专业英语课后习题答案Chapter1I. 1.Application software2. -128 1273. system software4. hardware system software system5.microcomputers, minicomputers, mainframe computers, supercomputersII. 1. false 2. false 3. false 4. true 5.trueIII. (1) b (2) c (3)a (4) dIV. (1)编码技术(2)应用软件(3) 浮点数据(4)分时(5)存储容量VIII．1.By using various coding techniques, groups of bits can be made to represent not only binary numbers but also other discrete symbols通过应用多种编码技术，一组二进制数字不但可以表示二进制数据，而且还可以表示其它的离散符号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.系统软件不仅包括技术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他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.数据是数字和其他的二进制代码信息，通过处理这些数据得到所需要的计算结果。
4.Rather than arithmetically or logically manipulating characters, a c omputer 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，用一些字符代替其他字符或另行处理字符串，而不是用算术方法或逻辑方法处理字符。
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、绘图程序及桌面印刷等进入商业市场，使更多的人去使用计算机。
Chapter2I. 1. the I/O subsystem2. Read Only Memory(ROM)3. SRAM4. I/O interface5. interruptsII. 1. false 2. true 3. false 4. false 5.falseIII. 1. c 2. d 3. a 4. bIV. 1.系统总线 2.虚拟存储器 3.计算机体系结构 4. 指令集 5.直接存储器读取VIII.1.By asserting these internal and external control signals in the proper sequence, the control unitcauses the CPU and the rest of the computer to perform the operation needed to correctly process instructions.通过维护内部和外部控制信号的正确顺序，控制单元促使CPU和计算机的其他部件根据正确的处理指令完成操作。
2.In a computer with virtual memory, less-used parts of programs are shifted from RAM to ahard disk and are moved back only when needed.在使用了虚拟存储器的计算机中，很少使用的程序被从RAM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 anextremely fast, small cache between the CPU and main memory whose access time is close to processor logic clock cycle time.用于弥补操作速度的不匹配的一项技术是在CPU和内存之间采用非常快的小容量高速缓冲存储器，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, andconsequently, a synchronization mechanism may be needed.外部设备的数据传输速率通常比CPU的数据传输率更慢，相应的，需要一种同步机制。
5.In some computers the interrupt vector is an address that points to a location in memory wherethe 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 服务程序其实地址的单元。
Chatper3I. 1. pipelines 2. the overlapping of computation 3. the length of the vector4. RISC CISC5. instruction stream data streamII. 1. false 2. false 3. true 4. true 5. falseIII. MISD, SIMD, MIMD, SISDIV. 1.并行处理 2.流水线处理3.向量处理4.标量处理器5.向下兼容VIII. 1.The purpose of parallel processing is to speed up the computer processing capability and increase its throughout, that is, the amount of processing that can be accomplished during a given interval of time.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，所谓吞吐量是在制定规定的时间间隔内所完成的指令。
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.为了获得所需要的高性能，有必要采用最快和最可靠的硬件并应用向量处理与并行处理等新技术的革新过程。
4. 总的来说，指令集中的指令书越多，CPU中的传播延迟越大。
5.尽管CISC处理器更为复杂，但这并不一定导致开发成本的增加。
Chapter4I. 1. its syntax, its semantics 2. pseudocode 3. running time 4. maximum 5. listII. a. false b. false c. true d. false e. falseIII. 1.First, divide the original problem into a number of subproblems.Next, solve the subproblems.2. dynamic programmingThe greedy strategy3. a binary tree can be empty, whereas a tree cannot.Each node in a binary tre has exactly two subtrees. Each node in a tree can have any number of subtrees.The subtrees of each node in a binary tree are ordered. The subtree in a tree are unordered. IV. 1.并行算法 2.穷举查找 3.动态规划（动态程序设计）4.双链表 5.二维数组VIII 1.简而言之，算法描述所采用的语言不具有精确的定义或者信息不够详细也会使交流产生问题。
2. 另一种常见的算法结构是当条件为“真”时，循环执行一条语句或者语句序列。
3.在众多算法中，影响运行时间的不仅有不同长度的输入，也包括相同长度的不同输入。
4.因此，动态程序设计是一种从下而上的方法，这种方法通常先解决最小的子问题，并保存其解，再利用这些解对较大问题求解，一步一步地进行直至得到原问题的解。
5.从这种概念性的一维的方式到机器内存中的实际安排的转换是非常直接的。
这些数据可以保存在由程序员想象的相同顺序的24个相邻的内存单元中。
Chapter5I．1. user documentation, operator documentation, programmer documentation2. program3. machine language4. 4GLs5. Natural languagesII. 1. false 2. false 3. false 4. true 5. trueIII1. the first step: problem definitionThe second step: program designThe third step: program codingThe fourth step: program testingThe fifth step: program documentation and maintenance2. machine language、assembly language、high-level language、very-high-level language、natural language3. High-level language programs are compiled, assembly language programs are assembled.High-level languages are platform-independent, the same high-level source code can be compiled to run on different microprocessor and operating systems. Each assembly language is specific to one microprocessor and assembly language programs usually run on only one platform. IV. 1.派生类 2.继承 3.标记语言 4. 超链接5.Java虚拟机VIII. 1.与程序设计相关的每一个人-用户、操作员和程序员都需要文档。