题目内容：
根据以下材料，回答题
ScientistsDevelopWaysofDetectingHeartAttack
Germanresearchershavecomeupwithanewgenerationofdefibrillatorsandearly-warningsoftwareaimedatofferingheartpatientsgreater（51）fromsuddendeathfromcardiacarrest.
InGermanyalonearound100,000peopledieannually（52）aresultofcardiacarrestandmanyofthesecasesarecausedbydisruptiontotheheart'srhythm.Thosemostat（53）arepatientswhohavealreadysufferedaheartattack,andforyearstheuseofdefibrillatorshasprovedusefulin（54）life-threateningdisruptiontoheartrhythmsandcorrectingthemautomaticallybyinterveningwithinseconds.Thesedevices（55）onarangeoffunctions,suchasthatofpacemaker(起搏器).
HeartspecialistsatFreiburg'sUniversityClinichavenowachievedabreakthroughwithanimplanteddefibrillator（56）ofgeneratingasix-channelelectrocardiogram(ECG)withinthebody.Thisintegratedsystemallows（57）diagnosisofacuteblood-flowproblemsandapendingheartattack.Itwillbeimplantedin（58）forthefirsttimethisyear.Meanwhile,researchersattheFraunhoferInstituteforAppliedMathematicsinKaiserslauternhavedevelopednewcomputersoftwarethat（59）theevaluationofECGdatamoreprecise.
Theoverwhelmingmajorityofpatientsatriskwillnothaveanimplanteddefibrillatorandmustforthis（60）undergoregularECGs."Manyofthecurrentprogramsonlygetinto（61）alinearcorrelationofthedata.Weare,however,makinguseinanon-linearprocess（62）revealsthechaoticpatternsofheartbeatsasanopenandcomplexsystem,"HagenKnafsays."Inthiswaychangesintheheart（63）overtimecanbemonitoredandindividualvariationsinpatientstakenintoaccount."AnoldstudyofECGdata,basedupon（60）0patientswhohad（64）asubsequentheartattack,enabledtheresearcherstocomparerisksandtoshowthatthenewsoftwareevaluatesthe（65）considerablybetter.
回答(51)题 A．service
B．discount
C．protection
D．advice
参考答案：
答案解析：