全国计算机等级考试四级笔试试题五(下)-计算机等级考试
A) 4 B) 8 C) 12 D) 16
(46)在存储保护模式中,可分为:
Ⅰ.执行级(Executive),用E表示;
Ⅱ.管理级(Supervisor),用S表示;
Ⅲ.核心级(Kernel),用K表示;
Ⅳ.用户级(User),用U表示
其优先级从高到低的次序为_____。
A)SKEU B)SEUK C)KSEU D)KESU
(47)在Cache块替换算法中,下述哪种说法是错误的?_____。
A)直接映射产生块失效时,无需进行选择即可直接替换
B)全相联映射产生块失效时,可使用随机算法
C)组相联映射产生块失效时,也可使用随机算法
D)全相联和组相联解决失效时都不能采用随机算法
(48)视频电子学标准协会制定的局部总线称为_____。
A)VESA B)VISA C)PCI D)EISA
(49)在相联处理机的特点中,下述哪种说法是不下确的? _____。(2分)
A)相联处理机的核心是采用了相联存储器
B)相联存储器的特点是每个存储单元都必须有一个处理单元
C)相联存储设有若干个寄存器如比较数寄存器、屏蔽寄存器等
D)因此,相联处理机不再需要中央处理部件
(50)我国研制的银河Ⅲ型超级计算机通过基准程序的测试,其峰值速度是_____。
A)80亿次 B)100亿次 C)130亿次 D)150亿次
(51)在PSK调制方式中,如果一种modem的调制速率为9600baud,采用的是8相调制,那么这种modem的数据传输速率可达到_____。
A)14.4Kbps B)28.8Kbps C)64Kbps D)9600bps
(52)误码率是描述数据通信系统质量的重要参数之一. 对误码率人们提出了以下四种看法,请指出哪一种看法是正确的?_____。
A)误码率是衡量数据通信系统正常工作状态下传输可靠性的参数
B)当用户一次传输1Kbyte的文件时,没有发现传输错误,那么该数据传输系统的误码率为0
C)当一个数据传输系统采用CRC校验技术后,这个数据传输系统的误码率可以减少为0
D)采用光纤作为传输介质的数据传输系统的误码率为0
(53)数据通信中曼彻斯特编码的波形如下图所示:
请指出它所表示的二进制比特序列的值_____。
A)1011001101 B)1101110110 C)1001100010 D)1101001110
(54)XMODEM与Kermit协议共同之处是定义了多种类型的信息包来控制通信,过程,如采用ASCII码字符SOH表示数据包的开始、EOT表示文件传输结束等.根据数据链路层协议的分类方法,它们应属于_____。
A)面向字符型通信协议 B)面向比特型通信协议
C)随机争用型通信协议 D)网络层协议
(55)在HDLC协议执行过程中,数据链路被置为正常响应模式NRM. 如果主站发送的数据帧中,N(S)=2、P=0、
N(R)=3;从站正确接收了该帧,并有一个数据帧需要发送. 那么,从站能否立即向主站发送这个数据帧?
如果可以立即发送的话, 那么这个数据帧的控制域参数N(S)、N(R)、P/F应该是什么值?_____。(2分)
A)从站不能立即向主站发送数据帧
B)从站可以立即向主站发送数据帧,帧控制域参数N(S)=3,F=1,N(R)=3
C)从站可以立即向主站发送数据帧,帧控制域参数N(S)=3,F=1,N(R)=2
D)从站可以立即向主站发送数据帧,帧控制域参数N(S)=2,F=0,N(R)=3
(56)典型的局域网操作系统的系统容错(SFT)分为三级,最高一级系统容错采用_____。
A)磁盘镜像 B)磁盘双工 C)服务器镜像 D)网卡冗余
(57)对于IEEE 802.3、802.4与802.5 三种类型局域网互连的组合中,从802.3到802.3的网桥设计最简单,只有一种情况会产生问题,那就是 _____。(2分)
A)当转发的帧超过最大帧长度时,只能丢弃该帧
B)当局域网负载很重,待传送的帧在网桥中堆积,超过了缓冲区空间时, 只能 将帧丢弃
C)如何设置帧优先级
D)如何设置数据传输速率
(58)网络文件访问是网络系统的基本功能,TCP/IP、XNS与SNA 均有网络文件访问协议.网络文件访问包括两种不同的形式:文件传输与文件访问. 文件访问又叫做在线访问(on-lineaccess),它_____。(2分)
A)要求用户直接将远地文件全部拷贝到本地文件系统
B)允许多个远地程序同时访问单个文件,在原文件上进行操作,而没有文件拷贝过程
C)要求本地用户连入局域网中
D)要求用户通过电子邮件方式交换信息
(59)ATM是一种面向连接的快速分组交换技术,它采用虚拟通道模式, 通道标识基于两种标识符_____。
A)(N)PDU、(N)IDU
B)VPI、VCI
C)CONNECT.reguest、CONNECT.indication
D)(N)SAP、(N+1)SAP
(60)在ISO“开放系统互连管理框架”中,将网络系统管理划分为五个功能域。这五个功能域是:配置管理、故障管理、安全管理、性能管理与_____。
A)设备管理 B)用户注册管理
C)计费管理 D)域名管理
(61)What is the decimal value of the following 32-bit two’s complement number?_____.
1111 1111 1111 1111 1111 1111 1100
A) -8 B) -4 C) 4 D) 8
(62)How many subsets does A have? _____.
Let A={E,O,A,W,P,V,B}
A) 12 B) 36 C) 64 D) 128
(63)Suppose V1=,V2=,where R is the set of real numbres,+, and.are respectively addition and multiplication. Let f: R→R and f(x) = ex, which of the following propositions
is true? _____.
A) f is a surjective homomorphism from V1 to V2
B) f is an injective homomorphism from V1 to V2
C) f is an isomorphism from V1 to V2
D) None of the above
(64) P(n) is the predicate’if 4 divides n then 2 divides n’.What is the truth value of P(12)? _____.
A) 10 B) F C) T D) None of the above
(65) An algorithm to solve a given problem has time complexity
T(n)=nlog2n-(n-1)
Given that the algorithm takes 0.8 second for a problem in which n=1024,how long should it take for a problem in which n=4096?_____. (2 Points)
A) 39 seconds B) 3.9 seconds C) 3.9 minutes D) 0.8 seconds
(66) What is the definition of a Path? _____.
A) A sequence of vertices and the edges formed by each successive pair of vertices.
B) A walk with distinct vertices.
C) A walk with distinct edges.
D) None of the above
(67) The figure below shows a record used for recording information about a named event. Which of the following statement is incorrect?_____. (2 Points)
VAR r: record
event:array[1..10] of char;
place:array[1..20] o
f record
plname:array[1..15] of char;
date: array[1..5] of record
mo:1..12;
day:1..31;
year:integer
end
end
end;
A)This is a one-dimensional array of records,also called a table.
B)This is so called record of arrays;
C)The event can occur in up to 20 places and on up to 5 different dates in each place.
D)A reference to r.place[i].date[j].mo will access the month of the jth occurrence, in the ith place,of the event named in r.event.
(68)Which of the following statements is true regarding simple sort techniques? _____.(2 Points)
A)Exchange sort is frequently referred to as a bubble sort.
B)Exchange sort is the least expensive
C)If random data are in an array that is to be sorted,an Insertion Sort will give the
best performance for large elements with small sort items.
D)Both Insertion Sort and Selection Sort require O(n)moves.
(69) Which UNIX command creates a symbolic link named myfile in the current directory to the file/etc/hosts?_____.
A) In -s /etc/hosts myfile B) In -s myfile /etc/hosts
C) link -s /etc/hosts myfile D) link -s myfile /etc/hosts
(70)Which MS-DOS command is correct? _____.
A) DEL /s *.bat B) DEL *.exe/sp
C) DEL *.obj >nul: D) DEL *.com *.sys
(71)A virtual memory system has five virtual pages numbered zero through four and three page frames. All the page frames are initially empty. How many page faults are generated with the following access sequence using a FIFO replacement policy? _____.
(2 Points)
0 1 2 3 0 1 5 0 1 2 3 4
A) 8 B) 9 C) 10 D) 11
(72)Which element is NOT part of a microkernel? _____.(2 Points)
A) basic I/O B) a file system
C) IPC mechanisms D) memory management
(73)Which is local to a thread instead of a process? _____.(2 Points)
A) a stack B) an open file C) a semaphores D) an address space
(74)What is a subselect statement?
A)a select statement that selects a subset of fields in a table
B)a select statement that returns a subset of the data in a table
C)a select statement that appears within another select statement
D)a select statement that returns a subset of the constraints on a field
(75)In developing a hospital database,it is determined that on the average,each patient will have 6 treatments during a hospital stay. The averge length of a stay is three days.The hospital has 1000 beds.There are on the average 800 patientsoccupying bedseachday.The relationship between PATIENT and TREATMENT is l:M.The relationship between PATIENT and BED is 1: 1,conditional. If treatment record occurrences are archived as soon as a patient is discharded from the hospital, how many occurrences of the TREATMENT records will be stored in the TREATMENT database file on the average? _____.(2 Points)
A) 6,000 B) 4,800 C) 18,000 D)1,600
(76)Which of the following conditions will make a relation that is in first normal form to be in second normal form? _____.
Ⅰ.every non-key attribute is functionally dependent on the full set of primary key
attributes.
Ⅱ.no non-key attributes exist in the relation.
Ⅲ.the primary key consists of only one attribute.
A) Ⅰ only B) Ⅰand Ⅱ only C) Ⅰand Ⅲ only D) any of them
(77)The most commonly used locking level in implementing concurrency control is at which of the following levels? _____.
A) database B) table C) record D)field
(78)Which function is NOT served by building a prototype? _____.
A) It takes the place of the final system.
B) It assists in gathering software requirements
C) It assists in estimating the cost of the project.
D) It is used as the foundation of the larger projects.
(79)Software document is an important part of software and a basis of software development phase.It also influnces software’s _____.(2 Points)
A) Reusability B) Maintanence
C) Expansibility D) Portability
(80) Which phase of the software development requires the most development time? _____.
A) the design phase B) the testing phase
C) the maintenance phase D) the development phase
(81) Which of the following statements is correct?_____. (2 Points)
A)The definition phase results in the Software Requirements Specification.
B)Testing is optional in software life cycle.
C)CASE tools can only aid in the design phase of a software life cycle.
D)A change during a later phase does not require the documentation of all earlierphases to be updated.
(82)Black-box and white-box testing method are often used in software testing phase,in which,the white-box is mainly used to test software's_____.
A)reasonableness of structure B)correctness of a program
C)external function of a program D)internal logic of a program
(83) How does Booth's Algorithm improve binary multiplication?_____.
A) It prevents overflow. B) It prevents underflow.
C) It preserves the sign of the multiplication operation.
D) It enhances the speed of the operation significantly.
(84) A cache has 64 blocks; each block is 16 bytes.Which block does byte 1200 map to ?_____.
A) 25 B) 60 C) 75 D)100
(85) Which is NOT a characteristic of an RISC processor?_____.
A) a high clock speed
B) a highly optimized pipeline
C) a few general-purpose registers
D) a limited amount of small instructions
(86)You are performing two sums: the first is a sum of two scalar variables and the second is a matrix sum of a pair of two-dimensional arrays-size 1000 by 1000. What speedup is achieved when the calculations are performed on size 1000 processors? _____.(2 Points)
A) 50 B) 100 C) 999 D) none of the above
(87)According to Shannon's equation,what is the channel capacity of an analog voice-grade phone line with a bandwidth of 3100 Hz and a signal-to-noise ratio or 30dB?_____.(2 Points)
A) 9.1 Kbps B) 9.3 Kbps C) 30.9 Kbps D) 30.17 Kbps
(88)The X.25 standard specifies three layers of functionality. Which layers of the OSI
model correspond to the X.25 layers?_____.
A) th e Physical,Network,and Session Layers
B) the Physical,Data Link,and Network Layers
C) the Physical,Data Link,and Transport Layers
D) the Physical,Session,and Presentation layers
(89)Which routing algorithm is described below?It is a mechanism in which the setding station determines the route the frame will follow and includes the routing information with the frame; bridges read the routing information to determine if they should forward the frame._____.
A) Fixed Routing B) Spanning Tree
C) Source Routing D) Frame Forwarding
(90) Which OSI layer does a bridge operate at?_____.
A) the Physical Layer B) the Network Layer
C) the Transport Layer D) the Data Link Layer
二、论述题(两个论述题可任选其一,并只选其一,多选无效,满分30分)
论述题 1
在计算机指令集的设计与实现过程中,出现了两种对立的技术路线或风格,即CISC 与RISC.
(1) 指出 CISC 的主要弊病.(8分)
(2) 概述 RISC 技术的基本要点.(12分)
(3) Intel X86 系列属于哪一种风格,当前它采用的是怎样的技术路线.(10分)
论述题 2
人们在管理实践中发现,数据库技术是信息资源的整理、保存、 管理和使用的最有效的手段。数据库按其数据结构模型分类,通常可分为层次型数据库、网络型数据库、关系型数据库和面向对象型数据库,各种类型的数据模型都有自身的特点。试从关系数据模型的优点和弱点论述:
(1)为什么人们在开发以事务处理为主的信息系统(例如管理信息系统)时, 大多选用关系型数据库作为开发环境?(18分)
(2)在许多含有复杂数据结构或丰富语义的实际应用领域中, 为什么要选用面向对象数据库或要对关系型数据库作某些扩充和修改?(12分)