计算机四级操作系统真题及解析（6）
一、单选题
1）从计算机应用角度来看，操作系统的主要作用是提供
A）人机交互接口
B）软件开发基础
C）第一道安全防线
D）虚拟机和扩展机
答案：A
2）共享性是操作系统的特征之一，下列共享设备中，哪种设备可以共享但是不能被抢占使用？
A）CPU
B）打印机
C）硬盘
D）内存
答案：B
3）内核态和用户态是用于操作系统运行安全而设置的一种状态标志，其含义是指
A）操作系统所处的状态
B）CPU在运行时所处的状态
C）内存在运行时所处的状态
D）安全系统所处的状态
答案：B
4）外部I/O设备向处理器发出的中断信号又称为
A）中断请求
B）中断断点
C）中断屏蔽
D）中断优先级排队
答案：A
5）编写程序时通常会使用过程调用和系统调用，下列选项中，系统调用不能实现的功能是
A）从当前程序跳转到调用程序
B）调用程序多次嵌套与递归
C）调用程序一般与当前程序有关
D）调用结束后返回原程序
答案：B
6）计算机操作系统中，所谓进程的唯一标志”是指
A）进程控制块
B）程序指令代码
C）程序堆栈段
D）程序变量和数组
答案：A
7）某一单核处理机的计算机系统中共有20个进程，那么，处于运行状态的
进程最少为几个？
A） 1
B）20
C）19
D）0
答案：D
8）当用户在编程中需要创建一个进程时，他可以采用下列哪一种方法？
A）调用进程创建原语由操作系统创建进程
B）填写进程控制块的数据结构并提交系统
C）填写进程控制块的数据结构并将其放入就绪队列
D）将用户所在进程的进程控制块复制一份给新进程
答案：A
9）
对于如下C语言程序
int mai n（）
{
prin tf（"Hello World'n"）;
fork();
prin tf("Hello World'n");
}
在UNIX操作系统中正确编译链接后，其正确的运行结果是
A) 共打印出2行Hello World
B) 共打印出3行Hello World
C) 共打印出4行Hello World
D) 共打印出5行Hello World
答案：B
10)
有如下C语言程序
void * th_f(void * arg)
{
prin tf("Hello World");
pthread _joi n(2);
}
int main(v oid)
{
pthread_t tid;
int st;
st = pthread_create(&tid, NULL, th_f, NULL); if(st==0) prin tf("Oops, I can not createthread\n");
exit(NULL);
}
针对上述程序，下列叙述中哪一个是正确的？
A）线程th」运行后主动退出
B）线程th_f运行后等待一个特定的线程退出
C）线程th_f运行后主动释放CPU给其他线程
D）线程th」运行后进入死循环
答案：B
11）某系统在打印数据时，读数据进程、处理数据进程和打印结果进程之间的相互关系是
A）互斥关系
B）同步关系
C）前趋关系
D）后趋关系
答案：B
12）为了保证临界资源的正确使用，进程在结束对临界资源的访问后必须通过下列哪一区才能离开？
A）进入区
B）临界区
C）退出区
D）剩余区
答案：C
13）利用内存中若干公共缓冲区组织成队列，以实现进程之间信息交换的通信方式称为
A）共享内存
B）消息机制
C）管道通信
D）套接字
答案：B
14）下列存储管理方案中，需要采用移动技术解决碎片问题的是
A）固定分区
B）可变分区
C）页式
D）段页式
答案：B
15）在虚拟页式系统中进行页面置换时，首先置换最长时间未被使用过的页
面，这一策略称为
A）先进先出页面置换算法（FIFO）
B）最近最少使用页面置换算法（LRU）
C）最近最不常用页面置换算法（LFU）
D）理想页面置换算法（OPT）
答案：B
16）简单页式存储管理方案中，若地址用22位二进制表示，页内地址部分占12个二进制位，则最大允许进程有多少个页面？
A）2048
B）1024
C）512
D）256
答案：B
17）下列关于页式存储管理方案的叙述中，哪一个是错误的？
A）页表长度寄存器保存了正在运行进程的页表长度
B）页内地址是地址的高位部分
C）大多数32位的操作系统采用了二级页表
D）页表在内存可以不连续存放
答案：B
18）
有一个虚拟页式存储系统，采用最近最少使用（LRU）页面置换算法，系统分给每个进程3页内存，其中一页用来存放程序和变量i,j （不作他用）。假设一个页面可以存放300个整数变量。某进程程序如下：
VAR A:ARRAY[1..150, 1..100] OF integer;
i,j:i nteger;
FOR i:=1 to 150 DO
FOR j:=1 to 100 DO
A[i,j]:=0;
设变量i,j放在程序页面中，初始时，程序及变量i,j已在内存，其余两页为空。矩阵A按行序存放。试问当程序执行完后，共缺页多少次？
A）100
B）50
C) 150
D) 200 答案：B
19）
假设某计算机系统的内存大小为256K,在某一时刻内存的使用情况如下表
所示。
此时，若进程顺序请求20K和5K的存储空间，系统采用某种算法为进程
分配内存，分配后的内存情况如下表所示
那么系统采用的是什么分配算法？
A）最佳适配
B）最差适配
C）首次适配
D）下次适配
答案：A
20）文件系统中，若将逻辑上连续的文件信息分散存放在若干不连续的磁盘块中，每个磁盘块中设置一个指向下一个磁盘块的指针，这种结构称为A）顺序结构
B）链接结构
C）索引结构
D）I节点结构
答案：B
21）文件系统中，文件访问控制信息存储的合理位置是
A）文件控制块
B）文件分配表
C）用户口令表
D）系统注册表
答案：A
22）下列对文件的描述中，哪一项与文件的物理结构相关？
A）文件长度
B）用户对文件的存取方式
C）文件中记录的个数
D）文件目录的结构
答案：B
23）假设磁头当前位于第105道，正在向磁道序号增加的方向移动。现有一个磁道访问请求序列为35,45,12,68,110,180,170,195采用SSF调度（最短寻道优先调度）算法得到的磁道访问序列是
A）110,170,180,195,68,45,35,12
B）110,68,45,35,12,170,180,195
C）110,170,180,195,12,35,45,68
D）12,35,45,68,110,170,180,195
答案：B
24）在一个采用三级索引结构的UNIX文件系统中，假设物理块大小为
512B，用32位表示一个物理块号。主索引表含有13个块地址指针，其中前10 个直接指向盘块号，第11个指向一级索引表，第12个指向二级索引表，第13 个指向三级索引表，那么，一个文件最大可有多少块？
A）10 + 512 + 5122+ 5123
B）10 + 256 + 25&+ 2563
C）10 + 128 + 12$+ 1283
D）256 + 2562+ 2563
答案：C
25）在实现文件系统时，可采用目
2017年12月大学英语四级考试真题及答案（第一套）Part I Writing （25 minutes） Directions: For this part, you are allowed 30 minutes to write a short easy on how to best handle the relationship between doctors and patients. You should write at least 120 words but no more than 180 words. Part II Listening Comprehension （25 minutes） Section A Directions: In this section, you will hear three news reports. At the end of each news report, you will hear two or three questions. Both the news report and the questions will be spoken only once. After you hear a question, you must choose the best answer from the four choices marked A), B), C) and D). Then mark the corresponding letter on Answer Sheet 1 with a single line through the centre. Questions 1 and 2 are based on the news report you have just heard. 1. A) Her friend Erika. C) Her grandfather. B) Her little brother. D) Her grandmother. 2. A) By taking pictures for passers-by. C) By selling lemonade and pictures. B) By working part time at a hospital. D) By asking for help on social media. Questions 3 and 4 are based on the news report you have just heard. 3. A) Finding cheaper ways of highway construction. B) Generating electric power for passing vehicles. C) Providing clean energy to five million people. D) Testing the efficiency of the new solar panel. 4. A) They can stand the wear and tear of natural elements. B) They can be laid right on top of existing highways. C) They are only about half an inch thick. D) They are made from cheap materials. Questions 5 to 7 are based on the news report you have just heard. 5. A) Endless fighting in the region. C) Inadequate funding for research. B) The hazards from the desert. D) The lack of clues about the species. 6. A) To observe the wildlife in the two national parks. B) To identify the reasons for the lions’ disappearance. C) To study the habitat of lions in Sudan and Ethiopia.
2017年6月大学英语四级真题及答案 (第一套) Part I Writing (25 minutes) (请于正式开考后半小时内完成该部分，之后将进行听力考试) Directions:For this part, you are allowed 30 minutes to write an advertisement on your campus website to sell a computer you used at college. Your advertisement may include its brand, specifications/features, condition and price, and your contact should write at least 120 words but no more than 180 words. Part II Listening Comprehension (30 minutes) Section A Directions:In this section, you will hear three news reports. At the end of each news report, you will hear two or three questions. Both the news report and questions will be spoken only once. After you hear questions, you must choose the best answer from the four choices marked A), B), C) and D). Then mark the corresponding letter on Answer Sheet 1 with a single line through the centre. 注意：此部分试题请在答题卡1上作答。 Questions 1 to 2 are based on the conversation you have just heard. 1. A) The man in the car was absent-minded. B) The test driver made a wrong judgement. C) The self-driving system was faulty. D) The car was moving at a fast speed. 2. A) They have done better than conventional cars. B) They have caused several severe crashes. C) They have posed a threat to other drivers. D) They have generally done quite well. Questions 3 to 4 are based on the conversation you have just heard. 3. A) He works at a national park. B) He is a queen been specialist. C) He removed the beyond from the boot.
2016年6月大学英语四级真题第一套 Part I Writing （30 minutes） Directions：For this part, you are allowed 30 minutes to write a letter to express your thanks to your parents or any family members upon making memorable achievement. You should write at least 120 words but no more than 180 words。 Part ⅡListening Comprehension （25 minutes） Section A Directions：In this section，you will hear three news reports。At the end of each news report，you will hear two or three questions。Both the news report and the questions will be spoken only once。After you hear a question，you must choose the best answer from the four choices marked A），B），C）and D）。Then mark the corresponding letter on Answer Sheet 1 with a single line through the centre。 Questions 1 and 2 are based on the news report you have just heard。 1。A）The International Labor Organization’s key objective。 B）The basic social protection for the most vulnerable。 C）Rising unemployment worldwide。 D）Global economic recovery。 2。A）Many countries have not taken measures to create enough jobs。 B）Few countries know how to address the current economic crisis。
大学英语四级历年真题及答案（经典版） 2012年6月英语四级 Part ⅠWriting (30minutes) Directions: For this part, you are allowed 30 minutes to write a short essay entitled Excessive Packaging following the outline given below. You should write at least 120 words but no more than 180 words. 1.目前许多商品存在过度包装的现象 2.出现这一现象的原因 3.我对这一现象的看法和建议 On Excessive Packaging Part ⅡReading Comprehension(Skimming and Scanning)(15minutes) Directions: In this part, you will have 15 minutes to go over the passage quickly and answer the questions on Answer sheet 1. For questions 1-7,choose the best answer from the four choices marked A)，B)，C）and D). For questions 8-10,complete the sentences with the information given in the passage. Small Schools Rising This year's list of the top 100 high schools shows that today, those with fewer students are flourishing. Fifty years ago, they were the latest thing in educational reform: big, modern, suburban high schools with students counted in the thousands. As baby boomers(二战后婴儿潮时期出生的人) came of high-school age, big schools promised economic efficiency. A greater choice of courses, and, of course, better football teams. Only years later did we understand the trade-offs this involved: the creation of excessive bureaucracies(官僚机构)，the difficulty of forging personal connections between teachers and students.SAT scores began dropping in 1963;today,on average,30% of students do not complete high school in four years, a figure that rises to 50% in poor urban neighborhoods. While the emphasis on teaching to higher, test-driven standards as set in No Child Left Behind resulted in significantly better performance in elementary(and some middle)schools, high schools for a variety of reasons seemed to have made little progress. Size isn't everything, but it does matter, and the past decade has seen a noticeable countertrend toward smaller schools. This has been due ,in part ,to the Bill and Melinda Gates Foundation, which has invested $1.8 billion in American high schools, helping to open about 1,000 small schools-most of them with about 400 kids each with an average enrollment of only 150 per grade, About 500 more are on the drawing board. Districts all over the country are taking notice, along with mayors in cities like New York, Chicago and
大学英语四级考试真题及答案(绝对完整） Part I Writing (30 minutes) Directions: For this part, you are allowed 30 minute to write a short essay on the topic of students selecting their lectures. You should write at least 120 words following the outline given bellow: 1. 越来越多的博物馆免费对外开放的目的是什么？ 2. 也会带来一些问题 3. 你的看法？ Part II Reading Comprehension (Skimming and Scanning) (15 minutes)Directions: In this part, you will have 15 minutes to go over the passage quickly and answer the questions on Answer Sheet 1. For questions 1-7, choose the best answer from the four choices marked A),B),C) and D). For questions 8-10, complete the sentences with the information given in the passage. How Do You See Diversity? As a manager, Tiffany is responsible for interviewing applicants for some of the positions with her company .During one interview, she noticed that the candidate never made direct eye contact. She was puzzled and somewhat disappointed because she liked the individual otherwise. He had a perfect resume and gave good responses to her questions, but the fact that he never looked her in the eye said “untrustworthy,” so she decided to offer the job to her second choice. “It wasn’t until I attended a diversity workshop that I realized the person we passed over was the perfect person,” Tiffany confesses. What she hadn’t known at the time of the interview was that the candidate’s “different” behavior was simply a cultural misunderstanding . He was an Asian-American raised in a household where respect for those in authority was shown by averting(避开) your eyes. “I was just thrown off by the lack of ye contact; not realizing it was cultural,” Tiffany says. “I missed out ,but will not miss that opportunity again.” Many of us have had similar encounters with behaviors we perceive as different. As the world becomes smaller and our workplaces more diverse, it is becoming essential to expand our under-standing of others and to reexamine some of our false assumptions . Hire Advantage At a time when hiring qualified people is becoming more difficult ,employers who can eliminate invalid biases(偏爱) from the process have a distinct advantage .My company, Mindsets LLC ,helps organizations and individuals see their own blind spots . A real estate recruiter we worked with illustrates the positive difference such training can make .
2018年6月大学英语四级真题试卷一及答案(完整版) Part I Writing (30 minutes) (请于正式开考后半小时内完成该部分，之后将进行听力考试) Directions:For this part, you are allowed 30 minutes to write an a short easy on the importance of speaking ability and how to develop should write at least120 words but no more than 180 words. Part II Listening Comprehension (25 minutes) Section A Directions:In this section, you will hear three news reports. At the end of each news report, you will hear two or three questions. Both the news report and questions will be spoken only once. After you hear questions, you must choose the best answer from the four choices marked A), B), C) and D). Then mark the corresponding letter on Answer Sheet 1 with a single line through the centre. 注意：此部分试题请在答题卡1上作答。 Questions 1 to 2 are based on the new report you have just heard. 1. A) The return of a bottled message to its owner's daughter.
2014年6月大学英语四级考试真题及答案(完整版) Part I Writing (30 minutes) Directions: You should write atleast 120 words but no more than 180 words. Supposea foreign friend of yours is coming to visit your hometown, what is the mostinteresting place you would like to take him/her to see and why? Part III Reading Comprehension (40 minutes) Section A Questions 36 to 45 are based onthe following passage. Global warming is a trend towardwarmer conditions around the world. Part of the warming is natural; we haveexperienced a 20,000 -year -long warming as the last ice age ended and the ice 36 away.However, we have already reached temperatures that are in 37 withother minimum-ice periods, so continued warming is likely not natural. We are 38 toa predicted worldwide increase in temperatures 39 between 1℃and 6℃over the next 100 years. The warming will be more 40 in some areas, less in others, and some placesmay even cool
精品文档 2014年6月大学英语四级考试真题及答案（完整版） 来源：文都教育 Part I Writing (30 minutes) Directions: For this part, you are allowed 30 minutes to write a short essay on the following topic. You should write at least 120 words but no more than 180 words. Suppose a foreign friend of yours is coming to visit your hometown, what is the most interesting place you would like to take him/her to see and why? 注意：此部分试题请在答题卡1上作答。 Part II Listening Comprehension (30 minutes) Section A Directions: In this section, you will hear 8 short conversations and 2 long conversations. At the end of each conversation, one or more questions will be asked about what was said. Both the conversation and the questions will be spoken only once. After each question there will be a pause. During the pause, you must read the four choices marked A), B), C) and D), and decide which is the best answer. Then mark the corresponding letter on Answer Sheet 1 with a single line through the centre. 注意：此部分试题请在答题卡1上作答。 1. A) See a doctor about her strained shoulder. B) Use a ladder to help her reach the tea. C) Replace the cupboard with a new one. D) Place the tea on a lower shelf next time. 2. A) At Mary Johnson's. C) In an exhibition hall. B) At a painter's studio. D) Outside an art gallery. 3. A) The teacher evaluated lacks teaching experience. B) She does not quite agree with what the man said. C) The man had better talk with the students himself. D) New students usually cannot offer a fair evaluation. 4. A) He helped Doris build up the furniture. B) Doris helped him arrange the furniture.
2018年12月大学英语四级真题完整版（第3套） Part I Writing (30 minutes) Directions: For this part，you are allowed 30 minutes to write a short essay on the challenges of studying abroad. You should write at least 120 words but no more than180 words. PartⅡ Listening Comprehension (25 minutes) Part Ⅲ Reading Comprehension ( 40 minutes) Section A Directions: In this section, there is a passage with ten blanks. You are required to select one word for each blank from a list of choices given in a word bank following the passage. Read the passage through carefully before making your choices. Each choice in the bank is identified by a letter. Please mark the corresponding letter for each item on Answer Sheet 2 with a single line through the centre. You may not use any of the words in the bank more than once． Questions 26 to 35 are based on the following passage. Have you ever used email to apologize to a colleague Delivered a 26 to a subordinate (下属) with a voice-mail message Flown by plane across the country just to deliver important news in person The various communication options at our fingertips today can be good for 27 and productivity---and at the same time very troublesome. With so many ways to communicate, how should a manager choose the one that’s best --- 28 when the message to be delivered is bad or unwelcome news for the recipient We’ve 29 business communication consultants and etiquette (礼仪) experts to come up with the following guidelines for 30 using the alterative ways of delivering difficult messages. First of all, choose how personal you want to be. A face-to-face communication is the most 31 .Other choices, in descending order of personalization, are: a real-time phone call, a voice-mail message, a handwritten note, a typewritten letter, and the most 32 is email. Some of these may change order according to the 33 situation or your own preferences; for example, a handwritten note might seem more personal than voice mail. How do you decide on the best choice for the difficult message you’ve got to deliver “My 34 concern is: How can I soften or civilize this message” says etiquette expert Dana Casperson. “So when
2014-2019历年大学英语四级真题及答案 2014年6月大学英语四级考试真题 Part I Writing （30 minutes） Directions: For this part, you are allowed 30 minutes to write a short essay on the following question. You should write at least 120 words but no more than 180 words. Suppose a foreign friend of yours is coming to visit China, what is the first place you would like to take him/her to see and why? Part II Listening Comprehension （30 minutes） Section A Directions: In this section, you will hear 8 short conversations and 2 long conversations. At the end of each conversation, one or more questions will be asked about what was said. Both the conversation and the questions will be spoken only once. After each question there will be a pause. During the pause, you must read the four choices marked A）, B）, C）and D）, and decide which is the best answer. Then mark the corresponding letter on Answer Sheet 1 with a single line through the centre. 1. A）The man should visit the museums. B）She can’t stand the hot weather. C）The beach resort is a good choice. D）She enjoys staying in Washington. 2. A）Her new responsibilities in the company. B）What her job prospects are. C）What the customers’ feedbac k is. D）The director’s opinion of her work. 3. A）Combine her training with dieting. B）Repeat the training every three days. C）Avoid excessive physical training. D）Include weightlifting in the program. 4. A）When she will return home. B）Whether she can go by herself. C）Whether she can travel by air. D）When she will completely recover. 5. A）The woman knows how to deal with the police. B）The woman had been fined many times before. C）The woman had violated traffic regulations. D）The woman is good at finding excuses. 6. A）Switch off the refrigerator for a while. B）Have someone repair the refrigerator. C）Ask the man to fix the refrigerator. D）Buy a refrigerator of better quality. 7. A）He owns a piece of land in the downtown area. B）He has got enough money to buy a house. C）He can finally do what he has dreamed of. D）He is moving into a bigger apartment. 8. A）She is black and blue all over. B）She has to go to see a doctor. C）She stayed away from work for a few days. D）She got hurt in an accident yesterday.
2016年6月大学英语四级考试真题试卷(一)及答案 Part Ⅰ Writing ? ?? （30minutes） (请于正式开考后半小时内完成该部分，之后将进行听力考试) Directions：For this part， you are allowed 30 minutes to write a letter to express your thanks to one of your friends who helped you most when you were in difficulty. You should write at least 120 words but no more than 180 words. Part Ⅱ Listening Comprehension (25minutes) Section A Directions: In this section, you will hear three news reports. At the end of each news report, you will hear two or three questions. Both the news reports and the questions will be spoken only once. After you hear a question, you must choose the best answer from the four choices marked A), B), C) and D). Then mark the corresponding letter on Answer Sheet 1 with a single line through the centre. Questions 1 and 2 are based on the news report you have just heard. 1.A) How college students can improve their sleep habits. B) Why sufficient sleep is important for college students. C) Why college students are more likely to have stress problems. D) How college students can handle their psychological problems. 2.A) It is not easy to improve on e’s sleep habits. B) It is not good for students play video games. C) Students who are better prepared generally get higher scores in examinations. D) Making last-minute preparations for tests may be less effective than sleeping. Questions 3 and 4 are based on the news report you have just heard. 3.A) Whether more airports should be built around London. B) Whether adequate investment is being made to improve airport facilities. C) Whether the British Airports Authority should sell off some of its assets. D) Whether the Spanish company could offer better service. 4.A) Inefficient management. C) Lack of innovation and competition B) Poor ownership structure. D) Lack of runway and terminal capacity Questions 5 and 7 are based on the news report you have just heard.