01-04-2020-Oxford_English_for_Infomation_Technology (1171844), страница 15
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Put the field, then a colonand then what you are looking for.For example,URL: UK +universities will find only Britishuniversities.title: 'English language' will find only sites whichcontain this phrase in their titles.AltaVista supports the use of wildcardsearches. If you insert a * to the rightof a partial word, say hydro*, it willfind matches for all words beginning with hydro suchas hydrocarbon and hydrofoil. Wildcards can also beused to search for pages containing plurals of thesearch terms as well as to catch possible spellingvariations, for example alumin*m will catch bothaluminium (UK) and aluminum (US).If you are looking for multimedia filesthen save yourself time by selectingimages, audio or video with the radiobuttons on AltaVista's search box and then enteringyour search.a street map of Edinburgh, Scotlandtrain times between London and Paristhe exchange rate of your currency against the US dollara recipe for chocolate chip or hazelnut browniesvideo clips of the Beatlessumo wrestler competitions in Japan this yearthe weather in New York city tomorrowheart disease amongst womenNew Zealand universities which offer courses in computingSir Isaac Newton's laws of motionTest your answers using AltaVista.WRITINGWrite your own description of how your browser finds the pageyou want.
Use Fig 2 to help you. When you have finished, compareyour answer with the listening script to Task 4 on page 198.94UNIT 13 The World Wide WebEmail ProtocolsFind the answers to these questions in thefollowing text.1 Name three different email protocolsmentioned in the text.2 Which email protocol is used to transfermessages between server computers?3 Why is SMTP unsuitable for deliveringmessages to desktop PCs?4 Name two host-based mail systemsAlthough the format of a mail message, astransmitted from one machine to another, isrigidly defined, different mail protocols transferand store messages in slightly different ways.
Themail system you're probably used to employs acombination of SMTP and POP3 to send andreceive mail respectively. Others may use IMAP4to retrieve mail, especially where bandwidth islimited or expensive.mentioned in the text.5 Where are email messages stored in anSMTP system?6 What happens when you use your Web mailaccount to access a POP3 mailbox?7 Give an advantage and a disadvantage of8having an option to leave POP3 messageson the server.What are the advantages of using the IMAP4protocol?Web mail systems use some of the same protocols asclient/server mail.
Some can access an ISP-based POP3mailbox, allowing you to read your mail anywhere you canfind a browser.SMTP is used to transfer messages between onemail server and another. It's also used by emailprograms on PCs to send mail to the server. SMTPis very straightforward, providing only facilities todeliver messages to one or more recipients inbatch mode. Once a message has been delivered,it can't be recalled or cancelled. It's also deletedfrom the sending server once it's been delivered.SMTP uses 'push' operation, meaning that theconnection is initiated by the sending serverrather than the receiver. This makes it unsuitablefor delivering messages to desktop PCs, whicharen't guaranteed to be switched on at all times.UNIT 13 The World Wide WebIn host-based mail systems, such as Unix and Webmail, SMTP is the only protocol the server uses.Received messages are stored locally and retrievedfrom the local file system by the mail program.
Inthe case of Web mail, the message is thentranslated into HTML and transmitted to yourbrowser. SMTP is the only protocol for transferringmessages between servers. How they're thenstored varies from system to system.0Since POP3 downloads all the messages in yourmailbox, there's an option to leave messages onthe server, so that they can be picked up fromdifferent machines without losing any. This doesmean that you'll get every message downloadedevery time you connect to the server. If you don'tclean out your mailbox regularly, this could meanlong downloads. When using a Web mail accountto retrieve POP3 mail, be careful about leavingmessages on the server - if too many build up.each download will take a long time and fill upyour inbox.
Many Web mail systems won'trecognise messages you've already downloaded, soyou'll get duplicates of ones you haven't deleted.Internet Mail Access ProtocolIMAP is similar in operation to POP, but allowsyou more choice over what messages youdownload. Initially, only message headers areretrieved, giving information about the sender andsubject.
You can then download just thosemessages you want to read. You can also deleteindividual messages from the server, and someIMAP4 servers let you organise your mail intofolders. This makes download times shorter andthere's no danger of losing messages.[Adapted from 'Using Web-based Email' by JonathanBennett, PC Magazine, November 1999]Re-read the text to find the answers tothese questions.1 Mark the following statements as True orFalse:aDifferent mail systems transfer emails indifferent ways.IMAP4 requires more bandwidth than theother email protocols.SMTP is used for sending emails from a PCto a server.SMTP delivers messages one at a time.SMTP does not allow a delivered message tobe cancelled.SMTP is only one of many protocols used tosend mail between servers.POP protocol allows the user to downloadone message at a time.bPost Office ProtocolPOP is a message-retrieval protocol used by manyPC mail clients to get messages from a server,typically your ISP's mail server.
It only allows youto download all messages in your mailbox at once.It works in 'pull' mode, the receiving PC initiatingthe connection. PC-based POP3 mail clients cando this automatically at a preset interval. Whenyou use your Web mail account to access a POP3mailbox, the mail server opens a connection tothe POP3 server just as a PC-based applicationwould. The messages are then copied into yourWeb mailbox and read via a browser.95cdefg2 Match the terms in Table A with thestatements in Table B.Table AaSMTPb'Push' operationcPOPd 'Pull' operationeIMAPTable BiAn email transfer process in which theconnection is initiated by the sendingcomputer rather than the receivingcomputer.iiA mail transfer protocol that initially onlyretrieves the message headers.iii An email transfer process in which thereceiving computer initiates theconnection.iv A simple mail transfer protocol that isused to send messages between servers.v A message-retrieval protocol thatdownloads all email messages at thesame time.UNIT 14WebsitesSTARTERWhat features make a good website? Make a list of the keyfeatures you look for.
Then compare your list with others in yourgroup.Study these seven points for evaluating websites. Whatquestions would you ask to evaluate a website on each point?1234567READINGDesignNavigationEase of useAccuracyUp to dateHelpful graphicsCompatibilityUnderstanding the writer's purpose Knowing who the writeris, what their purpose is and who they are writing for can help us tounderstand a text.Study these extracts from a text. Decide:1 What special expertise does the author have in this field?2 Who are the intended readers?3 What is the author's purpose?Title:Help Web-farers find their way.Source:Windows Magazine, E-Business sectionSubtitle:Here are nine ways to make it easy for visitors tonavigate your website.First paragraph:Author information:Matt Micklewicz offers advice and useful linksfor Webmasters at his Webmaster Resources site(www.
webmaster-resources. com).Your website may be chock full of informationabout your company and its products, but ifvisitors to the site can't easily find their wayaround its pages they may never return. Besidescontent, the most important aspect of a website isits navigation scheme. Unfortunately, that mayalso be the most commonly neglected designconsideration.
These nine site-design pointers willhelp you build an effective navigation system.Work in groups of 3, A, B and C. Summarise the advice in eachtext you read in one sentence.Student AStudent BStudent CRead texts 1 to 3Read texts 4 to 6Read texts 7 to 91 Trust TextIt's tempting to spice up pages with graphics — butsometimes even a little is too much.
If possibleyour navigation system should be based on textlinks, rather than image maps or graphical buttons.Studies have shown that visitors will look at andtry text links before clicking on graphical buttons.2 Next Best AlTernativeIf you must use a graphical navigation system,include descriptive ALT text captions. The ALTtext will make it possible for visitors who use textbrowsers such as Lynx or who browse withgraphics turned off, to find their way around.
Inaddition to the graphical navigation buttons, besure to include text links at the bottom of everypage that provide a clear route to the main areasof your site.3 Map ItA site map offers a good overview of your siteand will provide additional orientation for visitors.It should be in outline form and include all themajor sections of your site with key subpageslisted beneath those sections. For example, youmay group your FAQ, Contact andTroubleshooting pages so they're all accessiblefrom a Support page.
It's a good idea to visit a fewlarger sites to get some ideas on designing aneffective site map.4 Forego FramesAvoid frames wherever possible. Most veteranbrowsers dislike them and they can be confusingfor visitors who are suddenly presented withmultiple scrollbars. If you're committed to usingframes on your site, you'd better commit yourselfto some extra work too, because you'll have tocreate a no-frames version of your site for visitorswhose browsers don't support frames.5 Consistency CountsDon't change the location of your navigationelements, or the color of visited and not-visitedlinks from page to page. And don't get clever withlinks and buttons that appear and disappear:turning things on and off is usually done as anattempt to let visitors know where they are at asite but more often than not it ends up confusingthem.6 Just a Click AwayKeep content close at hand.
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