ATM的突出特点是可以灵活地支持现有的和将来可能出现的各种()业务，能达到很高的网络资源利用率，支持高速交换。
多媒体宽带
暂无解析
Highbloodpressure
YouaregoingtospendholidaysinHawaiiinJune.Suddenlyyoureceivedaletterfromanimportantcustomer,Mr.EltonDeland,whowillarriveon25thJuneanddiscusstheclaim.YouhavetodelaythetriptillJuly.
WriteashortmessagetoMs.AnneFolster,yoursecretary.
.ExplainWhyyoupostponeyourtrip.
.MentionthedatewhenMr.EltonDelandwillarrive.
.Askhertoarrangeyourmeeting.
.Write30-40wordsonyourAnswerSheet.
Youneedtospendplentyoftimesearchingforjobsandtreatit____itisajobitself.
Yourdonationscan_____poorchildren____foodandachancetostudy.
1.Thefailureofahigh-profilecholesteroldrughasthrownaspotlightonthecomplicatedmachinerythatregulatescholesterollevels.Butmanyresearchersremainconfidentthatdrugstoboostlevelsof'good'cholesterolarestilloneofthemostpromisingmeanstocombatspirallingheartdisease.
2.DrugcompanyPfizerannouncedon2Decemberthatitwascancellingallclinicaltrialsoftorcetrapib，adrugdesignedtoraiseheart-protectivehigh-densitylipoproteins(HDLs).Inatrialof15000patients，asafetyboardfoundthatmorepeoplediedorsufferedcardiovascularproblemsaftertakingthedrugplusacholesterol-loweringstatinthanthoseinacontrolgroupwhotookthestatinalone.
3.Thenewscameasakickintheteethtomanycardiologistsbecauseearliertestsinanimalsandpeoplesuggesteditwouldlowerratesofcardiovasculardisease."Therehavebeennoredflagstomyknowledge,"saysJohnChapman，aspecialistinlipoproteinsandatherosclerosisattheNationalInstituteforHealthandMedicalResearch(INSERM)inPariswhohasalsostudiedtorcetrapib."Thiscancellationcameasacompleteshock."
4.TorcetrapibisoneofthemostadvancedofanewbreedofdrugsdesignedtoraiselevelsofHDLs，whichferrycholesteroloutofartery-cloggingplaquestotheliverforremovalfromthebody.Specifically，torcetrapibblocksaproteincalledcholesterolestertransferprotein(CETP)，whichnormallytransfersthecholesterolfromhigh-densitylipoproteinstolowdensity，plaque-promotingones.Statins，incontrast，mainlyworkbyloweringthe'bad'low-densitylipoproteins.
Underpressure
5.Researchersarenowtryingtoworkoutwhyandhowthedrugbackfired，somethingthatwillnotbecomeclearuntiltheclinicaldetailsarereleasedbyPfizer.Onehintliesinevidencefromearliertrialsthatitslightlyraisesbloodpressureinsomepatients.Itwasthoughtthatthismildproblemwouldbeoffsetbytheheartbenefitsofthedrug.Butitispossiblethatitactuallyprovedfatalinsomepatientswhoalreadysufferedhighbloodpressure.Ifbloodpressureistheexplanation，itwouldactuallybegoodnewsfordrugdevelopersbecauseitsuggeststhattheproblemsarespecifictothiscompound.OtherprototypedrugsthatarebeingdevelopedtoblockCETPworkinaslightlydifferentwayandmightnotsufferthesamedownfall.
6.ButitisalsopossiblethatthewholeideaofblockingCETPisflawed，saysMotiKashyap，whodirectsatherosclerosisresearchattheVAMedicalCenterinLongBeach，California.WhenHDLsexcretecholesterolintheliver，theyactuallyrelyonLDLsforpartofthisprocess.SoinhibitingCETP，whichpreventsthetransferofcholesterolfromHDLtoLDL，mightactuallycauseanabnormalandirreversibleaccumulationofcholesterolinthebody."You'reblockingaphysiologicmechanismtoeliminatecholesterolandeffectivelyconstipatingthepathway,"saysKashyap.Goingup
7.Mostresearchersremainconfidentthatelevatinghighdensitylipoproteinslevelsbyonemeansoranotherisoneofthebestroutesforhelpingheartdiseasepatients.ButHDLsarecomplexandnotentirelyunderstood.Oneapproveddrug，calledniacin，isknowntobothraiseHDLandreducecardiovascularriskbutalsocausesanunpleasantsensationofheatandtingling.Researchersareexploringwhethertheycanbypassthissideeffectandwhetherniacincanlowerdiseaseriskmorethanstatinsalone.Scientistsarealsoworkingonseveralothermeanstobumpuphigh-densitylipoproteinsby，forexample，introducingsyntheticHDLs."Theonlythingweknowisdeadinthewateristorcetrapib，notthewholeideaofraisingHDL,"saysMichaelMiller，directorofpreventivecardiologyattheUniversityofMarylandMedicalCenter，Baltimore.
Questions7-13
Matchtorcetrapib，HDLs，statinandCETPwiththeirfunctions(Questions8-13)..WritethecorrectletterA，B，CorDinboxes8-13onyouranswersheet.NBYoumayuseanylettermorethanonce.
7.Ithasbeenadministeredtoover10,000subjectsinaclinicaltrial.
8.Itcouldhelpridhumanbodyofcholesterol.
9.Researchersareyettofindmoreaboutit.
10.Itwasusedtoreducethelevelofcholesterol.
11.AccordingtoKashyap，itmightleadtounwantedresultifit'sblocked.
12.Itproducedcontradictoryresultsindifferenttrials.
13.ItcouldinhibitLDLs.Listofchoices
A.TorcetrapicB.HDLSC.StatinD.CETP
