第一篇:2021屆高考信息技術(shù)復(fù)習(xí)講練測專題1.1,信息特征及信息安全(練)原卷版
題 專題 01 信息特征及信息安全(練)
1..(2020 屆 屆 第一學(xué)期名校協(xié)作)下列有關(guān)信息的說法,不正確的是()
A.信息可以通過 Wi-Fi 傳輸,說明信息的載體不一定是實體 B.信息可以加工和處理,加工和處理后信息的載體同步發(fā)生改變 C.信息息可以脫離它所反映的事物被存儲,但不能脫離載體單獨存在 D.信息自古就有,隨著時間的遷移,其價值也會發(fā)生改變 2..(2020 屆 屆 第一學(xué)期“七彩陽光”)下列關(guān)于信息的說法,正確的是()
A.無線電的發(fā)明是為了能讓信息脫離載體傳播 B.電子計算機 ENIAC 的發(fā)明標志著信息技術(shù)的產(chǎn)生 C.信息在傳遞的過程中會產(chǎn)生損耗,所以不能重復(fù)使用 D.聲音、視頻等信息在計算機中以二進制的形式存儲 3..(2020 屆 屆 Z20 第一次聯(lián)考)下列有關(guān)信息的說法中正確的是()
A.信息可以重復(fù)使用,也可以傳遞和共享,但是會產(chǎn)生損耗
B.數(shù)字、英文字母、圖像、音頻、視頻等在計算機內(nèi)部都采用二進制代碼存儲
C.信息作為一種社會資源自古就有,而信息技術(shù)是人類進入信息社會后才出現(xiàn)的D.信息可以脫離它所反映的事物被存儲、保存和傳播,即有些信息可以脫離載體而存在 4..(2019 屆浙江 “ 五校聯(lián)考 ” 第一次 考試)下列關(guān)于信息和信息技術(shù)的說法,正確的是()
A.信息、物質(zhì)、人力是人類社會的三大資源 B.為每位入校學(xué)生分配學(xué)號屬于信息的發(fā)布 C.現(xiàn)代信息技術(shù)包括微電子技術(shù)、光電子技術(shù)、廣播電視技術(shù)等 D.信息具有載體依附性,但是可以脫離它所反映的事物被存儲、保存和傳播 5..(2019 屆寧波 “ 十校聯(lián)考 ”))二維碼是近年來非常流行的編碼方式,以下關(guān)于二維碼的說法正確的是()
A.手機掃描二維碼,屬于信息的編碼過程 B.二維碼可以表示文字、圖像、超鏈接等信息 C.通過掃描二維碼獲取某 URL 的過程,涉及信息的加工與發(fā)布 D.某支付 APP 付款二維碼每隔一定時間自動更新,主要體現(xiàn)了信息的載體依附性 6..(2019 屆溫州普通高中選考適應(yīng)性測試)下列關(guān)于信息的說法正確的是()
A.新信息一定比舊信息更具價值 B.信息可重復(fù)使用,但會產(chǎn)生損耗 C.“盲人摸象”體現(xiàn)了信息具有真?zhèn)涡?D.信息不可以脫離它所反映的事物被存儲,必須依附于載體 7..(2019 屆杭州教學(xué)質(zhì)量檢測)下列有關(guān)信息技術(shù)的說法,正確的是()
A.信息技術(shù)是對文字信息進行加工和處理時使用的技術(shù) B.隨著信息技術(shù)的發(fā)展,只需要計算機就能完成信息的處理 C.1946 年第一臺電子計算機誕生后才有信息技術(shù) D.計算機技術(shù)的發(fā)展促進了信息技術(shù)的發(fā)展 8..(2019 屆麗水、衢州、湖州三地市教學(xué)質(zhì)量檢測)下列有關(guān)信息和信息技術(shù)的說法,正確的是()
A.隨著現(xiàn)代通信技術(shù)和計算機技術(shù)的發(fā)展產(chǎn)生了信息技術(shù) B.通過無線網(wǎng)絡(luò)傳輸?shù)男畔⒉灰栏接谳d體 C.信息可以脫離它所反映的事物被存儲、保存和傳播 D.網(wǎng)絡(luò)是信息的表達方式,可利用網(wǎng)絡(luò)發(fā)布信息 9..(2019 屆寧波期末“十校聯(lián)考”)下列關(guān)于信息及信息技術(shù)的說法正確的是()
A.近代信息技術(shù)包括微電子技術(shù)、光電子技術(shù)、計算機網(wǎng)絡(luò) B.文字、圖片、視頻等可以作為信息的載體 C.信息不能脫離它所反應(yīng)的事物而被保存 D.信息的加工和管理必須使用計算機才能完成 10..(2019 屆(Z20 聯(lián)盟)第二次聯(lián)考)下列關(guān)于信息的說法不正確的是()
A.“無中生有”體現(xiàn)了信息的真?zhèn)涡?B.在 12306 網(wǎng)站注冊時設(shè)置復(fù)雜密碼是為了提高信息的準確性 C.計算機內(nèi)的信息采用二進制代碼表示 D.同一條信息可以通過不同的載體保存和傳播 11..(2019 屆金華十校期末調(diào)研)下列關(guān)于信息的說法,不正確的是()
A.信息是指數(shù)據(jù)、信號消息中所包含的意義 B.信息可以脫離所反映的事物被存儲、保存和傳播 C.漢字信息在計算機內(nèi)都是采用 GB2312 編碼存儲和表示的 D.近代信息技術(shù)包括攝影技術(shù)、電影技術(shù)、廣播和電視技術(shù)等
12..(2019 屆紹興市適應(yīng)性試卷)下列關(guān)于信息的說法,不正確的是()
A.物質(zhì)、能源、信息是構(gòu)成人類社會的三大要素 B.信息的表示、傳播必須依附于某種載體 C.信息可脫離它的事物被存儲、保存和傳播 D.信息經(jīng)過加工處理后一定具有更高的使用價值 13..(2019 屆浙江十校聯(lián)盟)下列有關(guān)信息和信息技術(shù)的說法,正確的是()
A.從報紙上閱讀新聞,其中文字和紙張都屬于信息 B.微電子技術(shù)和光電子技術(shù)都是近代信息技術(shù) C.隨著造紙術(shù)和印刷術(shù)的問世,才誕生了信息技術(shù) D.信息可以被重復(fù)使用而不會像能源那樣產(chǎn)生損耗 14..(2019 屆臺州市教學(xué)質(zhì)量評估)下列有關(guān)信息與信息技術(shù)的說法,正確的是()
A.電影技術(shù)、計算機技術(shù)和傳感技術(shù)都屬于現(xiàn)代信息技術(shù) B.信息的表示、存儲和傳播需要依附于載體 C.信息只有通過計算機才能進行加工和處理 D.文字、聲音、圖像、視頻等都是信息 15..(2019 屆綠色評價聯(lián)盟)下列有關(guān)信息技術(shù)的說法,正確的是()
A.計算機出現(xiàn)后才存信息技術(shù)的出現(xiàn) B.信息技術(shù)的發(fā)展促進了計算機技術(shù)的發(fā)展 C.信息技術(shù)是對信息進行加工和處理時使用的技術(shù) D.隨著信息技術(shù)的發(fā)展,信息的處理不需要人類參與就可以完成各項任務(wù)
1..(2019 浙江 6 月 月 學(xué)考)關(guān)于信息表達方式與表達技術(shù)的說法,錯誤的是()
A.多媒體技術(shù)是信息表達技術(shù) B.同一信息只有一種表達方式
C.盲文是一種信息表達方式 D.文字、語言、圖形、圖像、聲音和形體動作等是常用的信息表達方式 2..(2019 浙江 4 月 月 選考)下列有關(guān)信息的說法,正確的是()
A.計算機中的信息是以十六進制形式存儲的 B.計算機信息處理能力只與 CPU 有關(guān)
C.離開計算機網(wǎng)絡(luò),信息便無法傳遞 D.使用加密技術(shù)可以提髙信息的安全性 3..(2018 浙江 11 月 月 選考)下列有關(guān)信息技術(shù)的說法,不正確的是()
A.信息技術(shù)是伴隨著計算機和互聯(lián)網(wǎng)技術(shù)的發(fā)展而誕生的 B.信息技術(shù)是對信息進行采集、處理、傳輸、存儲、表達和使用的技術(shù) C.信息技術(shù)包含微電子技術(shù)、通信技術(shù)、計算機技術(shù)和傳感技術(shù)等 D.物聯(lián)網(wǎng)、人工智能、云計算等技術(shù)都是當前信息技術(shù)發(fā)展的熱點 4..(2018 浙江 6 月 月 學(xué)考)下列有關(guān)信息的說法,正確的是()
A.信息一旦產(chǎn)生,其價值就不會改變 B.信息可以脫離載體而存在 C.信息有真實信息和虛假信息之分 D.網(wǎng)上的信息可以隨意轉(zhuǎn)發(fā) 5..(2018 浙江 4 月 月 選考)下列有關(guān)信息的說法,正確的是()
A.信息在計算機內(nèi)部采用二進制代碼表示 B.只有最新的信息才具有價值 C.只能借助計算機才能處理信息
D.信息不能脫離它所反應(yīng)的事物被存儲
第二篇:2014屆高考英語 復(fù)習(xí)講練測完形填空10
2014屆高考英語復(fù)習(xí)講練測:完形填空10
In the clinic, I asked if Michael could be retested, so the specialist tested him again.To my __36__, it was the same score.Later that evening, I _37_ told Frank what I had learned that day.After talking it over, we agree that we knew our _38_ much better than an IQ(智商)test.We _39_ that Michael’s score must have been a __40___ and we should treat him ___41___ as usual.We moved to Indiana in 1962, and Michael studied at Concordia High School in the same year.He got _42 _ grades in the school, especially _43_ biology and chemistry, which was a great comfort.Michael _44_ Indiana University in 1965 as a pre-medical student, soon afterwards, his teachers permitted him to take more courses than _45_.In 1968, he was accepted by the School of Medicine, Yale University.On graduation day in 1972, Frank and I _46_ the ceremony(典禮)at Yale.After the ceremony, we told Michael about the _47_ IQ score he got when he was six.Since that day, Michael sometimes would look at us and say _48_, “My dear mom and dad never told me that I couldn’t be a doctor, not until after I graduated from medical school!” It is his special way of thanking us for the _49_ we had in him.Interestingly, Michael then _50_ another IQ test.We went to the same clinic where he had _51_ the test eighteen years before.This time Michael scored 126, an increase of 36 points.A result like that was supposed to be _52_.Children often do as _53_ as what adults, particularly parents and teachers, _54_ of them.That is, tell a child he is “ _55_”, and he may play the role of a foolish child.36.A.joyB.surprise
B.fearfully
B.sonC.dislikeD.disappointmentD.hopefully 37.A.tearfully 38.A.student
39.A.argued
40.A.jokeC.cheerfullyC.friendC.decidedD.doctor B.realizedD.understood B.mistakeC.warningD wonder.41.A.specially 42.A.poor43.A.in
B.strictly
C.naturally
D.carefully
B.good
C.average
D.standard
D.for
D.entered
B.about B.chose
C.of
44.A.visited45.A.allowed46.A.missed47.A.high
C.passedC.required
B.described B.held
D.offered
C.delayed
D.attended
B.sameC.lowD.different
D.jokingly D.delight
D.prepared for
48.A.curiously 49.A.faith
B.eagerlyB.interest
C.calmlyC.pride
50.A.looked for B.asked for 51.A.received B.accepted52.A.imperfect
C.waited for
C.organized D.discussed
D.unsatisfactory
B.impossible
C.uncertain
53.A.honestly B.much54.A.hear55.A.wise
C.well
D.bravely
D.speak
B.learn
C.expect
B.rudeC.shyD.stupid
答案36.D37.A38.B39.C40.B41.C42.B43.A44.D45.C46.D47.C48.D49.A50.B51.A52.B53.C54.C55.D
It's fourteen years since I left the Philippines to live with my family in the USA.A month ago, while on summer vacation back in my motherland, I learned a lesson from mosquito(蚊子)bites.Right before36Kennedy Airport in New York, my grandma37me of the behavior of the native mosquitoes around the38like me.She said, “There's an old saying—the39you stay away from the motherland, the sweeter your blood40to the mosquitoes.” Not41it, I replied, “Grandmaaaa, that's just an old wives' tale!”
Well, less than a week42my arrival in Manila, I was already carpeted with a43of mosquito bites.I took many measures to keep myself from being44, but they all proved useless.Late one45in my cousin's home, I couldn't bear the46of the bites.Hoping to find some comfort, I47my cousin, who was sleeping peacefully in the bed next to mine.Unhappy for being48she said, “There is nothing you can do.Go back to sleep.”With a few turns, she slept again.Enviously(妒嫉地)49her sleep, I hoped a big mosquito would50on her face.However, the mosquitoes would just lightly dance around her forehead and fly away quickly, never biting her.Amazed(驚奇的), I ran to others'51, only to find they were all sleeping52as the same thing occurred again and again.From those bites, I came to53my grandma's silly tale.From then on, I've always tried to keep a(n)54mind about those strange old wives' tales55they do have some truth to them.36.A.leavingB.passingfinding
37.A.persuaded
B.remindedC.warnedD.informed
D.C.visitingD.38.A.studentsB.foreignersC.passengersvisitors
39.A.earlier40.A.growsremains
B.longerC.soonerD.later B.goes
C.flowsD.41.A.expectingB.understandingC.recognizingD.believing 42.A.afterB.before
C.whenD.as
D.43.A.shadeB.pileC.cloudblanket
44.A.touchedB.bittenC.defeatedD.discovered 45.A.morningB.afternoon46.A.noiseB.hiteffect
47.A.woke upB.shouted atC.looked fordropped on
48.A.blamedB.interruptedC.movedfrightened
49.A.having
C.eveningD.night C.pain
D.D.D.B.watchingC.makingD.helping
50.A.landB.fly
C.fall
D.wait
51.A.housesB.flatsC.roomsD.homes 52.A.joyfullyB.anxiouslyworriedly
53.A.tellB.knowC.remember
D.accept
C.soundlesslyD.54.A.openB.activeC.clear55.A.andB.so
C.because答案36.A37.C38.D39.B40.A41.D42.A43.D44.B45.D46.C47.A48.B49.B50.A51.C52.C53.D54.A55.C
D.honest D.until
第三篇:2014屆高考英語 復(fù)習(xí)講練測教案5
2014屆高考英語復(fù)習(xí)講練測:教案5 1.persuade vt.說服,勸服,使相信
persuade sb.to do sth.=persuade sb.into doing sth.說服某人做某事 persuade sb.not to do sth.=persuade sb.out of doing sth.說服某人不做某事 persuade sb.of sth.說服某人信服某事 persuade sb.+that-clause 使某人相信??
He persuaded me to study hard.=He persuaded me into studying hard.他說服我努力學(xué)習(xí)。易混辨析persuade與advise persuade sb.to do sth.表示成功地說服某人去做某事;其中try to persuade sb.to do sth.表示試圖說服某人做某事,含有沒有成功的意思。
advise sb.to do sth.表示建議某人做某事,對方是否采納則不一定。①Jack finally persuaded his father to give up smoking.杰克終于說服他父親戒了煙。
②We tried to persuade her to go out with us,but she refused.我們試圖說服她和我們一起出去,但被她拒絕了。
③I advised them to start early so that they could arrive there before dark.我建議他們早一點動身,以便能天黑前趕到那兒。
反饋1.1The boy was ______ to follow his friends' idea and was pleased to see it worked better than expected.A.a(chǎn)dvised
B.a(chǎn)llowed C.forbidden D.persuaded 反饋1.2 I ______ her to kick the habit of smoking,but she wouldn't listen.A.tried to persuade B.persuaded C.suggested D.expected 反饋1.3I ______ him not to smoke,but he didn't follow my advice.A.persuaded B.suggested C.a(chǎn)dvised D.hoped 反饋1.4(2012·浙江寧波十校聯(lián)考)One of us ______ us all taking shelter under the tree.Unluckily,one boy bought it and was struck by lightning as a result.A.a(chǎn)dvised B.suggested C.persuaded D.urged
①All possible means ______ been tried.②Every possible means ______ been tried.反饋2.4______ the underemployed university graduates,the hight-tech project is expected to create 10,000 or so jobs in the fields of computer programming and testing.A.Meaning to benefit B.Meaning benefiting C.Meant benefiting D.Meant to benefit 反饋2.5For him ______ stage is just ______ means of making a living.A.a(chǎn);a B.the;a C.the;the D.a(chǎn);the 3.benefit vt.有利于,使??受益 n.利益,福利,好處
benefit sb./sth.使某人/某物獲益 benefit from...從??中獲益 have/get/receive the benefit of 得益于 for the benefit of...為了??的利益 be of benefit to sb.對某人有益 beneficial adj.有益的,有利的
be beneficial to(=be of benefit to)對??有益
①Do you really benefit from playing computer games every day? 你真的能從每天玩電腦游戲中獲益嗎?
②This project is of great benefit to everyone.這項工程對每個人都大有好處。
易混辨析benefit,interest,profit與advantage benefit為普通用詞,指通過正當手段從物質(zhì)或精神方面得到的任何好處或利益。它的復(fù)數(shù)形式benefits表示“救濟金”;
interest作“利益”講時,多用復(fù)數(shù)形式,既可指集團、群體的利益,又可指個人的利益。interest作不可數(shù)名詞時,意為“利息”;
profit著重收益,尤指從物質(zhì)、錢財?shù)确矫娅@得的利益;
advantage指因某方面占優(yōu)勢或利用某機會以及對方弱點而獲得利益與好處。
①The interests of the individual must be subordinated to the interests of the collective.個人利益必須服從集體利益。
②All his wealth did not profit him.他所有的財富并沒有使他受益。
她建議坐地鐵去公園。
⑤I wouldn't recommend you to give up halfway.我不會勸你半途而廢。
⑥Our English teacher often recommends that we(should)practise speaking English in and out of class.我們的英語老師經(jīng)常勸告我們無論課堂內(nèi)外都要練習(xí)說英語。
⑦The doctor suggested that he(should)try his best to lose weight from now on.醫(yī)生建議他從現(xiàn)在開始盡力減肥。
⑧The bodyguards insisted that the president(should)keep away from the crowd for the sake of safety.出于安全考慮,警衛(wèi)人員堅決要求總統(tǒng)遠離人群。
⑨We suggest that students be sent abroad and stay there for two or three years.我們建議學(xué)生被送到國外并在那兒待上兩三年。
特別提醒當suggest,insist不表示建議或堅持要某人做某事,而表示“暗示、表明”或“堅持認為”時,則用陳述語氣。
She insisted that she was right.她堅持認為她是對的。
反饋4.1He's very well-connected,so there's surely somebody to ______ him for a good job when he graduates.A.refer B.a(chǎn)dvise C.recommend D.insist 反饋4.2 It is politely requested by the hotel management that radios ______ after 11 o'clock at night.A.were not played B.not be played C.not to play D.did not play 反饋4.3The doctor recommended I ______ here ______ the sunshine before I started for home.A.came;to B.come;for C.would come;with D.will come;in 反饋4.4The young man insisted that he ______ nothing wrong and ______ free.A.did;set
D.determined;went;hoping 反饋5.2 A ______ and strong-willed man is what it takes to achieve the task.A.determining B.determined C.deciding D.decided 反饋5.3She was full of ______ to achieve her goals.A.idea B.determination C.patience D.responsibility 6.a(chǎn)ppeal vi.懇求,呼吁;有吸引力;上訴 n.呼吁;懇求 appeal to sb.for sth./to do sth.呼吁/ 要求/懇求某人做某事 appeal to sb.=attract sb.吸引/引起某人的興趣 appeal against 為??上訴;訴諸 appeal to the law 訴諸法律
appeal to the higher court 向高級法院提出上訴 appeal n.呼吁;懇求
make/launch an appeal to sb.向某人發(fā)出緊急呼吁 appealing adj.動人心弦的,有魅力的,有感染力的
①Martin Luther King appealed to the blacks to appeal to the highest court against racial discrimination,which raised great concern all over the world.馬丁·路德·金呼吁黑人向最高法院提出上訴反對種族歧視,這引起了全世界極大的關(guān)注。
②Our English teacher's sense of humor appeals to every student in our class.我們英語老師的幽默感吸引了班里的每一位學(xué)生。③He appealed against the judge's decision.他不服法官判決而上訴。
④The teacher listened to his appeal.老師傾聽了他的要求。⑤She appealed to us to go with her.她懇求我們和她同行。
反饋6.1The idea of working abroad,together with your proposals,never ______to me.A.a(chǎn)ttracts B.a(chǎn)ttract C.a(chǎn)ppeal D.a(chǎn)ppeals 反饋6.2 The Republican candidate ______ to the young people to vote for him and make a difference to the country.A.called B.requested C.a(chǎn)sked D.a(chǎn)ppealed
⑤Even though/Though/Although I felt sorry for him,I was secretly pleased that he was having difficulties.雖然我為他感到惋惜,但對他的困難卻暗自高興。
⑥We thoroughly understand each other,even if/even though we don't always agree.我們彼此非常了解,雖然有時候也有一些分歧。
反饋8.1Many of them turned a deaf ear to his advice,______ they knew it to be valuable.A.a(chǎn)s if B.now that C.even though D.so that 反饋8.2 ______ when everybody else objects to his suggestion,he won't feel upset.A.Even if B.Although C.As if D.Even 反饋8.3______ you disagree with her,her idea is still worth considering.A.If only B.Even if C.Instead of D.Despite of 9.figure out 計算出,想出,理解,弄清楚
①Even the repairman couldn't figure out what had gone wrong with the washer.連修理工也弄不明白這洗衣機出了什么毛病。
②I can't figure why they ridicule this constructive suggestion.我弄不懂他們?yōu)槭裁闯靶@一建設(shè)性建議。
③Let's figure the expense first.我們先來算算費用吧。
反饋9The present situation is very complex,so I think it will take me some time to ______ its reality.A.make up B.figure out C.look through D.put off 10.get...across 講清楚;渡過 用法拓展含有g(shù)et的短語
get ahead of...領(lǐng)先
get along 進展,過活,相處 get away 逃掉 get away from...避免,擺脫,離開 get back 回來 get...back 收回,找回 get behind 落后 get down 記下來 get down to 認真做
get to know/love 逐漸地了解/愛上 get in 進來
反饋10.5 In China,nobody is to ______ with killing someone.A.get across B.get through C.get away D.get over
考點歸納拓展 【思路點撥】
1.1 D 根據(jù)was pleased to see it worked better可知這個男孩被勸服聽朋友的話,故答案為D項。
1.2 A 句意:我試圖說服她戒掉抽煙的習(xí)慣,但是她不聽。try to persuade sb.to do sth.表示試圖說服某人做某事,含有未能成功的意思,符合語境。
1.3 C 句意:我建議他不要抽煙,但是他沒有聽從我的建議。A項表示說服了他不抽煙,與后半句矛盾;advise sb.to do sth.建議某人做某事,符合語境,故C項正確。
1.4 B suggest sb.doing是唯一正確的搭配,意為“建議某人做某事”。
2.1 D 句意:如果你認為對女人好就意味著凡事都向她請示,那你恐怕就錯了。mean to do sth.意為“打算做某事”;mean doing sth.意為“意味著做某事”,故選D項。
2.2 A 句意:她本意是想幫他,卻反而讓情況變糟了。mean to do意為“意欲做某事”。2.3 ①have ②has means意為“方式;方法”,單復(fù)數(shù)同形。當means由every修飾時,顯然是單數(shù),謂語用單數(shù)形式。如果means由all修飾則為復(fù)數(shù),謂語用復(fù)數(shù)形式。
2.4 D 句意:旨在讓那些低端就業(yè)的大學(xué)生獲益,這個高科技項目有望創(chuàng)造1萬個左右計算機編程和測試領(lǐng)域的就業(yè)崗位。the project和mean是被動關(guān)系,故應(yīng)為meant;be meant to do是固定用法,為目的含義,故答案為D項。
2.5 B 句意:對于他來說,從藝是一種謀生手段。根據(jù)句意,stage 表示從藝,是一個抽象概念,其前不可以加不定冠詞;means為單復(fù)數(shù)同形的名詞,此處表示“一種方式”,用 a means of 表達。
3.1 A 句意:新的《勞動法》將使更多的人受益,特別是工人將從中受益。benefit sb.“使某人受益”;benefit from“從??中受益”,故A項正確。
3.2 D 句意:跟上亞洲形勢的發(fā)展會有幫助。beneficial “有益的”,符合題意。fortunate “幸運的”;dangerous “危險的”;safe“安全的”。
3.3 ①benefit ②advantage
3.4(1)for the benefit of(2)is beneficial to 4.1 C 句意:他很有關(guān)系,所以到畢業(yè)時肯定有人推薦他做一份好工作。recommend sb.for sth.為固定用法,意為“推薦某人某事物”,符合題意。
4.2 B 全句意思是:旅館管理部門懇請客人晚上11點后不要打開收音機。句中的謂語動詞request(請求)所引導(dǎo)的從句應(yīng)當用虛擬語氣,即動詞原形或“should+動詞原形”。本句的主語從句中,謂語應(yīng)當用被動語態(tài)。所以,答案應(yīng)為not be played。在上述這類句子中不能用動詞過去時形式表示虛擬語氣,所以A項不正確。not to play是動詞帶to的不定式,不能在句中作謂語。did not play也是動詞play的過去時形式,同樣不能在本句中作為
法還是值得考慮的。B make up“組成;化妝;編造”;figure out“理解;弄清楚”;look through“瀏覽”;put off“推遲”。句意:目前的形勢非常復(fù)雜,因此我認為要花費我一些時間來弄清楚它的真實性。
10.1 A 此題考查以get為中心詞的短語用法。get down to表示“開始認真對待”“開始認真考慮”。由題意可知應(yīng)為“我們該認真對待我們的學(xué)習(xí)了”,故答案為A項。
10.2 A 句意:那座火山劇烈的噴發(fā)而山腳下的那個村莊竟然安然渡過危險。此處用come through表示“(安然渡過)危機,疾病等”。
10.3 A 考查動詞短語的用法。get along“(勉強)生活;進展”;come on “開始”或用于祈使句表鼓勵、催促等;watch out“當心,注意”;set off “動身;出發(fā)”。根據(jù)句意可知A項正確。
10.4 B A項意為“偶遇”;B項意為“克服(困難等)”;C項意為“來訪”;D項意為“下車”。句意:如果我們能克服目前的困難,那么一切都會好起來的。
10.5 C 句意:在中國,沒有人在殺了人的情況下能逃脫懲罰。get away with(doing)sth.意為“在犯了某罪的情況下逃脫懲罰”。
第四篇:高考數(shù)學(xué)專題復(fù)習(xí)講練測——專題五 數(shù)列、數(shù)學(xué)歸納法 專題方法總結(jié)
專題方法總結(jié)
本專題由數(shù)列和數(shù)學(xué)歸納法兩部分主要內(nèi)容組成,它融代數(shù)、三角、幾何于一體,性質(zhì)多、技巧性強、方法靈活、應(yīng)用廣泛、綜合能力要求高.等差、等比數(shù)列的運算和性質(zhì)是本專題復(fù)習(xí)的重點,以等差、等比數(shù)列為載體的代數(shù)推理問題,數(shù)列的實際應(yīng)用問題及數(shù)學(xué)歸納法的應(yīng)用是難點,它們都是高考命題的熱點;方程觀點、等價轉(zhuǎn)換、消元法、待定系數(shù)法是貫穿于本專題的重要數(shù)學(xué)思想和方法;運算能力、邏輯思維能力、分析問題和解決問題的能力是復(fù)習(xí)好本專題的基本要求.
1.關(guān)于等差、等比數(shù)列
(1)等差、等比數(shù)列的判定:①利用定義判定;②an+an+2=2an+1
anan+2=an+1(an≠0)
22{an}是等差數(shù)列,{an}{an}是等差數(shù){an}是等比數(shù)列;③an=an+b(a,b為常數(shù))是等差數(shù)列,Sn=an+bn(a,b為常數(shù),Sn是數(shù)列{an}的前n項和)
列.
(2)等差、等比數(shù)列性質(zhì)的應(yīng)用:注意腳碼、奇偶項的特點等.
(3)數(shù)列是定義域為自然數(shù)集(或自然數(shù)集的子集)的函數(shù),即an=f(n)(n∈N).因此我們可運用函數(shù)的思想方法去研究處理數(shù)列問題.如等差數(shù)列當公差d≠0時的通項公式為n的一次函數(shù),前n項和為n的二次函數(shù),有關(guān)前n項和的最大、最小問題可運用二次函數(shù)的性質(zhì)來解決.
2.關(guān)于一般數(shù)列
(1)已知數(shù)列的前n項和,求通項公式,這類問題常利用
S1(n=1),an= Sn-Sn-1(n≥2)求解.
(2)用遞推公式給出來的數(shù)列,常利用“歸納—猜想—證明”的方法求解.
3.關(guān)于數(shù)列的求和
(1)公式法:①等差、等比數(shù)列的前n項和公式;②自然數(shù)的方冪和公式.
(2)錯位相減法.
(3)倒序相加法.
(4)裂(拆)項法.
4.關(guān)于數(shù)學(xué)歸納法
(1)數(shù)學(xué)歸納法的原理.
(2)數(shù)學(xué)歸納法的應(yīng)用:①證明與自然數(shù)有關(guān)的恒等式;②用數(shù)學(xué)歸納法證明不等式;③用數(shù)學(xué)歸納法證明整除性問題.
(3)歸納—猜想—證明.
第五篇:高考數(shù)學(xué)專題復(fù)習(xí)講練測——專題六 復(fù)數(shù) 專題復(fù)習(xí)講練 2 復(fù)數(shù)的應(yīng)用
§2 復(fù)數(shù)的應(yīng)用
一、復(fù)習(xí)要點
復(fù)數(shù)的三角形式、復(fù)數(shù)及其運算的幾何意義是數(shù)形結(jié)合的橋梁,是應(yīng)用復(fù)數(shù)知識解題的主要結(jié)合點.在系統(tǒng)復(fù)習(xí)的基礎(chǔ)上,本輪復(fù)習(xí)應(yīng)把握以下幾點:
1.《考試說明》對復(fù)數(shù)的應(yīng)用沒有提出特別要求,復(fù)習(xí)時只介紹一些簡單應(yīng)用,切忌隨意拔高.
2.使學(xué)生在思想上明確:
(1)應(yīng)用復(fù)數(shù)可以證明三角恒等式,求反三角函數(shù)的和;
(2)應(yīng)用復(fù)數(shù)可以證明不等式;
(3)應(yīng)用復(fù)數(shù)可以解決解析幾何問題;
(4)應(yīng)用復(fù)數(shù)可以證明平面幾何問題.
3.熟練掌握并應(yīng)用復(fù)平面內(nèi)的:
(1)兩點間的距離公式;
(2)過原點的射線、直線方程;
(3)線段垂直平分線的方程;
(4)圓的方程;
(5)橢圓的方程.
4.本節(jié)復(fù)習(xí)的重點應(yīng)放在復(fù)數(shù)運算的幾何意義及復(fù)數(shù)與三角、復(fù)數(shù)與幾何的簡單綜合問題上.
二、例題講解
例1(1)已知復(fù)數(shù)z1=3-i,|z2|=2,則|z1+z2|的最大值是().A.
B.
5C.2+
D.2+2-
2(2)已知復(fù)數(shù)z滿足|z-1|=|z-3|且arg(z-i)=π/4,則z等于________.講解:(1)本題的條件容易使我們聯(lián)想到復(fù)數(shù)及運算的幾何意義,首選數(shù)形結(jié)合的方法來解答.在復(fù)平面中,方程|z2|=2的圖形是以原點為圓心、半徑為2的圓,而|z1+z2|=|z2-(-z1)|表示z2與-z1所對應(yīng)的兩點P2與P1間的距離,即線段P1P2的長,如圖6-1所示.顯然當P1P2經(jīng)過原點時,線段P1P2最長,其值為2+.∴ 選C.
圖6-
1本題亦可選用代數(shù)方法解答,把z2用三角式表示后,則關(guān)于復(fù)數(shù)模的條件最值問題便轉(zhuǎn)化為三角函數(shù)的無條件最值問題.運用三角恒等變形方法和弦函數(shù)的值域性質(zhì)即得結(jié)論.簡解如下:
設(shè)z2=2(cosθ+isinθ)(0≤θ<2π),則
|z1+z2|=|2cosθ+3+i(2sinθ+1)|22
=(2cosθ+3)+(2sinθ+1)
=14+
4≤14+4sin(θ+φ)=(1+).222
當sin(θ+φ)=1時,等號成立.
∴ |z1+z2|的最大值為2+,選C.
圖6-
2(2)顯然用數(shù)形結(jié)合方法解答最為適宜.方程|z-1|=|z-3|的圖形是復(fù)平面中以實數(shù)1和3所對應(yīng)的點為端點的線段的垂直平分線;而方程arg(z-i)=(π/4)的圖形,是復(fù)平面中以復(fù)數(shù)i所對應(yīng)的點為端點,傾斜角為(π/4)的射線,如圖6-2所示.故射線與垂直平分線的交點所對應(yīng)的復(fù)數(shù)即為所求,即z=2+3i.
例2已知復(fù)數(shù)z1=cosα+isinα,z2=k(cosβ+isinβ),z3=(2-k)(cosγ+isinγ),且滿足z1+z2+z3=0.問k為何值時,cos(β-γ)分別取最大值、最小值(0<k<2).
講解:本例是復(fù)數(shù)與三角關(guān)系的問題,利用虛實轉(zhuǎn)化思想,由z1+z2+z3=0,應(yīng)用復(fù)數(shù)相等的充要條件,可轉(zhuǎn)化為三角條件最值問題.則有
解法1.由z1+z2+z3=0,得
cosα+kcosβ+(2-k)cosγ=0,sinα+ksinβ+(2-k)sinγ=
kcosβ+(2-k)cosγ=-cosα,ksinβ+(2-k)sinγ=-sinα.
①+②,得
cos(β-γ)=(2k-4k+3/2k(k-2))=1+[3/2k(k-2)].
若注意到復(fù)數(shù)的性質(zhì),可以考慮利用整體思想求解,則有
解法2.由z1+z2+z3=0,得
|z2+z3|=|z1|,兩邊平方,得|z2+z3|=|z1|,∴(z2+z3)(2222222① ② +3)=1,3即|z2|+|z3|+z2
注意到z2
232+2z3=1. +22z3=2|z2|·|z3|cos(β-γ),則k+(2-k)+2k(2-k)cos(β-γ)=1.
∴ cos(β-γ)=(2k-4k+3)/(2k-4k).
若注意到復(fù)數(shù)及其運算的幾何意義,則可以考慮利用數(shù)形結(jié)合的思想求解,從而有
解法3.∵ |z2-z3|=2(|z2|+|z3|)-|z2+z3|=2(|z2|+|z3|)-|z1|, 而且注意到復(fù)平面內(nèi)的余弦定理:
cos(β-γ)=(|z2|+|z3|-|z2-z3|/2|z2|·|z3|), ∴ cos(β-γ)=(2k-4k+3)/(2k-4k).
上面三種不同的解法是在三種不同的基本思想啟迪下得到的.這正是靈活運用基本數(shù)學(xué)思想的具體體現(xiàn),應(yīng)予足夠重視.
下面完成此題的解答.
令 y=f(k)=1+(3/2k(k-2))=1-(3/2k(2-k))(0<k<2)≤1-(3/2·((k+2-k/2)))=-(1/2).
∵ |cos(β-γ)|≤1,∴ -1≤y≤-(1/2).
由ymax=-(1/2),得
1+(3/2k(k-2))=-(1/2)k=1;
由ymin=-1,得1+(3/2k(k-2))=-1k=(1/2)或(3/2).
所以當k=1時,cos(β-γ)取最大值-(1/2);
當k=(1/2)或(3/2)時,cos(β-γ)取最小值-1.
此題實際上只是以復(fù)數(shù)作為載體,求給條件的余弦函數(shù)的最值,進而又轉(zhuǎn)化為求條件分式函數(shù)的最值.運用了均值不等式,也可利用判別式法求上述分式函數(shù)的最值.(留給讀者自己完成)
例3 設(shè)復(fù)平面內(nèi)兩點A、B對應(yīng)的復(fù)數(shù)分別為α、β,且|α-2|=1,β+(1+i)α=0,O為原點.試求△AOB面積的最大值和最小值,并且求相應(yīng)的復(fù)數(shù)α、β.
講解:由三角形面積公式S=(1/2)|OA|·|OB|·sin∠AOB知,只要求得|OA|、|OB|及∠AOB的值就行了.由復(fù)數(shù)的幾何意義知,|OA|=|α|,|OB|=|β|;由復(fù)數(shù)乘法的幾何意義可求得∠AOB的值.于是有如下解法:
由β+(1+i)α=0,得β=-(1+i)α.
∴ |β|=
β=|α|,222222222222222(cos(5π/4)+isin(5π/4))α.
由乘法的幾何意義及三角形內(nèi)角的范圍知
∠AOB=(3π/4),∴ S△AOB=(1/2)|α|·|β|sin(3π/4)=(1/2)|α|.
又∵ |α-2|=1, ∴ 可設(shè)α=2+cosφ+isinφ, 則|α|=
∴ S△AOB=(1/2)(5+4cosφ).
當cosφ=-1,即α=1,β=-1-i時,Smin=(1/2);當cosφ=1,即α=3,β=-3-3i時,Smax=(9/2).
若明確|α-2|=1是以(2,0)為圓心,1為半徑的圓的復(fù)數(shù)方程時,可畫出圖形,由圖形的直觀性可立即得出結(jié)果.
①在由|z-a|=r(a∈R)求|z|的最值時,可作出z=a+r(cosα+isinα)的巧妙變換,即可將求復(fù)數(shù)模的最值轉(zhuǎn)化為求三角函數(shù)式的最值,然后利用三角函數(shù)的有界性求解;,2
②若能注意到復(fù)平面內(nèi)一些特殊曲線的方程,畫出圖形后就可簡化求解過程.
三、專題訓(xùn)練
1.在復(fù)平面中設(shè)復(fù)數(shù)-3+3i對應(yīng)的點是P,以原點為極點,實軸正半軸為極軸,建立極坐標系.那么點P的極坐標是().
A.(B.(-
3,(3π/4)),(5π/4))
C.(3,(5π/4))
D.(-3,(3π/4))
2.設(shè)z1=-1,z2=(1/2)+(/2)i,則z1、z2、、所對應(yīng)的點:①在單位圓12
上;②它們是正方形的頂點;③它們關(guān)于y軸對稱;④它們可構(gòu)成正三角形.以上說法中,正確的只有().
A.①
B.③
C.①③
D.①④
3.設(shè)復(fù)數(shù)z=sin(π/6)+icos(π/6),若zn=
A.
3B.
4C.
5D.6
4.已知等邊三角形ABC的面積等于
虛軸正半軸上,則向量,若把三角形放到復(fù)平面中,使A點重合于原點,AB邊落在,則自然數(shù)n的最小值是(). 所對應(yīng)的復(fù)數(shù)是().
A.1+
B.1-
C.
D.±i i+i +i
25.設(shè)復(fù)數(shù)z=cosθ+(2-sinθ)i,當θ∈(-(π/2),(π/2))時,復(fù)數(shù)z在復(fù)平面內(nèi)對應(yīng)點的軌跡的方程是________.
6.設(shè)復(fù)數(shù)z在復(fù)平面內(nèi)對應(yīng)的點為Z,將點Z繞坐標原點按逆時針方向旋轉(zhuǎn)(π/4),再沿實軸正方向平移1個單位,向上平移1個單位,得到點z1.若點z1與點Z重合,則復(fù)數(shù)z的值等于________.
7.已知輻角分別為θ1、θ2的復(fù)數(shù)z1、z2滿足z1+z2=5i,|z1·z2|=14,則cos(θ1-θ2)的最大值是________.
8.設(shè)O為復(fù)平面的原點,A、B為單位圓上兩點,A、B所對應(yīng)的復(fù)數(shù)分別為z1、z2,z1、z2的輻角主值分別為α、β.若△AOB的重心G對應(yīng)的復(fù)數(shù)為(1/3)+(1/15)i,求tg(α+β).
9.如圖6-3,B是半圓O上的動點,OB=1,OA=2,△ABC是等腰直角三角形,BC為斜邊,建立適當?shù)淖?/p>
標系,利用復(fù)數(shù)求點B對應(yīng)何復(fù)數(shù)時,O、C兩點距離最大,并求此最大值.
圖6-
310.在平行四邊形OABC中,各頂點對應(yīng)的復(fù)數(shù)zO、zA、zB、zC依次是0、2+(a/2)i、-2a+3i、-b+ai(a,b∈R),求平行四邊形OABC的面積.