计算机专业英语教案第3章

第一篇：计算机专业英语教案第3章

计算机专业英语

第3章 Software knowledge

第3章

Software Knowledge

3.1 Data Structures 3.2 Operating System 3.3 Programming Languages 3.4 Software Engineering

3.5 Software Testing and Maintenance

3.2 Operating System • The purpose of an operating system is to provide an environment in which a user may execute programs.• Operating systems exist because they are a reasonable way to solve the problem of creating a usable computing system.• The primary goal of an operating system is convenience for the user.• A secondary goal is efficient operation of the computer system.Resource Management

• The operating system provides the means for the proper use of these resources in the operation of the computer system.• We can view an operating system as a resource allocates.• The operating system sets up the order in which programs are processed, and defines the sequence in which particular jobs are executed

教师: 游彦 计算机专业英语

第3章 Software knowledge

• I/O Management

• To facilitate execution of I/O operations, most operating systems have a standard set of control instructions to handle the processing of all input and output instructions.• These standard instructions, referred to as the input/output control system(IOCS), are an integral part of most operating systems.• The controlling software calls on the IOCS software to actually complete the I/O operation.Classification of Operating Systems

• A single-user operating system expects to deal with one set of input devices—those that can be controlled by one user at a time.• A multi-user operating system is designed to deal with input, output, and processing requests from many users-all at the same time.• A network operating system provides communications and routing services that allow computers to share data, programs and peripheral devices.• A multitasking operating system provides process and memory management services that allow two or more programs to run simultaneously.• All modern operating systems are multitasking and can run several processes simultaneously.教师: 游彦 计算机专业英语

第3章 Software knowledge

• A desktop operating system is one that is designed for a personal computer—either a desktop or notebook computer.•

3.3 Programming Languages • A programming language or computer language is a standardized communication technique for expressing instructions to a computer.• A language enables a programmer to precisely specify what data a computer will act upon, how these data will be stored/transmitted, and what actions to take under various circumstances of cases.• Programming languages are important tools for helping software engineers write better programs faster.Procedural programming and Object-oriented programming • Procedural programming involves using your knowledge of a programming language to create computer memory locations that can hold values and writing a series of steps or operations that manipulate those values.• A single procedural program often contains hundreds of variable and thousands of procedure calls.• Object-oriented programming is an extension of procedural programming in which you take a slightly different approach to writing computer programs.教师: 游彦 计算机专业英语

第3章 Software knowledge

• Writing object-oriented programs involves both creating objects and creating applications that use those objects.Machine Language

• An executable program is a sequence of extremely simple instructions known as machine code.• Machine code instructions are binary—that is, sequences of bits(0s and 1s).• Because these numbers are not understood easily by humans, computer instructions usually are not written in machine code.Assembly Language

• Assembly language uses commands that are easier for programmers to understand than are machine-language commands.• Each machine language instruction has an equivalent command in assembly language.• Assembly language is sometimes inserted into a high-level language program to carry out specific hardware tasks or to speed up a high-level program.High-Level Languages

• If the computer could translate convenient symbols into basic operations, why couldn’t it also perform other clerical coding functions? • A high-level programming language is a means of writing down, in

教师: 游彦 计算机专业英语

第3章 Software knowledge

formal terms, the steps that must be performed to process a given set of data in a uniquely defined way.• The high-level languages are often oriented toward a particular class of processing problems.Compiler and Interpreter

• A complier is a program that translates source code into object code.• Every high-level programming language comes with a compiler.• Because compilers translate source code into object code, which is unique for each type of computer, many compilers are available for the same language.• An interpreter translates high-level instructions into an intermediate form, which it then executes.• The advantage of an interpreter, however, is that it does not need to go through the compilation stage during which machine instructions are generated.•

3.4 Software Engineering • Software engineering is the application of tools, methods, and disciplines to produce and maintain an automated solution to a real-world problem.• Software engineering first emerged as a popular term in the title of

教师: 游彦 计算机专业英语

第3章 Software knowledge

a 1968 NATO conference held in Garmisch, Germany.• A large-scale software projects spans a considerable period of time.A number of distinct phases can be identified over this period of time.Together, these make up what is known as the “software life cycle”.The software life cycle

• Requirements definition: The requirements of the software are established and specified.• Design: A design is developed from an analysis of the requirements.• Implementation: The design is coded in a particular programming language on a particular machine.• Testing: The implemented system is tested to see that it meets the specified requirements.• Operation and maintenance: The system is installed and used.Errors found must be repaired.Requirements definition • The first phase, requirements definition, refers to the period during which the requirements of the system desired, that is, it’s functional characteristics and operational details, are specified.• The input to this phase is the stated(often rather loosely stated)needs for the software.教师: 游彦 计算机专业英语

第3章 Software knowledge

• Typically, a “requirements document” is the output of this phase, a set of precisely stated properties or constraints that the final product must satisfy.• As with any of the phases, it is important that errors not be allowed to move into subsequent phases.Design • The second phase, design, is predominantly creative, while some would argue that creativity is inherent and cannot be trained or improved, it can certainly be enhanced by the use of good procedures and tools.• The input to this phase is a(debugged and validated)requirements document: the output is a design expressed in some appropriate form(for example, pseudo-code).• Each requirement in the requirements document must have a corresponding design fragment to meet it.Implementation • The third phase, implementation, is the actual coding of the design developed in the second phase.• The lure of this phase is strong, and many a foolhardy programmer has been drawn to it before adequately laying the groundwork in the first two phases.• As a result, requirements are incompletely understood and the

教师: 游彦 计算机专业英语

第3章 Software knowledge

design is flawed.• The implementation proceeds blindly, and many problems arise as a result.Testing

• The fourth phase, testing, is concerned with demonstrating the correctness of the implemented program.Inevitably some testing is performed as part of the previous two phases as well.• Any experienced programmer mentally tests each line as it is produced and mentally simulates the execution of any module prior to any formal testing stage.• A “successful” test run means only that no errors were uncovered with the particular circumstances tested;it says nothing about other circumstances.• In theory, the only way that testing can show that a program is correct is if all possible cases are tried(known as an exhaustive test), a situation technically impossible for even the simplest programs.Program maintenance

• The fifth phase is program maintenance phase.Student programmers, unfortunately, rarely become involved in this phase.• Its importance in the real world, however, cannot be overemphasized, since the cost of maintaining a widely used

教师: 游彦 计算机专业英语

第3章 Software knowledge

program can match or exceed the cost of developing it.• Unlike hardware maintenance, software maintenance deals not with repair of deteriorated components, but with repair of design defects, which may include the provision of added functions to meet new needs.教师: 游彦

第二篇：计算机专业英语教案Unit 2

兰州外语职业学院教案专用纸

专业：

科目：

教师：

班级：

年

学

第 学期

授课时数：

授课时段：第 周Unit Two

What `s inside My Laptop? CLASS TYPE:

TEACHING OBJECTIVE 1.Master all the professional terms in this Unit.2.Understand the structure of Laptop 3.Understand the main function Of Laptop 4.Develop the students’ reading abilities.TEACHING APPROACH: 1.Method of Lecture 2.TBLT（Task Based Language Teaching）

3.CLTA(Communicative Language Teaching Approach)TEACHING AIDS Chalk，Blackboard, Tape-recorder，Multi-media equipment.IMPORTANT POINTS: 1.Words and terms:

2.What is the structure of Laptop? DIFFICULT POINTS: 1.Understand the main structure of Laptop TIME ALLOTMENT: 1).Warm up activities(2-3minutes)2).Homework checking& review(2minutes)3).Reading and translating(100minutes)4)Summary &Homework(5minutes)5).Reflections

TEACHING PROCEDURE:

ppt

I.LEAD IN

(1).What are the main components of desktop computer?(2).Which parts of computer are familiar to you? Why?(3).Which parts are totally new to you? Why? II.NEW WORDS AND TERMS a)CPU（中央处理单元）

b)RAM（随机存取内存），ROM（只读存取内存）RAM: c)BIOS（基本输入/输出系统,Basic Input/ Output System）d)Caching（缓冲存储）

e)OS（operating system,操作系统）

f)IDE（集成驱动电子,Integrated Drive Electronics）g)SCSI（小型计算机系统接口）III.TEACHING CONTENTS 1.Background of information

PPT(Omitted)2.Language points(A)Sentence translating

1.Everything that a computer does is overseen by the CPU.计算机所做的一切都由CPU监控

2.Space on a hard disk used to temporarily store data and swap it in and out of RAM as needed

硬盘空间临时存储数据，在需要时与RAM交换这些数据。

3.MotherboardThis is large-capacity permanent storage used to hold information such as programs and documents.硬盘是大容量永久存储器，保存程序和文档之类信息。

5.PCI uses a series of slots on the motherboard that PCI cards plug into.PCI使用主板上的一系列槽，插入PCI卡。

四、课堂练习(1)Questions 1.How many kinds of memory are there? What are they? 2.What is Virtual Memory?(2)Translate the text into Chinese The CPU and memory are usually on the motherboard.Other systems may be found directly on the motherboard or connected to it through a secondary connection.Operating systemThis is used by the computer to record and play audio by converting analog sound into digital information and back again.VI.Summary 1.Important terms 2.the main structure Of.Laptop VII.Homework Learn all the words and terms by heart.Discuss Exercise after class Review Unit3

1.VIII.REFLECTION

第三篇：计算机专业英语教案Unit 1

兰州外语职业学院教案专用纸

专业：

科目：

教师：

班级：

年

学

第 学期

授课时数：

授课时段：第 周Unit ONE

PC Overview CLASS TYPE:

TEACHING OBJECTIVE 1.Master all the professional terms in this Unit.2.Understand the definition of PC

3.Understand the main function Of Smartphone Tablet and Laptop 4.Develop the students’ reading abilities.TEACHING APPROACH: 1.Method of Lecture 2.TBLT（Task Based Language Teaching）

3.CLTA(Communicative Language Teaching Approach)TEACHING AIDS Chalk，Blackboard, Tape-recorder，Multi-media equipment.IMPORTANT POINTS: 1.Words and terms:

2.What is the structure of PC? DIFFICULT POINTS: 1.Understand the main structure of PC TIME ALLOTMENT: 1).Warm up activities(2-3minutes)2).Homework checking& review(2minutes)3).Reading and translating(100minutes)4)Summary &Homework(5minutes)5).Reflections

TEACHING PROCEDURE:

I.LEAD IN

(1).Which kinds of computers do you know?(2).Which parts of computer you know? What are their functions? II.NEW WORDS AND TERMS a)virtual terminal（虚拟终端）, virtual memory（虚拟内存）b)processor（处理器）,microprocessor（微处理器）c)computerized component（计算机化组件）d)browse the web（浏览网络）, browser（浏览器）e)keyboard（键盘），mouse（鼠标）f)floppy disk（软盘）, flash memory（优盘）g)monitor（显示器）

h)MP3（MP3文件格式或MP3播放器）i)GPS（全球定位系统）

III.TEACHING CONTENTS 1.Background of information

PPT(Omitted)2.Language points(A)Sentence translating

1.Virtually every facet of our lives has some computerized component.我们生活中的几乎每个方面都有一些计算机化的成份。

2.A PC is a general purpose tool built around a microprocessor.It has lots of different parts--memory, a hard disk, a modem, etc.PC机是利用微处理器建立的通用工具，具有相互配合的不同的部件，如内存、硬盘、调制解调器，等等。

3.Once processed, the information is shown to the user处理信息之后，结果向用户显示 4.A Gameboy is a specialized computer for handling games.掌机是处理游戏的专用计

算机

(B)exercises

a)What kind of household appliances have microprocessors built into? b)What does PC refer to in this book? c)What can you do with a PC? d)What can a general-purpose PC do? e)Give examples of special-purpose PCs in our life?(2)Translate the text into Chinese a)The appliances in our homes have microprocessors built into them, as do our televisions.b)It can take information from a person(through the keyboard and mouse), from a device(like a floppy disk or CD)or from the network(through a modem or a network card)and process it.c)An MP3 Player is a specialized computer for processing MP3 files.It can't do anything else VI.Summary 1.Important terms 2.the main function Of PC.VII.Homework Learn all the words and terms by heart.Discuss Exercise after class Review Unit 2 1.VIII.REFLECTION

第四篇：计算机专业英语教案第3章

计算机专业英语教案第3章

博主目录 2009-06-18 22:58 阅读32 评论0

字号： 大 中 小

第3章 Software Knowledge 3.1 Data Structures 3.2 Operating System 3.3 Programming Languages 3.4 Software Engineering

3.5 Software Testing and Maintenance

3.2 Operating System ? The purpose of an operating system is to provide an environment in which a user may execute programs.? Operating systems exist because they are a reasonable way to solve the problem of creating a usable computing system.? The primary goal of an operating system is convenience for the user.? A secondary goal is efficient operation of the computer system.Resource Management

? The operating system provides the means for the proper use of these resources in the operation of the computer system.? We can view an operating system as a resource allocates.? The operating system sets up the order in which programs are processed, and defines the sequence in which particular jobs are executed ? I/O Management ? To facilitate execution of I/O operations, most operating systems have a standard set of control instructions to handle the processing of all input and output instructions.? These standard instructions, referred to as the input/output control system(IOCS), are an integral part of most operating systems.? The controlling software calls on the IOCS software to actually complete the I/O operation.Classification of Operating Systems

? A single-user operating system expects to deal with one set of input devices—those that can be controlled by one user at a time.? A multi-user operating system is designed to deal with input, output, and processing requests from many users-all at the same time.? A network operating system provides communications and routing services that allow computers to share data, programs and peripheral devices.? A multitasking operating system provides process and memory management services that allow two or more programs to run simultaneously.? All modern operating systems are multitasking and can run several processes simultaneously.? A desktop operating system is one that is designed for a personal computer—either a desktop or notebook computer.?

3.3 Programming Languages ? A programming language or computer language is a standardized communication technique for expressing instructions to a computer.? A language enables a programmer to precisely specify what data a computer will act upon, how these data will be stored/transmitted, and what actions to take under various circumstances of cases.? Programming languages are important tools for helping software engineers write better programs faster.Procedural programming and Object-oriented programming ? Procedural programming involves using your knowledge of a programming language to create computer memory locations that can hold values and writing a series of steps or operations that manipulate those values.? A single procedural program often contains hundreds of variable and thousands of procedure calls.? Object-oriented programming is an extension of procedural programming in which you take a slightly different approach to writing computer programs.? Writing object-oriented programs involves both creating objects and creating applications that use those objects.Machine Language

? An executable program is a sequence of extremely simple instructions known as machine code.? Machine code instructions are binary—that is, sequences of bits(0s and 1s).? Because these numbers are not understood easily by humans, computer instructions usually are not written in machine code.Assembly Language

? Assembly language uses commands that are easier for programmers to understand than are machine-language commands.? Each machine language instruction has an equivalent command in assembly language.? Assembly language is sometimes inserted into a high-level language program to carry out specific hardware tasks or to speed up a high-level program.High-Level Languages

? If the computer could translate convenient symbols into basic operations, why couldn’t it also perform other clerical coding functions? ? A high-level programming language is a means of writing down, in formal terms, the steps that must be performed to process a given set of data in a uniquely defined way.? The high-level languages are often oriented toward a particular class of processing problems.Compiler and Interpreter ? A complier is a program that translates source code into object code.? Every high-level programming language comes with a compiler.? Because compilers translate source code into object code, which is unique for each type of computer, many compilers are available for the same language.? An interpreter translates high-level instructions into an intermediate form, which it then executes.? The advantage of an interpreter, however, is that it does not need to go through the compilation stage during which machine instructions are generated.?

3.4 Software Engineering ? Software engineering is the application of tools, methods, and disciplines to produce and maintain an automated solution to a real-world problem.? Software engineering first emerged as a popular term in the title of a 1968 NATO conference held in Garmisch, Germany.? A large-scale software projects spans a considerable period of time.A number of distinct phases can be identified over this period of time.Together, these make up what is known as the “software life cycle”.The software life cycle

? Requirements definition: The requirements of the software are established and specified.? Design: A design is developed from an analysis of the requirements.? Implementation: The design is coded in a particular programming language on a particular machine.? Testing: The implemented system is tested to see that it meets the specified requirements.? Operation and maintenance: The system is installed and used.Errors found must be repaired.Requirements definition ? The first phase, requirements definition, refers to the period during which the requirements of the system desired, that is, it’s functional characteristics and operational details, are specified.? The input to this phase is the stated(often rather loosely stated)needs for the software.? Typically, a “requirements document” is the output of this phase, a set of precisely stated properties or constraints that the final product must satisfy.? As with any of the phases, it is important that errors not be allowed to move into subsequent phases.Design ? The second phase, design, is predominantly creative, while some would argue that creativity is inherent and cannot be trained or improved, it can certainly be enhanced by the use of good procedures and tools.? The input to this phase is a(debugged and validated)requirements document: the output is a design expressed in some appropriate form(for example, pseudo-code).? Each requirement in the requirements document must have a corresponding design fragment to meet it.Implementation ? The third phase, implementation, is the actual coding of the design developed in the second phase.? The lure of this phase is strong, and many a foolhardy programmer has been drawn to it before adequately laying the groundwork in the first two phases.? As a result, requirements are incompletely understood and the design is flawed.? The implementation proceeds blindly, and many problems arise as a result.Testing

? The fourth phase, testing, is concerned with demonstrating the correctness of the implemented program.Inevitably some testing is performed as part of the previous two phases as well.? Any experienced programmer mentally tests each line as it is produced and mentally simulates the execution of any module prior to any formal testing stage.? A “successful” test run means only that no errors were uncovered with the particular circumstances tested;it says nothing about other circumstances.? In theory, the only way that testing can show that a program is correct is if all possible cases are tried(known as an exhaustive test), a situation technically impossible for even the simplest programs.Program maintenance

? The fifth phase is program maintenance phase.Student programmers, unfortunately, rarely become involved in this phase.? Its importance in the real world, however, cannot be overemphasized, since the cost of maintaining a widely used program can match or exceed the cost of developing it.? Unlike hardware maintenance, software maintenance deals not with repair of deteriorated components, but with repair of design defects, which may include the provision of added functions to meet new needs.

第五篇：专业英语教案

专业英语教案（其中放假1次，期中习题课1次）

Unit 1 TECTONICS(4课时)（1：The structure of the earth 2：plate tectonic

3：Earthquakes）

一、Word and phrase core;mantle;crust 地核；地幔；地壳 continental crust

大陆地壳

granite;basalt

花岗岩；玄武岩 sial;sima硅铝层；硅镁层

surface waves;body..面波；体波 epicentre;focus

震中；震源

lithosphere

岩石圈 tectonic plate

构造板块 continetal drift

大陆漂移

asthenosphere

软流层 ocean ridge 洋脊 ocean trench 海沟

subduction 俯冲作用

volcanism

火山作用

fold mountain

褶皱山脉

fold;fault

褶皱；断层 sedimentary rocks 沉积岩

vent

火山口

lava

熔岩 volcanic cones 火山锥

parasitic cone

寄生火山锥

plug

岩颈

volcanic ash

火山灰

二、重点内容

1..Within the crust, intricate patterns are created when rocks are redistributed and deposited in layers through the geologic processes of eruption and intrusion of lava, erosion, and consolidation of rock particles, and solidification and recrystallization of porous rock.2.The lithosphere is a relatively inflexible and buoyant layer.It is the layer which floats on the material underneath and as it moves carries the continents that produce continental drift.3.There are three types of plate boundaries:

Divergent(diverge, divergence)boundaries--where new crust is generated as the plates pull away from each other.Convergent(converge, convergent)boundaries--where crust is destroyed as one plate dives under another.Transform boundaries--where crust is neither produced nor destroyed as the plates slide horizontally past each other.4.Earthquakes occur when normal movement of the crust are concentrated into a single shock of a series of sudden shocks.三、词汇解释 ocean ridges continental rift rift valley convergent trench arc and back-arc-basin system transcurrent fault abyssal intrusion fold mountains sendimentary rock Unit 2 WEATHERING（4课时）

(1：Weathering 2：Controls on weathering)

一、Word and phrase mechanical weathering

机械风化 chemical weathering

化学风化 freeze-thaw

冻融

pressure release

卸荷释重 limestone

石灰岩

hydrolysis

水解作用 quartz

石英

hydration 水合作用 oxidation 氧化作用 alluvium

冲击层 gravel

砂砾

denudation

剥蚀作用 precipitation

降水 climatic zone

气候带 mid-latitude

中纬度

semi-arid

半干旱

tropical wet-dry

热带干湿季气候 watershed

分水岭 drainage basin

流域

regolith

风化层

二、重点

1.The disintegration(breaking into parts)of rock that takes place at or near the surface of the earth is called weathering.2.PHYSICAL WEATHERING It occurs when a force is applied to rock, causing it to disintegrate into its basic components(what it makes of).temperature changing--it expands and contracts rock particles to breaks rock apart.frost action--it condenses water vapor in cooling air to form water that seeps into cracks in rock.organic(have life)activity--plants or other organisms grow and burrow(go into)into cracks in rock, so the rock crumble over time.3.CHEMICAL WEATHERING The process that breaks down rock through chemical changes.The agents of chemical weathering Water Oxygen Carbon dioxide Living organisms Acid rain 4.WeatheringThe movement of weathered material from the site of weathering.Primary agent is gravity, but gravity acts in concert with running water.5.control on weathering-climate

-precipitation-variations in the depth of wreathing for climatic zones from the pole to the tropocs

-geology(chemical composition;the natural of cements in sedimentary rock;joint and bedding plants)

三、词语翻译 weathering crust weathering joint mineral deposit by weathering weathering of rock mass decomposition product decomposition reaction disintegration coefficient To move back and forth alternately.a mineral substance waste substance

A simple substance, mixture mechanical weathering landscape marble landscape ecosystem moisture equivalent

measurement of soil moisture constant.fluctuation of temperature

Unit 3 SLOPES（2课时）

(1：Slope

2：Slope controls 3：Theories of slope evolution movements)

一、words and phrase soil creep

土壤蠕动 mass movement

块体运动 strata

地层

overland runoff

地表径流 sheet wash

片状冲刷

pediment

山前侵蚀平原（山足面）rockfall山崩

landslide

滑坡

二、重点内容

1.slope(definition)2.factor of controlling slope development-climate-geology-vegetation-soil cover-human activity 3.theories of slope evolution-slope decline:w.m.davies

4：Mass

-slope replacement:waltherpenck

-slope retreat:l.c.king

4.mass movement-small movement(soil creep)-fast movement(avalanches)

三、翻译句子 Mass movements are part of a continuum of erosional processes between weathering and stream transport.Mass movement causes regolith and rock to move down-slope where sooner or later the loose particles will be picked up by another transporting agent and eventually moved to a site of deposition such as an ocean basin or lake bed.Unit 4 HYDTOLOGY（2课时）The river basin hydrological cycle 2：Drainage basin hydrology 3：Seasonal variations in river flow: the regime

一、words and phrase interception

截流

evapotranspiration 蒸发和蒸腾总量 capillary rise

毛管上升 aeration zone

包气带

overland flow;interflow;base flow

地表径流；壤中流；地下径流 water table

潜水面（水位）

basin length;area 流域长度;流域面积 tributary 支流； trunk stream 干流

drainage density

河网密度

二、重点内容

1.The basin hydrological cycle –input(precipitation)and outputs(evapotranspiration and runoff)-interception by vegetation-soil moisture and infiltration

2.The definition of the drainage basin is the area which drains into a particular river or river system.（precipitation via interception, soil moisture and groundwater storage, evapotranspiration）3.Basin plan

4.Stream ordering

6.Drainage density

三、课后练习

Main components P

precipitation E

evaporation T

transpiration I

infiltration R

runoff G

ground water flow Ic

interception Unit 5 The long profile and Rivers as sediment systems（2课时）

一、words and phrase upper;middle;lower reach 上中下游 vertical erosion

下切侵蚀 headward erosion

溯源侵蚀 lateral erosion

侧蚀 pot-hole

壶穴 meander

曲流 ox-bow lake

牛轭湖 delta

三角洲 lake basin

湖盆 levee

天然提

rill and gully erosion 细沟、冲沟侵蚀 clay;silt;sand;粘土；粉砂；砂

suspended sediment

悬浮沉积物 atmospherical fallout

大气沉降 laminar flow

层流 turbulent flow

紊流 riffle;pool 浅滩；深槽

channel roughness

河道粗糙度

二、重点内容

1.As rivers evolve through time and over distance the stream passes through a series of distinct stages: youth(lakes, waterfalls, and rapids, initial uplift)middle youth(headward erosion, deepening of channel)early maturity(a smoothly profile, floodplain)approaching full maturity(meanders, river in equilibrium)full maturity(broad floodplain and freely menders)

2.critical erosion velocity

3.type of flow-laminar flow and turbulent flow

三、理解下图内容

Cross-sectional shape varies with position in the stream, and discharge.Thedeepest part of channel occurs where the stream velocity is the highest.Both width and depth increase downstream because discharge increases downstream.As discharge increases the cross sectional shape will change, with the stream becoming deeper and wider.Unit 6 Meanders and Deltas and estuaries（2课时）

sandbar

沙坝 thalweg中泓线 estuary 河口

lagoon

泻湖 salinity

盐度 coastline

海岸线 dune

沙丘

suspension;saltation;creep

悬移；跃移；蠕移 dust storm

尘暴 windward;leeward

迎风；背风 prevailing wind

盛行风 deflation hollow

风蚀凹地

二、重点内容 1.helicoidal flow

2.the wavelength of meanders is dependent on three majors of factors: channel width, discharge, and the nature of the bed and banks.3.factors of affect the formation of deltas: amount and calibre of load, salinity, gradient of coastline , vegetation, low energy river discharge.4.three forms of deltas: arcuate, cuspate, bird’s foot.5.estuaries occur where a coastal area has recently subsided or the ocean level has risen, causing the lower part of the river to be drowned.三、理解下列句子

TerracesGlaciers erode in several ways.:Abrasion and plucking.sediment transportation Glacial Deposition 4.Landforms produced by mountain: Cirques, Glacial Valleys, Arêtes, Horns.三、理解下列图片内容。