计算机英语（第4版）全套PPT课件.ppt

AbbreviationsDoS拒绝访问（DenialofService）计算机英语（第4版）司爱侠张强华编ListeningtoTextA计算机英语（第4版）司爱侠张强华编[1]Firstofall,we’llgetintothetypesofthreatsthatareagainstnetworkedcomputers,andthensomethingsthatcanbedonetoprotectyouagainstvariousthreats.Notes原句本句中，thatareagainstnetworkedcomputers是一个定语从句，修饰和限定thetypesofthreats。thatcanbedonetoprotectyouagainstvariousthreats也是一个定语从句，修饰和限定somethings。firstofall的意思是“首先”。讲解计算机英语（第4版）司爱侠张强华编[2]Therearetoolkitsavailableintheundergroundcommunitythatmakethisasimplematterofrunningaprogramandtellingitwhichhosttoblastwithrequests.Notes原句本句中，thatmakethisasimplematterofrunningaprogramandtellingitwhichhosttoblastwithrequests是一个定语从句，修饰和限定toolkits。availableintheundergroundcommunity是一个形容词短语，作定语，也修饰和限定toolkits，它可以扩展为一个定语从句：whichareavailableintheundergroundcommunity。讲解计算机英语（第4版）司爱侠张强华编[3]However,thathostshouldnotprovidecommandshellaccesswithoutbeingsurethatthepersonmakingsucharequestissomeonewhoshouldgetit,suchasalocaladministrator.Notes原句本句中，withoutbeingsurethatthepersonmakingsucharequestissomeonewhoshouldgetit,suchasalocaladministrator是一个介词短语，作条件状语，修饰谓语shouldnotprovide。在该短语中，thatthepersonmakingsucharequestissomeonewhoshouldgetit,suchasalocaladministrator是一个宾语从句，作beingsure的宾语；makingsucharequest是一个现在分词短语，作定语，修饰和限定theperson；whoshouldgetit是一个定语从句，修饰和限定someone；suchasalocaladministrator是对someone的举例说明。讲解计算机英语（第4版）司爱侠张强华编(1)Multimediaisasetofmorethanonemediaelementusedtoproduceaconcreteandmorestructuredwayofcommunication./Multimediaisnothingbuttheprocessingandpresentationofinformationinamorestructuredandunderstandablemannerusingmorethanonemediasuchastext,graphics,animation,audioandvideo.KeystoExercises1〖Ex.1〗根据课文内容回答问题计算机英语（第4版）司爱侠张强华编(2)Itisacomputer