计算机专业英语的课文与翻译之令狐文艳创作
宋世风俗 日知录原文加翻译之令狐文艳创作
《宋史》言士大夫忠义之气，至于五季变化殆尽。
宋之初兴，范质、王溥犹有馀憾。
艺祖首褒韩通，次表卫融，以示意向。
真、仁之世，田锡、王禹、范仲淹、欧阳修、唐介诸贤，以直言谠论倡于朝。
于是中外荐绅知以名节为高，廉耻相尚，尽去五季之陋。
故靖康之变，志士投袂起而勤王，临难不屈，所在有之。
及宋之亡，忠节相望。
呜呼！观哀、平之可以变而为东京，五代之可以变而为宋，则知天下无不可变之风俗也。
《剥》上九之言硕果也，阳穷于上，则复生于下矣。
令狐文艳《宋史》上说，当官的忠诚和豪义的气概，到了五代的时候，都改变得差不多了;宋朝刚建立时,范质、王溥仍有遗憾。
赵匡胤最褒奖韩通，挨下来就是卫融了，用来表达他的意愿。
宋真宗、宋仁宗的时候，田锡、王禹偁、范仲淹、欧阳修、唐介众位贤能的人才，在朝廷倡导正直的言论，从此之后，朝廷内外的缙绅，知道用高尚的名节、正直而知耻崇尚对方，完全消除了五代的丑陋的风气。
因此靖康之变时，有志之士奋发而起义为皇帝献身，面临危难也不屈服，所在的各地都有这样的人。
等到宋朝灭亡，忠义有气节的人士互相指望扶持。
啊！我看西汉哀帝和平帝可以被王莽所灭并定都东京，五代可以灭亡变为宋朝，就知道了世上没有不可以改变的风俗了。
《周易》《剥》卦上多次说炼丹时，上面的火星灭了，那么又会在下面重燃。
人君御物之方，莫大乎抑浮止竟。
宋自仁宗在位四十徐年。
虽所用或非其人，而风俗醇厚，好尚端方，论世之士谓之君子道长。
及神宗朝荆公秉政，骤奖趋媚之徒，深锄异己之辈。
邓绾、李定、舒、蹇序辰、王子韶诸奸，一时擢用，而士大夫有“十钻”之目。
干进之流，乘机抵隙。
驯至绍圣、崇宁，而党祸大起，国事日非，膏育之疾遂不可治。
後之人但言其农田、水利、青苗、保甲诸法为百姓害，而不知其移人心、变士心为朝廷之害。
其害于百姓者，可以一日而更，而其害于朝廷者历数十百年，滔滔之势一位而不可反矣。
李应中谓：“自王安石用事，陷溺人心，至今不自知觉。
人趋利而不知义，则主势日孤。
高中英语必修3课文逐句翻译(人教新课标)之令狐文艳创作
高中英语必修3课文逐句翻译(人教新课标)之令狐文艳创作snow.（节日里）整个国度到处是盛开的樱花，看上去就像覆盖了一层粉红色的雪。
People love to get together to eat , drink and have fun with each other. 人们喜欢聚在一起吃、喝、玩耍。
节日让我们享受生活，Festivals let us enjoy life, be proud of our customs and forget our work for a little while.让我们为自己的习俗而自豪，还可以暂时忘掉工作中的烦恼。
2.令狐文艳3.必修三Unit 1 A SAD LOVE STORY一段伤心的爱情故事Li Fang was heart-broken.李方的心都碎了。
It was Valentine’s Day and Hu Jin had said she would meet him at the coffee shop after work. 这天是情人节，胡瑾说她下班后会在咖啡馆和他见面的。
But she didn’t turn up. 可现在她却不见人影。
She could be with her friends right now laughing at him. 也许她这会儿跟朋友在一起，正在取笑他呢。
She said she would be there at seven o’clock,令狐文艳and he thought she would keep her word. 她说她会在7点到达，他(李方)认为她会守信用的。
He had looked forward to meeting her all day, and now he was alone with his roses and chocolates, like a fool. 他一整天都期盼着见到她，而现在他拿着玫瑰花和巧克力独自一人守候着，像个傻瓜一样。
the_cask_of_Amontillado_翻译之令狐文艳创作
the cask of Amontillado Edgar Allan Poe令狐文艳阿芒提拉多的水桶埃德加艾伦坡福吐纳托对我百般迫害，我都尽量忍在心头，可是一旦他胆敢侮辱我，我就发誓要报仇了，您早就摸熟我生性脾气，总不见得当我说说吓唬人。
总有一天我要报仇雪恨；这个注意坚定不移，既然拿定主意不改，就没想到会出危险。
我不仅要给他吃吃苦头，还要干得绝了后患。
报仇的自己得到报应，这笔仇就没了清。
复仇的不让冤家知道是谁害他，这笔仇也没了清。
不消说，我一言一语，一举一动都没引起福吐纳托怀疑是存心不良。
还是照常对他笑脸相迎，可他没看出如今我是想到要送他命才笑呢。
福吐纳托这人在某些方面虽令人尊重，甚至令人敬畏，可就是有个弱点。
他自夸是品酒老手。
意大利人没几个具有真正行家的气质。
他们的热诚，多半都用来随机应变，看风使舵，好让英国和奥地利的大财主上当。
谈到古画和珠宝方面，福吐纳托跟他同胞一样，夸夸其谈，不过谈到陈酒方面，倒是真正识货。
这点我跟他大致相同——对意大利葡萄酒，我也算内行，只要办得到的话，就大量买进。
在热闹的狂欢节里，有天傍晚，正当暮色苍茫，我碰到了这位朋友。
他亲热的招呼我，因为他肚里灌饱了酒。
这家伙扮成小丑，身穿杂色条纹紧身衣，头戴圆尖帽，上面系着铃铛。
我看见他真是高兴极了，不由想握着他的手久久不放。
我对他说：“老兄啊，幸会，幸会。
你今天气色真是好到极点。
我弄到一大桶所谓白葡萄酒（西班牙蒙蒂利亚生产的一种甜酒），可我不放心。
”“怎的？”他说，“白葡萄酒？一大桶？不见得吧！在狂欢节期间哪弄得到？”“我不放心，”我答道，“我真笨透了，居然没跟你商量，就照白葡萄酒的价钱全付清了。
找又找不到你，可又生怕错过这笔买卖。
”“白葡萄酒！”“我不放心。
”“白葡萄酒！”“我一定得放下这条心！”“白葡萄酒！”“瞧你有事，我正想去找卢克雷西呢。
只有他才能品酒。
他会告诉我——”“可有些傻瓜硬说他眼力跟你不相上下呢。
”“快，咱们走吧。
初中英语全部课文之令狐文艳创作
初一上册Unit 1 My name’s Gina.令狐文艳Language Goals: Introduce yourself；Greet people； Ask for and give telephone number1. My name is Jenny Green. My phone number is 281-9176.My friend is Gina Smith. Her phone number is 232-4672.2. I’m Dale Miller and my frie nd is Eric Brown. His telephone number is 357-5689.My telephone number is 358-6344.3. My name is Mary Brown. My friend is in China. Her name is Zhang Mingming. My phone number is257-8900 and her number is 929-3155.Unit 2 This is my sister. Language Goals: Introduce people; Identify peopleMy FamilyHi, I’m Jenny, Here are two nice photos of my family. My grandfather and grandmother are in the first photo. These are my parents, Alan and Mary. In the next picture are my brothers, Bob and Eric. These two girls are my sister Cindy and cousin Helen. Coco is in my family too。
英语入门基础学习(免费版)之令狐文艳创作
英语学习攻略令狐文艳学习是件苦差事，自己不努力，资料再好也白搭。
不过还是希望这些有趣的句子能给你的学习带去些许的乐趣800个有趣句子帮你记忆7000个单词。
1. With my own ears I clearly heard the heart beat of the nuclear bomb. 我亲耳清楚地听到原子弹的心脏的跳动。
2. Next year the bearded bear will bear a dear baby in the rear. 明年，长胡子的熊将在后方产一头可爱的小崽。
3. Early I searched through the earth for earthenware so as to research in earthquake. 早先我在泥土中搜寻陶器以研究地震。
31. The maximum plus or minus the minimum makes minute difference. 最大值加上或者减去最小值只产生极小的差异。
32. The witty witness withdraws his words within minutes without any reason. 诙谐的证人在几分钟之内无故地收回了他说的话。
33. The cake maker shakes a naked snake with the quaking rake without sake. 蛋糕制造者无缘无故地用抖动的耙子摇一条赤裸的蛇。
34. By the crook, the cook looked through a cookbook before making hooked cookies. 在溪边，厨子在做钩形饼干之前查阅了一本食谱。
35. The writer writes the white book quitequietly in quilt. 作家在被子里十分平静地写白皮书。
仁爱英语九年级上册Unit1-Unit2课文翻译之令狐文艳创作
仁爱英语九年级上册Unit 1-Unit 2课文翻译令狐文艳Unit 1 The changing world变化中的世界Topic 1 Our country has developed rapidly我国发展迅速Section A1a：（After a long holiday, Kangkang is happy to see his friends.）（长假过后，康康很高兴会见到他的朋友们。
）Hi, Jane! Did you have a令狐文艳good summer holiday?你好，简，你暑假过得愉快吗？Yes. What about you?是的，你呢？Not bad. Rita, you have just come back from your hometown. How was your trip?不错。
丽塔，你刚从家乡回来，你的旅行怎么样？Great! I went to many places near my home in India. Great changes have taken place there and my hometown has become more and more beautiful. Where have you been, Jane? 好极令狐文艳了！在印度，我去了我家附近的很多地方。
那里发生了很大的变化，而且我的家乡变得越来越美丽了。
简，你去哪里了？I have been to Mount Huang with my parents. It's a beautiful place. But there were so many people that I couldn't find a good place to take photos. And where have you been, Kangkang ? 我和我的父母去过黄山，那是一个美丽的地方。
Topic D-3 Transaction Cycles之令狐文艳创作
It is far better, and easier in the long run, if you can relate general principles to each audit area rather than learning long lists of tests. This is partly because long lists of test are almost impossible to remember clearly and accurately and partly because the examiner might give you a slightly unusual situation which will require the approach to be modified slightly.Control objectives for all systems:Only authorized transactions are promptly recorded at the correct amount in the appropriate accounts in the proper accountingperiod, that access to assets is only in accordance with proper authorization and that recorded assets are compared with existing assets. Detailed control activities are often similar across sales, purchases and other areas and include for example: ·Sequential numbering ·Batch and control totals ·Controlaccounts ·Authorization REVENU ECYCLE Con trol objectives（1）To ensure that all sales revenues are included in the accounting records （2）to ensure that sales revenues included in the records are accurately stated（3）to minimise losses through bad debts and/or returns Segregation of duties（1）Accepting customer orders （2）Despatch department （3）Invoicing （4）Receiving and recording cash Authorisation and approval controls-examples（1）Check orders against credit limits （2）Orders should be authorised in writing （3）Sales invoices should be authorised in writing （4）Writing off bad debts should be authorised in writing.Physical controls-examples（1）Record orders on pre-numbered documents（2）No goods to be despatched without a despatch note （3）Goods returned should be used to prepare credit notes.Arithmetical controls-examples（1）Check calculations on invoices （2）Send statements to customers regularly （3）Identify overdue debts using age analysis （4）Chase customers for overdue debts.Segregation controls-examples （1）Credit notes should be authorised by someone unconnected with despatch or sales ledger functions （2）Sales invoices andcredit notes should be checked （prices, calculations etc） by a person other than the one preparing the invoice （3）Sales ledger personnel should be independent of despatch and cash receipt anisation controls-examples（1）Sequence checks on pre-numbered documents（2）Reconciliation of control account.Items to test·Customers vetted before credit is given ·Orders vetted against credit limits ·Goods despatched only against approvedcustomer orders ·All despatches and returns should be invoiced and recorded correctly （sales orders linked to despatch notes, linked to sales invoices; returns checked for quality andlogged）·Invoices/credit notes accurately prepared form price lists, customer trading termsetc ·Invoices prepared form despatch notes only ·Credit notes, bad debts and adjustments backed by appropriate documentation andauthorisation ·Salestransactions posted completely and accurately to ledgeraccounts ·Reconciliation of control account ·Chasing of overdue balances ·Segregation of duties.Analytical review procedures·Fluctuations in sales levels ·Cut-offproblems Check disclosure （eg, segmental information）.Note that one approach to designing tests of control is to list the documents involved in the system, and think of tests for each document. This is illustrated below for a salessystem.Test for evidence of approval. Test for evidence of a sequence check. Test for:（1）Evidence that a GRN is raised for all sales returns accepted.（2）Evidence of a sequence check. Test for: （1）Serial numbering. （2）Evidence of a sequence check. （3）Evidence of matching sales invoices to despatch notes andcustomer orders. （4）Correct accounting. Test for: （1）Evidence of approval and matching to GRN. （2）Correct accounting. Test for evidence of authorisation of adjustments to sales ledger Test for: （1）Evidence of review of reconciliation to sales ledger.（2）Evidence of authorisation of adjustments to sales ledger control account.The point made in the previous chapter applies here with equal force: though detailed, these descriptions of accounting systems and controls are of great examinationimportance.1.Introduction This chapter covers controls over payroll, and the assets of cash, inventory and non-current assets which must be safeguarded and used properly for companypurposes.2.Payroll·Control objectives ·To ensure that payments made represent value received for authorised work ·to ensure that payroll costs are completely and accurately recorded in the financial statements Segregation controls –examples ·Wages/sala riesdepartment should be separate from receipts or paymentsfunctions. ·Duties of wages staff should be rotated during theyear. ·The employee making up the pay packets should be different from the employee preparing the payroll. ·Periodic surprise attendance at payouts.Physical controls –examples ·Supervision of clock cards and timingdevices ·Control over unclaimed wages Authorisation and approval controls – examples ·Writtenauthorisation to employ or dismiss any employee, or to change rates of pay ·Authorisation ofovertime ·An independent official should check the payroll and signit ·Employees should sign for their wages ·Wages cheque should carry twosignatures.Arithmetical and accounting controls –examples ·A sample of calculations should bechecked ·Control accounts should be maintained Personnel controls - example ·A wagessupervisor should be appointed Management controls -example ·Overall checks to highlight major discrepancies （eg, check against budget）Items totest ·time re cords properly maintained andauthorised ·starters, leavers and changes in rates properly authorised by a department independent of the payroll department ·overtime, bonuses and commissions properly authorised andchecked ·deductions properly calculated andrecorded ·changes to tax rates, allowances properly authorised and correctly implemented ·correct amounts paid to tax authorities and other externalorganisations ·appropriate amounts recovered from external organisations ·total payroll authorised ·adequate security over cash transmissions ·payroll totals correctly posted to ledger accounts ·segregation of duties.3.Cash system·To ensure that all cash receipts are properly collected, recorded andbanked ·to ensure that payments made to suppliers are in respect of authorised invoicesonly ·to ensure that amounts charged to the band statement are authorised ·to ensure that receipts and payments are recorded accurately and completely in the accounting records. Controls over cash receipts post. Controls over cash collected by the sales force. Controls over cash sales. Controls over banking. Controls over cheque payments. Band reconciliations. Controls overpetty cash. Items to test·proper controls over receipts in the form of till receipts, other cash takings, cheques and creditcards ·prompt banding of notes, coins, cheques and credit card vouchers ·reconciliation of cash receipts（eg, to tillrolls）·Proper controls over opening of mail, including log of cheques received ·Reconciliati on of log to bankingrecords ·Agreement of receipts to remittance advices ·All receipts properly recorded and posted tocorrect ledgeraccounts ·Reconciliation of receivables controlaccount ·Secure storage of unused cheques, etc·all cheques accurately prepared on the basis of approved documentation authorised limits for chequesignatories ·Bank transfers properly authorised against supportingdocumentation ·direct debits and standing orders properly authorised and monitored ·All payments properly recorded andposted to correct ledgeraccounts ·reconciliation of payables controlaccount ·Segregation ofduties ·Regular bank reconciliations.4.Other systemsInventories Control objectives·to ensure that inventory consumption and inventory transfers are correctly and completely recorded ·to ensure that inventory figures in the income statement and balance sheet are correctly stated ·To ensure that physical amounts of inventory heldreconcile to book quantities ·To minimise loss and wastage of inventory.Items to test·Inventory requisitions are based on authorised reorderlevels ·sequentially numbered goods received notes ·goods in are properly inspected ·Goods rejected are properly recorded and credit notes chased ·All movements of inventory properly recorded ·Inventory records reconciled to physicalquantities ·Issues to work in progress properly and consistentlyvalued ·All inventory issues correctly authorised ·Adequate security in holding inventories areas ·Segregation ofduties.Non-current assets Control objectives·to ensure that non-current assets are correctly recorded, adequately secured and properly maintained ·To ensure that acquisitions and disposals of non-current assets are properly authorised ·To ensure that acquisitions and disposals of non-current assets are for the most favourable price possible.Items totest·all acquisitions properly authorised ·all acquisitions accuratelyrecorded ·depreciation calculations should be properly authorised, consistent and appropriate ·all assets safeguarded ·all assets logged in register ·regular reconciliation of physical assets to register ·all title deeds securely stored ·all disposals properlyauthorised ·disposals at arm’s length to ensure best price ·all disposals properlyrecorded ·segregation of duties.Investments Control objectives·to ensure secure title to the investment ·to ensure that all income accruing is received.Items to test·defined authorisation system for acquisitions and disposals ·all acquisitions and disposals correctly recorded ·all investment income monitored and chased ·control accounts maintained and regularly reconciled ·segregation of duties.History Exam Question Analysis（Q1/J2006）1 （a）Statethe control objectives for the ordering, despatch and invoicing of goods. （5 marks）（b）Atlantis Standard Goods （ASG） Ltd has a year end of 30 June 2006. ASG is a retailer of kitchen appliances such as washing machines, fridges and microwaves.All sales are made via the company’s Internet site with dispatch and delivery of goods to the customer’s house made using ASG’s vehicles. Appliances are purchased from many different manufacturers. The process of making a sale is as follows: （1）Potential customers visit ASG’s website and select the kitchen appliance that they require. The website ordering system accesses the stock specification file to obtain details of products ASG sells.（2）When the customer chooses an appliance, order information including price, item and quantity required are stored in the orders pending file. （3）Online authorisation of credit card details is obtained from the customer’s credit card company automatically by ASG’s computer systems.（4）Following authorisation, the sales amount is transferred to the computerised sales day book. At the end of each day the total from this ledger is transferred to the nominal ledger. （5）Reimbursement of the sales amount is obtained from each credit card company monthly, less the appropriate commission charged by the credit card company. （6）Following authorisation of the credit card, order details are transferred to a goods awaiting despatch file and allocated a unique order reference code. Order detailsare automatically transferred to the dispatch department’s computer system. （7）In the despatch department, goods are obtained from the physical stock, placed on ASG vehicles and the computerised stock system updated. Order information is downloaded on a hand held computer with a writable screen. （8）On delivery, the customer signs for the goods on the hand held computer. On return to ASG’s warehouse, images of the customer signature are uploaded to the orders file which is then flagged as ‘order complete’.This year’s audit planning documentation states that a substantive approach will be taken on the audit.Required:Tabulate the audit tests you should carry out on the sales and despatch system, explaining the reason for each test. （15 marks）（20 marks）[答疑编号10403101：针对该题提问]1 （a）Control objectives Ordering of goods – Goods are only supplied to authorised customers –Orders are recorded correctly regarding price, quantity, item and customer details Despatch andinvoicing of goods – Orders are despatched to the correct customer – All despatches are correctly recorded – Despatches only relate to goods ordered and paid for by customers – Invoices raised relate to goods supplied by the company（b）Audit tests on sales and despatch systemNote to candidates: The focus of the answer should be on substantive tests. Compliance tests are allowable where they relate to the system described.（Q3/D2001）3 （a）Errors and misappropriations Errors and misappropriations that may occur if purchases and capital expenditure are not properly controlled include:（i）Purchases for goods and capital items the company cannot use resulting in wasted resources and operational difficulties. （ii）Not obtaining the best prices available. （iii）Purchases for goods and capital items for the personal use of staff （i.e., misappropriation）. （iv）Incorrect recording and classification of purchases and capital items. （v）Non-payment for, or overpayment in respect of, purchases and capital items.（vi）Payment for purchases and capital items not received due to suppliers issuing fictitious invoices.（vii）Purchase of goods and capital items from suppliers with whom internal staff collude to pay inflated prices （segregation ofduties is necessary to prevent this）.（b）Report to management （i）Weakness and consequences: The overall structure of the system is complex, resulting in wasted management time in classifying purchases and capital items.Recommendation: That the systems should be simplified to avoid management time being spent onwhat are essentially clerical duties. The budget setting process should be more realistic to avoid the need to classify capital items as purchases. （ii）Weakness and consequences: There is an out of date ordering system and an informal method of inputting changes. This results in wasted time in correcting orders produced automatically. Recommendation: That the system be updated . the time spent making adjustments is almost certainly greater than the time it would take to update the system. （iii）Weakness and consequences: Buyers. consortium system and changes to orders: changes to orders are made by the production controller.s junior managers and the buyers. consortium system can only be used by them. This represents a lack of segregation of duties; those with access to the assets （those involved in production）should not also be able to execute the transaction （which should be done by the buying department）. Whilst collusion with the buyers. Consortium seems unlikely, it is possible that goods the company does not need at all could be purchased. Recommendation: That the buying department take over the responsibility for dealing with the buyers. consortiumand that staff operating the system are properly trained in its use. （iv）Weakness and consequences: The buyers. consortium system is taking up a large amount of system space and may be causing problems with other systems. Recommendation: That additional space be made to accommodate the system and that the software is investigated by systems engineers to establish the optimum technical solution.（v）Weakness and consequences: Only part of the buying takes place using the consortium which may be inefficient.Recommendation: That a review of the effectiveness of the use of the consortium be undertaken to establish whether to move more purchasing to the system.（vi）Weakness and consequences: The systems for budgeting and authorising capital expenditure and purchases are structurally weak as staff appear to find it necessary to circumvent the rules in order to do their jobs; the systems are also operating inefficiently as unauthorised capital expenditure is regularly incurred. It appears on the face of it that the structural problems are giving rise to the operational difficulties, although the operational difficultiesmay be independent of the structural weaknesses. Recommendation: That the structure and operation of both of the systems be reviewed in detail in the light of the operation of the business as a whole.Note: Answers might also be presented in a columnar format.[答疑编号10403102：针对该题提问]3 （a）Internal control systems are designed, amongst other things, to prevent error and misappropriation.Required:Describe the errors and misappropriations that may occur if purchases and capital expenditure are not properly controlled. （5 marks）（b）Cosmo is a high-quality, private motor manufacturing company. It has recently joined a consortium for the purchase of parts. Cosmo.s purchases and capital expenditure systems are not integrated.Purchases and capital expenditure There are complex internal rules relating to what constitutes a purchase, and what constitutes capital expenditure and the budgets for both are tightly controlled. Problems associated with the internal rules result in a significant number of manual adjustments to the management accounts which take up an excessive amount of management time. The systemfor authorising capital expenditure is not well controlled which results in some capital items being acquired without proper consideration, at the monthly meetings of the capital expenditure committee. Purchase orders Purchase orders are generated automatically by the computerised inventory system when inventory levels fall below a given level in the context of scheduled production. This system does not work well because the system uses outdated purchasing and production patterns and many manual adjustments are required. The orders are reviewed by the production controller and her junior managers and changes are made informally by junior clerical staff in the production controller.s department. Some of the purchases are input into the buying consortium system which shows the optimum supplier for any combination of cost, delivery time and specification. This system has only been in operation for a few months. The system takes up a substantial amount of disk space on the company.s computers and is suspected of causing problems in other systems. It is difficult to use and so far, only two of the production controller.s junior managers are able to use it. As aresult, the parts ordered through the system are sometimes of the incorrect specification or are delivered late. The remaining purchases are ordered directly from manufacturers, as before, through a reasonably well-controlled buying department.Required:Set out, in a form suitable for inclusion in a report to management, the weaknesses, potential consequences and your recommendations relating to the purchases and capital expenditure systems of Cosmo.（15 marks）（20 marks）。
计算机专业英语课文(第四版)全文翻译
1.2 总线互连总线是连接两个或多个设备的通信通路。
总线的关键特征是，它是一条共享传输介质。
多个设备连接到总线上，任一个设备发出的信号可以为其他所有连接到总线上的设备所接收。
如果两个设备同时传送，它们的信号将会重叠，引起混淆。
因此，一次只能有一个设备成功地（利用总线）发送数据。
典型的情况是，总线由多条通信通路或线路组成，每条线(路)能够传送代表二进制1和0的信号。
一段时间里，一条线能传送一串二进制数字。
总线的几条线放在一起能同时并行传送二进制数字。
例如, 一个8位的数据能在8条总线线上传送。
计算机系统包含有多种不同的总线，它们在计算机系统层次结构的各个层次提供部件之间的通路。
连接主要计算机部件(处理机, 存储器, I/O)的总线称为系统总线。
系统总线通常由50~100条分立的(导)线组成。
每条线被赋予一个特定的含义或功能。
虽然有许多不同的总线设计，但任何总线上的线都可以分成三个功能组：数据线、地址线和控制线。
此外可能还有为连接的模块提供电源的电源线。
数据线提供系统模块间传送数据的路径，这些线组合在一起称为数据总线。
典型的数据总线包含8、16或32根线，线的数量称为数据总线的宽度。
因为每条线每次传送1位，所以线的数目决定了每次能同时传送多少位。
数据总线的宽度是决定系统总体性能的关键因素。
地址线用于指定数据总线上数据的来源和去向。
例如，如果处理机希望从存储器中读一个字的数据，它将所需要字的地址放在地址线上。
显然，地址总线的宽度决定了系统最大可能的存储器容量。
控制线用来控制对数据线和地址线的访问和使用。
由于数据线和地址线被所有部件共享，因此必须用一种方法来控制它们的使用。
控制信号在系统模块之间传送命令和定时信息。
定时信息指定了数据和地址信息的有效性，命令信号指定了要执行的操作。
大多数计算机系统使用多总线，这些总线通常设计成层次结构。
图1.3显示了一个典型的高性能体系结构。
一条局部总线把处理机连接到高速缓存控制器，而高速缓存控制器又连接到支持主存储器的系统总线上。
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Unit 8 Computer NetworkingText 1令狐文艳Text 2 Data CommunicationsThe end equipmentcan be computers, printers, keyboards, CRTs, and so on.They are either generates the digital information for transmission oruses the received digital data. This equipment generally operates digital information internally in word units.DTE is data terminal equipment. A station controller (STACO)is the corresponding unit at the secondaries. At one time, the DTE was the last piece of equipment that belonged to the subscriber in a data link system. Between the DTEs, first is the modem, and then is the communications equipment. The communication equipment is owned and maintained by Telco. Data communications equipment (DCE) accepts the serial data stream from the DTE. And DCE converts it to some form of analog signal suitable for transmission on voice-grade lines. At the receive end, the DCE performs the reverse function. It converts the received analog signal to a serial digital data stream.The simplest form of DCE is a modem (modulator/demodulator) or data set. At the transmit end, the modem can be considered a form of digital-to-analog converter.While at the receive end, it can be considered a form of analog-to-digital converter.参考译文数据通信终端设备可以是计算机、打印机、键盘、CRT等。
它们可以生成要发送的数字信息，也可以使用所接收的数字数据。
这种设备通常在内部以字为单位处理数字信息。
DTE一般称为数据终端设备。
辅助设备一方的相应设备是工作站控制器（STACO）。
同时，DTE也是数据链路系统中属于用户端的最后一个设备。
在两个DTE之间，先是调制解调器，接着是属于Telco电话公司维护的通信设备。
数据通信设备（DCE）从DTE接收串行数据流，并将其转换成适合于在语音线路上发送的某种模拟信号形式。
在接收端，DCE完成相反的功能，把接收到的模拟信号转换成串行数字数据流。
最简单的DCE是调制解调器或数据传送机。
在发送端，调制解调器可以视为一种数/模转换器，而在接收端则可视为一种模／数转换器。
Text 3 Architecture of Computer Networks Computer network is a complex unit, it consists oftwo or more connected computing units. It is used for the purpose of data communication and resource sharing. Design of a network and its logical structure should comply with a set of design principles. They include: the organization of functions, the description of data formats and procedure.In the following two sections we will discuss two important network architectures, the OSI reference model and the TCP/IP reference model.(1)the OSI reference modelThe OSI (open systems interconnection) model was created by the ISO. This model is a foundation for comparing protocols; However, more protocols deviate from the rules set up by the OSI model.The OSI model has seven layers. Note that the OSI model itself is not a network architecture.It just tells what each layer should do. However, ISO has also produced standards for all the layers. Each one has been published as a separate international standard.(2)the TCP/IP reference modelTCP/IP is a communication protocol; it provides many different networking services.The TCP/IP Internet protocol suite is formed fromtwo standards: the TCP (Transmission Control Protocol) and the IP (Internet Protocol). TCP means it is on the transport layer. IP means it is on the network layer. On top of the transport layer is the application layer. It contains all the higher-level protocols. The early ones included virtual terminal (TELNET), file transfer (FTP), electronic mail (SMTP)and domain name service (DNS).As we know, TCP/IP is the foundation of the Internet.These protocols are continually changing and evolving to support the needs of the user community.参考译文计算机网络结构计算机网络是由两个或多个计算机设备互连而成的一种复合系统，它用于数据通信和资源共享。
网络设计及其逻辑结构应该遵循一套设计原则，其中包括：功能的组织以及数据格式和过程的说明。
在下面的两小节里，我们将讨论两个重要的网络体系结构，即OSI参考模型和TCP/IP参考模型。
(1)OSI参考模型OSI模型（开放系统互联参考模型）是由国际标准化组织（ISO）开发的一个建议。
相对于其他协议来说，此种模式为基础模式。
然而，更多的协议是背离OSI模型的。
OSI模型有7层。
应该注意的是，OSI模型本身并不是一种网络体系结构，它只是说明每一层应该做什么。
然而，ISO还是对各层制定了标准，每一层都是作为一个单独的国际标准来颁布的。
(2)TCP/IP参考模型TCP/IP参考模型是一种传输协议，提供了许多不同的网络服务。
TCP/IP协议组由TCP（传输控制协议）和IP（网际协议）两部分组成。
TCP表明是处于传输层，IP意为是在网络层。
在传输层上面是应用层。
应用层包括所有高层协议。
早期的协议包括虚拟终端TELNET、文件传送协议FTP、电子邮件SMTP和域名服务DNS。
现在我们知道，TCP/IP协议是因特网的基础。
这些协议在用户们的支持下不断地改变和进化着。
Text 4 Local Area NetworkA LAN (Local area data network) is a group of computers. The work devices connected together usually within the same building. By definition, the connections must be high-speed and relatively inexpensive (e.g. token ring or Ethernet). For example, a LAN may be used to interconnect workstations distributed around offices within a single building ora group of buildings such as a university campus.LANs consist of carefully selected groups of components (hardware and software). They are configured for the specific requirements of the organization. A LAN is generally limited to the size of a department or an organization. And a LAN often consists of 2 to 100 devices. LANs usually contain resources such as servers, printers, and connections to other networks through internetworking devices. The internetworking devices include switches and routers.In the next section we will discuss the structure of the different types of LAN.(1)TopologyMost wide area networks, such as the PSTN, use a mesh (sometimes referred to as a network) topology.With LANs, however, the limited physical separation of the subscriber DTEs allows simpler topologies to be used. The four topologies in common use are star, bus, ring and hub.The most widespread topology for LANs designed to function as data communication subnetworks for the interconnection of local computer-based equipment is the hub topology. It is a variation of the bus andring.(2)Transmission mediaTwisted pair, coaxial cable and optical fibre are the three main types of transmission medium used for LANs.(3)Medium access control methodsTwo techniques have been adopted for use of the medium access control in the LANs. One is carrier-sense-multiple-access with collision detection, and the other is control token.参考译文局域网局域数据网(局域网)由若干计算机组成。