2012练习册四解答
(2012秋)七年级练习册答案

A beautiful girl opened a book and it began to talk. Finally, I visited the Cooking Club. A girl put some food in a magic cooker, said some words, and opened the door. There was now a delicious cake in it. I like the Cooking Club best because I like to eat chocolate cakes very much. Integration
A 1 F In the Flying Club, Janet learnt to fly in the air like a bird. 2T 3T 4 F The people below looked very small to her. 5 F Flying was wonderful, but sometimes it was a bit dangerous. 6T
B
1 in 1978 2 last winter 3 in April 4 on Saturday afternoon 5 at 12:30 6 three days ago 7 yesterday 8 at midnight
C1
1 did, start 2 didn't start 3 started 4 didn't shout 5 Did, run 6 did, see
A3 1 Did you leave home early this morning? 2 When did you have lunch? 3 Did you return the book to the library yesterday? 4 What time did you come home? 5 When did you finish your homework? 6 Did you go to bed late last night?
2012届九年级英语综合试题4及答案

2012届九年级英语综合试题4(满分150分, 考试时间100 分钟)考生注意:本卷有9大题,共99小题。
试题均采用连续编号,所有答案务必按照规定在答题纸上完上,做在试卷上不给分。
Part 1 Listening (第一部分,听力)I. Listening Comprehension听力理解: (共30分)A. Listen and choose the right picture. (根据你听到的内容,选出相应的图片) (共6 分)(B) (C) (D)(F) ,(G)1. _________2. _________3._________4._________5. __________6. _________B. Listen to the dialogue and choose the best answer to the question you hear. (根据你所听到的对话和问题,选出最恰当的答案) (10分)( )7. A) The picnic. B) Theholiday plan.C) The weather today. D)The weather tomorrow.( ) 8. A) Every day B) Twice aday.C) Once a week. D) Twice a week.( ) 9. A) She stayed at home.B) She went shopping.C) She went fishing. D) She watched a match.( ) 10. A) No, she won’t B) Yes, she will.C) I don't know. D) She will go over hislessons.( )ll. A)100yuan. B) 120 yuan.C) 140 yuan. D) 160 yuan.( ) 12. A) Forty-five minutes. B) Fifteen minutes.C) Five minutes. D) Fiftyminutes. ( ) 13. A) Because his car isbroken.B)Because of the weather and the traffic.C)Because he sleeps late at night.D)Because he gets up too late.( ) 14. A) By train. B) By plane.C) On foot. D)By bus/( ) 15. A) At 9:50. B) At 10:00.C) At 10: 10. D) At 10:30.( ) 16. A) She is a nurse. B) She is a dentist,C) She is a bank clerk. D) She is abusinesswoman.C.L isten to the passage and tell whether the following statementsare true or false. (判断下列句子是否符合你所听到的短文内容,符合的用“T”表示,不符合的用“F”表示)(共7分)( ) 17. Everyone in the world enjoys sports.( ) 18. Sports help people to keep healthy andlive happily.( ) 19. People have different sports indifferent seasons.( ) 20. Sports don't change with the season.( ) 21. The Arabs don't like horses or camels.( ) 22. The Arabs use horses and camels not only in their work but also in their sports.( ) 23. People from different countries can be good friends after a game.D.Listen to the passage and fill in the blanks. (根据你所听到的短文内容,完成下列句子,每空格限填一词)(共7分)24.Here are some _____ o n how to help people when a fire happens.25.If there is a fire, everyone should ___________ t he escape planto get out.26.People do fire practice because they need to teach their childrenabout fire_________.27.D on't open a hot door! The fire can grow more ________if you openthe door.28.Stay close to the floor! Smoke can be more ________ than fire.29.Stop, drop, roll are the right steps you should take when yourhair or__________catch fire.30.There are quite a few possible causes for fires. A wise familyis always________ for a fire.Part 2 Vocabulary and Grammar(第二部分词汇和语法)II. Choose the best answer (选择最恰当的答案) : (ft 20 分)31. It's so hot. Let's go for __________swim, shall we?A)/ B)a C)an D)the32.1 hear our head teacher will be back from USA three weeks' time.A)at B) of C)in D)with33. The poor girl has to depend on _ for living because her parents/areboth ill in bed.A) she B) her C) hers D)herself34. of the money will go to the Red Cross to help those who need help.A) Many B)Much C) A little D)A few35. E very citizen should be responsible___________ his behaviors.A)for _____ B)with C)on D)to36._________can stop the young mean from going to Guangzhou towatch the basketball match.A) Something B) Nothing. C) Anything D)Everything37. Your grandpa usually wears glasses when he readsnewspapers,_________?A) hasn't he B) has he C) doesn't he D) does he38. ___________________________________ Do you think which means of transport is __________________________ , the underground or the plane?A) safe B) safety C) safest D) the safest39. ______________________________________ The story took place in Italy many years ago, ____________________ many people still remember it.A) so B) or C)but.D) and40. ___________________ Will you help him you.see an old man lying in the middle of the street?A) though B)when C) because D) unless41. —_____ do you Study German?—By listening to tapes.A) How B) Where C) When D) Why42. ____________________ The famous singer seven tour concerts sincethis May.A) gives B)gave C) is giving D)has given43. The 2011 Nobel Prize for Medicine _____________to three scientists last month.A) awards B) awarded C) was awarding D) was, awarded44. ___________________ W ould you mind another cup ofcoffee? _______________A) have B) having C) to have D)had45. — Must I finish my homework before I go to play basketball ?—Yes, you _____ .A) needn't B) can't C)must D)may46. Mum told his son ____ too much time on computer games.A) not spend B) not spending C) don't spend D) not tospend47. There ______ o nly three little dogs and a small cam that small petshop.A) am B)is C)are D)be48. Could vou tell me ___ ?A) when will the next bullettrain leave for NanjingB) when the next bullet trainwill leave for NanjingC)when would the next bullet train leave for NanjingD)when the next bullet train would leave for Nanjing49. —Are you sure you can do well intomorrow's test, Anna?—I've got everything ready.A) It's hard to say. B) I'm afraid not.C)I think so. D) I hope not.50. — May I nave your name?----______________.A) Yes, please. B) All right.C) Of course. D) Call me Yang, please.III. Complete the following passage with the words or phrases in the box. Each word can only be used once(将下列单词或词组填入空格。
2012教师资格证考试练习册题及答案—教学法

单选1布鲁纳所提倡的学习方法是(发现学习)2 20世纪70年代,合作学习兴起于(美国)3 20世纪70年代兴起于美国的学习方法是(合作学习)4兴起于美国的合作学习是在(20世纪70年代)5衡量默读能力的主要标准是对内容的(理解)6心理学家M﹒维特海默、W﹒苛勒、K﹒科夫卡提出的学历理论是(格式塔学习理论)7场学习理论的主要代表人物是德国的拓扑心理学家(K﹒勒温)8研究性学习强调(以学生为主)9研究性学习的基本特征是(实践性)10联结学习理论的主要代表人物是美国的心理学家(桑代克)11在理解和不漏内容的前提下,快速吸取书中内容的读书方法是(速度)12学习者为社会无偿做事奉献的有益的活动是(社会服务活动)13根据艾宾浩斯曲线,遗忘具有先快后慢的规律,因此,复习必须(及时)14在老师指导下学生亲自进行实践操作的学习活动是(实习作业活动)15备课的主要形式(个人备课)16教师在课堂教学活动开始时,有意识,有目的地引导学生引入新的学习时境的一种方式是(导入技能)17用线条,箭头,符号等组成某种文字图形的板书方式是(图示式板书)18收音机,扩音机,无线话筒,录音机等,以及相应的教学软件属于(音响媒体)19备课最深入,最具体的一步是(编写教案)20教师在课堂上利用幻灯,实验,图画,挂图,游戏等各种手段导入教学称为(情景式导入)21电影放映机,电视机,录像机等以及相应的教学软件属于(声像媒体)22语言实验,程序教学机,学习反映分析机,多媒体系统等及相应的教学软件属于(综合媒体)23意在引导学生从不同方向,不同角度,不同侧面进行思考的提问方式是(扩展式提问)24备课的辅助形式是(集体备课)25教师采用讲故事,做游戏,放录像等方式结尾称为(趣味性结尾)26按备课的时间,备课分为(课前备课)27幻灯机,投影仪以及相应的教学软件属于(光学媒体)28根据学生的回答进行追问,一直打到理想结果的提问方法是(跟踪式提问)29把教学内容的一系列要点从教材中提炼出来,书写在黑板上的板书方式是(提要式板书)30以教学内容的线索为板书的主体,其他内容书写与线索相关的位置上的板书方式是(线索式板书)31通过上下,左右两部分整体对称的排列,以区别相似或相异的教学内容的板书方式是(对称式板书)32基于信息技术支持的采用新型教学模式和教学方法的教学形式是(网络教学)33教师备课的中心是(钻研教科书)34教师备课不仅要备知识,备学生,而且要备(方法)35成长记录袋评价的特点是(反思性)36教育中应有最为广泛的评价方法是(纸笔测验)37安徽省芜湖铁路中学马章老师实现教学过程整体优化提出的教学方法是(层层深入,以线穿珠)38内蒙古达拉特旗民族中学樊向阳老师提出的教学方法是(引探式教学法)39江苏省姜堰市愈多乡初中翁如荣老师提出的教学方法是(三思三探式)40山东省鱼台县实验中学黄的陈老师提出的教学方法是(六环节教学方法)41江苏省扬州市第五中学陈玲玲老师提出的教学方法是(审美教学方法)42内蒙古海拉尔市教研工作者经过几年的改革试验提出的教学方法是(“引疑五步”教学法)43山东省东营市垦利县董集乡罗嘉小学盖永胜老师提出的教学方法是(五阶段教学法)44江苏省徐州市二十四中学徐娅萍老师提提出的教学方法是(三读式教学方法)45江苏省东海县中学将运盛老师提出的教学方法是(观察,论证,比较,应用,四步教学法)46山东省齐河县华店中学黄德臣老师提出的教学法是(导学式教学法)47教学方法的表达手段是(语言)。
2012练习册答案

KeysTest 7Part I Vocabulary and Structure1. D2. B3. C4. B5. D6. A7. D8. C9. B 10. A 11. D 12. C 13. B 14. A 15. A 16. B 17. B 18. D 19. A 20. BPart II Listening ComprehensionSection A 1-8 ACDCAADB 9-12 DDBA 13-15 ACDSection B 16-18 AAD 19-22 BDCA23-25 BDASection C 26. summed 27. mystery 28. senses 29. tasted30. similarly 31. harmless 32. masses 33. completely34. Your body will replace the dead cells with healthy ones.35. Serious damage can be done without the victim being aware at the time that damage has occurred36. Or a child can be born weak or liable to serious illness as a result of radiation absorbed by its grandparents.Part III Reading Comprehension (Reading in Depth)Section A 1—5 B E F G I 6—10 K N A J DSection B1—5 B A C B D 1—5 C C A B CPart IV Cloze1)D 2)B 3)A 4)C 5)B 6)C7)B 8)D 9)A 10)B 11)A 12)D13)C 14)A 15)B 16)C 17 )A 18)C19)A 20)DPart V Translation1 No sooner had I lit the candle than / Hardly had I lit the candle when2 instead of cutting the costs of production3 would he break his promise / commitment to pay back the money4 should not be addicted to computer games. / should not indulge themselves in computer games / should not abandon themselves to computer games.5 were most impressed with / by his efficiencyTest 8Part I Vocabulary and Structure1. B2. D3. A4. C5. C6. A7. B8.D9. A 10. B 11. D 12. B 13. D 14. C 15. C 16. B 17. A 18. C 19. A 20. APart II Listening ComprehensionSection A 1-8 DCBBBDBD 9-12 CBDA 13-15 CBASection B 16-18 BBB 19-22 AABC 23-25CAASection C 26. headquarters 27. priceless 28. valuable antique 29. Consequently30. status 31. threat 32. journalist 33. accused34. He claimed that art treasure were being illegally exported to London on a regular basis,35. They will severely damage London’s credibility as a centre of the world’s art trade.36. If passed in Britain, the EU laws would make London a much less attractive place to purchase art treasures.Part III Reading Comprehension (Reading in Depth)Section A 1—5 H J A G B 6—10 D N I M KSection B 1—5 A D C B B 1—5 C A B D APart IV Cloze1) D 2)B 3) A 4) C 5) A 6)B7)D 8)C 9) B 10) D 11)B 12)D13)A 14)C 15)A 16) D 17 ) A 18)A19)C 20)APart V Translation1 only to be told that she couldn’t come by then2 nothing (should) be touched until the police arrived3 have they undergone / endured tremendous hardship in the travel4 the more concern we should draw to its safety5 despite repeated assurances that it is safeTest 9Part I Vocabulary and Structure1.B2.D3.C4.B5.D6.D7.B8.A9.D 10.D 11.A 12.C 13.D 14.C 15.B 16.B 17.A 18.B 19.B 20.A Part II Listening ComprehensionSection A 1-8 DADCBBCC 9-12 CCDA 13-15BDDSection B 16-18 CAA 19-22 DCAA23-25 AADSection C 26.confusing 27. achieve 28. nervous29.confidence 30.range 31.equipped32. audio 33. socially34. Most schools offer General English courses which are either part time—usually 15 hours per week—or full time, which can be as much as 40 hours.35. General English course also give students the chance to discover new parts of Britain.36. Wherever they go in Britain, they are assured high quality courses.Part III Reading Comprehension (Reading in Depth)Section A 1—5 B O I E M 6—10 K H A G CSection B 1—5 C C D A B 1—5 B C D C APart IV Cloze1) C 2) D 3) B 4)B 5) A 6)D7) C 8) A 9) B 10)A 11) D 12)A13)B 14) D 15) C 16) D 17 )A 18)D19) B 20) APart V Translation1 decided not to punish those students who had been late for class2 which made the others jealous3 falling export rates would have an impact on the economy4 this dispute (should) be resolved / settled as soon as possible5 forgetting to call in advance to cancel the dateTest 10Part I Vocabulary and Structure1. A2. B3. B4. C5. A6. C7. B8. D9. B 10. B 11. C 12. D 13. D 14. A 15. A 16. D 17. A 18. B 19. C 20. BPart II Listening ComprehensionSection A 1-8 CBCDA ADB 9-12 BDAD 13-15 BCDSection B 16-18 ABA 19-22 BBAA 23-25 BADSection C 26.awake 27. quiet 28. hillside 29. pot30. boiled 31. share 32. fragrant 33. grinding34. For only a little money, they could meet friends, play chess, talk, and discuss the news of the day.35. Coffeehouses became popular in America, when settlers from Europe brought the idea with them.36. In all the ways coffee is served, it has become an international drink.Part III Reading Comprehension (Reading in Depth)Section A 1—5 C I A K N 6—10 G E L H DSection B 1—5 C A B B D 1—5 C A D C DPart IV Cloze1) D 2) C 3)C 4)B 5) A 6)B7) D 8) A 9)B 10) C 11) D 12)B13) A 14) D 15)C 16)B 17 )C 18)D19) A 20) BPart V Translation1 He might have thought his speech convincing2 derives pleasure from helping others3 how much you will be charged for your services4 he is not so much a photographer than a painter / he is more of a painter than a photographer5 largely due to the poor managementTest 11Part I Vocabulary and Structure1.A2.B3.B4.D5.C6.B7.A8.A9.D 10.B 11.A 12.D 13.B 14.A 15.C 16.A 17.C 18.C 19.C 20.D Part II Listening ComprehensionSection A 1-8 CCBADBDC 9-12 CBCD 13-15 DBASection B 16-18 ACA 19-22 BDDA 23-25 BBCSection C 26. rough 27. otherwise 28. hanging29.leaving 30. weight 341. stiff32.elastic 33. slightly34. This is enough to save the ship from breaking into pieces.35. The boy had a bag of nuts beside him, and every time the ship was lifted by a wave and the joint opened.36. The boy then took it out and put the next one in a s the joint opened again.Part III Reading Comprehension (Reading in Depth)Section A 1—5 F G A M N 6—10 B L C J DSection B 1—5 C A A A C 1—5 A C B A APart IV Cloze1) C 2)B 3) B 4) D 5) C 6)B7) A 8)B 9) D 10) C 11) B 12)A13)C 14) D 15) B 16) A 17 ) A 18)C19) B 20) DPart V Translation1.Having been damaged in the earthquake2.should we give up pursuing knowledge /should we abandon the pursuit of knowledge3.Being asked to give a performance4.hoping that we could reach the airport on time / in hopes that we could arrive at the airport ontime5.become aware of its serious consequencesTest 12Part I Reading Comprehension (Skimming and Scanning)1-7 B C C D B C A8 apply to them and their kids9 go to bed hungry10 80 percentPart III Reading Comprehension (Reading in Depth)Section A 1—5 C D B O K 6—10 F I L A GSection B 1—5 C A C D C 1—5 D B A C CPart IV Cloze1) C 2) D 3) A 4) B 5) A 6)D7) B 8) C 9) C 10)A 11)D 12)B13) A 14)C 15) D 16)B 17 )B 18)A19) C 20)DPart V Translation1 would not have broken into my house2 did he begin to realize his mistakes3 completely lost in it4 being invited to attend the opening ceremony5 the less likely it is to do so。
2012春奥鹏学习手册习题册标准答案

二、多选题 1.现代远程学习中的学习媒体包括(ABCD ) A.文字教材 B.音像教材 C.计算机辅助课件 D.网络学习资源 2.积极的自我谈话的建议包括(ABCD ) A.列出自己的特长或成功事例 B.定期回顾自己的特长或成功事例 C.情绪低落时回顾自己的特长或成功事例 D.更新自己的特长或成功事例列表 3.对远程学生来说,利用录音带进行学习,有(AB )优势 A.可以随时随地学习 B.可以根据自己的需要控制学习的进度 C.可以使学习过程充满情趣和更具人性化 D.可以不用认真听讲 4.目前,网络学习资源包括(ABCD )等主要媒体形式 A.文本 B.音、视频 C、网络 CAI 课件 D.网上答疑讨论 5.高质量的多媒体网络课件,一般具有(ABD )等特点 A.整合性 B.交互性 C.多变性 D.结构灵活性
习题二 一、 单选题 1. 通过两个或两个以上的个体在一起从事学习活动,相互交流、相互促进,从而提高学习效果 的一种学习形式,我们称之为( C) A.远程学习 B.网络学习 C.协作学习 D.共同学习 2.(A )是检验学生在奥鹏学习效果的重要环节。 A.课程作业 B.课程论坛 C.学习课件 D.导学资料 3.网上个别学习的前提条件是(A ) A.利用因特网或校园网 B.利用计算机辅助教学软件 C.利用教育电视台的节目 D.利用 VCD 光盘 4.( D)对生物、地理和社会科学类科目的学习尤其有用。 A.概念图 B.文氏图 C.鱼骨图 D.层级图 5.在《远程学习引导》一书中,提到了一种深入分析具体学习内容的方法 ——“AEIOU”分析方 法,其中“A”代表的含义是( B) A.证据 B.假设 C.举例说明 D.独特 6.狭义的信息技术指(A ) A.20世纪中叶以来得到广泛使用的电子信息通信技术 B.早期视听技术中的幻灯和投影等 C.可以用来存储、处理、传播、接收和呈现各类信息的技术 D.造纸技术和印刷技术 7.一般来讲,网站中的 FAQ 是指(C ) A.留言板 B.000室 C.常见问题解答 D.论坛 8.HTML 的中文名称是(D ) A.虚拟现实语言 B.超文本编辑语言 C.数据操作语言 D.超文本标记语言 9.对远程学生来说,非学习性上网不包括(C ) A.阅读新闻 B.玩游戏 C.浏览课程论坛 D.和陌生人000 10.远程教育的基本特征是(A ) A.时空分离 B.教学分离 C.空间分离 D.时间分离
(2012秋)七年级练习册答案(第02单元)

C
1Y 2Y 3N 4Y 5N 6 DK 7Y 8N
A
1 get up 2 wash my face and brush my teeth 3 7 a.m. 4 go to school 5 have a lunch break 6 4 p.m.
7 play table tennis with my classmates 8 go home 9 have dinner 10 do my homework 11 go to bed
B 1T 2 F Ted drives to get all the newspapers first. 3 F Ted puts the newspaper in the letter box at his neighbour's front door. 4T 5 F Ted does this job because he enjoys/ loves it.
A
1 He is a scientist. 2 He goes to work on foot every day. 3 She flies to a different country every week. 4 She does not like getting up early. 5 His elder brother really likes sport, but he doesn't like it very much. 6 (Possible answer) Yes, I do. Because they don't do the same things as other families.
6 end 7 takes 8 practice 9 together 10 good
2012年高考英语模拟试卷4(含答案).pdf

课题3利用化学方程式的简单计算 一.学习目标: (1)在正确书写化学方程式的基础上,进行简单的计算。
(2)培养学生按照化学特点进行思维及审题、分析、计算能力。
(3)认识定量研究对于化学科学发展的重大作用。
二.学习重点: 根据化学方程式计算及书写格式要规范化 【课前预习】 1、写出下列反应的化学方程式 (1)用高锰酸钾加热的方法制氧气 (2)氢气和氧化铜加热条件下的反应 (用氯酸钾在二氧化锰作催化剂并加热的条件下制氧气 2、在4P+5O22P2O5的反应中, 份质量的磷跟 份质量的氧气起反应,生成 份质量的五氧化二磷。
利用化学方程式计算的依据是( ) A.化学方程式表示了一种化学反应过程 B.化学方程式表示了反应物、生成物和反应条件 C.化学方程式表示了反应前后反应物和生成物的质量关系 D.化学方程式表示了各反应物质量比等于各生成物质量比 ) A.40克 B.60克 C.80克 D.160克 通电 3.在2H2O2H2↑+O2↑的反应中,各反应物及生成物的质量比为( )A.2:2:1B.17:2:6C.36:4:32D.1:8:9 4.相同质量的H2、CH4和CO完全燃烧需要氧气的质量 ( ) A.CO最多,H2最少 B.H2最多,CH4最少 C.H2最多,CO最少 D.CH4最多,CO最少 5.氮化铝(AlN)被广泛应用于电子工业、陶瓷工业等领域。
在一定条件下,氮化铝可通过如下反应制得:Al2O3+N2+3C=2AlN+3CO,现欲制备13.3吨氮化铝,需要参加反应的氮气质量多少? 参考答案:1.C 2.D 3.C 4.C 5. 4.5t 初中学习网,资料共分享!我们负责传递知识!。
2012年英语教材答案汇总(修正改)

目录一语音知识讲解与练习................................................................................. 错误!未定义书签。
二情景对话常用句式及范例......................................................................... 错误!未定义书签。
三词法讲解与练习......................................................................................... 错误!未定义书签。
四语法讲解与练习......................................................................................... 错误!未定义书签。
五英汉翻译技巧讲解与练习 (151)第二部分解题指导与能力训练……………………………错误!未定义书签。
一词汇与语法知识解题指导与能力训练......................................................... 错误!未定义书签。
二完型填空解题指导与能力训练..................................................................... 错误!未定义书签。
三阅读理解解题指导与能力训练..................................................................... 错误!未定义书签。
四汉译英解题指导与能力训练......................................................................... 错误!未定义书签。
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一.判断题(正确打√,错误打×)1. 若54321,,,,ααααα都是b Ax =的解,则543218634ααααα-+-+是0=Ax 的一个解.(√)解答:因为54321,,,,ααααα都是b Ax =的解,所以b A j =α,5,4,3,2,1=j . 于是00)86341()8634(54321==-+-+=-+-+b b A ααααα, 所以543218634ααααα-+-+是0=Ax 的一个解.注: 设s ααα,,,21 都是b Ax =的解, s k k k ,,,21 为任意常数,则 当121=+++s k k k 时,s s k k k ααα+++ 2211是b Ax =的解; 当021=+++s k k k 时,s s k k k ααα+++ 2211是0=Ax 的解.2. 方程组0=⨯x A n m 基础解系的个数等于)(n m A R n ⨯-. (×) 解答:正确定义:方程组0=⨯x A n m 基础解系所含解向量的个数等于 )(n m A R n ⨯-.3. 若方程组0=Ax 有非零解,则方程组b Ax =必有无穷多解.(×) 解答:正确命题:若方程组0=Ax 有非零解,则当方程组b Ax =有解时,必有无穷多解.反例:方程组00=x 有非零解,但方程组10=x 无解.4. 0=Ax 与0=Ax A T 为同解方程组. (√) 解答:设α为0=Ax 的解,那么0=αA ,于是00==T T A A A α,所以α也是0=Ax A T 的解;反之,如果α为0=Ax A T 的解,那么0=αA A T , 记T m b b b A ),,(21 ,=α,于是0)()(22221=+++==m T T T b b b A A A A αααα,所以021====m b b b ,所以0=αA ,所以α也是0=Ax 的解,所以0=Ax 与0=Ax A T 为同解方程组.注: 此题也说明)()(A A R A R T =.5. 方程组b Ax =有无穷多个解的充分必要条件是b Ax =至少有两个不同的解. (√) 解答:如果方程组b Ax =有无穷多个解,显然方程组b Ax =至少有两个不同的解, 反之, 如果方程组b Ax =至少有两个不同的解21ηη,, 那么021≠-ηη, 并且)(21ηηξ-=c 都是0=Ax 的解, 其中c 为任意常数, 所以0=Ax 有无穷多个解, 而b Ax =有解, 所以b Ax =有无穷多个解.二. 单项选择题1. 设A 为)2(≥n 阶方阵,且1)(-=n A R ,21,αα是0=Ax 的两个不同的解向量,k 为任意常数,则0=Ax 的通解为 (C).(A )1αk ; (B )2αk ; (C ))(21αα-k ;(D ))(21αα+k . 解答:因为A 为n 阶方阵, 1)(-=n A R , 所以0=Ax 的基础解系含 1)1(=--n n 个解向量.而21αα-是0=Ax 的线性无关解, 所以0=Ax 的通解为)(21αα-=k x .2. 当(D)时,齐次线性方程组0=⨯x A n m 一定有非零解. (A )n m ≠; (B )n m =;(C )n m >; (D )n m <. 解答:如果n m <, n m A R n m <≤⨯)(, 所以0=⨯x A n m 存在非零解.3. 方程组⎪⎩⎪⎨⎧=++=++=++0003213213221x x x x x x x x x λλλλ的系数矩阵记为A ,若存在三阶方阵O B ≠,使得O AB =,则 (A) .(A )1=λ且0=B ; (B )1≠λ且0≠B ; (C )1≠λ且0=B ; (D )1=λ且0≠B .解答:记),,(321βββ=B , 因为O AB =, 所以3,2,1,0==j A j β,即 321βββ,,都是0=Ax 的解, 而O B ≠, 至少存在一个0≠i β, 所以0=Ax 存在非零解, 所以系数行列式0)1(011-1101C -C 111112132=--=λλλλλλλλλ,所以1=λ, 此时0=Ax 系数矩阵为⎪⎪⎪⎭⎫⎝⎛=111111111A , 1)(=A R ,所以0=Ax 的基础解系含2个解向量,所以321βββ,,线性相关,所以0=B .注:O AB =意味着矩阵B 的列向量都是方程组0=Ax 的解向量.4. 设A 为)2(≥n 阶奇异方阵,A 中有一元素ij a 的代数余子式0≠ij A ,则方程组0=Ax 的基础解系所含向量个数为 (B) . (A )i ; (B ) 1; (C )j ; (D )n . 解答:因为A 为奇异方阵,所以0=A ,又因为, A 中有一元素ij a 的代数余子式0≠ij A ,即A 中存在非零的1-n 阶子式,所以1)(-=n A R , 所以方程组0=Ax 的基础解系所含向量个数为1)1(=--n n .5. 设321,,ααα是b Ax =的三个解向量,3)(=A R ,T )4,3,2,1(1=α, T )3,2,1,0(32=+αα,k 为任意常数,则b Ax =的通解为 (C) .(A )⎪⎪⎪⎪⎪⎭⎫ ⎝⎛+⎪⎪⎪⎪⎪⎭⎫ ⎝⎛11114321k (B )⎪⎪⎪⎪⎪⎭⎫ ⎝⎛+⎪⎪⎪⎪⎪⎭⎫ ⎝⎛32104321k (C )⎪⎪⎪⎪⎪⎭⎫ ⎝⎛+⎪⎪⎪⎪⎪⎭⎫ ⎝⎛54324321k (D )⎪⎪⎪⎪⎪⎭⎫ ⎝⎛+⎪⎪⎪⎪⎪⎭⎫ ⎝⎛65434321k解答:显然方程组b Ax =有解,并且4=n ,所以1)(=-A R n .因此只要求出0=Ax 的一个非零解即可得到b Ax =的通解.而0)5,4,3,2()(2321≠=+-=T αααξ, 并且0=ξA , 所以b Ax =的通解为ξαk x +=1, 故选(C ).6. 已知⎪⎪⎪⎭⎫⎝⎛=96342321t Q ,P 为三阶非零矩阵且O PQ =,则 (C) .(A )当6=t 时P 的秩必为1;(B )当6=t 时P 的秩必为2;(C )当6≠t 时P 的秩必为1;(D )当6≠t 时P 的秩必为2.解答:O PQ =表明Q 的列都是方程组0=Px 的解,当6≠t 时,2)(=Q R ,所以2)(3≥-P R ,即1)(≤P R ,而O P ≠,即1)(≥P R ,所以1)(=P R . 三.填空题1. 设四阶方阵1(α=A 2α 3α )4α且4321ααααβ-+-=,则方程组β=Ax 的一个解向量为()T1,1,1,1--.解答:因为4321ααααβ-+-=1(α= 2α 3α )4α⎪⎪⎪⎪⎪⎭⎫⎝⎛=⎪⎪⎪⎪⎪⎭⎫ ⎝⎛1-11-11-11-1A ,所以方程组β=Ax 的一个解向量⎪⎪⎪⎪⎪⎭⎫⎝⎛1-11-1.2. 方程110021=+++x x x 的通解为1003211x x x x ----= . 解答:因为系数矩阵()10011,,1,1⨯= A , 所以100=n ,1)(=A R ,因此99)(=-A R n ,显然()T 10010,,0,1⨯ 是110021=+++x x x 的一个特解,所以110021=+++x x x 的通解为⎪⎪⎪⎪⎪⎪⎭⎫⎝⎛-++⎪⎪⎪⎪⎪⎪⎭⎫ ⎝⎛-+⎪⎪⎪⎪⎪⎪⎭⎫ ⎝⎛-+⎪⎪⎪⎪⎪⎪⎭⎫ ⎝⎛=10010101001100019921 k k k x .或者简单地:方程110021=+++x x x 的通解为 1003211x x x x ----= , 其中10032,,x x x 为任意实数.3. 设方程组b x A n n =⨯+)1(有解,则其增广矩阵的行列式b A = 0 . 解答:因为方程组b x A n n =⨯+)1(有解,所以n A R b A R n n n ≤=⨯++)())(()1(1, 所以0 =b A .或者因为方程组b x A n n =⨯+)1(有解,所以向量b 可由A 的列向量线性表示,所以0 =b A .4. 已知A 是3阶矩阵,2)(=A R ,若A 的每行元素和都是零,则方程组0=Ax 的通解为=x 为任意常数,k k ⎪⎪⎪⎭⎫⎝⎛111.解答:因为A 是3阶矩阵,2)(=A R , 所以1)(=-A R n .又因为A的每行元素和都是零, 所以0111=⎪⎪⎪⎭⎫ ⎝⎛A , 于是方程组0=Ax 的通解为=x ⎪⎪⎪⎭⎫ ⎝⎛111k .5. 已知方程组⎪⎪⎪⎭⎫ ⎝⎛=⎪⎪⎪⎭⎫ ⎝⎛⎪⎪⎪⎭⎫ ⎝⎛-+03121232121321x x x a a 无解,则=a -1 .解答:由于⎪⎪⎪⎭⎫⎝⎛--+-−→−⎪⎪⎪⎭⎫ ⎝⎛---−→−⎪⎪⎪⎭⎫⎝⎛-+311)3)(1(00101211-113201012103121232121a a a aa aa a 行行所以当31≠-≠a a 且时方程组有唯一解; 时方程组有无穷多解;3=a .1时方程组无解-=a6.设A 是43⨯矩阵,且A 的秩为3,若21,ηη为非齐次线性方程组b Ax =的两个不同的解,则它的通解为121)(ηηη+-k .解答:由于21,ηη为b Ax =的两个不同的解,所以21ηη-是0=Ax 的非零解,而1=-r n ,所以)(21ηη-k 是0=Ax 的通解,所以121)(ηηη+-k 是b Ax =的通解. 四. 计算题1.求齐次线性方程组⎪⎩⎪⎨⎧=++=-+=++000543321521x x x x x x x x x 的一个基础解系.解答:方程组的系数矩阵⎪⎪⎪⎭⎫⎝⎛--−→−⎪⎪⎪⎭⎫ ⎝⎛-=010001010010011111000011110011行A ,所以⎪⎩⎪⎨⎧=-=+-=.0,,453512x x x x x x 所以一个基础解系为⎪⎪⎪⎪⎪⎪⎭⎫ ⎝⎛-=000111ξ,⎪⎪⎪⎪⎪⎪⎭⎫ ⎝⎛--=101102ξ. 2. 解齐次线性方程组⎪⎪⎩⎪⎪⎨⎧=-+=++=++=++040330220321321321321x x x x x x x x x x x x .解答:因为方程组系数矩阵⎪⎪⎪⎪⎪⎭⎫ ⎝⎛−→−⎪⎪⎪⎪⎪⎭⎫ ⎝⎛-=000100010001411133212111行A ,所以⎪⎩⎪⎨⎧===000321x x x . 3. 求方程组⎩⎨⎧=-=+004221x x x x 与⎩⎨⎧=+-=+-00432321x x x x x x 的非零公共解.解答:构造方程组⎪⎪⎩⎪⎪⎨⎧=+-=+-=-=+00004323214221x x x x x x x x x x ,因为方程组系数矩阵⎪⎪⎪⎪⎪⎭⎫⎝⎛--−→−⎪⎪⎪⎪⎪⎭⎫⎝⎛---=000021*********11110011110100011行A , 所以两个方程组的非零公共解⎪⎪⎪⎪⎪⎭⎫⎝⎛-=1211k x ,其中0≠k .4.求解线性方程组⎪⎩⎪⎨⎧=+--=--+=--+4433089513432143214321x x x x x x x x x x x x .解答:⎪⎪⎪⎪⎪⎪⎭⎫⎝⎛----→⎪⎪⎪⎭⎫ ⎝⎛------=000004147231045432301443130895111311~A , 所以⎪⎩⎪⎨⎧-+=+-=414723454323432431x x x x x x ,所以⎪⎪⎪⎪⎪⎪⎭⎫ ⎝⎛-+⎪⎪⎪⎪⎪⎪⎭⎫ ⎝⎛-+⎪⎪⎪⎪⎪⎪⎭⎫ ⎝⎛=00414510474301232321k k x . 5. 解矩阵方程⎪⎪⎭⎫⎝⎛=⎪⎪⎭⎫ ⎝⎛1001132321X .解答:设⎪⎪⎪⎭⎫⎝⎛=332211y x y x y x X ,由⎪⎪⎭⎫ ⎝⎛=⎪⎪⎭⎫ ⎝⎛1001132321X 得到两个方程组⎩⎨⎧=++=++032132321321x x x x x x 及⎩⎨⎧=++=++132032321321y y y y y y ,注意到两个方程组的系数矩阵一样,所以记⎪⎪⎭⎫ ⎝⎛+---−→−⎪⎪⎭⎫ ⎝⎛---−→−⎪⎪⎭⎫ ⎝⎛=a b a b a b a b a A 2510327012510321132321行行,所以⎩⎨⎧=++=++032132321321x x x x x x 的通解为⎩⎨⎧+-=-=25373231x x x x ;⎩⎨⎧=++=++132032321321y y y y y y 的通解为⎩⎨⎧--=+=15273231x y x y .所以⎪⎪⎪⎭⎫ ⎝⎛--+-+-=33333315252737y x y x y x X ,其中33,y x 是任意常数.6.设⎪⎪⎪⎭⎫ ⎝⎛=1113102112c a A ,⎪⎪⎪⎭⎫⎝⎛=010b ,⎪⎪⎪⎪⎪⎭⎫⎝⎛--=1111η,如果η是b Ax =的一个解,求b Ax =的通解.解答:因为η是b Ax =的一个解,所以b A =η,所以c a =.⎪⎪⎪⎪⎭⎫⎝⎛---→⎪⎪⎪⎭⎫ ⎝⎛=a a a a a A 2121210011310021120111131002112~, 所以,当21==c a 时,⎪⎪⎪⎪⎪⎭⎫⎝⎛--→⎪⎪⎪⎭⎫⎝⎛→00000113102121101000001131002112~A , 所以⎪⎩⎪⎨⎧+--=--=132121432431x x x x x x ,所以⎪⎪⎪⎪⎪⎪⎭⎫ ⎝⎛-+⎪⎪⎪⎪⎪⎪⎭⎫⎝⎛--+⎪⎪⎪⎪⎪⎭⎫ ⎝⎛-=0012110121013121k k x ;当21≠=c a 时,⎪⎪⎪⎪⎪⎪⎭⎫ ⎝⎛--→⎪⎪⎪⎪⎭⎫ ⎝⎛→212110021210100100121211001131002112~A , 所以⎪⎪⎪⎩⎪⎪⎪⎨⎧+-=-=-=21212121434241x x x x x x ,所以⎪⎪⎪⎪⎪⎪⎭⎫ ⎝⎛-+⎪⎪⎪⎪⎪⎭⎫ ⎝⎛--=021*******k x . 7. 已知T a )1,1,1(1+=α,T a )1,1,1(2+=α,T a )1,1,1(3+=α,T a a ),,0(2=β,讨论当a 为何值时:(1)β可由321,,ααα线性表示,且表示法唯一;(2)β可由321,,ααα线性表示,但表示法不唯一,并给出表示式;(3)β不能由321,,ααα线性表示.解答:考虑方程组⎪⎩⎪⎨⎧=+++=+++=+++2321321321)1()1(0)1a x a x x a x x a x x x x a (,因为 2)3(0000111)3(111111111)3(111111111a a aa a a a a a a a +=+=+++=+++,所以当30-≠≠a a 且时,β可由321,,ααα线性表示,且表示法唯一.当0=a 时,方程组变为0321=++x x x ,通解为123x x x --=,所以β3212211)(αααc c c c +-+=,其中21,c c 为任意实数.当3-=a 时,增广矩阵为⎪⎪⎪⎭⎫ ⎝⎛---−→−⎪⎪⎪⎭⎫ ⎝⎛----921131216000921131210112行, 增广矩阵的秩为3,系数矩阵的秩为2,所以β不能由321,,ααα线性表示.8. 设⎪⎪⎪⎭⎫ ⎝⎛-=λλλ1101011A ,⎪⎪⎪⎭⎫ ⎝⎛=11a b . 已知线性方程组b Ax =存在两个不同的解,(1)求a ,λ;(2)求方程组b Ax =的通解.解答:因为方程组b Ax =存在两个不同的解,所以0)1()1(11010112=+-=-=λλλλλA ,所以11-==λλ或者. 当1=λ时,⎪⎪⎪⎭⎫ ⎝⎛=11111000111)(a b A ,方程组无解;所以1=λ时无解;当1-=λ时⎪⎪⎪⎭⎫ ⎝⎛+--−→−⎪⎪⎪⎭⎫ ⎝⎛+--−→−⎪⎪⎪⎭⎫ ⎝⎛---=200010201111020102011111111020111)(a a a a a b A 行行所以当2-=a 时有无穷多解,通解为⎪⎩⎪⎨⎧-=+=2123231x x x ,即⎪⎪⎪⎪⎪⎪⎭⎫ ⎝⎛-+⎪⎪⎪⎭⎫ ⎝⎛=02123101k x .9.线性方程组⎪⎩⎪⎨⎧-=+-+-=-++=-+1)1(233)3(21321321321a bx x a x x x a x x x x 当b a ,为何值时,无解、有唯一解、有无穷多解?并在有有无穷多解时求解. 解答:)1)(1(3)1(2011011112332111-+=-+-+-=---+-=b a b a a b a a A ,所以当1-≠a 且1≠b 时,方程组有唯一解;当1-=a 时,⎪⎪⎪⎭⎫ ⎝⎛--→⎪⎪⎪⎭⎫ ⎝⎛-----=20001100001122233221111b b A , 所以当2≠b 时无解,当2=b 时,⎩⎨⎧-=-=1321x x x ,通解为⎪⎪⎪⎭⎫ ⎝⎛-+⎪⎪⎪⎭⎫ ⎝⎛-=100011k x ; 当1=b 时,⎪⎪⎪⎭⎫ ⎝⎛-+-→⎪⎪⎪⎭⎫ ⎝⎛----+-=a a a a a A 00011101111111233321111,所以当0≠a 时无解,当0=a 时,⎩⎨⎧+==10321x x x ,通解为⎪⎪⎪⎭⎫ ⎝⎛+⎪⎪⎪⎭⎫ ⎝⎛=010110k x . 综合得到:(1) 当1-≠a 且1≠b 时,方程组有唯一解;(2) 当1-=a 且2≠b ,或者0≠a 且1=b ,方程组无解;(3) 当1-=a 且2=b ,或者0=a 且1=b ,方程组有无穷多解,通解分别为⎪⎪⎪⎭⎫ ⎝⎛-+⎪⎪⎪⎭⎫ ⎝⎛-=1000111k x 及⎪⎪⎪⎭⎫ ⎝⎛+⎪⎪⎪⎭⎫ ⎝⎛=0101102k x .。