest doing in Transylvania?A.Helping to care for bears.B.Finding a job in the castle.C.Reading the novel Dracula.D.Visiting its modern buildings.2.Where can you earn money while traveling?A.Transylvania. B.Tuscany.C.Spain. D.Austria.3.What do we know about horse riding holidays in Tuscany?A.They suit experienced riders.B.They are unique to Tuscany.C.They are growing in popularity.D.They feature a typical guided tour.B[2024·广东七校联考试卷]Overlooking the DavisGant Varsity Soccer Field, a bed of overturned soil waits for further development. In a few years, this area will become a natural habitat and a playground for animals and residents. This peaceful area didn't appear naturally, but through planning and action taken by Catlin Gabel's Tiny Forest project launched by teacher Patrick Walsh.Forests typically take hundreds of years to mature, with four stages of growth. “Tiny forests flatten out time through the plant ing of all four layers (层),” Walsh explained. The end result is a fastgrowing, native forest in about 20 years. Over 600 plants from 43 species will be planted in the tiny forest, the first one in Oregon.Walsh was inspired to build a tiny forest after hearing about this idea, which emerged in Japan and has taken hold in North America. He shared his vision withseniors in his class. The seniors researched tiny forests and made a proposal resulting in Clean Water Services donating 60 trees and $5,000 from the National Oceanic and Atmospheric Administration. Armed with these resources, Walsh and the students started working. “Something I didn't really expect was the outpouring of students' enthusiasm. Seeing students from all grades volunteered to contribute to the ‘dirty work’ really blew me away,” Walsh said.Senior Megan Cover has been at the school since the first grade. “I'll graduate after working on this project, which is surely sad, but it's really rewarding and great to be a part of this project and to do my bit. We're creating this educational space for many young kids,” Cover said.Walsh summed up his goal of the project, which is to build a place where students can enjoy and learn about nature. “The forest will obviously not solve climate change, but it would deserve the efforts if the kids think about climate change and remember the importance of reforestation and trees when they look outside at the forest.”4.What is special about tiny forests?A.They originated in North America.B.They are usually planted in schools.C.They contain various types of trees.D.They become mature in a shorter time.5.What surprised Walsh in the process of planting the tiny forest?A.The abundance of native tree species.B. Public concern about the environment.C.The active participation of students.D.Support from local organizations.6.How does Megan Cover feel about the project?A.Proud. B.Hopeful.C.Excited. D.Grateful.7.What does Walsh want the forest to function as for the students?A.A source of enjoyment.B.A reminder.C.A source of inspiration.D.A witness.C[2024·唐山市模拟]Math anxiety is far from uncommon, but too often, those who fear the subject simply avoid it. Research from The University of Chicago offers evidence for the link between math anxiety and avoidance.Studying nearly 500 adults through a computer program called the ChooseAndSolve Task (CAST), the researchers gave participants a choice between math and word problems labeled “easy” and “hard”. The easy problems were always worth two cents, while the hard problems were worth up to six cents. They also informed participants the computer task would modify the questions in the process of testing based on their abilities, enabling them to handle about 70% of the hard problems.Although participants attempted hard word problems when promised higher monetary prizes, they rarely chose to do the same for math problems. “We found we couldn't even pay mathanxious individuals to do difficult math problems,” researcher Rozek says.The findings also contradict a widely held belief that feeling anxious about math and avoiding mathrelated problems is rooted in being bad at math. “If you take two students good at math, the mathanxious one will do worse at math than the one that isn't anxious.”Such a mentality does more than stopping people from taking calculus courses or pursuing a career in STEM. It can affect everyday interactions with math—like leaving a tip in a restaurant. But all is not lost. Reframing their anxiety from negative to positive cou ld help mathanxious people reengage. Giving those anxious about siting exams guidance may lead them to perform better. “Telling them if you're anxious, this is your body getting you ready to perform and focus,” Rozek says. Another path may be to create early positive experiences around math. For example, telling stories featuring math and tackling problems around the story may be helpful.8.What does the underlined word “modify” mean in Paragraph 2?A.Adjust. B.Design.C.Solve. D.Add.9.What does the study find?A.Math anxiety interacts with math avoidance.B.Word problems are often regarded as easier.C.Fear of math can outweigh higher rewards.D.People underrate their mathematical ability.10.What is a common misunderstanding about math anxiety?A.It is the cause of math avoidance.B.It causes people to be bored of math.C.It is a complex phenomenon in life.D.It results from poor math performance.11.What is the last paragraph mainly about?A.Consequences of math avoidance.B.Ways to break the anx ietyavoidance link.C.Explanations for math anxiety.D.Mental barriers to mathematical achievements.D[2024·厦门市高三质量检测]The burning of coal may be falling out of favor as a means of generating heat and electricity, but that doesn't mean it no longer has valuable uses. The team of King Abdullah University of Science and Technology (KAUST) is using coal for a new economy.The project is led by Associate Professor Andrea Fratalocchi. While reading about challenges of ending the use of coal in power generation, Fratalocchi was struck by a novel possible use for coal. “Why don't we use coal for seawater desalination (脱盐)?” Fratalocchi recalls, still excited. Capable of taking in sunlight, the black mineral adds to the list of substances in dark colors serving t he purpose, which the team is on a longstanding hunt for.Fratalocchi and his team began to explore the use of a material known ascarbonized compressed powder (压缩粉末), also CCP, which is created by breaking coal into powder, and then pressing that powder back into a solid that has more tiny holes—it can also be made into a desired shape. The team combined CCP with natural cotton fibers, producing a block which was then placed within a seawater containing container, with its bottom touching water surface. While sunlight heated the black surface of the block, the inside fibers helped water flow in and through the block from the bottom. When that liquid water reached the hot surface, it turned into steam which rose and condensed (冷凝) on the inside of a specially shaped cover. That condensation then flew down the cover and was collected as fresh, drinkable water. The seawater's salt content remained behind within the CCP. A simple wash was enough to remove most of it, so the material could be reused multiple times.KAUST has partnered with the Dutch startup PERA Complexity to promote the technology. The material will see its first use in a pilot plant in Brazil. “CCP is abundant in nature and reasonable to use, besides being lightweight and highly changeable,” says team member Marcella Bonifazi. “The device's desalination rate per unit of raw material is two to three times higher than that of any other solar desalination system, but it produces fresh water at around onethird the expense of current stateoftheart technologies.”12.What is Fratalocchi's team seeking for?A.Fibers functioning well with CCP.B.Green ways to desalinate seawater.C.Novel industrial applications of coal.D.Darkcolored materials for desalination.13.How did the team get water into the CCP device?A.By placing cotton fibers inside.B.By heating its black surface.C.By making the powder into a block.D.By installing a special cover.14.Which feature of CCP does Marcella Bonifazi stress?A.Being ecofriendly. B.Being lowcost.C.Being efficient. D.Being flexible.15.What does the text mainly talk about?A.Scientists have made a breakthrough in desalination.B.Coal finds new use in desalination technology.P is expected to be in reallife use soon.D.Drinkable water will be got from the sea.其次节(共5小题;每小题2.5分,满分12.5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。
2014届高考化学三轮复习简易通(广东专用)三级排查大提分Word版训练:专题十 金属元素及其化合物

专题十金属元素及其化合物(时间:40分钟满分:70分)小题限时满分练一、选择题(本题包括7小题,每小题4分,共28分,限时15分钟;除了标明双选的,其余每小题只有一个选项符合题意)1.(仿2012海南高考,10)下列有关金属的说法中,正确的是()。
①纯铁不容易生锈②锂和钠在空气中加热均生成过氧化物③铝在空气中耐腐蚀,所以铝是不活泼金属④缺钙会引起骨质疏松,缺铁会引起贫血⑤青铜、不锈钢、硬铝都是合金⑥KSCN溶液可以检验Fe3+A.①④⑤⑥B.②③④⑤C.①③④⑤D.①②⑤⑥答案 A2.(仿2013广东高考,11)下列钠的化合物与其性质或用途不相符的是()。
A.Na2O2可用作潜水艇供氧剂,Al2O3是一种很好的耐火材料B.Na2CO3和Al(OH)3都可用于治疗胃酸过多,作胃酸中和剂C.NaCl和醋酸都可作厨房调味品,明矾可用作净水剂D.NaHCO3受热易分解生成CO2,可用作发酵粉答案 B3.(仿2013广东,23)用黄色的FeCl3溶液分别进行下列实验,解释或结论不正确的是()。
33A 错误。
答案 A4.(仿2013上海高考,54)1 mol 过氧化钠与2 mol 碳酸氢钠固体混合后,在密闭容器中加热充分反应,排出气体物质后冷却,残留的固体物质是( )。
A .Na 2CO 3B .Na 2O 2、Na 2CO 3C .NaOH 、Na 2CO 3D .Na 2O 2、NaOH 、Na 2CO 3解析 Na 2O 2与NaHCO 3的混合物受热分解时,首先是NaHCO 3分解,2NaHCO 3 =====△Na 2CO 3 + H 2O + CO 2↑2 mol 1 mol 1 mol 1 mol)产生的CO 2、H 2O 均可与Na 2O 2反应,可以认为是CO 2先与Na 2O 2反应,CO 2耗尽后H 2O 才开始反应。
而根据2Na 2O 2+2CO 2====== 2Na 2CO 3+O 2可知,生成的1 mol CO 2恰好与1 mol Na 2O 2完全反应生成Na 2CO 3,H 2O 不参与反应,故最终固体产物只有Na 2CO 3。
【试卷】高二英语周练(十)

2023-2024学年第二学期高二英语周练(10)第一节阅读理解(共7小题;每小题35分,满分35分)San Francisco Fire Engine ToursRunning: February 1st through April 30thThis delicious tour goes through the city on its way to Treasure Island where we will stop at the famous Winery SF. Here you can enjoy 4 pours of some of the best wine San Francisco has to offer.(Included in tickets price)Departing from the Cannery: Tour times upon request.Duration(时长): 2 hours Price: $90Back to the Fifties TourRunning: August 16th through August 31stThis tour transports you back in time to one of San Francisco’s most fantastic periods, the 1950s! Enjoy fun history as we take you through San Francisco for a free taste of ice cream.Departing from the Cannery: 5:00 pm and 7:30 pmDuration: 2 hours Price: $90Spooky Halloween TourRunning: October 10th through October 31stJoin us for a ride through the historical Presidio district. Authentic fire gear(服装) is provided for your warmth as our entertainers take you to some of the most thrilling parts of San Francisco.Departing from the Cannery: 6:30 pm and 8:30 pmDuration: 1 hour and 30 minutes Price: Available upon requestHoliday Lights TourRunning: December 6th through December 23rdThis attractive tour takes you to some of San Francisco’s most cheerful holiday scenes. Authentic fire gear is provided for your warmth as you get into the holiday spirit.Departing from the Cannery: 7:00 pm and 9:00 pmDuration: 1 hour and 30 minutesAdvance reservations required.21. Which of the tours is available in March?A. San Francisco Winery Tour.B. Back to the Fifties Tour.C. Spooky Hallowen Tour.D. Holiday Lights Tour.22. What can tourists do on Back to the Fifties Tours?A. Go to Treasure Island.B. Enjoy the holiday scenes.C. Have free ice cream.D. Visit the Presidio district.23. What are tourists required to do to go on Holiday Lights Tour?A. Take some drinks.B. Set off early in the morning.C. Wear warm clothes.D. Make reservations in advance.CJaguar Land Rover has released new technology designed to constantly monitor drivers and passengers in order to adjust settings to match their mood(情绪). The carmaker has tested a special system which uses a camera to film drivers to monitor their facial expressions.If the system detects (探测)a driver who is stressed, it can automatically turn on calming mood lighting. The car could respond to a driver who was tired by lowering the car’s temperature, or by beginning to play a specific playlist of music. The carmaker has also developed headrest cameras to monitor the facial expressions of passengers. If the cameras detect sleepiness, then the car can automatically dim (使变暗) the passenger lighting to help people go to sleep. Jaguar Land Rover said that the system also uses artificial intelligence to learn people’s preferences, so that it could automatically adjust a car’s settings based on their previous interactions with the car.Dr Steve Iley, Jaguar Land Rover chief medical officer, said, “As we move towards a self-driving future, the focus for us remains as much on the driver as it ever has.”“By considering the overall behavior of drivers, and using much of what we’ve learned from the advances in research around personal well-being over the last 10 or 15 years, we can make sure our customers remain comfortable, involved and alert behind the wheel in all driving situations, even motorway journeys.”The system is still being developed and is not yet available in cars, Jaguar Land Rover said.In 2015, the company released a similar system which monitors drivers to detect signs of sleepiness. The system is now in use in Jaguar cars, and alerts drivers when they become too sleepy.28. What is Jaguar Land Rover’s new invention?A. An automatically adjusted headrest.B. An intelligent alarm system.C. A mood-detection system.D. A self-driving car.29. How is Paragraph 2 developed?A. By giving examples.B. By making comparisons.C. By following time order.D. By analyzing cause and effect.30. What does Dr St eve Iley think about the new invention?A. It is customer-friendly.B. It is environmentally friendly.C. It fails to meet drivers’ need.D. It should focus greatly on passengers.31. What is the present situation of the new invention?A. It has already been banned.B. It is doubted by customers.C. It still needs to be improved.D. It is widely used in Jaguar cars.第二节七选五(共5小题;每小题5分,满分25分)Stress-eating happens when you’re not hungry and eating more than necessary to be full. Often, we’re piling on the junk food. As a result, gaining weight, illnesses and low self-confidence can all occur due to stress-eating. 36 __________ Here are some tips.ExerciseWhen you feel like reaching for a snack when you know you’re not hungry, try to change that energy into exercising. 37 __________ Not only will the sunshine and exercise make you feel good and lessen feelings of pain and stress, you’ll also have some time to think about what’s behind your urge to eat. Exercise can help you get clear and find a solution to your problem.Write Down Your FeelingsWhen stress is kicking in and you’re reaching for junk food, stop and reach for a journal, your phone or computer instead. Open up a writing space and begin to examine what is causing your stress. Think of ways you can address your problem head on. Write out what it is you want to say. 38___________ If not, drink some more water and a handful of blueberries and keep writing.Discover New Hobbies39___________ Starting a fun and enjoyable hobby can help you manage stress and hardships in other areas of life, giving you more energy and a renewed sense of hope when it’s time to deal with those problems. Before you know it, you’ll be having more fun, enjoying life more and better equipped to handle stress in a healthy way. 40 ___________A. Give it a shot and try something new.B. Explore what you love to do and do it often.C. But how can we stop stress-eating right now?D. Get up from your desk and take a walk outside.E. You can listen to music or do sports to relax yourself.F. By the time you finish, your unhealthy desires should be gone.G. Take some time on Sunday and plan out what you’re going to do for the week.第三节(共15小题;每小题1分,满分15分)Anytime I travel on my bicycle across the country, I’m always amazed by how kind people can be to strangers.One night, my friends and I were camping in a town in Missouri. There was a severe storm and we were getting 41________. A complete stranger came by to 42________ us that there were tornadoes (龙卷风) heading our way. The stranger invited us to his home. We were surprised by his 43________ for our safety. Later we learned that there had been a lightening strike near the place where we had camped and several cattle had been 44________.Fortunately, we spent the night in a nice dry home. We were 45________ given the opportunity to take a shower. The next morning we had breakfast with the family and 46________ contact information. In a way we felt like the family had become a part of our journey. This was one of the most heartwarming 47________ of my life because this family had nothing to 48________ by being so kind to us. We were 49________ not the type they would usually 50________, but they treated us with respect and kindness. The kindness of a stranger always 51________ my faith in humanity. Whatever the person 52________ always comes with no strings attached(不附带任何条件)and that’s the most 53________ part.That family 54________ us so much that during the rest of the trip, we 55________ others out every chance we got. We even bought food with our busking(街头卖艺) tips for the homeless. It’s always heartwarming when giving feels as good as receiving.41.A.annoyed B.impatient C.excited D.nervous42.A.warn B.show C.convince D.guarantee43.A.demand B.concern C.desire D.responsibility44.A.drowned B.deserted C.killed D.trapped45.A.even B.merely C.often D.simply46.A.submitted B.exchanged C.checked D.updated47.A.experiences B.messages C.traditions ments48.A.fear B.order C.gain D.offer49.A.especially B.officially C.occasionally D.definitely50.A.ask about plain about C.agree with D.associate with51.A.reveals B.shakes C.strengthens D.shapes52.A.states B.wishes C.saves D.gives53.A.impressive B.practical C.satisfactory D.evident54.A.funded B.inspired C.owed D.delighted55.A.drove B.sought C.helped D.pointed第四节(共10小题;每小题2.5分,满分25分)Dunhuang, an oasis(绿洲) in the Taklamakan Desert, used to be a major stop along the Silk Road, but is now mainly a fascinating tourist destination.Those interested 56__________ Dunhuang’s colorful history will be attracted by the Mogao Caves, one of the city’s main attractions. The entrance to each cave 57_______________(block) by a locked door, which can only be opened by expert guides. Behind these doors are caves of all 58__________ (size)—from very small to absolutely huge. The caves contain thousands of priceless manuscripts (手稿)and silk paintings, which, upon their discovery, drew much 59__________(attend) to the area. Also, there are few things as special as walking across the desert oasis at sunrise. 60_______________ (catch) this incredible scene, you must rise early. It’s bitterly cold. But as the sun rises atop the golden dunes(沙丘) and paints a 61__________(true) picturesque scene, all your efforts pay off. Sunset is a popular time for a camel ride. Get off the camels 62__________ walk up a rather steep(陡峭的)dune overlooking Crescent Lake. From this position, 63__________(regard) as the best one, the incredible sunset is awe-inspiring.No trip to Dunhuang is complete without visiting the Dunhuang Museum, 64__________ it’s possible to put all of the city’s historical sites into proper historical context. The museum is expansive, 65_______________ (contain) many original artworks. Here, you are bound to be amazed by Dunhuang’s rich culture.2023-2024学年第二学期高二英语周练(10)二、阅读理解【文章大意】本文是一篇应用文,主要介绍了美国旧金山的四个旅游活动和路线。
八年级(下)语文教与学同步导练(十)附答案

八年级(下)语文教与学同步导练(十)(期中B卷)本卷共三道大题满分120分时量120分钟一、语言积累与运用(共35分,除未标注的外每小题3分)1、下列加点字注音、词语书写全部正确的一组是()。
A.绯.红(fēi)阴翳.(yì)粗制滥造冥思暇想B.髭.须(cī)禁锢.(gū)长吁短叹相形见绌C.眷.恋(juàn)鞭挞.(tà)众目睽睽美其名曰D.裸.露(luó)狩.猎(shòu)不容置疑黯然失色2、下列各项无错别字的是()A深恶痛疾翻来覆去B暗然失色落英缤纷C花团锦族粗制烂造D长吁短叹海誓山萌3、下列句子中加点的成语使用正确的一项是()A.这行云流水....般的歌声使所有在场的听众获得了极大的艺术享受。
B.一方困难百方支援,被洪水冲得囊空如洗....的灾区又重建了家园。
C.这么好的天气去郊游,同学们可以在大自然中尽情地享受天伦之乐....。
D.凡是优秀的演员,总能把剧中人物的内心世界表演得惟妙惟肖....。
4、与“天边漂浮着淡淡的白云”一句连接,构成最佳比喻句的是()A. 有如千万朵盛开的白莲B. 像千万条闪耀的银练C. 仿佛落入人间仓库的垛垛银棉D. 像从什么仙境飘来的银色羽毛5、下面对各句解说有错误的一项是()A.风!你咆哮吧!咆哮吧!尽力地咆哮吧!分析:作者反复使用“咆哮吧”,强烈地表现了屈原对风的热切期盼和对黑暗势力的痛恨。
B.我要看那滚滚的波涛,我要听那鞺鞺鞳鞳的咆哮,我要飘流到那没有阴谋、没有污秽、没有自私自利的没有人的小岛上去呀!分析:作者使用了排比兼反复的修辞方法,表现了屈原对“污秽”、“自私自利”、玩“阴谋”的社会的憎恶,对光明、纯洁、无私的社会的追求。
C.你们风,你们雷,你们电,你们在这黑暗中咆哮着的,闪耀着的一切的一切,你们都是诗,都是音乐,都是跳舞。
分析:作者运用了排比、拟人、反复、比喻的修辞方法,表现了屈原对风、雷、电的热情歌颂。
《平凡的世界》练习题及答案

《平凡的世界》练习题及答案姓名分数题型:单选题每题2.5分,共40小题,满分100分。
1.孙少平最先迷上的小说是(A)。
A.《钢铁是怎样炼成的》B.《简爱》C.《卓娅和舒拉的故事》D.《呐喊》2.孙少安到黄原找孙少平,住到黄原宾馆,花了多少钱?(D)A.100元B.50元C.30元D.18元3.刚上县立高中时,为什么孙少平和郝红梅常常最后去取饭?(C)A.因为他们爱好学习,常常最后离开教室。
B.因为他们抽签抽到最后去取饭。
C.因为贫穷,吃不起好饭和年轻而敏感的自尊心,而躲避公众的目光。
D.因为他们约好了,最后一起去取饭。
4.书中的“黄原”只指现实中的哪座城市?(A)A.西安B.延安C.咸阳D.榆林5.孙少平在上课时看小说,被谁告发了?(A)A.侯玉英B.田晓霞C.郝红梅D.顾养民6.“炸山拦坝”工程的搬家环节中,最后另田福堂使尽浑身解数说服的是?(B)A.金俊海B.金老太太C.王彩蛾D.金俊武7.孙少平在看哪本小说时,被人告发了?(B)A.《骆驼祥子》B.《红岩》C.《红星照耀中国》D.《小二黑结婚》8.让孙少平对顾养民看法产生敬佩改变的是什么事?(D)A.他和郝红梅走到了一起。
B.他是班长,每天都帮助困难的同学。
C.他家里很有钱,很有地位。
D.金波带人打了他,但他没有到学校告发。
9.《平凡的世界》描写的时代北景是(C)。
A.中国20世纪50年代中期到60年代中期十年间为背景。
B.中国20世纪60年代中期到70年代中期十年间为背景。
C.中国20世纪70年代中期到80年代中期十年间为背景。
D.中国20世纪80年代中期到90年代中期十年间为背景。
10.在石圪节赶集时,孙少安遇到了谁?(B)A.田晓霞B.刘根民C.田润叶D.金俊武11.县立高中的甲菜和乙菜有什么区别(B)A.甲菜放了油,乙菜没有油。
B.甲菜有些大肉片,乙菜则没有。
C.甲菜份量多,乙菜份量少。
D.甲菜是新鲜的,乙菜是过期的。
12.关于新任省委书记乔伯年,下列描述中有误的一项是?(C)A.带市委领导挤公交B.座驾是辆黑色伏尔加C.因某市洪水救灾不利被革职D.自家的花坛种庄稼13.润叶让在县立中学读书的少平带话,让少安到她那里找她的目的是什么?(D)A.帮他温习功课。
2021新高考数学二轮复习专题练:小题满分限时练

限时练(一)一、单项选择题:本大题共8小题,每小题5分,共40分.在每小题给出的四个选项中,只有一项是符合题目要求的.1.已知集合M ={x |x 2-2x <0},N ={-2,-1,0,1,2},则M ∩N =( ) A.∅ B.{1}C.{0,1}D.{-1,0,1}解析 ∵M ={x |0<x <2},N ={-2,-1,0,1,2},∴M ∩N ={1}. 答案 B2.设(2+i)(3-x i)=3+(y +5)i(i 为虚数单位),其中x ,y 是实数,则|x +y i|等于( ) A.5B.13C.2 2D.2解析 易得6+x +(3-2x )i =3+(y +5)i(x ,y ∈R ). ∴⎩⎨⎧6+x =3,3-2x =y +5,∴⎩⎨⎧x =-3,y =4,故|x +y i|=|-3+4i|=5. 答案 A3.已知等差数列{a n }的前n 项和为S n ,且a 2+a 8=0,S 11=33,则公差d 的值为( ) A.1B.2C.3D.4解析 ∵a 2+a 8=2a 5=0,∴a 5=0, 又S 11=(a 1+a 11)×112=11a 6=33,∴a 6=3,从而公差d =a 6-a 5=3. 答案 C4.设a ,b 是两条不同的直线,α,β是两个不同的平面,则α∥β的一个充分条件是( )A.存在一条直线a ,a ∥α,a ∥βB.存在一条直线a ,a ⊂α,a ∥βC.存在两条平行直线a ,b ,a ⊂α,b ⊂β,a ∥β,b ∥αD.存在两条异面直线a ,b ,a ⊂α,b ⊂β,a ∥β,b ∥α解析 对于A ,a ∥α,a ∥β,则平面α,β可能平行,也可能相交,所以A 不是α∥β的一个充分条件.对于B ,a ⊂α,a ∥β,则平面α,β可能平行,也可能相交,所以B 不是α∥β的一个充分条件.对于C ,由a ∥b ,a ⊂α,b ⊂β,a ∥β,b ∥α可得α∥β或α,β相交,所以C 不是α∥β的一个充分条件.对于D ,存在两条异面直线a ,b ,a ⊂α,b ⊂β,a ∥β,b ∥α,如图,在β内过b 上一点作c ∥a ,则c ∥α,所以β内有两条相交直线平行于α,则有α∥β,所以D 是α∥β的一个充分条件.答案 D5.设双曲线的一条渐近线为方程y =2x ,且一个焦点与抛物线y 2=4x 的焦点相同,则此双曲线的方程为( ) A.54x 2-5y 2=1 B.5y 2-54x 2=1 C.5x 2-54y 2=1D.54y 2-5x 2=1解析 抛物线y 2=4x 的焦点为点(1,0),则双曲线的一个焦点为(1,0),设双曲线的方程为x 2a 2-y 2b 2=1(a >0,b >0),由题意得⎩⎪⎨⎪⎧b a =2,a 2+b 2=1,解得⎩⎪⎨⎪⎧a =55,b =255,所以双曲线方程为5x 2-54y 2=1. 答案 C6.甲、乙、丙、丁四名同学报名参加假期社区服务活动,社区服务活动共有关怀老人、环境监测、教育咨询、交通宣传等四个项目,每人限报其中一项,记事件A 为“4名同学所报项目各不相同”,事件B 为“只有甲同学一人报关怀老人项目,则P (A |B )的值为( ) A.14B.34C.29D.59解析 ∵P (B )=3344,P (AB )=A 3344, 由条件概率P (A |B )=P (AB )P (B )=A 3333=29.答案 C7.在如图所示的△ABC 中,点D ,E 分别在边AB ,CD 上,AB =3,AC =2,∠BAC =60°,BD =2AD ,CE =2ED ,则向量BE →·AB→=( )A.9B.4C.-3D.-6解析 根据题意,AB =3,BD =2AD ,则AD =1, 在△ADC 中,又由AC =2,∠BAC =60°, 则DC 2=AD 2+AC 2-2AD ·AC cos ∠BAC =3, 即DC =3,所以AC 2=AD 2+DC 2, 则CD ⊥AB ,故BE →·AB →=(BD →+DE →)·AB →=BD →·AB →+DE →·AB →=BD →·AB →=3×2×cos 180°=-6. 答案 D8.设定义在R 上的偶函数f (x )满足:f (x )=f (4-x ),且当x ∈[0,2]时,f (x )=x -e x +1,若a =f (2 022),b =f (2 019),c =f (2 020),则a ,b ,c 的大小关系为( ) A.c <b <a B.a <b <c C.c <a <bD.b <a <c解析 因为f (x )是偶函数,所以f (-x )=f (x )=f (4-x ),则f (x )的周期为4,则a =f (2 022)=f (2),b =f (2 019)=f (3)=f (4-3)=f (1),c =f (2 020)=f (0). 又当x ∈[0,2]时,f (x )=x -e x +1,知f ′(x )=1-e x <0. ∴f (x )在区间[0,2]上单调递减, 因此f (2)<f (1)<f (0),即a <b <c . 答案 B二、多项选择题:本题共4小题,每小题5分,共20分.在每小题给出的四个选项中有多项符合题目要求,全部选对的得5分,部分选对的得3分,有选错的得0分.9.(2020·聊城模拟)已知双曲线C 过点(3,2)且渐近线为y =±33x ,则下列结论正确的是( )A.C 的方程为x 23-y 2=1 B.C 的离心率为 3C.曲线y =e x -2-1经过C 的一个焦点D.直线x -2y -1=0与C 有两个公共点解析 ∵双曲线的渐近线为y =±33x ,∴设双曲线C 的方程为x 23-y 2=λ(λ≠0).又双曲线C 过点(3,2),∴323-(2)2=λ,解得λ=1,故A 正确.此时C 的离心率为3+13=233,故B 错误.双曲线C 的焦点为(-2,0),(2,0),曲线y =e x -2-1经过点(2,0),故C 正确.把直线方程代入双曲线C 的方程并整理,得x 2-6x +9=0,所以Δ=0,故直线x -2y -1=0与双曲线C 只有一个公共点,所以D 错误.故选AC. 答案 AC10.(2020·青岛质检)已知函数f (x )=sin 2x +23sin x cos x -cos 2x ,x ∈R ,则( ) A.-2≤f (x )≤2B.f (x )在区间(0,π)上只有1个零点C.f (x )的最小正周期为πD.直线x =π3为函数f (x )图象的一条对称轴解析 已知函数f (x )=sin 2x +23sin x cos x -cos 2x =3sin 2x -cos 2x =2sin ⎝ ⎛⎭⎪⎫2x -π6,x ∈R ,则-2≤f (x )≤2,A 正确;令2x -π6=k π,k ∈Z ,则x =k π2+π12,k ∈Z ,则f (x )在区间(0,π)上有2个零点,B 错误;f (x )的最小正周期为π,C 正确;当x =π3时,f ⎝ ⎛⎭⎪⎫π3=2sin(2×π3-π6)=2,所以直线x =π3为函数f (x )图象的一条对称轴,D正确.故选ACD.答案ACD11.在某次高中学科竞赛中,4 000名考生的竞赛成绩(单位:分)统计如图所示,60分以下视为不及格,若同一组中的数据用该组区间的中点值为代表,则下列说法中正确的是()A.成绩在[70,80)的考生人数最多B.不及格的考生人数为1 000C.考生竞赛成绩的平均数约为70.5D.考生竞赛成绩的中位数约为75解析由频率分布直方图可知,成绩在[70,80)的考生人数最多,所以A正确.不及格的人数为4 000×(0.01+0.015)×10=1 000,所以B正确.考生竞赛成绩的平均数约为(45×0.01+55×0.015+65×0.02+75×0.03+85×0.015+95×0.01)×10=70.5,所以C正确.设考生竞赛成绩的中位数约为x0,因为(0.01+0.015+0.02)×10=0.45<0.5,(0.01+0.015+0.02+0.03)×10=0.75>0.5,所以0.45+(x0-70)×0.03=0.5,解得x0≈71.7,D错误.故选ABC.答案ABC12.下列结论正确的是()A.若a>b>0,c<d<0,则一定有b c> a dB.若x>y>0,且xy=1,则x+1y>y2x>log2(x+y)C.设{a n}是等差数列,若a2>a1>0,则a2>a1a3D.若x∈[0,+∞),则ln(1+x)≥x-1 8x2解析对于A,由c<d<0,可得-c>-d>0,则-1d>-1c>0,又a>b>0,所以-ad>-bc,则bc>ad,故A正确.对于B,取x=2,y=12,则x+1y=4,y2x=18,log2(x+y)=log 252>1,故B 不正确.对于C ,由题意得a 1+a 3=2a 2且a 1≠a 3,所以a 2=12(a 1+a 3)>12×2a 1a 3=a 1a 3,故C 正确.对于D ,设h (x )=ln(1+x )-x +18x 2,则h ′(x )=11+x -1+x 4=x (x -3)4(x +1),当0<x <3时,h ′(x )<0,则h (x )单调递减,h (x )<h (0)=0,故D不正确.故选AC. 答案 AC三、填空题:本题共4小题,每小题5分,共20分.请把正确的答案填写在各小题的横线上.13.已知圆C :(x -2)2+y 2=r 2(r >0)与双曲线E :x 2-y 2=1的渐近线相切,则r =________.解析 ∵双曲线x 2-y 2=1的渐近线为x ±y =0.依题意,得r =21+1=1. 答案 114.已知等差数列{a n },其前n 项和为S n .若a 2+a 5=24,S 3=S 9,则a 6=________,S n 的最大值为________.(本小题第一空2分,第二空3分)解析 由S 3=S 9,得a 4+a 5+…+a 9=0,则a 6+a 7=0.又a 2+a 5=24,所以设等差数列{a n }的公差为d ,可得⎩⎨⎧a 1+5d +a 1+6d =0,a 1+d +a 1+4d =24,解得⎩⎨⎧a 1=22,d =-4,所以a 6=a 1+5d =2,S n =-2n 2+24n =-2(n -6)2+72,故当n =6时,S n 取得最大值72. 答案 2 7215.若(x +a )(1+2x )5的展开式中x 3的系数为20,则a =________. 解析 由已知得C 25·22+a ·C 35·23=20,解得a =-14. 答案 -1416.(2020·河南百校大联考)魏晋时期数学家刘徽在他的著作《九章算术注》中,称一个正方体内两个互相垂直的内切圆柱所围成的几何体为“牟合方盖”(如图所示),刘徽通过计算得知正方体的内切球的体积与“牟合方盖”的体积之比应为π∶4.若“牟合方盖”的体积为163,则正方体的外接球的表面积为________.解析因为“牟合方盖”的体积为163,又正方体的内切球的体积与“牟合方盖”的体积之比应为π∶4,所以正方体的内切球的体积V球=π4×163=43π.则内切球的半径r=1,正方体的棱长为2.所以正方体的体对角线d=23,因此正方体外接球的直径2R=d=23,则半径R= 3.所以正方体的外接球的表面积为S=4πR2=4π(3)2=12π.答案12π限时练(二)一、单项选择题:本大题共8小题,每小题5分,共40分.在每小题给出的四个选项中,只有一项是符合题目要求的.1.已知i是虚数单位,复数z=1-3i1+i在复平面内对应的点位于()A.第四象限B.第三象限C.第二象限D.第一象限解析z=1-3i1+i=(1-3i)(1-i)(1+i)(1-i)=-1-2i,∴复数z在复平面内对应的点(-1,-2)在第三象限.答案 B2.若集合A={x|x(x-2)>0},B={x|x-1≤0},则A∩(∁R B)=()A.{x|x>1或x<0}B.{x|1<x<2}C.{x|x>2}D.{x|x>1}解析易知A={x|x>2或x<0},∁R B={x|x>1},∴A∩(∁R B)={x|x>2}.答案 C3.某公司一种型号的产品近期销售情况如下表:根据上表可得到回归直线方程y ^=0.75x +a ^,据此估计,该公司7月份这种型号产品的销售额为( ) A.19.5万元 B.19.25万元 C.19.15万元D.19.05万元解析 易知x -=4,y -=16.8.∵回归直线y ^=0.75x +a ^过点(4,16.8),∴a ^=16.8-4×0.75=13.8,则y ^=0.75x +13.8.故7月份的销售额y ^=0.75×7+13.8=19.05(万元). 答案 D4.⎝ ⎛⎭⎪⎫2x 2-x 43的展开式中的常数项为( ) A.-3 2B.3 2C.6D.-6解析 通项T r +1=C r 3⎝ ⎛⎭⎪⎫2x 23-r(-x 4)r=C r 3(2)3-r(-1)r x -6+6r , 当-6+6r =0,即r =1时为常数项,T 2=-6. 答案 D5.已知等比数列{a n }中,a 1=2,数列{b n }满足b n =log 2a n ,且b 2+b 3+b 4=9,则a 5=( ) A.8B.16C.32D.64解析 由{a n }是等比数列,且b n =log 2a n , ∴{b n }是等差数列,又b 2+b 3+b 4=9,所以b 3=3.由b 1=log 2a 1=1,知公差d =1,从而b n =n , 因此a n =2n ,于是a 5=25=32. 答案 C6.(2020·青岛质检)某单位举行诗词大会比赛,给每位参赛者设计了“保留题型”“升级题型”“创新题型”三类题型,每类题型均指定一道题让参赛者回答.已知某位参赛者答对每道题的概率均为45,且各次答对与否相互独立,则该参赛者答完三道题后至少答对两道题的概率是( ) A.112125B.80125C.113125D.124125解析 某单位举行诗词大会比赛,给每位参赛者设计了“保留题型”“升级题型”“创新题型”三类题型,每类题型均指定一道题让参赛者回答.某位参赛者答对每道题的概率均为45,且各次答对与否相应独立,则该参赛者答完三道题后至少答对两道题的概率:P =⎝ ⎛⎭⎪⎫453+C 23⎝ ⎛⎭⎪⎫452⎝ ⎛⎭⎪⎫15=112125. 答案 A7.函数f (x )=⎝ ⎛⎭⎪⎫x -1x cos x (-π≤x ≤π,且x ≠0)的图象可能为( )解析 由f (-x )=-f (x )及-π≤x ≤π,且x ≠0判定函数f (x )为奇函数,其图象关于原点对称,排除A ,B 选项;当x >0且x →0时,-1x →-∞,cos x →1,此时f (x )→-∞,排除C 选项,故选D. 答案 D8.在△ABC 中,AB =3,AC =2,∠BAC =120°,点D 为BC 边上的一点,且BD →=2DC →,则AB →·AD →=( ) A.13B.23C.1D.2解析 以A 为坐标原点,AB 所在的直线为x 轴建立平面直角坐标系,如图所示.则A (0,0),B (3,0),C (-1,3),∵BD→=2DC →,∴BD →=23BC →=23(-4,3)=⎝ ⎛⎭⎪⎫-83,233,则D ⎝ ⎛⎭⎪⎫13,233,∴AD→=⎝ ⎛⎭⎪⎫13,233,AB →=(3,0), 所以AB →·AD→=3×13+0×233=1. 答案 C二、多项选择题:本题共4小题,每小题5分,共20分.在每小题给出的四个选项中有多项符合题目要求,全部选对的得5分,部分选对的得3分,有选错的得0分.9.(2020·淄博模拟)甲、乙、丙三家企业的产品成本(万元)分别为10 000,12 000,15 000,其成本构成比例如图,则下列关于这三家企业的说法正确的是( )A.成本最大的企业是丙B.其他费用支出最高的企业是丙C.支付工资最少的企业是乙D.材料成本最高的企业是丙解析 由扇形统计图可知,甲企业的材料成本为10 000×60%=6 000(万元),支付工资10 000×35%=3 500(万元),其他费用支出为10 000×5%=500(万元); 乙企业的材料成本为12 000×53%=6 360(万元),支付工资为12 000×30%= 3 600(万元),其他费用支出为12 000×17%=2 040(万元);丙企业的材料成本为15 000×60%=9 000(万元),支付工资为15 000×25%= 3 750(万元),其他费用支出为15 000×15%=2 250(万元).所以成本最大的企业是丙,其他费用支出最高的企业是丙,支付工资最少的企业是甲,材料成本最高的企业是丙.故选ABD.答案 ABD10.(2020·海南模拟)将函数f (x )=sin(2x +φ)(0<φ<π)的图象向右平移π4个单位长度后得到函数g (x )=sin ⎝ ⎛⎭⎪⎫2x +π6的图象,则下列说法正确的是( )A.φ=π6B.函数f (x )的最小正周期为πC.函数f (x )的图象关于点⎝ ⎛⎭⎪⎫π3,0成中心对称D.函数f (x )的一个单调递减区间为⎣⎢⎡⎦⎥⎤-π12,5π12解析 由题意可知函数f (x )的最小正周期T =2π2=π,B 正确;将函数f (x )=sin(2x +φ)(0<φ<π)的图象向右平移π4个单位长度后得到函数g (x )=sin ⎝ ⎛⎭⎪⎫2x +π6的图象,所以sin ⎣⎢⎡⎦⎥⎤2⎝ ⎛⎭⎪⎫x -π4+φ=sin ⎝ ⎛⎭⎪⎫2x -π2+φ=sin ⎝ ⎛⎭⎪⎫2x +π6,所以-π2+φ=π6,所以φ=2π3∈(0,π),A 错误;f (x )=sin ⎝ ⎛⎭⎪⎫2x +2π3,令2x +2π3=k π,k ∈Z ,则x =k π2-π3,k ∈Z ,C 错误;令2k π+π2≤2x +2π3≤2k π+3π2,k ∈Z ,解得k π-π12≤x ≤k π+5π12,k ∈Z ,所以函数f (x )的一个单调递减区间为⎣⎢⎡⎦⎥⎤-π12,5π12,D 正确.故选BD.答案 BD11.已知实数a >b >0,则下列不等关系正确的是( ) A.b a <b +4a +4B.lga +b 2>lg a +lg b2C.a +1b <b +1aD.a -b >a -b解析 对于A ,因为b a -b +4a +4=b (a +4)-a (b +4)a (a +4)=4(b -a )a (a +4),又a >b >0,所以b a <b +4a +4,故A 正确;因为lg a +lgb 2=lg ab ,又a +b 2≥ab ,当且仅当a =b 时等号成立,由a >b >0,得a +b 2>ab ,所以lg a +b 2>lg ab ,即lg a +b 2>lg a +lg b2,故B 正确;因为a +1b -⎝ ⎛⎭⎪⎫b +1a =(a -b )+⎝ ⎛⎭⎪⎫1b -1a =(a -b )+a -b ab =(a -b )·⎝ ⎛⎭⎪⎫1+1ab ,又a >b >0,所以a +1b -⎝ ⎛⎭⎪⎫b +1a >0,即a +1b >b +1a ,故C 错误;因为a >b >0,所以a-b >0,则(a -b )2=a +b -2ab ,而(a -b )2=a -b ,即(a -b )2-(a -b )2=2b -2ab =2(b -ab ),又a >b >0,所以b -ab <0,所以(a -b )2<(a -b )2,即a -b <a -b ,故D 错误.故选AB. 答案 AB12.(2020·临沂模拟)已知点P 在双曲线C :x 216-y 29=1上,点F 1,F 2是双曲线C 的左、右焦点.若△PF 1F 2的面积为20,则下列说法正确的是( ) A.点P 到x 轴的距离为203 B.|PF 1|+|PF 2|=503 C.△PF 1F 2为钝角三角形 D.∠F 1PF 2=π3解析 由双曲线C :x 216-y 29=1可得,a =4,b =3,c =5,不妨设P (x P ,y P ),由△PF 1F 2的面积为20,可得12|F 1F 2||y P |=c |y P |=5|y p |=20,所以|y P |=4,选项A 错误.将|y P |=4代入双曲线C 的方程x 216-y 29=1中,得x 2P16-429=1,解得|x P |=203.由双曲线的对称性,不妨设点P 在第一象限,则P ⎝ ⎛⎭⎪⎫203,4,可知|PF 2|=⎝ ⎛⎭⎪⎫203-52+(4-0)2=133.由双曲线的定义可知|PF 1|=|PF 2|+2a =133+8=373,所以|PF 1|+|PF 2|=373+133=503,选项B 正确.在△PF 1F 2中,|PF 1|=373>2c =10>|PF 2|=133,且cos ∠PF 2F 1=|PF 2|2+|F 1F 2|2-|PF 1|22|PF 2|·|F 1F 2|=-513<0,则∠PF 2F 1为钝角,所以△PF 1F 2为钝角三角形,选项C 正确.由余弦定理得cos ∠F 1PF 2=|PF 1|2+|PF 2|2-|F 1F 2|22|PF 1|·|PF 2|=319481≠12,所以∠F 1PF 2≠π3,选项D 错误.故选BC. 答案 BC三、填空题:本题共4小题,每小题5分,共20分.请把正确的答案填写在各小题的横线上.13.某年级有1 000名学生,一次数学考试成绩服从正态分布X ~N (105,102),P (95≤X ≤105)=0.34,则该年级学生此次数学成绩在115分以上的人数大约为________.解析 ∵数学考试成绩服从正态分布X ~N (105,102),∴考试成绩关于X =105对称.∵P (95≤X ≤105)=0.34,∴P (X >115)=12×(1-0.68)=0.16,∴该年级学生此次数学成绩在115分以上的人数大约为0.16×1 000=160. 答案 160 14.曲线y =1-2x +2在点(-1,-1)处的切线方程为________. 解析 ∵y =1-2x +2=x x +2,∴y ′=x +2-x (x +2)2=2(x +2)2,∴y ′|x =-1=2,∴曲线在点(-1,-1)处的切线斜率为2,∴所求切线方程为y +1=2(x +1),即2x -y +1=0.答案 2x -y +1=015.已知集合A ={x |x =2n -1,n ∈N *},B ={x |x =2n ,n ∈N *}.将A ∪B 的所有元素从小到大依次排列构成一个数列{a n }.记S n 为数列{a n }的前n 项和,则使得S n >12a n+1成立的n 的最小值为________,此时S n =________.(本小题第一空3分,第二空2分)解析 所有的正奇数和2n (n ∈N *)按照从小到大的顺序排列构成{a n },在数列{a n }中,25前面有16个正奇数,即a 21=25,a 38=26.当n =1时,S 1=1<12a 2=24,不符合题意;当n =2时,S 2=3<12a 3=36,不符合题意;当n =3时,S 3=6<12a 4=48,不符合题意;当n =4时,S 4=10<12a 5=60,不符合题意;……;当n =26时,S 26=21×(1+41)2+2×(1-25)1-2=441+62=503<12a 27=516,不符合题意;当n =27时,S 27=22×(1+43)2+2×(1-25)1-2=484+62=546>12a 28=540,符合题意.故使得S n >12a n +1成立的n 的最小值为27. 答案 27 54616.如图,在正方体ABCD -A 1B 1C 1D 1中,点P 在线段BC 1上运动,有下列判断:①平面PB 1D ⊥平面ACD 1; ②A 1P ∥平面ACD 1;③异面直线A 1P 与AD 1所成角的取值范围是⎝ ⎛⎦⎥⎤0,π3;④三棱锥D 1-APC 的体积不变.其中,正确的是________(把所有正确判断的序号都填上). 解析 在正方体中,B 1D ⊥平面ACD 1,B 1D ⊂平面PB 1D ,所以平面PB 1D ⊥平面ACD 1,所以①正确.连接A 1B ,A 1C 1,如图,容易证明平面A 1BC 1∥平面ACD 1,又A 1P ⊂平面A 1BC 1,所以A 1P ∥平面ACD 1,所以②正确.因为BC 1∥AD 1,所以异面直线A 1P 与AD 1所成的角就是直线A 1P 与BC 1所成的角,在△A 1BC 1中,易知所求角的范围是⎣⎢⎡⎦⎥⎤π3,π2,所以③错误.VD 1-APC =VC -AD 1P ,因为点C 到平面AD 1P 的距离不变,且△AD 1P 的面积不变,所以三棱锥D 1-APC 的体积不变,所以④正确. 答案 ①②④限时练(三)一、单项选择题:本大题共8小题,每小题5分,共40分.在每小题给出的四个选项中,只有一项是符合题目要求的.1.(2020·河南联检)已知集合A ={x ∈N |x 2<8x },B ={2,3,6},C ={2,3,7},则B ∪(∁A C )=( ) A.{2,3,4,5} B.{2,3,4,5,6} C.{1,2,3,4,5,6}D.{1,3,4,5,6,7}解析 因为A ={x ∈N |0<x <8}={1,2,3,4,5,6,7},所以∁A C ={1,4,5,6},所以B∪(∁A C)={1,2,3,4,5,6}.故选C.答案 C2.若z=(3-i)(a+2i)(a∈R)为纯虚数,则z=()A.163i B.6i C.203i D.20解析因为z=3a+2+(6-a)i为纯虚数,所以3a+2=0,解得a=-23,所以z=203i.故选C.答案 C3.(2020·潍坊模拟)甲、乙、丙、丁四位同学各自对变量x,y的线性相关性进行试验,并分别用回归分析法求得相关系数r,如下表:哪位同学的试验结果能体现出两变量有更强的线性相关性?()A.甲B.乙C.丙D.丁解析由于丁同学求得的相关系数r的绝对值最接近于1,因此丁同学的试验结果能体现出两变量有更强的线性相关性.故选D.答案 D4.设a=ln 12,b=-5-12,c=log132,则()A.c<b<aB.a<c<bC.c<a<bD.b<a<c解析由题意易知-a=ln 2,-b=5-12,-c=log32.因为12=log33<log32<ln 2<1,0<5-12<4-12=12,所以-b<-c<-a,所以a<c<b.故选B.答案 B5.(2020·青岛质检)已知某市居民在2019年用手机支付的个人消费额ξ(元)服从正态分布N(2 000,1002),则该市某居民在2019年用手机支付的消费额在(1 900,2 200]内的概率为()附:随机变量ξ服从正态分布N(μ,σ2),则P(μ-σ<ξ≤μ+σ)≈0.682 7,P(μ-2σ<ξ≤μ+2σ)≈0.954 5,P(μ-3σ<ξ≤μ+3σ)≈0.997 3.A.0.975 9B.0.84C.0.818 6D.0.477 2解析 ∵ξ服从正态分布N (2 000,1002),∴μ=2 000,σ=100,则P (1 900<ξ≤ 2 200)=P (μ-σ<ξ≤μ+σ)+12[P (μ-2σ<ξ≤μ+2σ)-P (μ-σ<ξ≤μ+σ)]≈0.682 7+12(0.954 5-0.682 7)=0.818 6.故选C. 答案 C6.设抛物线C :y 2=2px (p >0)的焦点为F ,斜率为k 的直线过F 交C 于点A ,B ,且AF →=2FB →,则直线AB 的斜率为( ) A.2 2 B.2 3 C.±2 2D.±2 3解析 由题意知k ≠0,F ⎝ ⎛⎭⎪⎫p 2,0,则直线AB 的方程为y =k ⎝ ⎛⎭⎪⎫x -p 2,代入抛物线方程消去x ,得y 2-2p k y -p 2=0.不妨设A (x 1,y 1)(x 1>0,y 1>0),B (x 2,y 2).因为AF →=2FB →,所以y 1=-2y 2.又y 1y 2=-p 2.所以y 2=-22p ,x 2=p 4,所以k AB=-22p -0p 4-p 2=2 2.根据对称性,直线AB 的斜率为±2 2. 答案 C7.已知点A (1,0),B (1,3),点C 在第二象限,且∠AOC =150°,OC →=-4OA →+λOB →,则λ=( ) A.12B.1C.2D.3解析 设|OC→|=r ,则OC →=⎝ ⎛⎭⎪⎫-32r ,12r ,由已知,得OA →=(1,0),OB →=(1,3),又OC→=-4OA →+λOB →,∴⎝ ⎛⎭⎪⎫-32r ,12r =-4(1,0)+λ(1,3)=(-4+λ,3λ),∴⎩⎪⎨⎪⎧-32r =-4+λ,12r =3λ,解得λ=1.答案 B8.在△ABC中,AB=AC,D,E分别在AB,AC上,DE∥BC,AD=3BD,将△ADE 沿DE折起,连接AB,AC,当四棱锥A-BCED体积最大时,二面角A-BC-D 的大小为()A.π6 B.π4 C.π3 D.π2解析因为AB=AC,所以△ABC为等腰三角形,过A作BC的垂线AH,垂足为H,交DE于O,∴当△ADE⊥平面BCED时,四棱锥A-BCED体积最大.由DE⊥AO,DE⊥OH,AO∩OH=O,可得DE⊥平面AOH,又BC∥DE,则BC⊥平面AOH,∴∠AHO为二面角A-BC-D的平面角,在Rt△AOH中,由AOOH=ADDB=3,∴tan∠AHO=AOOH=3,则二面角A-BC-D的大小为π3.答案 C二、多项选择题:本题共4小题,每小题5分,共20分.在每小题给出的四个选项中有多项符合题目要求,全部选对的得5分,部分选对的得3分,有选错的得0分.9.(2020·济宁模拟)“悦跑圈”是一款社交型的跑步应用,用户通过该平台可查看自己某时间段的运动情况.某人根据2019年1月至2019年11月每月跑步的里程(十公里)的数据绘制了下面的折线图,根据该折线图,下列结论正确的是()A.月跑步里程数逐月增加B.月跑步里程数的最大值出现在9月C.月跑步里程的中位数为8月份对应的里程数D.1月至5月的月跑步里程数相于6月至11月波动性更小,变化比较平稳 解析 根据折线图可知,2月跑步里程数比1月小,7月跑步里程数比6月小,10月跑步里程数比9月小,A 错误.根据折线图可知,9月的跑步里程数最大,B 正确.一共11个月份,将月跑步里程数从小到大排列,根据折线图可知,跑步里程的中位数为8月份对应的里程数,C 正确.根据折线图可知D 正确.故选BCD. 答案 BCD10.下列各式中,值为12的是( ) A.sin 15°cos 15°B.cos 2π6-sin 2π6C.1+cos π62D.tan 22.5°1-tan 222.5°解析 sin 15°cos 15°=sin 30°2=14,排除A ;cos 2π6-sin 2π6=cos π3=12,B 正确;1+cos π62=1+322=2+32,排除C ;tan 45°=2tan 22.5°1-tan 222.5°,得tan 22.5°1-tan 222.5°=12,D 正确.故选BD.答案 BD11.已知{a n }是等比数列,若a 6=8a 3=8a 22,则( )A.a n =2n -1B.a n =2nC.S n =2n -1D.S n =2n +1-2解析 设数列{a n }的公比为q ,由a 6=8a 3,得a 3·q 3=8a 3,则q 3=8,所以q =2.又8a 3=8a 22,则a 2·q =a 22,又a 2≠0,所以a 2=2,即a n =a 2q n -2=2n -1,所以a 1=1,S n =a 1(1-q n )1-q =2n -1,故选AC.答案 AC12.数列{F n }:1,1,2,3,5,8,13,21,34,…,称为斐波那契数列,是由十三世纪意大利数学家列昂纳多·斐波那契以兔子繁殖为例子而引入的,故又称为“兔子数列”.该数列从第三项开始,每项等于其前相邻两项之和.记数列{F n }的前n项和为S n,则下列结论正确的是()A.F n=F n-1+F n-2(n≥3)B.S4=F6-1C.S2 019=F2 020-1D.S2 019=F2 021-1解析根据题意有F n=F n-1+F n-2(n≥3),所以S3=F1+F2+F3=1+F1+F2+F3-1=F3+F2+F3-1=F4+F3-1=F5-1,S4=F4+S3=F4+F5-1=F6-1,S5=F5+S4=F5+F6-1=F7-1,…,所以S2 019=F2 021-1.答案ABD三、填空题:本题共4小题,每小题5分,共20分.请把正确的答案填写在各小题的横线上.13.设a=210+1211+1,b=212+1213+1,则a,b的大小关系为________.解析法一由题意知,a-b=210+1211+1-212+1213+1=(210+1)(213+1)-(212+1)(211+1)(211+1)(213+1)=3×210(211+1)(213+1)>0,故a>b.法二可考虑用函数的单调性解题.令f(x)=2x+12x+1+1=12⎝⎛⎭⎪⎫1+12x+1+1,则f(x)在定义域内单调递减,所以a=f(10)>b=f(12).答案a>b14.(2020·深圳统测)很多网站利用验证码来防止恶意登录,以提升网络安全.某马拉松赛事报名网站的登录验证码由0,1,2,…,9中的四个数字随机组成,将从左往右数字依次增大的验证码称为“递增型验证码”(如0123).已知某人收到了一个“递增型验证码”,则该验证码的首位数字是1的概率为________.解析由0,1,2,…,9中的四个数字随机组成的“递增型验证码”共有C410个,而首位数字是1的“递增型验证码”有C38个.因此某人收到的“递增型验证码”的首位数字是1的概率p=C38C410=415.答案4 1515.设双曲线C:x2a2-y2b2=1(a>0,b>0)的左焦点为F,直线4x-3y+20=0过点F且与双曲线C在第二象限的交点为P,O为原点,|OP|=|OF|,则双曲线C的右焦点的坐标为________,离心率为________.(本小题第一空2分,第二空3分)解析如图,∵直线4x-3y+20=0过点F,∴F(-5,0),半焦距c=5,则右焦点为F2(5,0).连接PF2.设点A为PF的中点,连接OA,则OA∥PF2.∵|OP|=|OF|,∴OA⊥PF,∴PF2⊥PF.由点到直线的距离公式可得|OA|=205=4,∴|PF2|=2|OA|=8.由勾股定理,得|FP|=|FF2|2-|PF2|2=6.由双曲线的定义,得|PF2|-|PF|=2a=2,∴a=1,∴离心率e=ca=5.答案(5,0) 516.(2020·厦门质检)已知正方体ABCD-A1B1C1D1的棱长为3,点N是棱A1B1的中点,点T是棱CC1上靠近点C的三等分点,动点Q在侧面D1DAA1(包含边界)内运动,且QB∥平面D1NT,则动点Q所形成的轨迹的长度为________.解析因为QB∥平面D1NT,所以点Q在过点B且与平面D1NT平行的平面内,如图,取DC的中点E1,取A1G=1,则平面BGE1∥平面D1NT.延长BE1,交AD 的延长线于点E,连接EG,交DD1于点I.显然,平面BGE∩平面D1DAA1=GI,所以点Q的轨迹是线段GI.∵DE1綊12AB,∴DE1为△EAB的中位线,∴D为AE的中点.又DI∥AG,∴DI=12AG=1,∴GI=(2-1)2+32=10.答案10限时练(四)一、单项选择题:本大题共8小题,每小题5分,共40分.在每小题给出的四个选项中,只有一项是符合题目要求的.1.已知集合A={x|y=log2(x-2)},B={x|x2≥9},则A∩(∁R B)=()A.[2,3)B.(2,3)C.(3,+∞)D.(2,+∞)解析A={x|y=log2(x-2)}=(2,+∞),∵B={x|x2≥9}=(-∞,-3]∪[3,+∞),∴∁R B=(-3,3),则A∩(∁R B)=(2,3).答案 B2.设x,y∈R,i为虚数单位,且3+4iz=1+2i,则z=x+y i的共轭复数在复平面内对应的点在()A.第一象限B.第二象限C.第三象限D.第四象限解析z=3+4i1+2i=(3+4i)(1-2i)5=115-25i,则z-=115+25i,z-对应点⎝⎛⎭⎪⎫115,25在第一象限.答案 A3.(2020·福建漳州适应性测试)如图是某地区从1月21日至2月24日的新冠肺炎每日新增确诊病例变化曲线图.若该地区从1月21日至2月24日的新冠肺炎每日新增确诊人数按日期顺序排列构成数列{a n},{a n}的前n项和为S n,则下列说法中正确的是()A.数列{a n}是递增数列B.数列{S n}是递增数列C.数列{a n}的最大项是a11D.数列{S n}的最大项是S11解析因为1月28日新增确诊人数小于1月27日新增确诊人数,即a7>a8,所以{a n }不是递增数列,所以A 错误;因为2月23日新增确诊病例数为0,所以S 33=S 34,所以数列{S n }不是递增数列,所以B 错误;因为1月31日新增病例数最多,从1月21日算起,1月31日是第11天,所以数列{a n }的最大项是a 11,所以C 正确;由a n ≥0,知S n +1≥S n ,故数列{S n }的最大项是最后一项,所以D 错误.故选C. 答案 C4.大学生小明与另外3名大学生一起分配到某乡镇甲、乙、丙3个村小学进行支教,若每个村小学至少分配1名大学生,则小明恰好分配到甲村小学的概率为( ) A.112B.12C.13D.16解析 大学生小明与另外3名大学生一起分配到某乡镇甲、乙、丙3个村小学进行支教,每个村小学至少分配1名大学生,基本事件总个数n =C 24A 33=36,小明恰好分配到甲村小学包含的基本事件个数m =A 33+C 23A 22=12,所以小明恰好分配到甲村小学的概率p =m n =1236=13. 答案 C5.(2020·荆门模拟)在二项式⎝ ⎛⎭⎪⎫x 12+12x 7的展开式中,有理项的项数为( ) A.1B.2C.3D.4解析 该二项展开式的通项为T r +1=C r 7x7-r 2⎝ ⎛⎭⎪⎫12x r=C r 7⎝ ⎛⎭⎪⎫12r ·x 7-3r 2,r =0,1,2,…,7.当r =1,3,5,7时,T r +1为有理项,共有4项.故选D. 答案 D6.如图,在直三棱柱ABC -A 1B 1C 1中,AB =AC =AA 1=2,BC =2,点D 为BC 的中点,则异面直线AD 与A 1C 所成的角为( )A.π2 B.π3 C.π4D.π6解析 以A 为原点,AB ,AC ,AA 1所在直线分别为x 轴、y 轴、z 轴建立如图所示的空间直角坐标系,则A (0,0,0),A 1(0,0,2),B (2,0,0),C (0,2,0),∴D ⎝ ⎛⎭⎪⎫22,22,0,∴AD →=⎝ ⎛⎭⎪⎫22,22,0,A 1C →=(0,2,-2), ∴cos 〈AD →,A 1C →〉=AD →·A 1C →|AD →||A 1C →|=12,∴〈AD →,A 1C →〉=π3. 答案 B7.已知A ,B 是圆O :x 2+y 2=4上的两个动点,|AB→|=2,OC →=13OA →+23OB →,若M是线段AB 的中点,则OC →·OM →的值为( )A. 3B.2 3C.2D.3解析 由OC→=13OA →+23OB →,又OM →=12(OA →+OB →), 所以OC →·OM →=⎝ ⎛⎭⎪⎫13OA →+23OB →·12(OA →+OB →)=16(OA →2+2OB →2+3OA →·OB →), 又△OAB 为等边三角形,所以OA →·OB →=2×2cos 60°=2,OA →2=4,OB →2=4,所以OC →·OM →=3. 答案 D8.(2020·天津适应性测试)已知函数f (x )=⎩⎪⎨⎪⎧x 2+2x ,x ≤0,2x -4x ,x >0.若函数F (x )=f (x )-|kx -1|有且只有3个零点,则实数k 的取值范围是( ) A.⎝ ⎛⎭⎪⎫0,916 B.⎝ ⎛⎭⎪⎫916,+∞C.⎝ ⎛⎭⎪⎫0,12 D.⎝ ⎛⎭⎪⎫-116,0∪⎝ ⎛⎭⎪⎫0,916解析 当k =12时,|kx -1|=⎪⎪⎪⎪⎪⎪12x -1=⎩⎪⎨⎪⎧12x -1,x ≥2,1-12x ,x <2.作出函数y =f (x )与y =⎪⎪⎪⎪⎪⎪12x -1的图象,如图.此时两函数的图象有且只有3个交点,此时F (x )有且只有3个零点,排除B ,C.当k =-120时,|kx -1|=⎪⎪⎪⎪⎪⎪-120x -1=⎩⎪⎨⎪⎧-120x -1,x ≤-20,1+120x ,x >-20,作出函数y =⎪⎪⎪⎪⎪⎪-120x -1的图象,如图.由图可得函数y =f (x )的图象与y =⎪⎪⎪⎪⎪⎪-120x -1的图象有且只有3个交点,此时F (x )有且只有3个零点,排除A.故选D. 答案 D二、多项选择题:本题共4小题,每小题5分,共20分.在每小题给出的四个选项中有多项符合题目要求,全部选对的得5分,部分选对的得3分,有选错的得0分.9.已知0<c <1,1>a >b >0,则下列不等式成立的是( )A.c a <c bB.a a +c <b b +cC.ba c >ab cD.log a c >log b c解析 构造函数y =c x ,因为0<c <1,所以函数y =c x 是减函数,而a >b >0,根据指数函数的单调性得c a<c b,故A 正确;由题意得a +c a =1+c a ,b +c b =1+cb ,因为0<c <1,1>a >b >0,所以0<c a <c b ,即0<a +c b <b +c b ,取倒数得a a +c >b b +c ,故B 错误;由题意得⎝ ⎛⎭⎪⎫a b c <a b ,整理得ba c <ab c ,故C 错误;由已知得log a c >0,log b c >0,又0<log c a <log c b ,所以1log c a >1log c b ,则log a c >log b c ,故D 正确.故选AD.答案 AD10.已知f (x )=A sin(ωx +φ)+B ⎝ ⎛⎭⎪⎫A >0,ω>0,|φ|<π2的图象如图所示,则函数f (x )的对称中心可以为( )A.⎝ ⎛⎭⎪⎫2π3,0B.⎝ ⎛⎭⎪⎫π6,1 C.⎝ ⎛⎭⎪⎫-π6,1 D.⎝ ⎛⎭⎪⎫π3,1 解析 由图象知A =3+12=2,B =3-12=1,又T =2⎝ ⎛⎭⎪⎫7π12-π12=π,所以ω=2.由2×π12+φ=π2+2k π(k ∈Z )且|φ|<π2,得φ=π3,故f (x )=2sin ⎝ ⎛⎭⎪⎫2x +π3+1.令2x +π3=k π(k ∈Z ),得x =-π6+k π2(k ∈Z ),取k =0,有x =-π6;k =1,x =π3. 答案 CD11.对于函数f (x )=ln xx ,下列说法正确的是( )A.f (x )在x =e 处取得极大值1eB.f (x )有两个不同的零点C.f (4)<f (π)<f (3)D.π4<4π解析 f (x )的定义域为(0,+∞),且f ′(x )=1-ln xx 2.令f ′(x )=0,得x =e.∴f (x )在(0,e)上单调递增,在(e ,+∞)上单调递减,因此f (x )在x =e 处取得极大值f (e)=1e ,A 正确.令f (x )=0,解得x =1,故函数f (x )有且仅有一个零点,B 错误.由f (x )在(e ,+∞)上单调递减,得f (4)<f (π)<f (3),则C 正确.因为f (4)<f (π),即ln 44<ln ππ,所以ln 4π<ln π4,则4π<π4,D 错误.综上知,正确的为AC. 答案 AC12.(2020·烟台诊断)已知P 是双曲线C :x 23-y 2m =1(m >0)上任意一点,A ,B 是双曲线C 上关于坐标原点对称的两点.设直线P A ,PB 的斜率分别为k 1,k 2(k 1k 2≠0),若|k 1|+|k 2|≥t 恒成立,且实数t 的最大值为233,则下列说法正确的是( )A.双曲线C 的方程为x 23-y 2=1 B.双曲线C 的离心率为2C.函数y =log a (x -1)(a >0,a ≠1)的图象恒过双曲线C 的一个焦点D.直线2x -3y =0与双曲线C 有两个交点解析 设A (x 1,y 1),P (x 2,y 2).由A ,B 是双曲线C 上关于坐标原点对称的两点,得B (-x 1,-y 1),则x 213-y 21m =1,x 223-y 22m =1.两式相减,得x 21-x 223=y 21-y 22m ,所以y 21-y 22x 21-x 22=m 3.又直线P A ,PB 的斜率分别为k 1,k 2,所以k 1k 2=y 1-y 2x 1-x 2×-y 1-y 2-x 1-x 2=y 21-y 22x 21-x 22=m3.所以|k 1|+|k 2|≥2|k 1||k 2|=2m3,当且仅当|k 1|=|k 2|时取等号.又|k 1|+|k 2|≥t 恒成立,且实数t 的最大值为233,所以2m 3=233,解得m =1.因此双曲线C 的方程为x 23-y 2=1,则A 项正确.因为a =3,b =1,所以c =a 2+b 2=2,所以双曲线C 的离心率e =c a =23=233,则B 项不正确.双曲线C 的左、右焦点分别为(-2,0),(2,0),而当x =2时,y =log a (2-1)=log a 1=0,所以函数y =log a (x -1)(a >0,a ≠1)的图象恒过双曲线C 的一个焦点(2,0),则C 项正确.由⎩⎪⎨⎪⎧2x -3y =0,x 23-y 2=1消去y ,得x 2=-9,此方程无实数解,所以直线2x -3y =0与双曲线C 没有交点,则D 项不正确.故选AC. 答案 AC三、填空题:本题共4小题,每小题5分,共20分.请把正确的答案填写在各小题的横线上.13.设{a n }是公差不为零的等差数列,S n 为其前n 项和.已知S 1,S 2,S 4成等比数列,且a 3=5,则数列{a n }的通项公式为________.解析 设等差数列{a n }的公差为d (d ≠0),则由S 1,S 2,S 4成等比数列,得S 22=S 1S 4,即(2a 3-3d )2=(a 3-2d )·(4a 3-2d ).又a 3=5,所以(10-3d )2=(5-2d )(20-2d ),解得d =2.所以数列{a n }的通项公式为a n =a 3+(n -3)d =2n -1. 答案 a n =2n -114.已知点E 在y 轴上,点F 是抛物线y 2=2px (p >0)的焦点,直线EF 与抛物线交于M ,N 两点,若点M 为线段EF 的中点,且|NF |=12,则p =________. 解析 由题意知,直线EF 的斜率存在且不为0,故设直线EF 的方程为y =k ⎝ ⎛⎭⎪⎫x -p 2,与抛物线方程y 2=2px 联立,得k 2x 2-p (k 2+2)x +p 2k 24=0.设M (x 1,y 1),N (x 2,y 2),则x 1x 2=p 24.又F ⎝ ⎛⎭⎪⎫p 2,0,点M 为线段EF 的中点,得x 1=p 22=p 4.由|NF |=x 2+p 2=12,得x 2=12-p2.由x 1x 2=p 4⎝ ⎛⎭⎪⎫12-p 2=p 24,得p =8或p =0(舍去).答案 815.(2020·长郡中学适应性考试)如图,在棱长为2的正方体ABCD -A 1B 1C 1D 1中,点M ,N ,E 分别为棱AA 1,AB ,AD 的中点,以A 为圆心,1为半径,分别在面ABB 1A 1和面ABCD 内作弧MN 和NE ,并将两弧各五等分,分点依次为M ,P 1,P 2,P 3,P 4,N 以及N ,Q 1,Q 2,Q 3,Q 4,E .一只蚂蚁欲从点P 1出发,沿正方体的表面爬行至点Q 4,则其爬行的最短距离为________.(参考数据:cos 9°≈0.987 7,cos 18°≈0.951 1,cos 27°≈0.891 0)解析 在棱长为2的正方体ABCD -A 1B 1C 1D 1中,点M ,N ,E 分别为棱AA 1,AB ,AD 的中点,以A 为圆心,1为半径,分别在平面ABB 1A 1和平面ABCD 内作弧MN 和NE .将平面ABCD 绕AB 旋转至与平面ABB 1A 1共面的位置,如图(1),则∠P 1AQ 4=180°10×8=144°,所以P 1Q 4=2sin 72°.将平面ABCD 绕AD 旋转至与平面ADD 1A 1共面的位置,将ABB 1A 1绕AA 1旋转至与平面ADD 1A 1共面的位置,如图(2),则∠P 1AQ 4=90°5×2+90°=126°,所以P 1Q 4=2sin 63°.因为sin 63°<sin 72°,且由诱导公式可得sin 63°=cos 27°,所以最短距离为|P 1Q 4|=2sin 63°≈2×0.891 0=1.782 0.图(1)图(2)答案 1.782 016.已知函数f (x )=⎩⎨⎧x +2,x <a ,x 2,x ≥a ,若函数f (x )在R 上是单调的,则实数a 的取值范围是________;若对任意的实数x 1<a ,总存在实数x 2≥a ,使得f (x 1)+f (x 2)=0,则实数a 的取值范围是________(本小题第一空2分,第二空3分).解析 令x +2=x 2,得x =-1或x =2.作出函数y =f (x )的图象如图所示,若函数f (x )在R 上单调,只需a ≥2.若对任意的实数x 1<a ,总存在实数x 2≥a ,使得f (x 1)+f (x 2)=0,可得x 1+2+x 22=0,即-x 22=x 1+2,即有a +2≤0,解得a ≤-2.答案 [2,+∞) (-∞,-2]限时练(五)一、单项选择题:本大题共8小题,每小题5分,共40分.在每小题给出的四个选项中,只有一项是符合题目要求的. 1.复数z =i1+i(i 是虚数单位)的虚部是( ) A.12B.-12C.12iD.-12i解析 z =i 1+i =i (1-i )(1+i )(1-i )=i 2+12,∴z 的虚部为12.答案 A 2.已知集合A ={-1,0,1,2,3},B =⎩⎪⎨⎪⎧⎭⎪⎬⎪⎫x |x -2x +1≥0,则A ∩B 中元素的个数为( )A.1B.2C.3D.4解析 由x -2x +1≥0,得x ≥2或x <-1,则B ={x |x ≥2,或x <-1},∴A ∩B ={2,3},A ∩B 中有2个元素.答案 B3.已知函数f (x )=⎩⎪⎨⎪⎧sin ⎝ ⎛⎭⎪⎫πx +π6,x ≤0,2x +1,x >0,则f (-2)+f (1)=( )A.6+32B.6-32C.72D.52解析 f (-2)=sin ⎝ ⎛⎭⎪⎫-2π+π6=12,f (1)=21+1=3.∴f (-2)+f (1)=3+12=72. 答案 C4.在某项检测中,测量结果服从正态分布N (2,1),若P (X <1)=P (X >1+λ),则λ=( ) A.0B.2C.3D.5解析 依题意,正态曲线关于x =2对称,又P (X <1)=P (X >1+λ),因此1+λ=3,∴λ=2. 答案 B5.(2020·天津适应性测试)如图,长方体ABCD -A 1B 1C 1D 1的体积为36,E 为棱CC 1上的点,且CE =2EC 1,则三棱锥E -BCD 的体积是( )A.3B.4C.6D.12解析 ∵CE =2EC 1,∴V E -BCD =13×12×23×V ABCD -A 1B 1C 1D 1=19×36=4.故选B. 答案 B6.函数f (x )=x 2-2ln|x |的图象大致是( )。
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小题满分练(十)
(限时20分钟)
北京时间2016年11月6日17时27分,一架载有92吨蓝莓和樱桃的包机经过28个小时飞行后,从南美智利首都圣地亚哥(70°39′W)机场抵达郑州市新郑国际机场。
水果在机场经检验合格后再分拨配送到市内、北京、上海等地。
郑州航空港已成为国内进境水果的主要集散地之一。
据此完成1~3题。
1.该架水果包机从圣地亚哥机场起飞时,当地正值( )
A.黎明时分B.正午前后
C.黄昏时分D.子夜前后
2.我国商人选择11月~12月从智利进口水果的主要原因是( )
A.气温较低,水果易保存
B.半球不同,水果错季成熟
C.春节临近,市场需求旺
D.气流稳定,适宜航空飞行
3.与国内其他大城市相比,郑州航空港成为国内进境水果主要集散地的有利条件是( )
A.装卸成本更低廉B.航空运输更便利
C.地理位置更优越D.检验技术更先进
前郭尔罗斯蒙古族自治县(简称前郭县)位于吉林省西北部,地处松嫩平原南部。
下表示意“1986~1996年前郭县土地利用面积变化状况”。
据此完成4~5题。
(单位:km2)
4.前郭县在1986~1996年期间,土地利用转化的主要表现有( )
A.大面积草地转化为未利用土地
B.旱田分布范围基本未变
C.大量林地、草地转化为水田
D.由以旱田为主转变为以水田为主
5.前郭县在1986~1996年期间土地利用转化带来的影响有( )
A.生态环境改善B.农业污水增加
C.生物多样性增加D.土地质量上升
江苏无锡是中国光伏产业最为集中的地区。
自2001年首家中澳合资光伏企业成立至2011年,无锡光伏产业发展实行两头在外的发展模式(关键零部件、生产设备和销售市场主要依赖国外)参与国际市场竞争。
2016年,无
锡市太阳能电池产能占全国总规模的50%以上,已形成包括光伏材料、电池原件、光伏组件、逆变器、运维服务、数据管理等各生产环节的全产业链竞争优势。
光伏制造设备的本地化率已经超过50%;企业在为客户提供电子化学品原料的同时,还针对单晶硅和多晶硅生产中的化学品污染问题,主动研发废化学品的回收再利用技术;开发了可以通过互联网实现对遥远地区的风能、光伏等发电装置的远程监控、运行管理和维护技术。
据此完成6~8题。
6.与发达国家相比,2001~2011年间无锡光伏产业参与国际市场竞争的主要有利条件是( )
A.生产成本较低B.原料资源丰富
C.交通位置优越D.市场需求量大
7.无锡光伏产业在短短10多年间,从两头在外发展模式到形成全球性竞争优势,主要得益于( )
A.生产规模不断扩大
B.智能化的运行管理和维护服务
C.技术研发和创新
D.废化学品的回收再利用
8.2016年,江苏省光伏累计装机容量位列全国第五,仅次于4个太阳能资源一类地区——新疆、甘肃、青海和内蒙古。
在东部沿海各省区中,江苏省光伏累计装机容量居首位的比较优势是( )
A.太阳能资源丰富
B.国家新能源政策的扶持
C.清洁能源市场需求量大
D.光伏全产业链的强力支撑
“明修栈道,暗渡陈仓”中的“栈道”是指褒斜古道。
此道始建于殷周,是古代关中通往汉中、蜀地最著名的交通要道,也是中国最早在悬崖峭壁上开凿的道路之一。
东汉永平年间,工匠采用“火焚水激”法(先用火烧石,待石温很高时突然用凉水淋浇)在山上破石开路。
下图为“褒斜古道线路图”。
据此完成9~11题。
9.与“火焚水激”法相似的外力作用是( )
A.溶蚀作用B.侵蚀作用
C.搬运作用D.风化作用
10.甲地的地貌类型及古人在甲地修路时采取的对策是( )
A.河谷地貌沿河成路
B.低山垭口横岭越垭
C.断块山“之”字盘旋
D.悬崖峭壁凿壁而栈
11.三国时一队蜀军在褒斜古道驱木牛流马运军粮,行至甲地时,木牛的影子恰好与木牛垂直并指向北方,按古人天干地支时辰,此时应属( )
A.子时 B.卯时 C.午时 D.酉时
地理试题答案
答案 1.D 2.B 3.C
解析第1题,根据智利首都圣地亚哥位于70°39′W,可以计算智利位于西5区,飞机降落时北京时间(东8区)为11月6日17时27分,可以计算降落时的圣地亚哥的区时为17:27-(8+5)=4:27,因飞机此前飞行了28小时,故当飞机起飞时,圣地亚哥区时为0:27,处于子夜前后,故D正确。
第2题,智利位于南半球,11月~12月为南半球的夏季,大量水果上市;我国夏秋季节水果较为丰富,冬季缺乏,故B正确。
目前冷藏保鲜技术较为先进,冬季易于保存不是进口南半球水果的主要原因,故A错误;我国春节是1~2月份,水果保鲜期时间较短,11~12月距离春节还有一段时间,故C错误;市场需求是进口水果的主要原因,和气流稳定无关,故D错误。
第3题,由材料可知,郑州航空港为我国国内进境水果的主要集散地,是因为郑州位于我国中部地区,与市场需求量大的发达地区距离较近,地理位置优越,同时交通便利,能够快速运输到全国各地,故C正确;郑州为河南省会城市,人口稠密,和西部大部分省会相比较,劳动力价格并不便宜,故A错误;上海和北京的航空运输比郑州更为发达,故B错误;郑州为我国中部城市,检验技术和东部经济更为发达的地区相比无明显优势,故D错误。
答案 4.A 5.B
解析第4题,土地开发利用一般是先易后难。
前郭县率先开发的旱田区域应为水热条件较好区域,开发过程中也形成较完备的基础设施,新转化水田部分,应主要来自旱田的转化。
以此类推,草地大量减少是因为转化为旱田,或开发不当而成为未利用地;森林转化为旱田或草地;未利用地增加主要是由于有大面积草地在这一期间转化。
期间旱田面积变化很小,但是分布区域已发生较大的变化;水田明显增加,但依然以旱田为主。
第5题,区域大量林地、草地遭到破坏,土地退化,未利用地增加,生态环境恶化,生物多样性减少。
农业种植面积增加,特别是水田增加,更多的农药、化肥及其他污染物进入水体,造成水体污染加剧。
答案 6.A 7.C 8.D
解析第6题,与发达国家相比,无锡的光伏产业劳动力、土地等要素成本较低,使得无锡光伏产业参与国际市场竞争力较强,A正确;光伏产业的原料主要是硅,无锡矿产资源缺乏,所以无锡光伏产业原料资源不丰富,B错误;无锡是内陆城市,对外交流中交通位置优势不突出,C错误;由于当时光伏产业属于新兴产业,技术不成熟,受天气等自然因素影响较大,市场需求量不是很大,D错误。
故答案选A。
第7题,由材料可知,无锡光伏产业已形成包括光伏材料、电池原件、光伏组件、逆变器、运维服务、数据管理等各生产环节的全产业链竞争优势,这些生产环节都是高技术含量的环节,可知我国在光伏产业中不断进行技术研发和创新,使得无锡光伏制造设备的本地化率不断提升,故答案选C。
第8题,根据所学知识,江苏为亚热带季风气候,降水量大,雨季长,太阳能资源不丰富,故A错误;国家新能源政策针对所有地区,并不单单针对江苏一个省份,故B错误;我国东部地区各省份能源缺乏,对清洁能源需求量都比较大,故C错误;由材料可知,江苏无锡是中国光伏产业最为集中的地区,光伏制造设备的本地化率超过一半,光伏产业的快速发展为江苏省光伏累计装机容量提供设备和技术支撑,使得江苏省在东部沿海各省区中光伏累计装机容量居首位。
故答案选D。
答案9.D 10.B 11.C
解析第9题,“火焚水激”法是先用火烧石,待石温很高时突然用凉水淋浇,岩石热胀冷缩变化,导致裂开。
这种因温度变化导致岩石遭受破坏,产生裂隙,形成松散物的作用属于风化作用,D对。
第10题,读图,甲地位于褒斜古道上。
甲地没有河流,没有河谷地貌,不会是沿河成路,A错。
图中甲地位于两条河流之间,应该是河流的分水岭。
横岭越垭就是在山岭处找一个海拔比较低的垭口穿越过去,古道又是横贯而过,B对。
“之”字盘旋是
沿着山地迂回盘旋,甲地古道是直接通过,C错。
根据图例,甲处为古道线路,不是栈道遗址,不是在峭壁上凿壁而栈,D错。
第11题,三国时一队蜀军在褒斜古道驱木牛流马运军粮,行至甲地时,甲地线路呈东西向,木牛的影子恰好与木牛垂直并指向北方,说明当地地方时为12时,按古人天干地支时辰,12时应属午时,约11时至13时之间,C对。