《计算机专业英语（第4版）》Unit 2 Software Knowledge

Unit 2 Software Knowledge 2.1 C Language 2.2 Data Structure
2.3 Operating System 2.4 Database Technologies 2.5 P
rinciples of Compiler 2.6 Software Engineering 2.7 计算机专业英
语的阅读与翻译 2.8 习题答案与参考译文2.1 C Language2.1.1 Text AC is a gener
al-purpose, structured programming language. Its instructions con
sist of terms that resemble algebraic expressions, augmented by c
ertain English keywords such as if, else, for, do and while. C wa
s developed in the early 1970s. C might best be described as a “m
edium-level language.” Compared to most high-level language, C ha
s a very small set of constructs.In addition, unlike most high-le
vel language, C lets you easily do chores (such as bit and pointe
r manipulation) additionally performed by assembly language. Stru
ctured languageIn C, all subroutines are discrete functions. Func
tions are the building blocks of C, in which all program activity
occurs. They allow you to define and code specific tasks in a pr
ogram separately. Program execution must begin with a function ca
lled main (). Other functions included in the program are named b
y the programmer. Characteristics C is characterized by the abili
ty to write very concise source programs, due in part to the larg
e number of operators included within the language. It has a rela
tively small instruction set, though actual implementations inclu
de extensive library functions which enhance the basic instructio
ns. Another important characteristic of C is that its programs ar
e highly portable, even more so than with other high-level langua
ges. Key Words algebraic 代数的，关于代数的as
sembly 汇编，装配，集合augment
增强，加强compartmentalization 划分，分门别类compi
ler 编译器creep
蔓延，爬行debug 调试Ke
y Words flexibility 灵活性，适应性levera
ge 杠杆作用nest
嵌套，一套物件portable
手提的，轻便的resemble 相似，一致，类似standard
ized 标准的，定型的strictly
严格地，完全地Notes [1] However, compared to most high
-level language, C has a very small set of constructs. 说明：本句中的 “c
ompared to”的含义是“将…与…比较”。译文：与大多数高级语言相比，C语言有一个小的结构集。Notes [2] Alth
ough the term block-structured language does not strictly apply t
o C in an academic sense, C is informally part of that language g
roup.说明：本句中“Although”引导的是让步状语从句。译文：尽管块结构语言这个术语从学术上考虑并不能严格地应用于C语言，
但是C语言是那个语言族的非正式成员。Notes [3] C compilers are commonly available f
or computers of all sizes, and C interpreters are becoming increa
singly common.说明：本句是一个并列句，“C compilers”和“C interpreters”是主语。译文：C语
言的编译程序普遍适用于各种容量的计算机，并且C语言的解释程序正变得越来越普通。Notes [4] Thus, every ver
sion of C is accompanied by its own set of library functions, whi
ch are written for the particular characteristics of the host com
puter.说明：本句中的“which are written for…”做非限定性定语从句，修饰“library functio
ns”。译文：因此，每个版本的C语言都伴有它自己的库函数集，这些库函数集是按主机的特点而编写的。2.1.2 Text B The
difference between a declaration and a definition in C is subtle
but important. A declaration associates a data type with an iden
tifier but does not actually allocate any storage for it. A defin
ition, on the other hand, actually allocates memory. There are th
ree ways that you create a global variable: Create a variable at
the top-level with the extern storage class specifier. Create a v
ariable at the head-of block with the extern storage class specif
ier.Create a variable at the top-level and omit a storage class s
pecifier. In C language, every global variable can be declared ze
ro or more times (in different files), but must be defined at lea
st once, and may be defined more than once in different files. Th
e scope of a variable is the region in source code over which the
variable is active. There are four types of scope: BlockFunction
File ProgramKey Words anew 从新，又declar
ation 声明definition 定义dura
tion 持续时间，持续explicitly
明白地，明确地identifier 标识符initializer
初始程序，初始化remainder 剩余的，留存下的sco
pe 范围，眼界，地域specifier
区分符，分类符subtle 微小的2.1 C Language
习题答案1. Translate the following phrases into English高级语言
high-level language源代码 source co
de全局变量 global variable数学公式
mathematical equation库函数 library function2.
Translate the following phrases into Chinesestructured programmi
ng language 结构化编程语言machine language
机器语言local variable 局部变量run-time system
实时系统assembly language 汇编语言3
. Identify the following to be True or False according to the tex
tF T F T T4. Reading Comprehensiond Fixed variablesa sour
ce codea 1970sd calling function2.2 Data Structure2.2.1 Tex
t AA data structure is a data type whose values are composed of c
omponent elements that are related by some structure. If we provi
de a set of possible data values and a set of operations that act
on the values, we can think of the combination as a data type. D
ata typeLet us look at two classes of data types. We will call an
y data type whose values we choose to consider atomic an atomic d
ata type. We will call any data type whose values are composed of
component elements that are related by some structure a structur
ed data type, or data structure. Object-oriented data structure O
bject-oriented software development is a contemporary approach to
the design of reliable and robust software. The object-oriented
approach emphasizes the role of objects, along with their attribu
tes and operations, that form the nucleus of the solution. Object
-oriented data structure From the point of view of deciding which
data structure should represent that attributes of objects in a
specific class, the emphasis that the object –oriented approach p
laces on abstraction is very important to the software developmen
t process. Abstraction means hiding unnecessary details. The stru
ctured data and its related operations could be encapsulated in a
single object which may be reused and easily upgraded, augmented
, replaced. Key Words abstract 抽象，摘要atomic
原子的，极微的contemporary 当代的，现代的dec
omposable 可分解的encapsulation 封装，压
缩essence 本质，实质，精华，要素extendibility
可扩充性，可扩展性，可延伸性illustration
说明，例证ingredient 组成，成分quantity 数
量，定量representational 代表的，表现的unbounded
无限的，无边际的，极大的Notes [1] A data structure is a data type
whose values are composed of component elements that are related
by some structure.说明：由whose引导的限定性定语从句修饰a data type，that引导的限定性定语从句
修饰component elements。译文：数据结构是一种数据类型，其值是由与某些结构有关的组成元素所构成的。Notes [2
] The essence of a data type is that it attempts to identify qua
lities common to a group of individuals or objects that distingui
sh it as an identifiable class or kind.说明：本句由两个复合句构成，均由that引导。第一个
that引导表语从句；第二个that引导限定性定语从句，修饰qualities，it代表a group of individual
s or objects。译文：数据类型的本质是标识一组个体或目标所共有的特性，这些特性把该组个体作为可识别的种类。Notes [
3] After an abstraction and representation are chosen, there are
competing methods to encapsulate data structures.说明：句中的“After”引导
的是时间状语从句。译文：在选择了抽象和表示后，就有各种不同的方法来封装数据结构。Notes [4] Object-Oriente
d programming differs from procedural programming because it uses
objects as data structure.说明：句中的“because”引导的是原因状语从句。译文：由于面向对象程序设
计把对象当作数据结构，所以它不同于过程程序设计。2.2.2 Text BA stack is a data type whose
major attributes are determined by the rules governing the inser
tion and deletion of its elements. The only element that can be d
eleted or removed is the one that was inserted most recently. Suc
h a structure is said to have a last-in/first-out (LIFO) behavior
, or protocol. The line of people waiting for service at a bank o
r for tickets at a movie theater and the line of autos at a traff
ic light are examples of queues. Contrary to a stack, in which th
e latest element inserted is the first removed or served, in queu
es the earliest element inserted is the first served. In social s
ettings, the rule appeals to our sense of equality and fairness.
There are many applications of the first-in/first-out (FIFO) prot
ocol of queues in computing. The jobs and I/O requests are servic
ed in order of their arrival, that is, the first in is the first
out. There is a second kind of queue that is important. When a ca
ll is made to a new function, all the variables local to the call
ing routine need to be saved by the system, since otherwise the n
ew function will overwrite the calling routine’s variables. When
there is a function call, all the important information that need
s to be saved, such as register values and the return address, is
saved “on a piece of paper” in an abstract way and put at the to
p of a pile. Key Words appeal 要求，呼吁，倾向于
assign 分派，指派，赋值conflict
冲突，矛盾deletion 删除emergency 紧急，
应急injured 受伤的，受损害的insertion
插入overflow 溢出pile
堆priority 优先权，优先级
recursion 递归，循环routine
例行的，常规的，程序stack 栈，堆栈survive
生存2.2 Data Structure 习题答案1. Translate th
e following phrases into English内部结构 internal
construction数据类型 data type结构数据类型 s
tructured data type算术表达式 arithmetic expression函数调用
function call2. Translate the following phras
es into Chineselast in/first out 后进先出atomic d
ata type 原子数据类型stack space
堆栈空间data structure 数据结构return address
返回地址3. Identify the following to be True or False ac
cording to the textT F T F T4. Reading Comprehensionc
either component values or component elementsa an atomic data ty
ped first-in/first-outb first-in/last-out2.3 Operating System2
.3.1 Text AThe purpose of an operating system is to provide an e
nvironment in which a user may execute programs. The first operat
ing systems were developed by manufactures for the computers in t
heir product line. Today, however, the trend is away from operati
ng system limited to a specific model and toward operating system
s that will run on any model by a particular manufacturer. There
are many important reasons for learning operating system; the mos
t notable are:The user must interact with the operating system in
order to accomplish task since it is his primary interface with
the computer;The selection of the operating system and its option
s is a major decision for most computer installations;Many concep
ts and techniques found in operating systems have general applica
bility in other applications;For special-purpose usage you may ha
ve to design your own operating system or modify on existing one.
An operating system is similar to a government. The operating sys
tem provides the means for the proper use of these resources in t
he operation of the computer system. A computer system has many r
esources which may be required to solve a problem: CPU time, memo
ry space, file storage space, input/output devices, and so on. Th
e operating system acts as the manager of these resources and all
ocates them to specific programs and users as necessary for their
tasks.Operating systems are either single-tasking or multitaskin
g. All modern operating systems are multitasking and can run seve
ral processes simultaneously. In most computers there is only one
CPU, so a multitasking operating system creates the illusion of
several processes running simultaneously on the CPU. The operatin
g system sets up the order in which programs are processed, and d
efines the sequence in which particular jobs are executed. The te
rm job queue is often used to describe the series of jobs awaitin
g execution. The operating system weighs a variety of factors in
creating the job queue. Key Words applicability
应用性，适用性bookkeeping 簿记，记帐environment 环境fundamen
tal 基本的，原则government 政府，政体hand
le 操作，操纵illusion
幻影，错觉installation 安装mechanism
机制Key Words perceptible 可察觉的，看得见的preserve
保存，维持primitive 原始的，基本的proper
适当的，正式的reasonable 合理的，适当的resource
资源responsibility 职责，责任suspend 暂停，挂起vendor
供应商，卖主Notes [1] An operating system is a progra
m, which acts as an interface between a user of a computer and th
e computer hardware.说明：由“which”引导非限定性定语从句，修饰“program”。译文：操作系统是一种程
序，它是用户与计算机硬件之间的接口。Notes [2] Since there may be many, possibly co
nflicting, requests for resources, the operating system must deci
de which requests are allocated resources to operate the computer
system fairly and efficiently.说明：本句由“Since”引导原因状语从句，主语是“the oper
ating system”，“which requests are allocated…”是宾语从句。译文：因为有许多资源请求方面
可能存在冲突，操作系统必须决定给哪些请求分配资源以便计算机系统能合理而有效地运行。Notes [3] The most commo
n mechanism used to create this illusion is time slice multitaski
ng, whereby each process is run individually for a fixed period o
f time.说明：过去分词短语used to create this illusion作定语，修饰mechanism；由wher
eby引导的是非限制性定语从句。译文：产生这种错觉的最常用机制是时间分割多任务处理，以每个进程各自运行固定的一段时间的方式来实现的
。Notes [4] A very important responsibility of any operational so
ftware is the scheduling of jobs to be handled by a computer syst
em.说明：这里的“to be handled by a computer system”是不定式短语作定语。译文：操作软件的一个
非常重要的职责是调度计算机系统将要处理的作业。2.3.2 Text BWindows XP is the next versio
n of Microsoft Windows beyond Windows 2000 and Windows Millennium
. Windows XP is built on an enhanced Windows 2000 code base, with
different versions aimed at home users and business users.LinuxL
inux is an operating system, which acts as a communication servic
e between the hardware and the software of a computer system. Unl
ike Windows, Linux is inherently modular and can be easily scaled
into compact configurations.Open-source Linux has created a new
operating system development and support paradigm wherein thousan
ds of developers continually contribute to a constantly evolving
Linux code base. Windows VistaWindows Vista is the latest generat
ion of Microsoft’s operating system. As Microsoft’s newest operat
ing system, Vista has introduced “Life Immersion” concept for the
first time, namely, it integrates many human factors in the syst
em and everything is people-oriented, causing the operating syste
m to close to the user as best as possible, to understand user’s
feeling, and to make convenience for the user.Key Words boost
促进，提高，增加cadre
核心，骨干confidently 确信地，肯定地，自信地consolidate
合并，联合inherently 固有地，天性地inno
vative 革新的，创新的manageability 易
管理，易处理paradigm 范例，样式robustness
坚固性，健壮性strength 力度，力量，强度surpass
超过，优于2.3 Operating System 习题答案1. Trans
late the following phrases into English文件存储空间 file s
torage space多用户系统 multi-user system操作系统
operating system资源管理器 resource manag
er作业队列 job queue2. Translate the following p
hrases into Chineseallocate resource 分配资源multi-task
多任务 single-task 单任务 dynami
c audio-video output 动态音频—视频输出graphics function
图形功能3. Identify the following to be True or False according
to the text T F F T T4. Reading Comprehensionc operating sy
stemc job queuea 800 MHzd source code2.4 Database Technologie
s2.4.1 Text AA database-management system (DBMS) consists of a c
ollection of interrelated data and a set of programs to access th
ose data.Database systems are designed to manage large bodies of
information. The storage structure and access methods used by the
database system are specified by a set of definitions in a speci
al of DDL called a data storage and definition language. Transact
ion ManagementA transaction is a collection of operations that pe
rforms a single logical function in a database application. Each
transaction is a unit of both atomicity and consistency. Thus, we
require that transactions do not violate any database-consistenc
y constraints. Storage ManagementDatabase typically requires a l
arge amount of storage space. Corporate databases are usually mea
sured in terms of gigabytes or, for the largest databases, teraby
tes of data. The performance of a system depends on what the effi
ciency is of the data structures used to represent the data in th
e database, and on how efficiently the system is able to operate
on these data structures. A storage manager is a program module t
hat provides the interface between the low-level data stored in t
he database and the application programs and queries submitted to
the system.The storage manager translates the various DML statem
ents into low-level file-system commands. Key Words anomalous
不规则的，反常的burden 负担，
责任compilation 编辑，编纂consistent
一致的，坚持的diminish 使减少，使变小elsewh
ere 在别处，到别处impetrative
祈求，恳求implementation 实行，履行Key Words inconsisten
cy 不一致性interaction 合作，互动，
互相影响interrelate （使）相互关联metadata
元数据provision 提供，收集，预备，准备ter
abyte 太字节，万亿字节tradeoff
交换，交易，折中trillion 万亿unaut
horized 未经许可的Notes [1] In addition, the databa
se system must provide for the safety of the information stored,
despite system crashes or attempts at unauthorized access.说明：此句中“
despite”引导的是让步状语从句。译文：另外，数据库系统还必须提供所存储信息的安全性保证，即使在系统崩溃或有人企图越权访问时也
应保障信息的安全性。Notes [2] The storage structure and access methods use
d by the database system are specified by a set of definitions in
a special of DDL called a data storage and definition language.说
明：“The storage structure and access methods”是本句的主语，而“used by the
database system”做主语的定语。译文：数据库系统所使用的存储结构和访问方式通过一系列特殊的DDL语句来定义，这种特殊
的DDL语句称作数据存储定义语言。Notes [3] The goal of a database system is to si
mplify and facilitate access to data.说明：“to simplify and facilita
te access to data”作表语，“a database system”是定语，修饰主语“the goal”。译文：数据
库系统的目标是要简化和辅助数据访问。Notes [4] If the response time for a request i
s too long, the value of the system is diminished.说明：本句中，“If the
response time for a request is too long”做条件状语从句，“the system”作主语的定
语。译文：如果一个请求的响应速度太慢，系统的价值就会下降。2.4.2 Text BA data warehouse is a r
epository (or archive) of information gathered from multiple sour
ces, stored under a unified schema, at a single site. Once gather
ed, the data are stored for a long time, permitting access to his
torical data. Figure 2-1 shows the architecture of a typical data
warehouse, and illustrates the gathering of data, the storage of
data, and the querying and data-analysis support. Among the issu
es to be addressed in building a warehouse are the following:When
and how to gather data. What schema to use. How to propagate upd
ates. What data to summarize. In a source-driven architecture for
fathering data, the data sources transmit new information, eithe
r continually, as transaction processing takes place, or periodic
ally, such as each night. In a destination-driven architecture, t
he data warehouse periodically sends requests for new data to the
sources. Data sources that have been constructed independently a
re likely to have different schemas. Updates on relations at the
data sources must be propagated to the data warehouse. The raw da
ta generated by a transaction-processing system may be too large
to store on-line. Key Words aggregation 聚集，集成
，集结category 种类，类别，类型commit
提交，承诺propagate 扩散，繁荣，繁衍query
查询，质疑repository
仓库，仓储室straightforward 直接地，坦率地，明确地transaction
事务，处理，交易warehouse 仓库，
货栈，批发商店workload 工作量，负载2.4 Database Tech
nologies 习题答案1. Translate the following phrases into English数据库管理
系统 database management system数据定义语言
data definition language数据字典 data dic
tionary物理细节 physical details完整性约束
integrity constraint2. Translate the following p
hrases into Chinesedatabase system 数据库系统database
schema 数据库模式storage manager 存储管理器
data warehouse 数据仓库decision-support
决策支持3. Identify the following to be True or False according t
o the textF F T T T4. Reading Comprehensiond the userb file
systema transactionc a database system2.5 Principles of Compi
ler2.5.1 Text AA compiler is a program which takes text in high-
level language and converts it into equivalent text in a low-leve
l assembly or machine language. The seven components are as follo
w: ScannerParserIntermediate code generatorSemantic processorOpti
mizerCode generatorTablesThe scanner has several roles:Identify t
he basic lexical units of the program, which are called tokens;Re
move extraneous blanks, carriage returns and other characteristic
s of the input medium;Remove comments;Report errors which the sca
nner discovers.Each programming language has its own set of gramm
ar rules characterizing the correct form of programs in the langu
age. The parser or syntactic analyzer accepts the output of the s
canner; i.e., token and verifies that the source program satisfie
s the grammatical rules of the language being compiles. In Englis
h, the grammar rules are normally not stated with great precision
. The tree output by the parser is transformed into a “program” o
f sorts written in an intermediate code, which is closer in form
to assembly language than source text and yet is in a form which
makes further manipulation easier than if actual assembly (or mac
hine) code were emitted. Intermediate code can be converted direc
tly into the language by the code generator. The optimizer modifi
es the code which it is given into a more efficient version. The
code generator takes the intermediate code it receives the optimi
zer and produces assembly or machine language code.Key Words conc
eptually 概念地continuation 连续，继续delimiter
界符equivalent 相等的，相当的，等价的extraneou
s 非必要的，无关的grammar 语法，语法书illegally
不合规定的，非法的immune 不受影响的inse
nsitive 敏感的，灵敏的Key Words intermediate
中间的，中间体lexical 词汇的，词法的notatio
n 记号，标记法optimizer
优化器parser 语法分析器reflect
反射，反映，映出scanner
扫描器，扫描设备semantic 语义的，语义学的superficially
表面地，肤浅地syntactic 句法的N
otes [1] A compiler is a program which takes text in high-level
language and converts it into equivalent text in a low-level asse
mbly or machine language.说明：本句中，由“which”引导的定语从句，修饰“program”。译文：编译
程序是指将用高级语言书写的文本转换成等价的用低级的汇编语言或机器语言书写的文本。Notes [2] The scanner co
nverts this external view of the source program into an internal
format more suited for further manipulation by the remainder of t
he compiler.说明：这里的“the source program”作定语，修饰“this external view”，
“more suited for…”也是定语，修饰“an internal format”。译文：扫描程序是把源程序这种外部形式转
换成更适用于编译程序其它部分操作的内部形式。Notes [3] Since the intermediate level cod
e is machine-like in character, but not in form, it will normally
vary with the machine for which the object code is being generat
ed.说明：由“Since”引导的原因状语从句阐述中间代码的特性，“it”指代“the intermediate level co
de”。译文：由于中间级代码在特性上类似于机器代码，但在形式上不同，它通常随着机器的不同而产生不同的目标代码。Notes [4]
If the code generator transforms intermediate level text into as
sembly language in a straightforward manner, the generated object
codes probably not as efficient with respect to execution time a
nd storage space as it might be.说明：这个句子比较长，主要有两部分，由“If”引导的是条件状语从句
，主句在后，主语为“the generated object codes”。译文：如果中间代码直接由代码生成器转换成汇编代码，则产
生的目标代码在执行时间和存储空间方面的效率往往不高。2.5.2 Text BIn the past, compilers wer
e divided into many passes to save space. A pass in this context
is a run of the compiler through the source code of the program t
o be compiled, resulting in the building up of the internal data
of the compiler. When each pass is finished, the compiler can fre
e the internal data space needed during that pass. Many modern co
mpilers share a common ‘two stage’ design.The front end translate
s the source language into an intermediate representation. The se
cond stage is the back end, which works with the internal represe
ntation to produce code in the output language. Often, optimizers
and error checkers can be shared by both front ends and back end
s if they are designed to operate on the intermediate language th
at a front-end passes to a back end. A compiler should try to fin
d as many errors as possible in source program. There are three s
tages of error processing:DetectionReportingRecoveryThe first in
error processing is the detection of any error. The second stage
in error processing is the report of an error. The final stage of
error processing concerns the actions taken after an error has b
een reported. Key Words abbreviate 缩写ab
ort 使中止，中断，中止计划detection
发现，探测erroneous 错误的
indicate 表明，指示，标示mitigate
减轻，使缓和，使平息pinpoint
精确地找到Key Words representation 表现，表示，陈述re
covery 恢复reuse
再用，重新使用revolve 旋转，循环
出现severity 严格similarly
相似地，类似地subroutine 子程序
，子例程2.5 Principles of Compiler 习题答案1. Translate the following ph
rases into English语法规则 grammar rule代码生成器
code generator上下文无关语法 context-free grammar词法分析器
lexical analyzer中间代码 intermediate code2. Tr
anslate the following phrases into Chinesesyntactic analyzer
语法分析器code optimization 代码优化internal
format 内部格式semantic processor
语义处理器programming language 编程语言3. Identify the following
to be True or False according to the textT F T F T4. Reading
Comprehensiond operating systema scannerb the report of an err
ord grammar rules2.6 Software Engineering2.6.1 Text AEarly app
roaches to software engineering insisted on performing analysis,
design, implementation, and testing in a strictly sequential mann
er. The first phase, requirements definition, refers to the perio
d during which the requirements of the system desired.After the s
ystem requirements are identified, they are converted into more s
ystem technical specifications. DesignThe second phase is design.
Design concentrates on how the system will accomplish the goals.
Formal verification, while possible to a limited extent, can be e
xceedingly difficult. More informal revolve the entire design tea
m, management, and even the client.It is a well-established princ
iple that the best structure for a large software system is a mod
ular one. ImplementationThe third phase, implementation, is the a
ctual coding of the design developed in the second phase. The des
ign must be translated into a machine-readable form. The coding s
tep performs this task. If design is performed in a detailed mann
er, coding can be accomplished mechanistically. TestingThe forth
phase is software testing. Testing is closely associated with imp
lementation, because each module of the system is normally tested
as it is implemented. In the development of a large system, test
ing involves several stages. The test team checks the internal da
ta structures, the logic, and the boundary conditions for the inp
ut and output data. Key Words analogy 相似，类似，比拟
breakdown 崩溃，损坏competitive 竞争的，对立的，竞赛
的decomposition 分解，解体exceedingly 非常，极其，极度地fa
ulty 不完善的，有错误的foolhardy 蛮
干的fragment 分段，碎片，片段groundwork 基础，基本
原理，地基inventory 清查，存货清单，编制…的目录Key Words investiga
tion 调查，研究likewise 同样地，也，
而且mechanistically 机械地prescription 指
示，训令，法规，规则pseudo 假，伪，冒充的readable
易读的，易懂的restrict 限制，约束s
equential 按次序的，相继的，时序substantial
充实的，实质的，本质terminology 专有名词，术语veri
fication 证明，证实，核实Notes [1] The first phase
, requirements definition, refers to the period during which the
requirements of the system desired, that is, it’s functional char
acteristics and operational details, are specified.说明：“requiremen
ts definition”作主语“The first phase”的同位语，“that is, it’s functional…
”是定语。译文：第一阶段，需求定义阶段，是指系统期望的需求分析，即描述功能特征和操作细节的阶段。Notes [2] If, h
owever, the system is to be designed for a specific user, then th
e process would be a more narrow investigation.说明：本句由“If”引导条件状语从句
。译文：但是，如果系统是为特殊用户设计的，那么这个过程就是一个更专业的调查。Notes [3] Another might be
that the data must reflect the current state of the inventory as
of the end of the last business day or that the arrangement of t
he data as displayed on the computer screen must adhere to the fo
rmat of the paper forms currently in use.说明：本句有两个并列的表语从句“that the
data must…”和“that the arrangement…”，而“as of the end of the last
business day”是时间状语。译文：另一种可能是当最后一个工作日结束时，数据必须反映目前的清单状态，或者可能是在计算机屏幕
上的数据组织必须按照目前使用的纸质形式的格式来显示。Notes [4] Unit testing is done in a co
ntrolled environment whenever possible so that the test team can
feed a predetermined set of data to the module being tested and o
bserve what output data are produced.说明：本句由“so that”引导目的状语从句。译文：在
任何可能的时候，单元测试是在控制环境下进行的，这是为了让测试小组能提供被测试模块先前确定的数据并观察产生的输出数据。2.6.2
Text BNo matter how capably we write programs, it is clear from t
he variety of possible errors that we should check to insure that
our modules are coded correctly. Many programmers view testing a
s a demonstration that their programs perform properly. We test a
program in order to demonstrate the existence of an error. Once
an error is found, “debugging” or error correction is the process
of determining what causes the error and of making changes to th
e system so that the error no longer exists. When collections of
modules have been unit-tested, the next step is to insure that th
e interfaces among the modules are defined and handled properly.
Integration testing is the process of verifying that the componen
ts of a system work together as described in the program design a
nd system design specifications.Once we are sure that information
is passed among modules according to the design prescriptions, w
e test the system to assure that it has the desired functionality
. A function test evaluates the system to determine if the functi
ons described by the requirements specification are actually perf
ormed by the integrated system. Maintenance begins after the syst
em is released. Maintenance activities involve making enhancement
s to software products, adapting products to new environments, an
d correcting problems. Problem correction involves modification a
nd revalidation of software to correct errors. Key Words acceptan
ce 接受，同意boundary 边界，界限confer
比较，对照，商议，磋商feed 满足，提供，注入isolate
隔离，孤立recall 回忆，回顾reverse
相反，背面validated 证实，确认2.6 Software Engineering 习题答案1. Translate the following phrases into English内部数据结构 internal data structure仿真环境 simulated environment维护阶段 maintenance phase软件开发 software development集成测试 integration testing2. Translate the following phrases into Chinesesoftware engineering 软件工程waterfall model 瀑布模型software testing 软件测试boundary condition 边界条件requirements specification 需求说明3. Identify the following to be True or False according to the text T T F T F 4. Reading Comprehensionc Integration testinga A function testd actual working environmentb correcting problems2.7 计算机专业英语的阅读与翻译2.7.1 阅读方法常用的有效的阅读方法有三种，即略读（Skimming）、查读（Scanning）和精读（Reading for full understanding）。 略读是指以尽可能快的速度进行阅读，了解文章的主旨和大意，对文章的结构和内容获得总的概念和印象。 查读的目的主要是有目的地去找出文章中某些特定的信息。精读是指仔细地阅读，力求对文章有深层次的理解，以获得具体的信息。 阅读技能掌握所读材料的主旨大意。了解阐述主旨的事实和细节。根据上下文判断某些词汇和短语的含义。既理解个别句子的意义，也理解上下文之间的逻辑关系。根据所读材料进行一定的判断、推理和引申。领会作者的观点、意图和态度。阅读专业文章的技巧鉴别阅读法鉴别阅读法是一种快速提炼文章的段意、主要内容和中心思想的阅读方法。 默读法在阅读时，大脑直接感受文字的意思，不必通过发音器官将文字转换为声音，这种阅读方式就叫无声阅读。视觉辅助阅读法2.7.2 翻译的方法与过程要作好翻译工作，必须从深刻理解原文入手，力求做到确切表达译文。原文是翻译的出发点和唯一依据，只有彻底理解原文含义，才有可能完成确切的翻译。1．专业词汇的翻译如果把一种语言的所有词汇作为一个词汇总集来看待，则各种词汇的分布情况和运用频率是不一样的。在词汇的总体分布中，有些词属于语言的共核部分，如功能词和日常用词。这些词构成了语言的基础词汇。此外，各个学术领域的技术术语和行业词构成了词汇总集的外缘，而处于基础词汇和外缘之间的是那些准技术词汇(sub-technical words)。常用翻译词汇的方法有：音译音译就是根据英语单词的发音译成读音与原词大致相同的汉字。意译意译就是对原词所表达的具体事物和概念进行仔细推敲，以准确译出该词的科学概念。 形译用英语常用字母的形象来为形状相似的物体定名，翻译时也可以通过具体形象来表达原义，也称为“象译”。科技文献常涉及到型号、牌号、商标名称及代表某种概念的字母。词义的选择与引伸英汉两种语言在表达方式方法上差异较大，英语一词多义现象使得在汉语中很难找到绝对相同的词。如果仅按词典意义原样照搬，不仅使译文生硬晦涩，而且可能会词不达意，造成误解。因此，有必要结合语言环境透过外延看内涵，把词义做一定程度的扩展、引伸。 词语的增减与变序由于英语和汉语各自独立演变发展，因而在表达方法和语法结构上有很大的差别。在英译汉时，不可能要求二者在词的数量上绝对相等。通常应该依据句子的意义和结构适当增加、减少或重复一些词，以使译文符合汉语习惯。语法成分的转换为了使译文达到“明确”、“通顺”和“简练”的要求，有时需要把原语句中的某种成分转译为另一种成分。成分的转换在大多数情况下并不引起词性的转换，而词性的转换经常会引起成分的转换。2．翻译方法与过程科技文献本身体裁多样，而且随着时代的推进，越来越多的科技文献开始显示出其内容及文体风格上的创新和活跃。如果没有一定的翻译技巧，是翻译不好具有不同特点的科技文章的。一般来说，科技文献主要是述说事理、描写现象、推导公式及论证规律的，因此其特点是结构严谨、逻辑严密、行文规范、用词准确、技术术语正确、修辞手段较少。专业科技文献中长句难句较多，各种短语和从句相互搭配、相互修饰，使人感到头绪纷繁、无所适从。在这种情况下更应重视语法分析，突出句子骨架，采用分解归类，化繁为简，逐层推进理解的策略。在翻译的过程中，理解是第一位的，表达是第二位的。理解原文（1）领略全文大意，分析语法关系（2）理解原作事理，注意逻辑判断汉语表达表达是指用适当的译文把已经理解的原文再现出来。为了使译文准确通顺，在表达阶段一般要注意以下几个方面。 （1）表达的规范性 （2）表达的逻辑性 （3）表达的主动权校对阶段校对阶段，是理解和表达的进一步深化，是使译文符合标准的一个必不可少阶段，是对原文内容的进一步核实，对译文的进一步推敲。校对对于科技文章的译文来说尤为重要，因为科技文章要求高度精确，公式、数据较多，稍一疏忽就会给工作造成严重的损失。