东北大学2007分布式操作系统考博真题

2022年东北大学计算机科学与技术专业《操作系统》科目期末试卷A（有答案）一、选择题1、某文件系统的簇和磁盘扇区大小分别为1KB和512B。

若一个文件的大小为1026B，则系统分配给该文件的磁盘空间大小是（）。

A.1026BB.1536BC.1538BD.2048B2、考虑一个文件存放在100个数据块中。

文件控制块、索引块或索引信息都驻留内存。

那么如果（）.不需要做任何磁盘I/O操作。

A.采用连续分配策略，将最后一个数据块搬到文件头部，B.采用单级索引分配策略，将最后一个数据块插入文件头部C.采用隐式链接分配策略，将最后一个数据块插入文件头部D.采用隐式链接分配策略，将第一个数据块插入文件尾部，3、下面有关选择进程调度算法的准则，错误的是（）A.尽量提高处理器利用率B.尽可能提高系统吞吐量C.适当增长进程在就绪队列中的等待时间D.尽快响应交互式用户的要求4、在使用信号量机制实现互斥时，互斥信号量的初值一般为（）：而使用信号量机，制实现同步时，同步信号量的初值般为（）。

A.0：1B.1：0C.不确定：1D.1：不确定5、若系统S1采用死锁避免方法，S2采用死锁检测方法。

下列叙述中，正确的是（）。

I.S1会限制用户申请资源的顺序，而S2不会II.S1需要进程运行所需资源总最信息，而S2不需要III.SI不会给可能导致死锁的进程分配资源，而S2会A.仅I、IIB.仅II、IIIC. 仅I、IID. I、II、III6、下列关于虚拟存储的叙述中，正确的是（）A.虚拟存储只能基于连续分配技术B.虚拟存储只能基于非连续分配技术C.虚拟存储容量只受外存容量的限制D.虚拟存储容量只受内存容量的限制7、在请求分页系统中，页面分配策略与页面置换策略不能组合使用的是（）。

A.可变分配，全局置换B.可变分配，局部置换C.固定分配，全局置换D.固定分配，局部置换8、在单处理器系统中，可并行的是（）I.进程与进程II.处理器与设备III.处理器与通道IV.设备与设备A.I、II和IIIB.I、II和IVC.I、III和IVD.II、III和IV9、 OS通常为用户提供4种使用接口，它们是终端命令、图标菜单、系统调用和（）A.计算机高级指令B.宏命令C.类似DOS的批命令文件或UNIX的shell文件D.汇编语言10、下列关于SPOOLing的叙述中，不正确的是（）A.SPOOLing系统中必须使用独占设备B.SPOOLing系统加快了作业执行的速度C.SPOOLing系统使独占设备变成了共享设备D.SPOOLing系统利用了处理器与通道并行上作的能力11、通道又称I/O处理器，用于实现（）之间的信息传输。

2007年东北大学博士入学考试试题(分布式操作系统)
1 简述分布OS与NET OS的不同
2 解释可伸缩性的含义，举一个限制可伸缩性的实例，提出解决方案。

3 一远程调用，除法：R=FRIBFR(I，J)，两实参I，J，返回I/J的结果。

描述RPC中传递值参数进行计算的方法，说明如果第一个参数是I地址，将要面临的问题及解决方法。

4 多线程的几种实现方式
5 K层移动问题
6 时钟滴答问题
7 BULL Y算法的图示，描述，选举冲突时的解决办法。

8 两进程P1、P2，两个整数变量X、Y，初始为0，T为时间印
P1 P2
X=1(T=1) Y=1(T=2)
IF(Y==0)KILL(P2) (T=3) IF(X==0)KILL(P1) (T=4)
8-1 严格一致性模型下，P1，P2能否同时被终止。

8-2 顺序一致性模型下，所有可能的语句交叉模式，判断是否会出现P1，P2两进程之一或全部终止的情况。

8-3 FIFO一致性模型下，两进程能否被同进终止，为什么。

9 将TMR方法推广到2容错度，分别对于FAIL_STOP故障和拜占庭故障给出系统结构图，并解释原因。

东北大学《工程热力学》试题A2009年7月8日星期三1．气体常数R g 由气体的种类所决定，其大小与相对分子质量有关，由此我们可以计算诸如氮气、氧气等的气体常数。

通常情况下水不能作为理想气体处理，因为水分子往往借助非常强的氢键结合成为分子链，使得它在常温常压下呈液态而与周围群众格格不入（图一）。

现在的问题是：水的气体常数该如何确定？一种想法是，与其他气体一样，由其单个分子的相对分子质量确定。

另一种想法是，水的气体常数与它所缔合成的分子链大小有关，从而不能称其为常数，如果非要确定一个值的话，可以借助试验等手段给出一个平均值。

请谈谈你的看法，你的理由。

（10分）2．想用一个套管热交换器（Heat exchanger ）将140℃的石油制品冷却到40℃。

已知石油制品的比热容约为2.1kJ/(kg ⋅K)，套管换热器内管流通截面积是外通道流通截面积的一半。

冷却水进口温度25℃，比热容约为4.2kJ/(kg ⋅K)。

介质流速需控制在8 m/s 以下以避免阻力过大。

假定换热器足够长，两种介质的密度均为1000 kg/m 3，请合理安排两种介质的流程以达到效果最好。

(15分)3．标准状态下，1kmol 的气体压力是多少？温度是多少？体积是多少（取三位有效数字）？高炉热风炉将空气从20℃加热到1100℃，已知20℃到1100℃之间空气的平均体积比热为1.4215kJ/(m 3⋅K)（1.4215千焦耳每标准立方米每开），问100标准立方米的空气完成加热后体积是多少？加热过程吸热量是多少？（15分）4．20世纪末蒸汽参数最高的大功率汽轮机是日本三菱公司和日立公司生产的1000MW-24.5MPa/600℃/600℃超临界一次中间再热汽轮机。

假定再热压力为4.0MPa ，排汽参数为0.005MPa ，试求该机组的理论热效率。

（20分）图一图二5．T–s图上两条定容线可以相交吗？两条定压线呢？为什么？（5分）6．p–v图上两条绝热过程线相交会导致什么结果？请说清楚。

2007一、词汇1. There are as good fish in the sea ________ ever came out of it.（C）A. thanB. likeC. asD. so2. All the President's Men ________ one of the important books for historians who study the Watergate Scandal.（B）A. remainB. remainsC. remainedD. is remaining3. You ________ borrow my notes provided you take care of them,' I told my friend.（A）A. couldB. shouldC. mustD. can4. If only the patient ________ a different treatment instead of using the antibiotics, he might still be alive now.（A）A. had receivedB. receivedC. should receiveD. were receiving5. Linda was ________ to experiment a month ago, but she changed her mind at the last minute.（B）A. to startB. to have startedC. to be startingD. to have been starting6. She ________ fifty or so when I first met her at the conference.（D）A. must beB. had beenC. could beD. must have been7. It is not ________ much the language as the background that makes the book difficult to understand.（C）A. thatB. asC. soD. very8. The committee has anticipated the problems that ________ in the road construction project.（D）A. ariseB. will ariseC. aroseD. have arisen9. The student said there were a few points in the essay he ________ impossible to comprehend.（A）A. had foundB. findsC. has foundD. would find10. He would have finished his college education, but he ________ to quit and find a job to support his family.（C）A. had hadB. hasC. hadD. would have11. The research requires more money than ________.（B）A. have been put inB. has been put inC. being put inD. to be put in12. Overpopulation poses a terrible threat to the human race. Yet it is probably ________ a threat to the human race than enviromental destruction.（B）A. no moreB. not moreC. even moreD. much more13. It is not uncommon for there ________ problems of communication between the old and the young.（D）A. beingB. would beC. beD. to be14.________ at in his way, the situation does not seem so desperate.（B）A. Looking.B. lookedC. Being looked.D. to look15. It is absolutely essential that William ________ his study in spite of some learning difficulties.（C）A. will continueB. continuedC. continueD. continues16. The painting he bought at the street market the other day was a ________ forgery.（D）A. man-madeB. naturalC. crudeD. real17. She's always been kind to me –I can't just turn ________ on her now that she needs my help.（A）A. my backB. my headC. my eyeD. shoulder18. The bar in the club is for the ________ use of its members.（B）A. extensiveB. exclusiveC. inclusiveD. comprehensive19. The tutition fees are ________ to students coming from low-income families.（D）A. approachableB. payableC. reachableD. affordable20. The medical experts warned the authorities of the danger of diseases in the ________ of the earthquake.（A）A. consequenceB. aftermathC. resultsD. effect21. This sort of rude behaviour in public hardly ________ a person in your position.（B）A. becomesB. fitsC. supportsD. improves22. I must leave now.________, if you want that book I'll bring it next time.（B）A. Accidentally.B. Incidentally.C. Eventually.D. Naturally.23. After a long delay, she ________ replying to my e-mail.（D）A. got away withB. got back atC. got backD. got round to24. Personal computers are no longer something beyond the ordinary people; they are ________ available these days.（C）A. promptlyB. instantlyC. readilyD. quickly25. In my first year at the university I learnt the ________ of journalism.（A）A. basicsB. basicC. elementaryD. elements26. According to the new tax law, any money earned over that level is taxed at the ________ of 59 percent ________.（D）A. ratioB. percentageC. proportionD. rate27. Thousands of ________ at the stadium came to their feet to pay tribute to an outstanding performance.（C）A. audienceB. participantsC. spectatorsD. observers28. We stood still, gazing out over the limitless ________ of the dessert.（C）A. spaceB. expanseC. stretchD. land29. Doctor often ________ uneasiness in the people they deal with.（C）A. smellB. hearC. senseD. tough30. Mary sat at the table, looked at the plate and ________ her lips.（A）A. smackedB. openedC. partedD. seperated二、阅读TEXT AIf you like the idea of staying with with a family, living in house might be the answer. Good landladies – those who are superb cooks and launderers, are figures as popular in fiction as the bad ones who terrorize their guest and overcharge them atthe slightest opportunity. The truth is probably somewhere between the two extremes. If you are lucky, the food will be adequate, some of your laundry may be done for you and you will have a reasonable amount of comfort and chompanionship. For the less fortune, house rules may restrict the freedom to invite friends to vistit, and shared cooking and bathroom facilities can be frustrating and row-provoking if tidy and untidy guest are living under the same roof.The same disadvantages can apply to flat sharing, with the added difficulties that arise from deciding who pays for what, and in what proportion. One person may spend hours on the phone, while another rarely makes calls. If you want privacy with guest, how do you persuade the others to go out; how do you persuade them to leave you in peace, especially if you are student and want to study?Conversely, flat sharing can be very cheap, there will always be someone to talk to and go out with, and the chores, in theory, can be shared.1. According to the passage, landladies are ________.（D）A. usually strictB. always meanC. adequately competentD. very popular with their guest2. What is the additional disadvantage of flat sharing?（A）A. Problems of sharing and paying.B. Differences in living habits.C. Shared cooking and bathroom facilities.D. Restriction to invite friends to visit.3. What is NOT mentioned as a benefit of flat sharing?（D）A. Rent is affordable.B. There is companionship.C. Housework.D. There is peace and quiet.TEXT B1. Travelling through the country a couple of weeks ago on business, I was listening to the talk of the late UK writer Douglas Adams' master work "The Hitchhiker's Guide to the Galaxy" on the radio and thought-I know, I'll pick up the next hitchhikers I see and ask them wahat the state of real hitching is today in Britain.2. I drove and drove on main roads and side roads for the next few days and never saw a single one.3. When I was in my teens and 20s, hitchhiking was a main form of long-distance transport. The kindness or curiosity of strangers took me all over Europe, North America, Asiaand southern Africa, Some of the lift-givers became friends, many provided hospitality on the road.4. Not only did you find out much more about a country than when traveling by train or plane, but there was that lelement of excitement about where you would finish up that night.Hitchhiking featured importantly in Western culture. It has books and songs about it. So what has happened to it?5. A few years ago, I was asked the same question about hitching in a column of a newspaper. Hundreds of people from all over the world responded with theirview on the state of hitchhiking.6. Rural Ireland was recommended as a friendly place for hitching, as was Quebec, Canada-"if you don't mind being criticized for not speaking French".7. But while hitchhiking was clearly still alive and well in some places, the general feeling was that throughout much of the west it was doomed.8. With so much news about crime in the media, people assumed that anyone on the open road without the money for even a bus ticket must present a danger. But do we need to be so wary both to hitch and to give a lift?9. In Poland in the 1960s, according to a Polish woman who e-mail me,＂the authorities introduced the Hitchhiker's Booklet. The booklet contained coupons for drivers, so each time a driver picked somebody, he or she received a coupon. At the end of the season, drivers who had picked up the most hikers were rewarded with various prizes. Everyone was hitchhiking then".10. Surely this is a good idea for society. Hitchhiking would increase respect by breaking down barriers between strangers. It would help fight global warming by cutting down on fuel consumption as hitchhikers would be using existing fuels. It would also improveeducational standards by delivering instant lessons in geography, history, politics and sociology.11. A century before Douglas Adams wrote his "Hitchhiker's Guide", another adventure story writer, Robert Louis Stevenson, gave us that what should be the hitchhiker's motto:＂To travel hopefully is a better thing than to arrive." What better time than putting a holiday weekend into practice. Either put it to the test yourself, or help out someone who is trying to travel hopefully with thumb outstreched.4. In which paragraph (s) does the writer comment on his experience of hitchhiking?（C）A. 大3家B. 大4家C. 大3家and 大4家D. 大4家and 大5家5. What is the current situation of hitchhiking?（A）A. It is popular in some parts of the world.B. It is popular throughout the west.C. It is popular in Poland.6. What is the writer's attitude towards the practice in Poland?（D）A. Critical.B. Unclear.C. Somewhat favourable.D. Strongly favourable.7. The writer has mentioned all the following benefits of hitchhiking EXCEPT（B）A. promoting mutual respect between strangersB. increasing one's confidence in strangersC. protecting enviromentD. enrich one's knowledge8.＂Either put it to the test yourself…"in Paragraph 大11家means（D）A. to experience the hopefulnessB. to read Adams' bookC. to offer someone a lift TEXT CI am afraid to sleep. I have been afraid to sleep for the last few weeks. I am so tired that, finally, I do sleep, but only for a few minutes. It is not a bad dream that wakes me; it is the realiry I took with me into sleep. I try to think of something else. Immediately the woman in the marketplace comes into my mind.I was on my way to dinner last night when I saw her. She was selling skirts. She moved with the same ease and loveliness I often saw in the women of Laos. Her long black hair was as shiny as the black silk of the skirts she was selling. In her hair, she wore three silk ribbons, blue, green, and white. They meminded me of my childhood and how my girlfriends and I used to spend hours braiding ribbons into our hair.I don't know the word for "ribbons", so I put my hand to my own hair and, with three fingers against my head, I looked at her ribbons and said "Beautiful." She lowered her eyes and said nothing. I wasn't sure if she understood me (I don't speak Laotian very well).I looked back down at the skirts. They ahd designs in them: squares and triangles and circles of pink and green silk. They were very pretty. I decided to buy one of those skirts, and I began to bargain with her over the price. It is the custom to bargain in Asia. In Laos bargaining is done in soft voices and easy moves with the sort of quiet peacefulness.She smiled, more with her eyes than with her lips. She was pleased by the few words I was able to say in her language, although they were mostly numbers, and she saw that I understood something about the soft playfulness of bargaining. We shook our heads in disagreement over the price; then, immediately, we made another offer and then another shake of the head. She was so pleased that unexpectedly, she accepted the last offer I made. But it was too soon. The price was too low. She was being too generous and wouldn't make enough money. I moved quickly and picked up two more skirts and paid for all three at the price set; that way I was able to pay her three times as much before she had a chance to lower the price for the larger purchase. She smiled openly then, and, for the first time in months, my spirit lifted. I almost felt happy.The feeling stayed with me while she wrapped the skirts in a newspaper and handed them to me. When I left, though, the feeling left, too. It was as though it stayed behind in marketplace. I left tears in my throat. I wanted to cry. I didn't, of course.I have learned to defend myself against what is hard; without knowing it, I have also learned to defend myself against what is soft and what should be easy.I get up, light a candle and want to look at the skirts. They are still in the newspaper that the woman wrapped them in. I remove the paper, and raise the skirts up to look at them again before I pack them. Something falls to floor. I reach down and feel something cool in my hand. I move close to the candlelight to see what I have. There are five long silk ribbons in my hand, all different colours. The woman in the maketplace! She has given these ribbons to me!There is no defense against a generous spirit, and this time I cry, and very hard, as if I could make up for all the months that I didn't cry.10. Which of the following in NOT corret?（A）A. The writer was not used to bargaining.B. People in Asia always bargain when buying things.C. Bargaining in Laos was quiet and peaceful.D. The writer was ready to bargain with the woman.11. The writer assumed that the voman accepted the last offer mainly because woman ________.（B）A. thought that the last offer was reasonableB. thought she could still make much moneyC. was glad that the writer knew their way of bargainningD. was tired of bargainning with the writer any more12. Why did the writer finally decide to buy three skirts?（C）A. The skirts were cheap and pretty.B. She liked the patterns on the skirts.C. She wanted to do something as compensation.D. She was fed up with further bargainning with the woman.13. When did the writer left the marketplace, she wanted to cry, but did not because ________.（D）A. she had learned to stay cool and unfeelingB. she was afraid of crying in publicC. she had learned to face difficulties bravelyD. she had to show in public that she was strong14. Why did the writer cry eventually when she looked at the skirts again?（C）A. she suddently felt very sadB. she liked the ribbons so muchC. she was overcome by emotionD. she felt sorry for the womanTEXT DThe kids are hanging out. I pass small bands of students, in my way to work these morings. They have become a familiar part of the summer landscape.These kids are not old enough for jobs. Nor are they rich enough for camp. They are school children without school. The calendar called the school year ran out on them a few weeks ago. Once supervised by teachers and principals, they now appear to be "self care".Passing them is like passing through a time zone. For much of our history, after all, Americans arranged the school year around the needs of work and family. In 19th-century cities, schools were open seven or eight hours a day, 11 months a year. In rural America, the year was arranged around the growing season. Now, only 3 percent of families follow the agricultural model, but nearly all schools are scheduled as if our children went home early to milk the cows and took months off to work the crops. Now, three-quarters of the mothers of school-age children work, but the calendar is written as if they were home waiting for the school bus.The six-hour day, the 180-day school year is regarded as something holy. Butwhen parents work an eight-hour day and a 240-day year, it means something different. It means that many kids go home to empty houses. It means that, in the summer, they hang out."We have a huge mismatch between the school calendar and realisties of family life,"says Dr. Ernest Boyer, head of the Carnegie Foundation for the Advancement of Teaching.Dr. Boyer is one of many who believe that a radical revision of the school calendar is inevitable.＂School, whether we like it or not, is educational. It always has been."His is not popular idea. School are routinely burdened with the job of solving all our social problems. Can they be asked to meet the needs of our work and family lives?It may be easier to promote a linger school year on its educational merits and, indeed, the educational case is compelling. Despite the complaints and studies about our kids' lack of learning, the United State still has a shorter school year than any industrial nation. In most of Europe, the school year is 220 days. In Japan, it is 240 days long. While classroom time alone doesn't produce a well-educated child, learning takes time and more learning takes more time. The long summers of forgetting take a toll.The opposition to a longer school year comes from families that want to and can provide other experiences for their children. It comes from teachers. It comes from tradition. And surely from kids. But the most important part of the conflict has been over the money.15. Which of the following is an opinion of the auther's?（B）A. ＂The kids are hanging out."B. ＂They are school children without school."C. ＂These kids are not old enough for jobs."D. "The calendar called the school year ran out on them a few weeks ago."16. The current American school calendar was developed in the 19th century according to ________.（A）A. the growing season on nation's formB. the labour demands of the industrial ageC. teachers' demands for more vacation timeD. parents' demands for other experiences for their kids17. The author thinks that the current school calendar ________.（B）A. is still validB. is out of dateC. can not be revisedD. can not be defended18. Why was Dr. Boy's idea unpopular?（D）A. He argues for the role of school in solving social problems.B. He supports the current school calendar.C. He thinks that school year and family life should be donsidered separately.D. He strongly believes in the educational role of school.19."The long summers of forgetting take a toll"in the last paragraph but one means that（C）A. long summer vacation slows down the progress go learningB. long summer vacation has been abandoned in EuropeC. long summers result in less learning timeD. long summers are a result of tradition20. The main purpose of the passage is ________.（C）A. to describe how American children spend their summerB. to explain the needs of the modern working familiesC. to discuss the problems of the current school calendarD. to persuade parents to stay at home to look after their kids。

计算机考博试题及答案1. 数据结构与算法1.1 平衡二叉树平衡二叉树，也称为AVL树，是一种特殊的二叉搜索树，它的左右子树的高度差不超过1。

请说明如何插入和删除节点以保持平衡。

答案：当向平衡二叉树中插入一个节点时，需要按照二叉搜索树的规则找到对应的位置。

插入节点后，如果破坏了平衡二叉树的平衡性，则需要进行相应的调整。

插入节点后，从插入节点到根节点的路径上的所有节点的平衡因子需要更新，并沿着路径向上检查，如果某个节点的平衡因子超过了1或小于-1，则需要进行旋转操作来恢复平衡。

当删除一个节点时，同样需要按照二叉搜索树的规则找到对应的位置，并将该节点删除。

删除节点后，同样需要从删除节点到根节点的路径上的所有节点的平衡因子进行更新，并进行相应的旋转操作来恢复平衡。

1.2 Dijkstra算法Dijkstra算法是一种用于求解加权有向图中单源最短路径问题的算法。

请简要介绍Dijkstra算法的原理及步骤。

答案：Dijkstra算法的原理是，通过不断找出当前距离源点最近的顶点，并更新其他顶点的距离和路径，最终得到源点到其他所有顶点的最短路径。

步骤如下：1) 初始化：将源点设置为当前顶点，将源点到其他顶点的距离初始化为无穷大，将源点到自身的距离初始化为0。

2) 循环：在未遍历的顶点中，选择当前距离源点最近的顶点作为当前顶点。

3) 更新：计算当前顶点的邻居顶点经过当前顶点到达源点的距离，若经过当前顶点到达邻居顶点的距离比已知的距离更短，则更新邻居顶点的距离和路径。

4) 标记：将当前顶点标记为已遍历。

5) 终止条件：当所有顶点都被标记为已遍历时，算法终止。

2. 操作系统2.1 进程和线程的区别进程和线程是操作系统中的两个重要概念，请简要说明它们的区别。

答案：进程是操作系统资源分配的基本单位，每个进程都拥有独立的内存空间和系统资源，进程之间通过进程间通信(IPC)来进行数据交换。

而线程是进程中的执行单元，每个进程可以包含多个线程，线程共享进程的内存空间和系统资源，线程之间可以直接访问共享的内存数据。

2006级(嵌入式软件与系统、计算机应用方向)《数据结构》期终考试试卷答案一、单项选择题 (每题1分，共15分)答案：C, A, B, B, C, D, D, C, D, A, B, B, A, C, A二、已知一个无向图的顶点集为{ a , b , c , d , e , f }，其邻接矩阵如下所示(0-无边,1-有边)。

⎥⎥⎥⎥⎥⎥⎥⎥⎦⎤⎢⎢⎢⎢⎢⎢⎢⎢⎣⎡00110001101110110111010001101010010fe d c b af e d c b a(1). 画出该图的图形；(2). 根据邻接矩阵从顶点a 出发进行广度优先遍历，画出相应的广度优先遍历树。

(15分) 解：(1). 该邻接矩阵所对应的的图2.1所示(2). 从顶点a 出发进行广度优先遍历的遍历树如图2.2所示三、已知一个散列表如下图所示：其散列函数为h (key ) = key % 13，处理冲突的方法为双重散列法，探查序列为:h i = (h (key ) + i * 3) % 13, i = 1, 2, …问：对表中关键字61进行查找时，所需进行的比较次数为多少？依次写出每次的计算公式和值。

(10分)解：在表中查找关键字61时，所需进行的计算公式如下:h (61) = 61 % 13 = 9h 1 = (9 + 1 * 3) % 13 = 12图2.1 图2.2 a b e d f ch 2 = (9 + 2 * 3) % 13 = 15 % 13 = 2由上过程可知：在表中查找关键字61时，需要进行3次比较。

四、阅读下面程序，回答问题 (10分)void function(Link **Head) {Link *pt1, *pt2, *tmp; pt1 = *Head;if (pt1 == NULL) return;pt2 = pt1->next; pt1->next = NULL;// 语句行S 1while (pt2 != NULL) { tmp = pt2->next;pt2->next = pt1; pt1 = pt2; pt2 = tmp; }*Head = pt1;// 语句行S 2}回答下列问题：(1). 说明语句行S 1和S 2的作用(指对单向链表中所起的作用)；(2). 简洁地给出函数function 的功能描述(非每条语句的语义说明)；(3). 若链表Head 的线性表形式为(a 1, a 2, …, a n )，写出函数执行后链表Head 的线性表形式。

东北大学博士研究生英语考试真题全文共3篇示例，供读者参考篇1Northeastern University Doctoral Graduate English ExamWelcome to the English exam for doctoral graduate students at Northeastern University. This exam is designed to assess your proficiency in English and your ability to effectively communicate in an academic setting. The exam consists of four sections: Reading Comprehension, Writing, Listening, and Speaking.Reading Comprehension:In this section, you will be given a series of passages to read and questions to answer. The passages will cover a range of topics related to your field of study and will test your ability to understand and analyze complex written material.Writing:The writing section of the exam will require you to respond to a prompt by writing an essay. You will be expected to demonstrate your ability to develop a coherent argument, useappropriate academic language, and provide evidence to support your claims.Listening:For the listening section, you will listen to a series of audio recordings and answer questions based on the content. This section will test your ability to understand spoken English and follow along with academic lectures or conversations.Speaking:In the speaking section, you will engage in a conversation with an examiner. You will be asked to discuss a variety of topics related to your field of study and to express your ideas clearly and fluently.Overall, the English exam is designed to assess your ability to use English in an academic setting, including reading, writing, listening, and speaking. It is important to prepare for the exam by reviewing academic English vocabulary, practicing reading and writing in English, and developing your listening and speaking skills.Good luck on the exam, and we look forward to seeing you succeed in your academic pursuits at Northeastern University!篇2Northeastern University Doctoral Graduate School English Exam----------------------------------------------------Part I: Reading Comprehension (40 points)Directions: There are 4 reading passages in this part. Each passage is followed by some questions. Read the passage carefully and answer the questions based on the information presented in the passage.Passage 1In recent years, the issue of climate change has become a hot topic in the international community. Many scientists believe that the increase in greenhouse gas emissions is causing global temperatures to rise at an unprecedented rate. This is leading to a number of negative consequences, including more frequent and severe natural disasters, such as hurricanes and droughts. In order to combat climate change, it is essential that countries work together to reduce their carbon footprint and transition to more sustainable forms of energy.1. What is the main topic of this passage?2. What are some of the negative consequences of climate change mentioned in the passage?3. What does the author believe is essential in order to combat climate change?Passage 2The field of artificial intelligence (AI) has made significant advancements in recent years, with AI technologies becoming increasingly integrated into our daily lives. From self-driving cars to virtual assistants, AI has the potential to revolutionize the way we live and work. However, there are concerns about the implications of AI on job displacement and privacy. As AI continues to develop, it is important for policymakers to consider the ethical and social implications of these technologies.1. What is the main topic of this passage?2. What are some examples of AI technologies mentioned in the passage?3. What concerns are raised about the implications of AI?Passage 3The rise of social media has had a profound impact on the way we communicate and interact with one another. With platforms such as Facebook, Twitter, and Instagram, we are able to connect with people from all over the world and share our thoughts and experiences instantly. However, there are concerns about the negative effects of social media on mental health, such as increased feelings of loneliness and anxiety. It is important for individuals to use social media responsibly and in moderation.1. What is the main topic of this passage?2. What are some of the benefits of social media mentioned in the passage?3. What concerns are raised about the negative effects of social media?Passage 4The study of biodiversity is essential for understanding the complexity of ecosystems and the importance of conserving our natural resources. Biodiversity is the variety of life on Earth, including plants, animals, and microorganisms. It plays a crucial role in maintaining ecosystem balance and providing ecosystem services, such as pollination and nutrient cycling. Despite itsimportance, biodiversity is under threat from human activities, such as deforestation and pollution.1. What is the main topic of this passage?2. What is biodiversity, according to the passage?3. What are some of the threats to biodiversity mentioned in the passage?Part II: Writing (60 points)Directions: In this part, you are required to write an essay on the given topic. You should write at least 250 words.Topic: Discuss the impact of technology on education. How has technology transformed the way we learn and teach? What are some advantages and disadvantages of using technology in the classroom?Part III: Listening Comprehension (40 points)Directions: In this part, you will listen to 4 short conversations and 2 long conversations. After each conversation, you will hear some questions. The conversations and questions will be spoken only once. Listen carefully and choose the best answer to each question.Conversation 11. What is the woman's name?A. SarahB. EmilyC. Jessica2. Where is the man from?A. CanadaB. UKC. AustraliaConversation 23. When are they planning to go on vacation?A. Next monthB. Next weekC. Next year4. What does the man recommend bringing on the trip?A. SunscreenB. UmbrellaC. Jacket(......)This is just a sample of the types of questions that may appear on the Northeastern University Doctoral Graduate School English Exam. Good luck to all the test-takers!篇3Northeastern University Doctoral Graduate English ExamReading ComprehensionDirections: There are 4 passages in this section. After reading each passage, answer the questions that follow.Passage 1Climate change is a pressing issue that affects the entire planet. From melting polar ice caps to extreme weather events, the impact of climate change is becoming increasingly apparent. However, there are still those who deny the existence of climate change or its human-caused origins. The scientific community is in overwhelming agreement that climate change is real and that human activities, such as burning fossil fuels and deforestation, are major contributors to the problem. It is crucial that we take action now to mitigate the effects of climate change before it is too late.1. What is the main topic of the passage?A. Climate change denialB. The impact of climate changeC. Human activities contributing to climate changeD. The urgency of taking action on climate change2. According to the passage, what are some human activities that contribute to climate change?A. DeforestationB. RecyclingC. Using public transportationD. Planting treesPassage 2Artificial intelligence (AI) has the potential to revolutionize many aspects of our lives, from healthcare to transportation.AI-powered technologies can analyze large amounts of data at speeds far beyond human capabilities, leading to improved efficiency and decision-making. However, there are concerns about the ethical implications of AI, such as bias in algorithms and the potential for job displacement due to automation. It isimportant for policymakers and the public to address these issues as AI continues to advance.3. What is the main benefit of AI-powered technologies mentioned in the passage?A. Increased job opportunitiesB. Enhanced decision-makingC. Reduced efficiencyD. Limited data analysis4. What are some ethical concerns associated with AI, according to the passage?A. Lack of bias in algorithmsB. Potential job displacementC. Transparency in decision-makingD. Positive impact on societyPassage 3Renewable energy sources, such as solar and wind power, are gaining popularity as alternatives to fossil fuels. These clean energy sources produce fewer greenhouse gas emissions and have the potential to reduce our reliance on non-renewableresources. However, there are challenges to scaling up renewable energy production, such as cost and infrastructure limitations. Despite these challenges, investing in renewable energy is essential for a sustainable future.5. What are some benefits of renewable energy sources mentioned in the passage?A. Reduced greenhouse gas emissionsB. Increased reliance on non-renewable resourcesC. Lower cost compared to fossil fuelsD. Limited infrastructure requirements6. According to the passage, what is a challenge to scaling up renewable energy production?A. Lack of public supportB. High costsC. Easy access to infrastructureD. Compatibility with fossil fuel technologiesPassage 4The COVID-19 pandemic has had a profound impact on global health and the economy. As countries around the worldimplement measures to contain the spread of the virus, many industries have faced disruptions, leading to job losses and economic instability. The pandemic has also highlighted existing inequalities in healthcare access and healthcare systems. Moving forward, it is crucial for governments and organizations to work together to address these challenges and build resilience for future crises.7. What is the main impact of the COVID-19 pandemic mentioned in the passage?A. Economic stabilityB. Job growthC. Disruptions in industriesD. Improved healthcare access8. According to the passage, what is a key issue highlighted by the pandemic?A. Inequalities in healthcare accessB. Increased global cooperationC. Strong healthcare systemsD. Prevention of future crisesThese questions are just a sample of the types of questions that may appear on the Northeastern University Doctoral Graduate English Exam. Students are encouraged to practice their reading comprehension skills and familiarize themselves with a variety of topics in preparation for the exam.。

2007年全国医学博士外语统一考试听力真题Part I Listening ComprehensionSection ADirections: In this section you will hear fifteen short conversations between two speakers. At the end of each conversation, you will hear a question about what is said. The question will be read only once. After you hear each question, read the four possible answers marked A, B, C and D. Choose the best answer and mark the letter of your choice on the ANSWER SHEET.1. A. To do some experimentsB. To attend a class.C. To review his lesson.D. To take a test.2. A. In a hotel.B. In the hospital.C. In the prison.D. At the airport.3 A. He got an ulcer in his stomach.B. He got hurt in the soccer game.C. He will be discharged soon.D .He got his tumor removed4 A. She told a lie so as not to hurt Jimmy.B. She left because she had a headache.C. She hurt Jimmy by telling him a lie.D. She slept off her headache.5 A. His new car is not fast enough.B. His new car moves very fast.C. His new car is a real bargain.D. His new car is somewhat of a financial burden.6 A. Get more time to relax.B. Take some tranquilizers.C. Seek a second opinion.D. Avoid her responsibilities.7 A. He got a headache while establishing the institute.B .He had a hard time getting the institute started.C. Everything was OK at the beginning.D. It is impossible to open such an institute in Seoul.8 A. Excited.B. Frustrated.C. Annoyed.D. Relieved.9 A. Each class lasts an hour.B. The class is meeting in an hour and a half.C. The class meets four hours and an half per week.D. The class meets for half an hour three times a week.10 A. The woman was a good skier.B. The woman couldn‟t ski.C. The woman didn‟t intend to go skiing.D. The woman didn‟t like Swiss.11 A. She‟s an insurance agent.B. She‟s an insurance client.C. She…s a bank clerk.D. She‟s a driver.12 A. He tripped over some crutches.B. He had rheumatism in his legs.C. He sprained his foot.D. He broke his leg.13 A. The vacation is almost gone.B. The vacation has just started.C. They are prepared for the new semester.D. They can‟t wait for the new semester.14 A. She was knocked down by a feather.B. She is shamed of Larry.C. She was really surprised.D. She was proud of Larry.15 A. To visit his son.B. To perform an operation.C. To have an operation.D. To send his son for an operation.Section BDirections: In this section you will hear three passages. After each one, you will hear five questions. After each question, read the four possible answers marked A, B, C and D. Choose the best answer and mark the letter of your choice on the ANSWER SHEET.Passage One16 A. A pharmacist.B. A visitor.C. A physician.D. A dieter.17 A. Cough.B. Diarrhea.C. Headache.D. Stomach upset18 A. Pain-killers.B. Cough syrup.C. Antidiarrheas.D. Indigestion tablets.19 A. The cold weather.B. Tiredness caused by traveling.C. The strange food he had eaten.D. The greasy food he had eaten.20 A. Take the medicine from the woman.B. Go to see a specialist.C. Stop eating and drinking for a few days.D. Stay in bed for a couple of days.Passage Two21 A. Headaches.B. Insomnia.C. Respiratory problems.D. Digestive problems.22 A. On Monday in Edinburgh.B. On Wednesday in Edinburgh.C. On Monday at Staffordshire University.D. On Wednesday at Staffordshire University.23 A. 94.B. 41.C.130.D. 135.24 A. The subjects were asked to write of their free will.B. The subjects were asked to write in a systematic way.C. The subjects were asked to say how often they made entries.D. The subjects were asked if they had written down anything traumatic.25 A. The diarists who write of their free will.B. The diarists who were students at Staffordshire University.C. The diarists who had written about trauma.D. The non-diarists who were susceptible to headaches.Passage Three26 A. A brief history of British pubs.B. Beer—the British national drink.C. Various attempts made to curb drinking in British.D. The frustrating opening and closing hours of British pubs.27 A. As early as 659AD.B. After 659ADC. Before the Roman invasion.D. After the Roman invasion.28 A. To restrict drinking hours.B. To restrict travelers to certain drinks.C. To encourage the locals to drink in other towns.D. To encourage inns to lodge various kinds of people.29 A. People were better off.B. The government failed to persuade people from drinking.C. There appeared a new cheap drink.D. Drinkers had found various ways to get around the laws.30 A. The licensing hours have been extended.B. Old people are not allowed to drink in pubs.C. Children are not allowed yet to drink in pubs.D. Big changes have taken place in pubs.Keys: 1-5 DBBAD 6-10 ABDCB 11-15 ADACC16-20 BADDA 21-25 CBDAC 26-30 ACACC2007年医学博士听力原文Part I1.W: Where are you heading now? You seem to be in a bit of a hurry.M: I‟m on my way to the biology building. I have an exam in about 20 minutes.Q: What is the man going to do?2.M: Hello. I was wondering if Tayler Smith has checked out yet.W: Just a moment. I will check with the cancer ward desk.M: Thank you.W: Well, Mr. Smith is still here. But he‟ll be released tomorrow.Q: Where is Mr. Smith now?3.W: You know Tom has been in the hospital for a couple of days.M: And I am the one who put him there with my soccer moves.Q: Which of the following is true about Tom?4.M: You left Jimmy‟s birthday party early last night. Did you have a headache?W: Well, I told Jimmy a white lie when I said that I had to leave early because I had a headache.Q: What does the woman mean?5.W: Your new car is fabulous.M: Not so fast. I won‟t finish paying for it until 2010.Q: What does the man mean?6.M: Well, I‟ve checked you over pretty thoroughly and I can‟t find anything wrong. It soundsto me as if you have been overdoing things.W: Yes, I have.M: I want you to take things easier. See if you can share your responsibilities so that you can make more time for yourself.Q: What does the man suggest the woman do?7.W: I‟ve heard that you have opened an institute of mental health in Seoul. How is it going?M: Everything is OK now. but it was quite a headache getting started.Q: What does the man mean?8.M: Hi, Susan. How are your finals?W: Hi, Dan. I finished my last exam this morning and my last term paper a few minutes ago. Ireally feel like I can see the light.Q: How is the woman feeling now?9.W: Can you tell me how often the chemistry class meets ?M: It meets three times a week for an hour and a half each time.Q: What does the man mean?10.M: You look fresh and energetic. Where did you go for the holiday?W: I went to a skiing resort in Switzerland and had a wonderful time.M: So you can ski.Q: What had the man assumed?11.W: Would you like to take out collision insurance?M: No, thanks. I won‟t need any insurance.Q: What does the woman do?12.M: Did you see Robert?W: Yes, I did. His leg was in a cast. And he was on crutches.Q: What happened to Robert?13.W: I feel like it‟s only been a few days since the vacation started.M: And it is almost time for the new semester.Q: What do the speakers mean?14.M: Did you hear that Larry got a 630 on the TOEFL test?W: You could have knocked me over with a feather.Q: What does the woman mean?15.W: Good morning. Welcome to our ward. I am Nurse Brown. Can I help you?M: Yes, please. I‟m Mr. Watson and this is my son, Ritchie who drove me here. I‟ve come in for my operation.Q: Why did Mr. Watson come to the hospital?Part IIPassage IW: Good morning. Can I help you?M: Yes, let‟s hope so. Thank God, you speak English.W: Well, just a little. What seems to be wrong?M: …I‟ve got an upset stomach. It‟s pretty bad. I‟ve been up all night with it. Now I‟ve got a bad headache as well.W: I see. When did it first start?M: When I went to bed.W: Do you think it‟s something you‟ve eaten?M: Oh, for sure. I‟m not used to all this wining and dining.W: Yes, you‟ve really eat a lot.M: You can say that again.W: Have you got diarrhea? Is it very loose?M: That‟s what it feels like.W: How often do you have to go?M: I have to go every few minutes.W: Are you drinking plenty of water? Bottled water?M: I‟ve had a few sips of water. I feel terribly thirsty.W: Hmmm, have you taken anything? Did you bring anything from home?M: I have got only these indigestion tablets.W: Can I see the packet?M: Here you are. Look.W: Have you taken anything for the headache?M: I‟ve taken a couple of pill Pacasedimals. That‟s all.W: Do you feel tired?M: Worn out? I can hardly keep my eyes open.W: Well, I think you‟ve probably just eaten something a bit too rich for you. You know you are not used to it. I‟m sure you‟ll be all right in a couple of days with what I am going to give you.Questions:16: Which of the following best describes the man in the dialogue?17: The man suffered from the following symptoms except_________.18: What medicine did the man bring with him from home?19: What might be the cause of the man‟s illness?20: What will the man probably do next?Passage II“Keeping a diary is bad for your health.” say UK psychologists. They found that people who regularly keep a diary from headaches, sleeplessness, digestive problems and social awkwardness more than people who don‟t. This finding challenges the assumption that people find it easier to get over a traumatic event if they write about it. “We expected diary-keepers to have more benefit or be the same. But they were worst off.” says Elaine Duncan of Glasgow Caledonian University. “I n fact you are probably much better off if you don‟t write anything at all.” she adds. The study carried out with David Safford of Staffordshire University was presented on Wednesday at a meeting of the British psychological society in Edinburgh.The peer studied 94 regular diarists and compared their health with that of 41 non- diarists. The subjects --- all students at Staffordshire University answer questions about their diary keeping habits and filled in a standard questionnaire. “We decided to test the idea that writing is cathartic.”says Duncan. She claims that her study is the first to investigate subjects who write of their own free will. In most other studies, volunteers are actually asked to write about traumatic experiences in a systematic way. The researchers asked the diarists recruited to say how often they made entries and for how long they had kept diaries. They were also asked if they had written about anything traumatic. Statistically, the diarists scored much worse on health measures than the non-diarists. The worst affected of all were those who had written about trauma. “They were susceptible to headaches and the like.” says Duncan.Questions:21: According to UK psychologists, regular diarists were more likely to suffer from the following except_________.22: When and where was Duncan‟s study presented?23: How many subjects were there in Duncan‟s study?24: What is special about Duncan‟s study?25: According to Duncan‟s study, who scored worst on health measures?Passage IIIMost foreigners find British pubs both fascinating and frustrating. Fascinating because they are unique to Great Britain and not at all like the bars you find in most other countries, and frustrating because of their peculiar opening and closing hours. In fact, much of the long-history of pubs in Britain is to do with people who wanted to drink and others who wanted to stop them. The development of pubs and laws surrounding them is an interesting way of learning a little more about our social history.Foreigners often think of tea as the British national drink. But compared to beer drinking, tea drinking is a very recent development. Beer has been drunk in Britain since before the Roman invasion. The earliest breweries were part of the monasteries, and as early as 659 AD, the king of Kent was making laws in an attempt to stop priests from getting drunk. By the late 16th Century, drunkenness was a real problem and laws were passed to restrict drinking hours. In 1606, a law was passed, which stated that the purpose of inns was to lodge wayfaring people only.Travelers were allowed to buy drinks at times forbidden to local people. However, the ingenuity of the dedicated drinkers got around this problem and the result was that the locals would simply move on to the next town or village when they want to continue drinking after time in their own village. In the 19th Century, cheap Gin appeared in Britain. It was very popular among poor people. Drunkenness again increased and more laws were passed. The temperance society was formed to fight against Demon drink. This group of dedicated tea totalers tried to persuade people to abstain from drinking by getting them to sign a pledge. In spite of the various attempts to curb drinking or stamp it out completely, pubs continued to provide a major part of British social life. Their opening and closing hours are still restricted by law although there have been recommendations recently for big changes including extending licensing hours and admitting children. But nothing has happened yet.Questions:26: What is this talk mainly about?27: When did people start to drink beer in Britain?28: What was the purpose of the law passed in 1606?29: Which of the following factors contributes to the rise of drunkenness in the 19th century?30: Which of the following is true about English pubs today?2007年全国医学博士外语统一考试词汇试题PartⅡVocabulary (10%)Section ADirections:In this section all the sentences are incomplete. Four words or pareses, marked A, B, C and D, are given beneath each of them. You are to choosethe word or phrase that best completes the sentence. Then, mark youranswer on the ANSWER SHEET.31. The doctor gave him an injection in order to _______ the pain.A. alleviateB. aggregateC. abolishD. allocate32. His broken arm healed will, but she died of the pneumonia which followed as a _______.A. complementB. complimentC. complexionD. complication33. Unfortunately, our vacation plans _____ on account of transport strikes.A. fell backB. fell throughC. fell uponD. fell to34. The ______ climate of Hawaii attracts visitors form all over the world every year.A. genialB. frigidC. genuineD. foul35. This is the ______ in which the organism lives most effectively.A. optimumB. optionC. ordealD. orbit36. The doctor suggests that a good holiday in the country should ____ him nicely after his operation.A. set…offB. set …upC. set…offD. set…aside37. His behavior was so ______ that even the merciful people could not forgive him.A. uniqueB. unconventionalC. brutalD. brilliant38. ______ to your present job until you can get a better one.A. Hang aboutB. Hang backC. Hang behindD. Hang on39. Suffering from his leg illness, Tom is very _______ nowadays.A. emaciatedB. eligibleC. elasticD. exceptional40. He saved some money for artistic _______ such as fine paintings.A. donationsB. profitsC. luxuriesD. luresSection BDirections: In this section each of the following sentences has a word or phrase underlined, beneath which are four words or phrases. Choose the word or phrase which wouldbest keep the meaning of the original sentence if it is substituted for the underlinedpart. Then mark the letter of your choice on the ANSWER SHEET.41. It has been proved that the chemical is lethal to rats but safe for cattle.A. fatalB. reactiveC. uniqueD. vital42. To their surprise, she has been nominated as candidate for the Presidency.A. recognizedB. definedC. appointedD. promoted43. We cannot look down upon our opponent, who is an experienced swimmer.A. playerB. competitorC. refereeD. partner44. She is regarded as a good nurse in that she attends to patients without any complaint.A. sees throughB. looks overC. takes inD. cares for45. It is well known that the minimum penalty for this crime is 2 years‟ imprisonment.A. convictionB. spanC. mercyD. punishment46. The whole area of the national and local governments tried to wipe out rats to preventthe spread of disease.A. exterminateB. dominateC. determinateD. contaminate47. All the students are afraid of him since he is always severe with them.A. vigorousB. rigorousC. vigilantD. rigid48. The biggest engineering project that they undertook was encumbered by lack of funds.A canceled B. condensed C. hampered D. haunted49. In order to be a successful diplomat you must be enthusiastic and magnetic.A. arrogantB. industriousC. zealousD. attractive50. He is successful as a doctor because of this dynamic personality, he seems to have unlimited energy.A. meticulousB. vigorousC. aggressiveD. arbitrary试题解析Section A31. A【选项释义】alleviate 减轻(痛苦等), 缓和(情绪) aggravate 使恶化, 加重abolish 废止, 废除(法律、制度、习俗等) allocate 分配, 分派【题干信息】医生给他打了一针，为的是减轻疼痛。