专升本练习题4
生产和运作管理(专升本)阶段性作业4
生产与运作管理(专升本)阶段性作业4总分: 100分考试时间:分钟单选题1. 供应链成员间缺乏同步性的效果是_____。
(4分)(A) 提前购买(B) 持续补充(C) 牛鞭效应(D) 时钟效应参考答案：C2. 做外包决策时，公司要避免什么_____。
(4分)(A) 取消非核心业务(B) 提供机会使得外包合作企业成为强有力竞争者(C) 允许雇员加入外包合作企业(D) 允许外包合作企业参与创新设计参考答案：B3. 供应链响应时间是对哪项标准的衡量_____。
(4分)(A) 系统的可靠性(B) 柔性(C) 设备利用率(D) 产品质量参考答案：D4. 供应链的组成包括_____。
(4分)(A) 供应商(B) 顾客(C) 内部供应链(D) 以上都是参考答案：D5. 供应链管理下的采购与传统采购不同在于_____。
(4分)(A) 为库存采购(B) 与供应商是一般买卖关系(C) 与供应商结成战略伙伴关系(D) 让供应商竞争已得利参考答案：C6. 项目管理主要是控制_____。
(4分)(A) 质量(B) 进度(C) 成本(D) 以上都是参考答案：D7. 关键路线是_____。
(4分)(A) 活动最多的路线(B) 节点最多的路线(C) 时间最长的路线(D) 将时间时差为零的节点连起来的路线参考答案：C8. 事件时差是_____。
(4分)(A) 最悲观时间和最乐观时间之差(B) 结束时间和开始时间之差(C) 事件最迟时间和最早时间之差(D) 以上都是参考答案：C9. 以下哪一条是项目的特点_____。
(4分)(A) 一次性(B) 重复(C) 产出是标准的(D) 重复性工作多参考答案：A10. 活动的最早可能完成时间是_____。
(4分)(A) 该活动箭头事件的最早可能发生时间(B) 该活动箭尾事件的最早可能发生时间(C) 该活动箭头事件的最迟必须发生时间(D) 该活动箭尾事件的最早可能发生时间加上活动所需时间参考答案：D判断题11. 供应链是纵向（垂直）一体化的产物。
专升本复习题4
专升本复习题四一、判断正误题1、通常所说的CPU芯片包括控制器、运算器和寄存器组。
√2、ASCII码的作用是把要处理的字符转换为二进制代码,以便计算机进行传送和处理。
√3、计算机病毒只能通过可执行文件进行传播。
×4、程序一定要调入内存后才能运行。
√5、在计算机内部，用"+"号表示正数。
×6、CAD指的是计算机辅助制造。
×7、程序设计语言是计算机可以直接执行的语言。
×8、在Windows中按Shift+空格键，可以在英文和中文输入法之间切换。
×9、Windows允许文件名最多有255个字符，可以使用空格。
√10、在字号中，磅值越大，表示的字越大。
√11、单击菜单中带有省略号(...)的命令会产生一个对话框。
√12、WORD只能编辑文档，不能编辑图形。
×13、若COUNT（A1：A3）=2，则COUNT（A1：A3，3）=5 。
×14、在Excel中不仅可以进行算术运算，还提供了可以操作文字的运算。
√15、在Excel工作表中，自动填充不能填充序列：零件1、零件2、零件3、零件4….√16、在Excel工作表中可以完成超过三个关键字的排序。
×17、PowerPoint在放映幻灯片时，必须从第一张幻灯片开始放映。
×18、E-Mail地址的格式是主机名@域名。
×19、IP协议对应OSI七层协议的传输层×。
20、/default.htm中http是一种传输协议。
√二、单项选择题1、10进制数127转换为8进制数是( B )A、157B、177C、167D、2072、通常所说的主机主要包括( B )A、CPUB、CPU和内存C、CPU、内存与外存D、CPU、内存与硬盘3、在计算机系统中，衡量内存大小的单位是( B )A、二进制位B、字节C、汉字数量D、字4、某台微机的硬盘容量为1GB，其中G表示（C ）A、1024KBB、1024MBC、1000MBD、1000KB5、某单位人事管理系统程序属于（C ）。
操作系统专升本考试(习题卷4)
操作系统专升本考试(习题卷4)第1部分：单项选择题，共72题，每题只有一个正确答案,多选或少选均不得分。
1.[单选题]实现“按名存取”属于操作系统中的 ( )A)处理器管理B)存储管理C)文件管理D)设备管理答案:C解析:2.[单选题]进程间高级通信机制有共享存储器系统、消息传递系统和（）。
A)信箱通信B)数据通信C)管道通信D)协议通信答案:C解析:3.[单选题]终端用户的注册过程就是对终端作业的( )A)作业调度B)进程调度C)中级调度D)内存调度答案:A解析:4.[单选题]分配到必要的资源并获得处理机时的进程状态是（）。
A)就绪状态B)阻塞状态C)执行状态D)新状态答案:C解析:5.[单选题]进程是( )。
A)与程序等效的概念B)并发环境中程序的执行过程C)一个系统软件D)存放在内存中的程序答案:B解析:6.[单选题]在多进程的系统中,进程以不可预知的速度向前推进,这种特性称为进程的( )A)动态性D)同步性答案:C解析:7.[单选题]对如图所示的内存分配情况(其中,阴影部分表示已占用块,空白部分表示空闲块),若要申请一块40KB的内存,对于最佳适应算法,给出分配区域的首地址______。
A)100KBB)190KBC)330KBD)410KB答案:C解析:8.[单选题]同步机制应遵循的准则不包括A)空闲让进B)忙则等待C)无限等待D)让权等待答案:C解析:本题主要考查的知识点为同步机制应遵循的准则。
同步机制应遵循的准则有:(1)空闲让进。
(2)忙则等待。
(3)有限等待。
(4)让权等待。
9.[单选题]设m为同类资源R的数目，n为系统中的并发进程数。
当n个进程共享m个互斥资源R时，每个进程对R的最大需求是w；则下列情况会出现死锁的是（ ）。
A)m=2,n=1,w=2B)m=2,n=2,w=1C)m=4,n=3,w=2D)m=4,n=2,w=3答案:D解析:10.[单选题]在下列死锁的解决办法中,属于预防死锁策略的是____。
点动词专升本练习题
点动词专升本练习题### 专升本练习题：点动词解析点动词，也称为瞬间动词或非延续性动词，是指表示动作发生但不会持续进行的动词。
这类动词通常不能与时间段连用，而只能与时间点连用。
以下是一些专升本练习题，帮助学生更好地理解和掌握点动词的用法。
#### 练习一：选择正确的点动词1. The company launched a new product line last month.- A. launched- B. was launching- C. has launched2. She arrived at the airport just in time for her flight. - A. arrived- B. was arriving- C. has arrived3. He broke his leg while playing soccer.- A. broke- B. was breaking- C. has broken#### 练习二：用点动词完成句子1. The concert ________ (开始) at 8 p.m. sharp.2. I ________ (收到) your email yesterday morning.3. They ________ (完成) the project before the deadline.#### 练习三：将下列句子转换为点动词形式1. The train is leaving. → The train left.2. She is graduating. → She graduated.3. They are moving. → They moved.#### 练习四：判断下列句子是否正确使用点动词1. Correct: The company was established in 1995.- 错误：The company is establishing in 1995.2. Correct: He has passed the exam.- 错误：He is passing the exam.3. Correct: She got married last year.- 错误：She is getting married last year.#### 练习五：填空并解释为什么选择该点动词1. The athlete ________ (跳) over the high jump bar. 选择此动词的原因是：_______2. The baby ________ (哭) when it was hungry. 选择此动词的原因是：_______3. The lights ________ (亮) up as soon as the room went dark. 选择此动词的原因是：_______#### 练习六：改错1. The teacher is explaining the lesson. → The teacher explained the lesson.2. They are buying a new house. → They bought a new house.3. She is becoming a doctor. → She became a doctor.#### 结语通过以上练习，学生可以加深对点动词的理解，掌握其在不同语境中的恰当使用。
高数练习题专升本广东
高数练习题专升本广东### 高数练习题：专升本广东#### 一、选择题（每题4分，共20分）1. 若函数 \( f(x) \) 在点 \( x_0 \) 处的导数存在，则 \( f(x) \) 在 \( x_0 \) 处一定连续。
（）A. 正确B. 错误C. 不确定D. 无法判断2. 函数 \( f(x) = x^2 - 4x + 4 \) 的最小值是（）。
A. 0B. 4C. -4D. 13. 曲线 \( y = x^3 - 3x^2 + 2 \) 在 \( x = 1 \) 处的切线斜率是（）。
A. 0B. 1C. -1D. 24. 函数 \( f(x) = \sin(x) \) 的不定积分是（）。
A. \( -\cos(x) + C \)B. \( \cos(x) + C \)C. \( \sin(x) + C \)D. \( \tan(x) + C \)5. 极限 \( \lim_{x \to 0} \frac{\sin(x)}{x} \) 的值是（）。
A. 0B. 1C. \( \infty \)D. 不存在#### 二、填空题（每题4分，共20分）1. 函数 \( f(x) = e^x \) 的导数是 \( \_\_\_\_\_\_ \)。
2. 函数 \( y = \ln(x) \) 的反函数是 \( \_\_\_\_\_\_ \)。
3. 曲线 \( y = x^2 \) 在点 \( (1, 1) \) 处的切线方程是\( \_\_\_\_\_\_ \)。
4. 定积分 \( \int_{0}^{1} x^2 dx \) 的值是 \( \_\_\_\_\_\_ \)。
5. 函数 \( y = \tan(x) \) 在 \( x = \frac{\pi}{4} \) 处的导数值是 \( \_\_\_\_\_\_ \)。
#### 三、解答题（每题15分，共40分）1. 求函数 \( f(x) = x^3 - 3x^2 + 2x \) 的极值点。
专升本中计算机练习题
专升本中计算机练习题一、选择题1. 在计算机中，字节（Byte）是最基本的存储单位，1字节等于多少位（bit）？A. 4位B. 8位C. 16位D. 32位2. 下列哪个不是操作系统的功能？A. 文件管理B. 设备管理C. 程序编译D. 进程管理3. 计算机网络中，IP地址的主要作用是什么？A. 标识网络设备的唯一性B. 传输数据C. 连接网络D. 存储数据4. 在数据库管理系统中，SQL代表什么？A. Simple Query LanguageB. Structured Query LanguageC. Standard Query LanguageD. Sequential Query Language5. 下列哪个是计算机病毒的特征？A. 无传染性B. 无破坏性C. 无潜伏性D. 有传染性二、填空题6. 计算机的三大基本组成部分是______、______和______。
7. 在计算机系统中，______是连接硬件和软件的桥梁。
8. 数据加密的目的是保证数据的______和______。
9. 在网络通信中，______协议是用于在互联网上进行数据传输的协议。
10. 数据库设计通常分为______、______和______三个阶段。
三、简答题11. 简述计算机操作系统的五大基本功能。
12. 解释什么是计算机网络，并列举其主要功能。
13. 描述数据库管理系统（DBMS）的主要作用。
14. 什么是程序设计语言？请列举至少三种常用的程序设计语言。
15. 什么是计算机病毒？请简述其传播途径和预防措施。
四、计算题16. 假设一个计算机系统的内存地址空间为64GB，如果每个内存单元存储1个字节，那么该系统最多可以存储多少个内存单元？17. 如果一个文件的大小为1.5GB，而一个存储设备的容量为500GB，请计算该存储设备最多可以存储多少个这样的文件？五、论述题18. 论述计算机硬件和软件之间的关系，并给出一个实际的例子。
成人高考专升本《英语》练习题及答案解析(4)
成人高考专升本《英语》练习题及答案解析(4)1. Motorists _____ of speeding may be banned from driving for a year.A. convictedB. arrestedC. chargedD. judged[答案] A. convicted.[注释]be convicted to 被判有...... (罪) ：He was convicted of murder. (他被法院判有谋杀罪。
)2. The reason why he adapted to the new situations quickly is that he has a _____ attitude.A. changeableB. alternateC. movableD. flexible[答案] D. flexible.[注释] flexible 灵活的, 可变通的; We need a foreign policy that is more fle xible.3. Will all those _____ the proposal raise their hands?A. in relation toB. in excess ofC. in contrast toD. in favor of[答案] D. in favor of.4. An early typewriter produced letters quickly and neatly; the typist, ___ __ couldn't see his work on his machine.A. howeverB. thereforeC. yetD. although[答案] A. however.[注释] however 然而。
本题译文：早期的打字机打起字来又快又整齐, 然而打字员不能看着机器键盘打字。
专升本英语模拟试题 4
模拟试题（四）Part I Vocabulary and Structure ( 30 %)Directions: There are 30 incomplete sentences in this part. For each sentence there are four choices marked A) , B) , C) and D). Choose the ONE that best completes the sentence.1. He really objects so long.A. to waitB. at waitingC. to waitingD. waiting2. It's the first time that he has been to China, ?A. isn't heB. isn't itC. hasn't heD. hasn't it3. I'm able to do it than you are.A. moreB. betterC. muchD. nor4. His watch doesn't show the correct time, does my watch.A. notB. alsoC. eitherD. nor5. Jim was popular with those who would vote, and he was that he could win the election.A. confidenceB. confidentlyC. confidentD. to confident6. Would you mind me how to use this computer.A. to tellB. tellingC. tellD. told7.Even though they for twenty years. The two neighbors are not very friendly.A. having been lived side by sideB. having been living side by sideC. had been living side by sideD. have been living side by side8. Please look after the house and the flowers in my yard during my .A. absentB. absenceC. absentlyD. being absent9. I can him to you for the job. He is a very good worker.A. recommendateB. recommendableC. recommendationD. recommend10. He listened with to the beautiful music at the party.A. pleasureB. pleasedC. pleasurableD. pleasurably11. He was only one man in the city of lending you $10 000.A. capableB. ableC. willingD. generous12. We are so busy that we had to our vacation till next month.A. put awayB. put downC. put offD. put out13. Mrs. George took of the fine weather to do some washing.A. advantageB. chanceC. effectD. interest14. Don't to let me know if there is anything I can do for you.A. rejectB. refuseC. preventD. hesitate15. he realized it was too late to return home.A. No sooner it grew dark whenB. Hardly it grew dark thanC. It was not until dark thatD. Before it grew dark16. I writing the paper had I not run out of ink.A. finishedB. have finishedC. had finishedD. would have finished17. the fog, we should have reached our destination.A. In spite ofB. In case ofC. Because ofD. But for18. There was no reason the meeting yesterday.A. for you not attendB. for your not attendingC. for you not to attendD. for your not to attend19. Since he and I work in the same hospital, I can hardly avoid him.A. to meetB. to have metC. meetingD. having met20. -- Can you guess what kind of food there is?-- it is, I'm sure there is not much taste in it.A. WhateverB. HoweverC. WhereverD. Whoever21. One of Bettie's brothers was killed in action, another .A. takes prisonerB. took prisonerC. taken prisonerD. taking prisoner22. The visit to the school his memory of his childhood.A. brought aboutB. brought inC. brought forthD. brought back23. clear was his statement that it couldn't be misunderstood.A. TooB. EnoughC. MuchD. So24. , Jane couldn't help smiling.A. Being very angryB. Angry as she wasC. Angry even though she wasD. As she was very angry25. People are less superstitious than .A. they used toB. they are used to beingC. they used to beD. they are used26. Immediately behind the two cars was happened to be a learner. She suddenly gotinto a panic and stopped her car.A. a womanB. the womanC. a woman whoD. there was the woman who27. The coach, together with his team players, warmly welcomed when they got off the train.A. wereB. wasC. has beenD. be28. On second day, he had his car thoroughly before embarking on the journey.A. to be examinedB. being examinedC. examinedD. was examined29. There is no good too much every day.A. to drinkB. drinkingC. in drinkingD. being drunk30. as Johnny is, he's published five volumes of poems.A. A boy of tenB. A ten-year old boyC. Boy of tenD. Boy of ten-year old Part II Cloze (20%)Directions:For each blank in the following passage, there are four choices given below and marked A), B) , C) and D). Choose the one that is most suitable.Smoking, which may be a pleasure for some people, is a serious source of 31 for their fellows. Further. medical authorities express their 32 about the effect of smoking 33 the health not only 34 those who smoke but also of those who do not. In fact, nonsmokers who must 35 inhale the air polluted by tobacco smoke may 36 more than the smokers themselves.As you are doubtless 37 , a considerable number of our students have 38 in an effort to 39 the university to forbid 40 in the classrooms. I believe they are entirely right in their aim.41 I would hope that it is 42 to achieve this by 43 the smokers to use good judgment and show concern 44 others rather than by regulation.Smoking is 45 by City bylaws in theatres and in halls used for 46 films as well as in labs where there 47 be a fire hazard. Elsewhere it is up to your good sense.I am 48 asking you to maintain 49 in the auditoriums, classrooms and seminar rooms. This will prove that you have the nonsmokers' health and well-being 50 which is very important to a large number of our students.31. A. comfort B. uncomfortable C. discomfort D. misbehavior32. A. concern B. trouble C. interest D. displeasure33. A. on B. in C. with D. to34. A. to B. about C. with D. of35. A. involuntarily B. instinctively C. surprisingly D. reluctantly36. A. endure B. suffer C. undergo D. undertake37. A. alert B. awake C. aware D. informed38. A. linked B. connected C. associated D. joined39. A. make B. persuade C. cause D. tell40. A. smoking B. to smoke C. smoke D. to be smoked41. A. But then B. However C. Further D. Moreover42. A. able B. potential C. capable D. possible43. A. dwelling on B. sitting on C. insisting on D. calling on44. A. with B. for C. to D. in45. A. prohibited B. stopped C. suppressed D. discourage46. A. playing B. demonstrating C. showing D. exhibiting47. A. will B. shall C. may D. must48. A. hence B. therefore C. then D. however49. A. "No Smoking" B. "Smoking C. Non-smokers" D. "Free-smoking"50. A. in heart B. on mind C. in mind D. on your mindPart III Reading Comprehension ( 30 %)Directions: There are three reading passages in this part . Each passage is followed by some questions or unfinished statements. For each of them there are four choices marked A),B ) , C) and D). You should decide on the best choice.Passage One:Are some people born clever, and others born stupid? Or is intelligence developed by our environment and our experience? Strangely enough, the answer to these questions is yes. To some extent our intelligence is given to us at birth, and no amount of special education can make a genius out of a child born with low intelligence. On the other hand, a child who lives in a boring environment will develop his intelligence less than one who lives in rich and varied surroundings. Thus the limits of person's intelligence are fixed at birth, whether or not he reaches those limits will depend on his environment. This view, now held by most experts, can be supported in a number of ways.It is easy to show that intelligence is to some extent something we are born with. The closer the blood relationship between two people, the closer they are likely to be in intelligence. Thus if we take two unrelated people at random from the population, it is likely that their degree of intelligence will be completely different. If, on the other hand, we take two identical twins, they will very likely be as intelligent as each other. Relations like brothers and sisters, parents and children, usually have similar intelligence, and this clearly suggests that intelligence depends on birth.Imagine now that we take two identical twins and put them in different environments. We might send one for example, to a university and the other to a factory where the work is boring We would soon find differences in intelligence developing, and this indicates that environment as well as birth plays a part. This conclusion is also suggested by the fact that people who live inclose contact with each other, but who are not related at all are likely to have similar degree of intelligence.51. The writer holds the view that man's intelligence is given to him .A. at birthB. through educationC. both at birth and through educationD. neither at birth nor through education52. If a child is born with low intelligence, he can .A. become a geniusB. still become a genius if he should be given special educationC. exceed his intelligence limits in rich surroundingsD. not reach his intelligence in his life53. In the second paragraph "if we take two unrelated people at random from the population"means "if we "A. pick any two personsB. pick two persons after careful considerationC. choose two person who are relativeD. choose two person with average intelligence54. The example of the twins going to a university and to a factory separately showsA. the importance of their intelligenceB. the role of environment on intelligenceC. the importance of their positionsD. the part that birth plays55. The best title of this passage can be “”A. SurroundingsB. IntelligenceC. Dependence on EnvironmentD. Effect of EducationPassage Two:Above all higher education has traditionally been primarily for those who delight in knowledge for its own sake. Through the ages students have gathered around the greatest scholars of the time, not for the riches or power that knowledge might bring, but for the sake of wisdom that is the ability to understand and judge correctly. Those who seek after wisdom have always felt a need to withdraw from the world, at least for a time, and so traditional universities have to a considerable extent secluded themselves from the outer world, offering a peaceful heaven for those who wish to devote themselves to the affairs of the mind.However, in our own times this concept of higher education has been changing rapidly. A few centuries ago a university education was truly "universal"; one person could learn all there was to be known within his own culture, and all educated people shared a common background of knowledge and ideas. Today, on the other hand, because of the enormous expansion of knowledge in all fields, the mastery, of even one subject in its entirely has become impracticable. Studies have in consequence grown increasingly narrow in scope, and it has become necessary to set up specialized institutions like colleges of technology to cope with the new disciplines that have emerged. This fragmentation of knowledge tends to restrict communication amongst those working in different fields and means that individual scholars and students have a narrower range of interests and, therefore, a narrower view of life as a whole.56. Traditionally the main reason for pursuing higher education has been .A. desire of powerB. love of studyC. wish to withdrawal from the worldD. wish to improve one's conduct57. The main reward of higher education has been regarded as .A. richesB. statusC. happinessD. wisdom58. Narrow disciplines in modem times resulted from the fact that .A. intellectual standards have risenB. the old subjects of study are no longer of interestC. the amount of knowledge has increasedD. scholars and students now have a different view of life59. The phrase "secluded themselves from the outer world" (Para. 1 Line 6) most probablymeans" "A. kept themselves away from the world outsideB. enjoyed themselves from the outer worldC. enabled themselves to get knowledge from the outer worldD. enjoyed and learned from the lives60. Which of the following is the best title for the passage?A. Changing Concept of Higher Education.B. Discipline Changes.C. Traditional and Modem Universities.D. Wisdom and Narrow Discipline.Passage Three:The kings of old Egypt were very rich and powerful, and their tombs tell much about their lives. Archaeologists have looked for these tombs for many years. One man -- Lord Carnarvon of England -- was not an archaeologist. But he was very much interested in the way people lived in Egypt long ago. He was given permission to dig in some of the old tombs in a place called the Valley of the Kings. He hired an archeologist named Carter to take charge.For more than five years, the two men worked there with a group of diggers, but they found very little. Lord Carnarvon went back to England. Carter had almost lost hope of making an important discovery. But he kept on with the work.Then one day in the fall of 1922, one of his workers uncovered something that looked like a step cut into a rocky hill. He brushed away some loose stones and saw a second step below. It took four days to clear sixteen steps leading down into the hill. At the bottom of the steps, there was a wall of stone blocks. On the wait, they found the seal of a king called Tutankhamen.When Lord Carbnarvon heard the news, he sailed on the first ship to Egypt. They began the work of clearing out the tomb. It had to be done so carefully that it took six years to finish the job! There were four rooms in the tomb. Three of them were piled high with boxes, vases, jewels, and many other beautiful things. There was a golden throne, several golden chariots, the king's hunting bows and even his gold-trimmed sandals. All these things were put near the king in case he should need them in his own special afterworld.The fourth room held a huge carved coffin. In it, there were three more coffins, one inside the other. The last one was made of gold, and in it was the body of Tutankhamen. The body had been prepared with chemicals and was tightly wrapped in cloth. A body that is protected in this way is called a mummy. There were three layers of cloth wrappings on the body and a mask of pure gold.All the things found in the tomb were taken to museums, and archaeologists have been studying them ever since. Because Tutankhamen was a king, everything he left behind is very beautiful and very valuable. The gold itself is worth millions of dollars.But most important of all is the meaning of the objects themselves. They show how people lived in Egypt more than 3 000 years ago.61. When did one of the workers discover a step that led to the discovery of the tombs?A. In the spring.B. In the summer.C. In the autumn.D. In the winter.62. Where is the exact place to keep Tutankhamen's dead body?A. In the tombB. In the three coffinsC. In the four roomsD. In the gold coffin63. The body had been so well preserved because it was .A. kept in a good coffinB. tightly wrapped, in three layers of clothC. prepared with chemicalsD. covered with pure gold64. How many coffins were there in the fourth room?A. 4 coffins.B. 5 coffins,C. 3 coffins.D. 7 coffins.65. The most valuable of the discovery is .A. the knowledge of how people lived in Egypt more than 3 000 years agoB. the gold itself that is worth millions of dollarsC. all the things that were put near the kingD. the coffins in the fourth roomPart IV Mistake spotting ( 10%)Directions: Each of the following sentences has four underlined parts and marked A,B,C and D.Identify the one that needs correction .66. You certainly lose no time to come to see me when you are in troubleA B C D67. The instructor had gone over the problems many times before the students will take the finalA B C D examination.68. The director of the program advised the students to avoid to waste time reading material thatA B Cwas so out-of-D69. The dentist said that if my tooth went worse should have to have it pull out.A B C D70. I'll get my bike repaired if I shall have time this afternoonA B C D71. When I read the novel I can't help to thinkA B C D72. George always arrives at the office in time, but because the heavy rain, he was one hour lateA B C D73. Never before has so many people in China been interestedA B C D74. He's perfectly content living in a hut and paint picture all dayA B C D75. Of course she behaved awfully, but at allA B C DPart V Translation ( 10%)Section ADirections: Translate the following sentences into English.76．很明显是他的年轻助手在经营这家书店。
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练习题1
1、选择合适答案填入空内。
（1）在本征半导体中加入元素可形成N型半导体，加入元素可形成P型半导体。
A. 五价
B. 四价
C. 三价
（2）当温度升高时，二极管的反向饱和电流将。
A. 增大
B. 不变
C. 减小
（3）工作在放大区的某三极管，如果当I B从12μA增大到22μA时，I C 从1mA变为2mA，那么它的β约为。
A. 83
B. 91
C. 100
4）当场效应管的漏极直流电流I D从2mA变为4mA时，它的低频跨导g m将。
A.增大
B.不变
C.减小
2、能否将1.5V的干电池以正向接法接到二极管两端？为什么？
3、电路如图P1.3所示，已知u i＝10sinωt(v)，试画出u i与u O的波形。
设二极管正向导通电压可忽略不计。
图P1.3
4、电路如图P1.4所示，已知u i＝5sinωt (V)，二极管导通电压U D＝0.7V。
试画出u i与u O的波形，并标出幅值。
解图P1.4
5、电路如图P1.5（a）所示，其输入电压u I1和u I2的波形如图（b）所示，二极管导通电压U D＝0.7V。
试画出输出电压u O的波形，并标出幅值。
6、电路如图P1.6所示，二极管导通电压U D＝0.7V，常温下U T≈26mV，电容C对交流信号可视为短路；u i为正弦波，有效值为10mV。
试问二极管中流过的交流电流有效值为多少？
图P1.6
7、现有两只稳压管，它们的稳定电压分别为6V和8V，正向导通电压为0.7V。
试问：
（1）若将它们串联相接，则可得到几种稳压值？各为多少？
（2）若将它们并联相接，则又可得到几种稳压值？各为多少？
8、已知稳压管的稳定电压U Z＝6V，稳定电流的最小值I Z mi n＝5mA，最大功耗P Z M＝150mW。
试求图P1.8所示电路中电阻R的取值范围。
9、已知图P1.9所示电路中稳压管的稳定电压U Z＝6V，最小稳定电流I Z mi n ＝5mA，最大稳定电流I Z ma x＝25mA。
（1）分别计算U I为10V、15V、35V三种情况下输出电压U O的值；
（2）若U I＝35V时负载开路，则会出现什么现象?为什么？
10、在图P1.10所示电路中，发光二极管导通电压U D＝1.5V，正向电流在5～15mA时才能正常工作。
试问：
（1）开关S在什么位置时发光二极管才能发光？
（2）R的取值范围是多少？
11、电路如图P1.11（a）、（b）所示，稳压管的稳定电压U Z＝3V，R的取值合适，u I的波形如图（c）所示。
试分别画出u O1和u O2的波形。
图P1.11
12、有两只晶体管，一只的β＝200，I C E O＝200μA；另一只的β＝100，
I C E O＝10μA，其它参数大致相同。
你认为应选用哪只管子？为什么？
13、已知两只晶体管的电流放大系数β分别为50和100，现测得放大电路中这两只管子两个电极的电流如图P1.13所示。
分别求另一电极的电流，标出其实际方向，并在圆圈中画出管子。
14、测得放大电路中六只晶体管的直流电位如图P1.14所示。
在圆圈中画出管子，并分别说明它们是硅管还是锗管。
15、电路如图P1.15所示，晶体管导通时U B E＝0.7V，β=50。
试分析V B B 为0V、1V、1.5V三种情况下T的工作状态及输出电压u O的值。
16、电路如图P1.16所示，试问β大于多少时晶体管饱和？
17、分别判断图P1.17所示各电路中晶体管是否有可能工作在放大状态。