计算机专业英语课后答案清华大学出版社第二版.pdf

第一章 Computer system overview 操作系统概述 I Pre reading Questions 1 What is a digital computer The digital computer is a digital system that performs various computational tasks The word digital implies that theinformation in the computer is represented by variables that take a limited number of discrete values These values are processed internally by components that can maintain a limited number of discrete states Digital computer is also called electronic computer or computer 2 Are there any differences between the binary number system and the common decimal number system The decimal digits has ten digits 0 1 2 and 9 The binary number system has two digits 0 and 1 The binary numbers use a base 2 The decimal digits use a base 10 3 How many types of computers do you know Name at least four of them Computers are usually classified into four broad categories microcomputers minicomputers mainframe computers and supercomputers II Fill in the following blanks 1 Application software is designed to accomplish real world tasks in fields 2 An 8 bit signed integer can have any value between 128 and 127 3 System software controls the computer and enables it to run the hardware and applications software 4 A computer system consists of hardware system and software system 5 List four types of computers microcomputers minicomputers mainframe computers and supercomputers III True or False 1 The software system is the physical equipment that you can see and touch 1 F 2 Typically a data value is set to zero to represent FALSE and 1 value forTRUE 2 F 3 In the earliest general purpose computer most input and output media were magnetic disks 3 F 4 Supercomputers are largest fastest and most expensive computer available 4 T 5 A computer system consists of hardware system and software system 5 T IV Matching terms 1 b CPUThe processing unit is at the heart of a computer 2 c bit A unit of information conveyed by a single binary digit 3 a integrated circuit IC A complete electronic circuit that packages transistors and other electronic components on a small silicon chip 4 d ASCII A system for encoding characters as binary digits V Translating Terms 1 coding techniques 编码技术 2 application software 应用软件 3 floating point data 浮点数据 4 timesharing 分时 分时技术 5 storage capacities 存储容量 VI Choose the best one of the four answers given to fill in each blank This chapter introduces digital computer data types the evolution of computers and types of computers 1 is known to all it s hard to find a field in 2 computers are not being used Digital computer also called electronic computer or computer is a digital system that 3 various computational tasks Digital computers use the 4 number system which has two digits 0 and 1 By using various coding 5 groups of bits can be made to represent not only binary numbers 6 other discrete symbols such as decimal digits or letters of the alphabet A computer system consists of hardware system and software system Programs tell the hardware what to do 7 software is designed to accomplish real world tasks in fields such as accounting entertainment and engineering Computers are usually 8 into four broad categories microcomputers minicomputers mainframe computers and supercomputers It s hard to give a 9 definition to each type because computer speeds and storage 10 change rapidly 1 A As B It C As it D That 2 A what B which C where D when 3 A performs B carries C makes D integrates 4 A decimal B binary C Arabian D American 5 A technique B Technology C techniques D technologies 6 A instead of B rather than C but also D as well 7 A Application B System C Word D Excel 8 A put B made C conducted D classified 9 A precious B progress C proceeding D precise 10 A capacities B capable C capabilities D capacity 1 A 2 B 3 A 4 B 5 C 6 C 7 A 8 D 9 D 1 0 C VII Translate the following into English 1 By using various coding techniques groups of bits can be made to represent not only binary numbers but also other discrete symbols 通过应用各种编码技术 一组二进制不但可以表示二进制数据 而且还可以表示其他离散符 号 如十进制数字或字母表中的字母 2 System software includes not only the complex programs used by technicians to create application software in the first place but also the organizational programs needed to start up the computer and govern its use of other programs 另一方面 系 统软件控制计算机系统 它不仅包括专业人员用于创建应用软件的复杂程序 而 且还包括用于启动计算机和提供给其它程序使用的管理程序 3 Data are numbers and other binary code information that are operated on to achieve required computational results 数据是数字和其他二进制代码信息 这些二进制代 码信息是可操作并能满足要求的计算机结果 4 4 Rather than arithmetically or logically manipulating characters a computer may concatenate strings of characters replace some characters with others or otherwise manipulate character strings 计算机能将若干字符连成串 而不是用算术方法或逻 辑方法处理字符 用串代替其它字符或另行处理字符串 5 Software applications like word processing electronic spreadsheets database management programs painting and drawing programs desktop publishing and so forth became commercially available giving more people reasons to use a computer 软件应用像文字处理 电子表格 数据库管理程序 画图程序及桌面印刷等等起 到一定的商业效力 使更多的人去使用计算机 第二章 Computer System Organization I Pre reading Questions 1 What is a computer system A computer system consists of hardware system and software system The hardware of the computer is usually divided into three major parts or three primary subsystems the CPU the memory subsystem and the I O subsystem The software system can be divided into two broad categories application software and system software 2 How many levels of memory hierarchy do you know Name at least three of them The memory hierarchy system consists of three levels They are a cache the main memory and the auxiliary memory 3 Identify the types of data transfer modes Data transfer has three modes programmed I O interrupts and direct memory access DMA II Fill in the following blanks 1 The computer hardware consists of three major parts which are the CPU the memory subsystem and the I O subsystem 2 There are two major types of memory Random Access Memory RAM and Read Only Memory ROM 3 The cache memory in personal computers is constructed from SRAM 4 input output interface I O interface provides a method for transferring information between internal storage and external I O devices 5 Data transfer between the central computer and I O devices may be handled in a variety of modes These modes are programmed I O interrupts and direct memory access DMA IIITrue or False 1 FThe data bus always receives data from the CPU and the CPU never reads the data bus 2 TMain memory holds whatever programs and data are available for immediate use by the CPU 3 FDynamic RAM does not have to be refreshed 4 FDot matrix printer work by squirting tiny droplets of liquid ink at the paper 5 FThe auxiliary memory is very small relatively expensive and has very high access speed IV Matching terms 1 E2PROM an electrically erasable PROM 2 DMAA transfer mode that can be improved is the transfer of data between memory and I O devices 3 ALU The unit which performs most arithmetic and logical operations 4 RAM Memory that is erased when the computer is turned off V Translating Terms 1 system buses 系统总线 2 virtual memory 虚拟存储器 3 computer architecture 计算机体系结构 4 instruction set 指令集 5 direct memory access 直接存储器存取 VI Choose the best one of the four answers given to fill in each blank A computer system 1 of hardware system and software system The hardware of the computer is usually divided into three major parts or three 2 subsystems the CPU the memory subsystem and the I O 3 The CPU is made up of three major parts Register Set the 4 logic unit or ALU and Control Unit It performs many operations and controls computer Memory is also known as 5 memory or main memory which is cataloged into two major types of memory Random Access Memory RAM and Read Only Memory ROM It refers to the 6 in the computer that hold whatever programs and data are available 7 immediate use by the CPU along with the program s data Computer systems include special hardware 8 between the CPU and peripherals to supervise and synchronize all input and output transfers These components are called 9 units because they interface between the processor bus and the peripheral device The I O subsystem allows the CPU to 10 with input and output devices 1 A Consists B makes up C Constitutes D comprise 2 A premier B Primary C preliminary D elementary 3 A system B machine C subsystem D device 4 A mathematic B authorative C Arithmetic D authoritative 5 A external B exterior C Interior D internal 6 A circuits B wires C lines D hardware 7 A by B for C with D in 8 A software B setting C listing D components 9 A singular B dual C interface D compact 10 A handle B interact C respond D link 1 A 2 B 3 C 4 C 5 D 6 A 7 B 8 D 9 C 10 B VII Translate the following into English 1 By asserting these internal and external control signals in the proper sequence the control unit causes the CPU and the rest of the computer to perform the operation needed to correctly process instructions 为了保证内部和外部控制信号的序列正确 控制单元保证CPU 和计算机的其他 部件提供需要正确执行的指令操作 2 In a computer with virtual memory less used parts of programs are shifted from RAM to a hard disk and are moved back only when needed 在使用了虚拟存储器的计算机中 很少使用的程序从RAM 被移到硬盘中 仅当 需要时才被移回来 3 A technique used to compensate for the mismatch in operating speeds is to employ an extremely fast small cache between the CPU and main memory whose access time is close to processor logic clock cycle time 为了弥补操作速度的不匹配 在CPU 和主存之间采用非常快的小缓存 它的存 取时间接近于处理器的逻辑时钟周期 4 The data transfer rate of peripherals is usually slower than the transfer rate of the CPU and consequently a synchronization mechanism may be needed 外设的数据传输速率通常比CPU 的传输速率慢 因此就需要一个同步装置 5 In some computers the interrupt vector is an address that points to a location in memory where the beginning address of the I O service routine is stored 在一些计算机中 中断向量是一个地址 它指向存储器中存储I O 服务程序起始 地址的单元 第三章 Computer system architecture I Pre reading Questions 1 How many types of parallel processing do you know Name at least four of them There are a variety of ways that parallel processing can be classified One classification introduced by M J Flynn considers the organization of a computer system by the number of instructions and data items that are manipulated simultaneously Flynn s classification divides computers into four major groups as follows 1 Single instruction stream single data stream SISD 2 Single instruction stream multiple data stream SIMD 3 Multiple instruction stream single data stream MISD 4 Multiple instruction stream multiple data stream MIMD 2 What is a pipelining Pipelining is a technique of decomposing a sequential process into suboperations with each subprocess being executed in a special dedicated segment that operates concurrently with all other segments 3 What is a RISC RISC processors exclude these instructions opting for a smaller instruction set with simpler instructions II Fill in the following blanks 1 It is characteristic of pipelines that several computations can be in process in distinct segments at the same time 2 The overlapping of computation is made possible by associating a register with each segment in the pipeline 3 The vector instruction includes the initial address of the operands the length of the vector and the operation to be performed 4 RISC processors have fewer and simpler instructions than CISC processors 5 The sequence of instructions read from memory constitutes an instruction stream The operations performed on the data in the processor constitutes a data stream III True or False 1 Shift registers operate in serial fashion all the bits of the word at a time 1 F 2 RISC processors have larger instruction sets that often include some particularly complex instructions 2 F 3 SIMD represents an organization that includes many processing units under the supervision of a common control unit 3 T 4 Parallel processing is established by distributing the data among the multiple functional units 4 T 5 RISC is a complex instruction set computer 5 F IV Matching terms a SISD b SIMD c MISD d MIMD 1 c multiple instruction stream single data stream 2 b single instruction stream multiple data stream 3 d multiple instruction stream multiple data stream 4 a single instruction stream single data stream V Translating Terms 1 parallel processing 1 并行处理 2 pipeline processing 2流水线处理 3 vector processing 3 向量处理 4 scalar processor 4 标量处理器 1 5 backward compatibility 5 向下兼容 VI Choose the best one of the four answers given to fill in each blank In computer engineering computer architecture is the 1 design and fundamental operational structure of a computer system It is a 2 and functional description of requirements especially speeds and interconnections and design implementations for the various parts of a computer 3 largely on the way by which the central processing unit CPU performs internally and accesses addresses in memory Computer system architecture 4 the design of the four 5 parallel processing pipelining vector processing and RISC Parallel processing system is used to provide simultaneous data processing tasks for the purpose of increasing the 6 speed of a computer system and is able to perform 7 data processing to achieve faster execution time A pipeline is a set of data processing elements connected in series so that the output of one element is the input of the next one The elements of a pipeline are often 8 in parallel or in time sliced fashion A vector processor is a CPU design that is able to run mathematical operations on multiple data elements simultaneously Computers with vector processing capabilities are in demand in 9 applications RISC processors have fewer and 10 instructions than CISC processors As a result their control units are less complex and easier to design 1 A lastest B conceptual C ideal D simple 2 A plan B design C blueprint D concept 3 A relying B depending C attaching D focusing 4 A refers B speaks C involves D interacts 5 A ingredients B types C kinds D lists 6 A computational B computer C computation D computing 7 A current B compound C concurrent D massive 8 A displayed B carried C accomplished D executed 9 A special B specialized C specific D especial 10 A simple B simplifying C singular D Simpler 1 B 2 C 3 D 4 C 5 A 6 A 7 C 8 D 9 B 10 D VII Translate the following into English 1 The purpose of parallel processing is to speed up the computer processing capability and increase its throughput that is the amount of processing that can be accomplished during a given interval of time 1 并行处理的目的是加快计算机的处理速度并增加其吞吐量 所谓吞吐量是指 在规定的时间间隔内所完成的指令 2 It is characteristic of pipelines that several computations can be in process in distinct segments at the same time 2 流水线的特征就在于在同一时间里可以在不同的子过程中处理几个不同的运 算 3 To achieve the required level of high performance it is necessary to utilize the fastest and most reliable hardware and apply innovative procedures from vector and parallel processing techniques 3 只有采用最快和最可靠的硬件并应用向量处理和并行处理等新技术才能获得 这些高性能的处理能力 4 In general the greater the number of instructions in an instruction set the larger the propagation delay is within the CPU 4 一般来说 指令集中的指令数量越多 CPU 内部的传播延迟时间就越长 5 Although CISC processors are more complex this complexity does not necessarily increase development costs 5 虽然 CISC 处理器更为复杂 但这并不一定必然会导致开发成本的增加 第四章 Algorithms and Data Structure I Pre reading Questions 1 What is an algorithm An algorithm is an ordered set of unambiguous executable steps defining a terminating process 2 Name at least four of algorithmic techniques 1 Brute force Algorithms 2 Divide and Conquer Algorithms 3 Dynamic Programming 4 Greedy Algorithms 3 How many classes of data structures do you know Name at least four of them The data structures have five classes They are the array list linked list stacks and queues a tree II Fill in the following blanks 1 Each primitive consists of two parts its syntax and its semantics 2 A pseudocode is a notational system in which ideas can be expressed informally during the algorithm development process 3 The running time is refer to the computational time required by an algorithm 4 We define the worst case running time of an algorithm to be the maximum running time of that algorithm over all possible inputs of size n 5 A list is one of the most fundamental data structures used to store a collection of data items III True or False 1 A number of different algorithms can exist for solving a computational problem and each of these algorithms could have a same running time complexity F 2 The divide and conquer algorithm is a bottom up technique that usually begins by solving the smallest subproblems the dynamic programming solves problems in a top down fashion F 3 An important property of arrays is that their size and shape are constant T 4 If all of the elements stored in a list are of the same type then the list is said to be heterogeneous However if different types of elements are stored in the list then the list is said to be homogeneous F 5 A queue is a dynamic set that obeys the LIFO property F IV Answer the following question 1 List the steps involved in a divide and conquer algorithm 1 The steps involved in a divide and conquer algorithm can be summarized as follows First divide the original problem into a number of subproblems Next solve i e conquer the subproblems If the subproblems are small enough they should be solved directly otherwise they should be solved recursively Finally combine the solutions to the subproblems to produce the final solution 2 List approach that is often used to solve optimization problems Brute force Algorithms Divide and conquer Algorithms Dynamic Programming Greedy Algorithms Randomized Algorithms 3 Describe differences between a binary tree and a tree The essential differences between a binary tree and a tree as follows A binary tree can be empty whereas a tree cannot Each node in a binary tree has exactly two subtrees one or both of these subtrees may be empty Each node in a tree can have any number of subtrees The subtrees of each node in a binary tree are ordered The subtrees in a tree are unordered V Tran