《计算机专业英语》课件unit3

Unit1ComputerHardwareUnit2ComputerSoftware

Unit3ComputerNetwork

Unit4MultimediaCONTENTS目录

Unit5E-commerce

Unit6ComputerSecurity

Unit7BigData

Unit8CloudComputingUnit3ComputerNetworkSpeakingListeningReadingWritingSpeakingInternetProtocolSuite网络协议组

Physical物理层Link链接层

Network网络层TransportApplication应用层传输层1LookatthefollowinggraphicandspeakouteachpartofInternetprotocolsuite.SpeakingInputdevice输入装置

Mainbus主总线Node/PC节点

Connectionwire连接线TransportApplication应用层传输层2.ListtheChinesenamesofthemarksinthefollowingnetworktopologies.Speaking3.Supposeyouareanetworkadministrator.GiveapresentationtoeachpictureinEnglish.Picture1Introducethecommonnetworkdevicestoyourcustomers.SpeakingPicture2Tellyourfriendswhatdoyouusuallydoinyourdailywork.3.Supposeyouareanetworkadministrator.GiveapresentationtoeachpictureinEnglish.Listening1.Listencarefullyandchoosethewordsyouhear.1.A.cloud B.round C.loud D.ground2.A.past B.pass C.fast D.last3.A.father B.further C.leather D.weather4.A.shop B.shot C.shoot D.soft5.A.white B.right C.red D.light6.A.book B.boot C.foot D.fork7.A.shoes B.whose C.nose D.mouse8.A.message B.massage C.methods D.markets9.A.show B.snow C.whole D.shoe10.A.sink B.think C.sick D.thick

Keys:1.A.2.B.3.D.4.C.5.B.6.D.7.B.8.C.9.C.10.A.Listening2.Listentotheshortpassageandchoosetheproperwordstofillintheblanks.GSM(GlobalSystemforMobilecommunicationsisthemostpopular1(qualification,standard,popularity)formobilephonesintheworld.Itspromoter,theGMSAssociation,estimatesthat2(85%,90%,80%)oftheglobalmobilemarketusesthestandard.GSMisusedbyover33(billion,million)peopleacrossmorethan212countriesandterritories.Itsubiquitymakesinternationalroamingverycommonbetweenmobilephonesoperators,enablingsubscriberstousetheirphonesinmanypartsoftheworld.GSMdiffersfromitspredecessorsinthatbothsignalingandspeechchannelsare4(digital,digitized,dignified),andthusisconsideredasecondgeneration(2G)mobilephonesystem.Thishasalsomeantthat5(data,digital,stimulus)communicationwaseasytobuildintothesystem

Listening3.Listentothedialogueandchoosethebestresponsestowhatyouhear.1.A.I’mflyingbacktomorrow.B.Seeyounexttime.C.It’smypleasure.D.It’sTuesday._________2.A.Speaking B.I’dliketoputupatelephoneservice,please.C.IsthereSusanspeaking? D.Youmusthavethewrongnumber._________3.A.It’sdelicious.B.It’slucky.C.It’ssure.D.It'sfine._________4.A.Yes,Ithinkso.B.Doyoureallythinkso?C.No,it’snotverybeautiful.D.Oh,thankyou._________

ABDDListening3.Listentothedialogueandchoosethebestresponsestowhatyouhear.5.A.Maybe.B.Thesametoyou.C.Whereareyougoing?D.OK.I’llvisitmyparents._________6.A.Sorry,I’mastrangerhere.B.Well,I’llneverknowwhatyousay.C.Sorry,Iwon’tgiveyoutheway.D.Well,I’lltellyounexttime._________7.A.Nicetoseeyou. B.Howaboutyou?C.Nottoobad.D.Howdoyoufeelit?________8.A.Youaresopolite.B.Wearesoclosefriends.C.Don’tsayso.D.Youaresowelcome._________

BACDListening4.Listentothedialoguesandchoosethebestanswertoeachquestionyouhear.1.A.strict B.friendlyC.kind D.patient2.A.aterribletrafficaccident B.arushhourC.aterribleaircrash D.anairport3.A.thepronunciationoftheword B.thespellingofthewordC.themeaningoftheword Dtheexplanationoftheword4.A.somecoffee B.somejuice.C.somecakes D.someoranges5.A.Traveling B.ReadingstoriesC.Writingstories D.writingmagazinesListening5.Listentothedialogueandanswerthefollowingquestionsbyfillingintheblanks.1.WhoisAliceWhite?Sheisa__________________.2.Howoldisshenow?Sheis____.3.Whendidshebecomefamous?Shebecamefamous__________________.4.Whyhasshegivenupswimming?Because_________________.5.Whattimedidshegetuptogotothepoolwhenshewasyoung?Shegetup___________.

swimmingplayer20

attheageof15Sheistiredofit

the6a.m.

Listening

6.Listentothepassageandfillintheblankswithwordsyouhear.Somenewwordsgivenbelowwillbeofsomehelptoyou.

HowBabiesCommunicateBabiesarebornwiththe1tocry,whichishowthey2forawhile.Yourbaby’scriesgenerallytellyouthatsomethingis3:anemptybelly,awetbottom,coldfeet,beingtired,oraneedtobeheldandcuddled,etc.Soonyou’llbeableto4whichneedyourbabyisexpressingandrespondaccordingly.Infact,sometimeswhatababyneedscanbeidentifiedbythetypeofcry—forexample,the“I’mhungry”crymaybeshortandlow-pitched,while“I’mupset”may5choppy.Yourbabymayalsocrywhenoverwhelmedbyallofthe6and7oftheworld,orfornoapparentreasonatall.Don’tbetoo8whenyourbabycriesandyouaren’tabletoconsolehimorher9:cryingisonewaybabiesshoutoutstimuliwhenthey're10.

Keys:1.ability2.communicate

3.wrong

4.recognize

5.sound

6.sights

7.sounds

8.upset

9.immediately

10.overloadedReadingPassageA

ComputernetworkAcomputernetworkordatanetworkisadigitaltelecommunicationsnetworkwhichallowsnodestoshareresources.Incomputernetworks,networkedcomputingdevicesexchangedatawitheachotherusingadatalink.Theconnectionsbetweennodesareestablishedusingeithercablemediaorwirelessmedia.

ReadingPassageA

NetworknodesAcomputerorotherdeviceconnectedtoanetwork,whichhasauniqueaddressandiscapableofsendingorreceivingdataarecallednetworknodes.Nodescanincludehostssuchaspersonalcomputers,phones,serversaswellasnetworkinghardware.Twosuchdevicescanbesaidtobenetworkedtogetherwhenonedeviceisabletoexchangeinformationwiththeotherdevice,whetherornottheyhaveadirectconnectiontoeachother.

ReadingPassageA

NetworkProtocolsInordertogettrafficflowing,youneedprotocolsrulinghowdataissent,receivedandinterpretedbythenetworkeddevices.TheprotocolsarestackedinseverallayersandtogethertheymakeuptheInternetProtocolSuite.Onthelowestlayer(thelinklayer)thereisaprotocoldealingwithdigitalelectronics.InaLANorLocalAreaNetwork,thisistheEthernetProtocol.OntopofthiscomestheInternetlayer.HerewehavetheInternetProtocol((IP).Fromthispointonaconcept,referredtoasIPaddressingbecomesavailable.NextintheTransportLayer,wefindtheTransmissionControlProtocolorTCPforshort,andUserDatagramProtocol(UDP).Again,theremaybeotherprotocolsinthislayer.OnemorelayerupistheApplicationLayer,whichhasprotocolsweknowfromeverydayuse,suchasHTTP,SMTPandalsoP2P(peertopeer)voicecommunication.

ReadingPassageA

ComputernetworkssupportanenormousnumberofapplicationsandservicessuchasaccesstotheWorldWideWeb,digitalvideo,digitalaudio,shareduseofapplicationandstorageservers,printers,andfaxmachines,anduseofemailandinstantmessagingapplicationsaswellasmanyothers.Computernetworksdifferinthetransmissionmediumusedtocarrytheirsignals,communicationsprotocolstoorganizenetworktraffic,thenetwork'ssize,topologyandorganizationalintent.Thebest-knowncomputernetworkistheInternet.

ReadingPassageAAcomputernetworkordatanetworkisadigitaltelecommunicationsnetworkwhichallows______(1)toshare__________(2).Incomputernetworks,networkedcomputingdevicesexchange______(3)witheachotherusinga________(4).Theconnectionsbetweennodesareestablishedusingeither___________(5)or_______________(6).

1.Fillintheblankswithoutreferringtothepassagenodesresourcesdata

_datalink

cablemediaWirelessmediaReadingPassageA(1).Whatiscomputernetwork?Acomputernetworkordatanetworkisadigitaltelecommunicationsnetworkwhichallowsnodestoshareresources.(2).Howtodefinenetworknodes？Listseveralexamples.Acomputerorotherdeviceconnectedtoanetwork,whichhasauniqueaddressandiscapableofsendingorreceivingdataarecallednetworknodes.Nodescanincludehostssuchaspersonalcomputers,phones,serversaswellasnetworkinghardware.(3).DescribeinyourownwordshowtheInternetProtocolSuiteisorganized.Accordingtothepassage,InternetProtocolSuitemainlyincludeslinklayer,Internetlayer,TransportLayer,ApplicationLayer.

2.Answerthefollowingquestionsaccordingtothepassage

ReadingPassageA(4).WhatisthetoplayerintheInternetProtocolSuite?Canyouspeakoutseveralprotocolsweusuallyuseinthelayer?ItistheApplicationLayer,whichhasprotocolsweknowfromeverydayuse,suchasHTTP,SMTPandalsoP2P(peertopeer)voicecommunication.(5).Whichisthebest-knowncomputernetwork?

2.Answerthefollowingquestionsaccordingtothepassage.

Thebest-knowncomputernetworkistheInternet.ReadingPassageA1.Acomputernetworkordatanetworkisadigitaltelecommunicationsnetworkwhichallows_______toshareresources.2.Incomputernetworks,networkedcomputingdevicesexchangedatawitheachotherusinga__________.3.Acomputerorotherdeviceconnectedtoanetwork,whichhasauniqueaddressandiscapableofsendingorreceivingdataarecalled_________________.4.Inordertogettrafficflowing,youneed____________rulinghowdataissent,receivedandinterpretedbythenetworkeddevices.5.Onthelowestlayer(thelinklayer)thereisaprotocoldealingwith____________________.6.Computernetworksdifferin_____________________________________________________________________________________________________________

3.Completeeachofthefollowingstatementsaccordingtothepassage

nodesdatalinknetworknodesprotocolsdigitalelectronicsthetransmissionmedium,communicationsprotocols,thenetworksize,topologyorganizationalinternet.ReadingPassageA(1)因特网是一个全球计算机网络系统。(network)TheInternetisaworldwidecomputernetwork.(2)我们认为她完全能够照顾自己。（becapableof）

Wethinkthatsheisabsolutelycapableoftakingcareofherself.(3)钱是用来买卖的一种媒介。（medium）

Moneyisamediumforbuyingandselling.(4)他的吉他弹得和你一样好。（aswellas）Heplaystheguitaraswellasyou.

4.TranslatethefollowingsentencesintoEnglish.

ReadingPassageA(5)女警察构成警力的13%。(makeup)Womenofficersmakeup13percentofthepoliceforce.(6)唯一一点是不能用无线设备。(wireless)Heonlythingisnowirelessdevices.(7)到镇上唯一的通路是经过那座桥。(accessto)Theonlyaccesstothetownisacrossthebridge.(8).人们对失败持有不同的态度。（differin)

4.TranslatethefollowingsentencesintoEnglish.

Peopledifferintheirattitudestowardsfailure.ReadingPassageA(1)Acomputernetworkordatanetworkisadigitaltelecommunicationsnetworkwhichallowsnodestoshareresources.

计算机网络或数据网络是一个允许节点共享资源的数字通信网络。(2)Incomputernetworks,networkedcomputingdevicesexchangedatawitheachotherusingadatalink.

在计算机网络中，联网的计算设备利用数据传输器互相交换数据。

5.TranslatethefollowingsentencesintoChinese.

ReadingPassageA(3)Acomputerorotherdeviceconnectedtoanetwork,whichhasauniqueaddressandiscapableofsendingorreceivingdataarecallednetworknodes.网络节点指与网络连接的电脑或其它设备，它们拥有独立地址，并能够发送和接受数据。(4)Twosuchdevicescanbesaidtobenetworkedtogetherwhenonedeviceisabletoexchangeinformationwiththeotherdevice,whetherornottheyhaveadirectconnectiontoeachother.不管是否是直接连接，当其中一个设备能够与其它设备交换信息时，这两种设备就可看做联网了。

5.TranslatethefollowingsentencesintoChinese.

ReadingPassageA(5)TheprotocolsarestackedinseverallayersandtogethertheymakeuptheInternetProtocolSuite.协议在几个层面堆积起来，形成互联网协议组。(6)NextintheTransportLayer,wefindtheTransmissionControlProtocolorTCPforshort,andUserDatagramProtocol(UDP).在传输层，我们发现了传输控制协议，简称TCP，和用户数据报协议（UDP）。

Task5.TranslatethefollowingsentencesintoChinese.

ReadingPassageA(7)OnemorelayerupistheApplicationLayer,whichhasprotocolsweknowfromeverydayuse。

再往上一层是应用层，这里有我们从日常使用中了解的协议。(8)Computernetworksdifferinthetransmissionandcommunicationprotocols.计算机网络在传输和通信协议方面会有所不同。

5.TranslatethefollowingsentencesintoChinese.

ReadingPassageA(9)Thebest-knowncomputernetworkistheInternet.最著名的计算机网络是因特网。

(10)ComputernetworkssupportanenormousnumberofapplicationsandservicessuchasaccesstotheWorldWideWeb.计算机网络支持大量的应用和服务，如万维网。

5.TranslatethefollowingsentencesintoChinese.

PassageBNetworkTopologyNetworktopologyisthearrangementofthevariouselementsofacommunicationnetwork,includingitsnodesandconnectinglines.Therearetwowaysofdefiningnetworkgeometry:thephysicaltopologyandthelogical(orsignal)topology.Thephysicaltopologyofanetworkistheactualgeometriclayoutofworkstations.Thereareseveralcommonphysicaltopologies,asdescribedbelowandasshownintheillustration.

ReadingPassageB

ReadingInthebusnetworktopology,everyworkstationisconnectedtoamaincablecalledthebus.Therefore,ineffect,eachworkstationisdirectlyconnectedtoeveryotherworkstationinthenetwork.Inthestarnetworktopology,thereisacentralcomputerorservertowhichalltheworkstationsaredirectlyconnected.Everyworkstationisindirectlyconnectedtoeveryotherthroughthecentralcomputer.PassageBIntheringnetworktopology,theworkstationsareconnectedinaclosedloopconfiguration.Adjacentpairsofworkstationsaredirectlyconnected.Otherpairsofworkstationsareindirectlyconnected,thedatapassingthroughoneormoreintermediatenodes.IfaTokenRingprotocolisusedinastarorringtopology,thesignaltravelsinonlyonedirection,carriedbyaso-calledtokenfromnodetonode.

ReadingPassageBThemeshnetworktopologyemployseitheroftwoschemes,calledfullmeshandpartialmesh.Inthefullmeshtopology,eachworkstationisconnecteddirectlytoeachoftheothers.Inthepartialmeshtopology,someworkstationsareconnectedtoalltheothers,andsomeareconnectedonlytothoseothernodeswithwhichtheyexchangethemostdata.Thetreenetworktopologyusestwoormorestarnetworksconnectedtogether.Thecentralcomputersofthestarnetworksareconnectedtoamainbus.Thus,atreenetworkisabusnetworkofstarnetworks.

ReadingPassageB

Logical(orsignal)topologyreferstothenatureofthepathsthesignalsfollowfromnodetonode.Inmanyinstances,thelogicaltopologyisthesameasthephysicaltopology.Butthisisnotalwaysthecase.Forexample,somenetworksarephysicallylaidoutinastarconfiguration,buttheyoperatelogicallyasbusorringnetworks.

ReadingPassageBReading1.MatchthefollowingEnglishphrasesinColumnAwiththeirChineseequivalentsinColumnB.TranslatethefollowingsentencesintoChinese.

AB1.networktopology a.中间节点2.connectinglines b.网状网络拓扑3.physicaltopology c.逻辑拓扑4.logicaltopology d.环状网络拓扑5.starnetworktopology e.物理拓扑6.centralcomputer f.中央计算机7.ringnetworktopology g.网络拓扑8.intermediatenodes h.主总线

9.meshnetworktopology i.星状网络拓扑10.mainbus j.连接线PassageBReading2.DecidewhetherthefollowingstatementsareT(true)orF(false)accordingtothepassage.

1.Networktopologyisjustthearrangementofthenodes.()2.Inthebusnetworktopology,everyworkstationisconnectedtoamaincablecalledthebus.()3.Inthebusnetworktopology,eachworkstationisindirectlyconnectedtoeveryotherworkstationinthenetwork.()4.Inthestarnetworktopology,everyworkstationisindirectlyconnectedtoeveryotherthroughthecentralcomputer.()5.Intheringnetworktopology,allworkstationsaredirectlyconnected.()6.IfaTokenRingprotocolisused,thesignaltravelsinonlyonedirection,carriedbyaso-calledtokenfromnodetonode.()7.Inthefullmeshtopology,eachworkstationisconnecteddirectlytoeachoftheothers.()8Inthepartialmeshtopology,notallworkstationsareconnectedtoalltheothers.()9.Allthecomputersofthestarnetworksareconnectedtoamainbus.()10.thelogicaltopologyisdefinitelydifferentfromthephysicaltopology.()FTFTFTT

TF

FPassageBReading

3.TranslatethefollowingpassageintoChinese.

Logical(orsignal)topologyreferstothenatureofthepathsthesignalsfollowfromnodetonode.Inmanyinstances,thelogicaltopologyisthesameasthephysicaltopology.Butthisisnotalwaysthecase.Forexample,somenetworksarephysicallylaidoutinastarconfiguration,buttheyoperatelogicallyasbusorringnetworks.

逻辑（或信号）拓扑指的是信号从一个节点到另一个节点的传输路径。在许多情况下，逻辑拓扑与物理拓扑无异。但是情况并非一直如此。例如，一些网络以星型结构的物理拓扑布局，却以总线或环状网络的逻辑拓扑进行操作。

1WhatisWi-Fi?A.Itisaphysicaldevicetocatchthesignalofinternet.B.Itisatechnologyforwirelesslocalareanetworking.C.Itisacentralcomputerwhichcansendsignalstoothers.D.ItisWLAN.2.WhichofthefollowingdevicescanuseWi-Fitechnology?A.PersonalcomputersB.Video-gameconsolesC.DigitalcamerasD.Alloftheabove3.WhichofthefollowingcitiesistheearliesttoconstructcitywideWi-Finetworks?A.Mysore.B.London.C.Florida.D.California.ExtraReadingReadthefollowingpassageandchoosethebestanswertoeachquestion.✓

✓

✓

ExtraReadingReadthefollowingpassageandchoosethebestanswertoeachquestion.4.Accordingtothepassage,whichofthefollowingstatementsistrue?A.OfficialsinSeoulintendedtocompletethewholecity’sWi-Finetworkin2015.B.TheofficialsinSouthKoreawillchargepeopleforusingWi-Fi.C.OfficialsinSouthKorea'scapitalarenotmovingtoprovidefreeInternetindenselypopulatedresidentialareas.D.SouthKoreagovernmenthastheirowntelecommunicationcompany.5.CarnegieMellonUniversitybuiltthefirstcampus-widewirelessInternetnetworkin_______.A.1997B.2012C.1993D.2015✓

✓

Writing合同／协议(Contract／Agreement)

合同或协议是指为明确双方或多方在某一事务中的责任、义务和权利，在商务活动开始前，经相互讨论协商，双方或所涉及各方所签署的具有法律效应的书面正式文件。一般包括以下要素：1、标题：要标明合同/协议性质。标题下是合同或协议参考号。2、正文：包括开头、具体条款和结尾。开头写清合同或协议双方或各方全名和地址。一般在名称和地址后注上“以下简称甲/乙方、买/卖方或雇佣方/被雇佣方”，接着简要说明签订合同/协议的目的。具体条款要逐行排列，表明1、2、3等。结尾写明签署的时间、地点、份数及有效文字等。3、签字：有关责任人签字或单位盖章。Writing合同／协议(Contract／Agreement)CONTRACTDate(日期)：ContractNo.（合同号）：TheBuyers（买方）:Address/TEL/FAX/E-mail（地址/电话/传真）:TheSellers（卖方）：Address/TEL/FAX/E-mail（地址/电话/传真）:ThiscontractismadebyandbetweentheBuyersandtheSellers;wherebytheBuyersagreetobuyandtheSellersagreetoselltheunder-mentionedgoodssubjecttothetermsandconditionsasstipulatedhereinafter（兹经买卖双方同意按照以下条款由买方购进，卖方售出以下商品）：(1)NameofCommodity（商品名称）：(2)Quantity（数量）：(3)Unitprice（单价）：(4)TotalValue（总值）：(5)Packing（包装）：(6)CountryofOrigin(生产国别)：Writing合同／协议(Contract／Agreement)(7)TermsofPayment(支付条款)：(8)insurance(保险)：(9)TimeofShipment(装运期限)：(10)PortofLading(起运港)：(11)PortofDestination(目的港)：

(12)Claims(索赔)：Within45daysafterthearrivalofthegoodsatthedestination，shouldthequality,specificationsorquantitybefoundnotinconformitywiththestipulationsofthecontractexceptthoseclaimsforwhichtheinsurancecompanyortheownersofthevesselareliable,theBuyersshall,havetherightonthestrengthoftheinspectioncertificateissuedbytheC.C.I.CandtherelativedocumentstoclaimforcompensationtotheSellers.(在货到目的口岸45天内如发现货物品质，规格和数量与合同不附，除属保险公司或船方责任外，买方有权凭中国商检出具的检验证书或有关文件向卖方索赔换货或赔款。)Writing合同／协议(Contract／Agreement)(13)ForceMajeure（不可抗力）Thesellersshallnotbeheldresponsibleforthedelayinshipmentornon-deli-veryofthegoodsduetoForceMajeure,whichmightoccurduringtheprocessofmanufacturingorinthecourseofloadingortransit.ThesellersshalladvisetheBuyersimmediatelyoftheoccurrencementionedabovethewithinfourteendaysthereafter.theSellersshallsendbyairmailtotheBuyersfortheiracceptanceacertificateoftheaccident.UndersuchcircumstancestheSellers,however,arestillundertheobligationtotakeallnecessarymeasurestohastenthedeliveryofthegoods.（由于人力不可抗力的原由发生在制造，装载或运输的过程中导致卖方延期交货或不能交货者，卖方可免除责任，在不可抗力发生后，卖方须立即电告买方及在14天内以空邮方式向买方提供事故发生的证明文件，在上述情况下，卖方仍须负责采取措施尽快发货。）Writing合同／协议(Contract／Agreement)(14)Arbitration（仲裁）AlldisputesinconnectionwiththeexecutionofthisContractshallbesettledfriendlythroughnegotiation.incasenosettlementcanbereached,thecasethenmaybesubmittedforarbitrationtotheArbitrationCommissionoftheChinaCouncilforthePromotionofInternationalTradeinaccordancewiththeProvisionalRulesofProcedurepromulgatedbythesaidArbitrationCommission.theArbitrationcommitteeshallbefinalandbindinguponbothparties.andtheArbitrationfeeshallbebornebythelosingparties.（凡有关执行合同所发生的一切争议应通过友好协商解决，如协商不能解决，则将分歧提交中国国际贸易促进委员会按有关仲裁程序进行仲裁，仲裁将是终局的，双方均受其约束，仲裁费用由败诉方承担。）

TheBuyers（买方）:TheSellers（卖方）：Writing合同／协议(Contract／Agreement)◆常用语句◆①PartyAandPartyBagreetothefollowingtermsafterfriendlynegotiationsbasedontheprinciplesofmutualinterestandequalrights.(甲、乙双方经友好协商，在互惠互利、平等公正基础上，达成以下协议。)②Ifanytermsneedtobealtered,thetwopartiesshallsignanewsupplementalagreement,whichshallhavethesameforceasthisagreement.(其他未尽事宜，双方协商解决并另定补充协议。)③ThisleaseiswritteninbothChineseandEnglish,andbothofwhichareauthentic.(本合同以中、英两种文字写成，具同等法律效力。)④Thetwopartiesshallsettledisputesthroughfriendlynegotiations.(如有争议，双方应协商解决。)⑤Thisagreementhastwooriginalcopies,oneforeachparty.(本合同文本一式两份，甲、乙双方各执一份。)⑥Thetwopartiesshallstrictlyfollowtheitemsinthisagreement.(双方应严格遵守本合同所有条款。)⑦ThisagreementiseffectivefromthedatewhenbothPartyAandPartyBhavesignedit.(本合同自双方签署之日起生效。)

Writing1.YouarerequiredtowriteacontractaccordingtothefollowinginstructionsgiveninChinese.名称：销售合同正文：本合同由加拿大CBD公司和中国DL公司通过友好协商签订，条款如下。(1)货物名称：玉米(2)数量：2万吨(3)单价：4美元/公斤(4)总值：8000万美元(5)包装：货物应具有防潮、防震并适合远洋运输的包装(6)本合同以中、英文两种文字写成，具有同等法律效力.(7)原产地：美国(8)装运期限：4月10日前(9)装运口岸：美国纽约(10)目的口岸：中国大连(11)保险：由卖方按发票金额110%投保一切风险(12)付款方式：信用证付款

Writing1.YouarerequiredtowriteacontractaccordingtothefollowinginstructionsgiveninChinese.

［参考范文］CONTRACT

Date：July25,2015Contract