题目内容：
根据以下材料，回答题 CellPhoneLetsYourSecretOut
Yourcellphoneholdssecretsaboutyou．Besidesthenamesand(51)thatyou'veprogrammedintoit,tracesofyourDNAlinger(逗留)onthedevice,accordingtoanewstudy.
DNAisgeneticmaterialthat(52)ineverycell．Likeyourfingerprint,yourDNAisuniquetoyou(53)youhaveanidenticaltwin．ScientiststodayroutinelyanalyzeDNAinblood,saliva(唾液),orhairleft(54)atthesceneofacrime．Theresultsoftenhelpdetectivesidentify(55)andtheirvictims．Yourcellphonecanrevealmoreaboutyou(56)youmightthink.
MeghanJ．McFadden,ascientistatMcMasterUniversityinHamilton,Ontario,heardaboutacrimeinwhichthesuspectbledontoacellphoneandlaterdroppedthe(57)．ThismadeherwonderwhethertracesofDNAlingeredoncellphones--evenwhennobloodwasinvolved．(58),sheandcolleagueMargaretWallaceoftheCityUniversityofNewYorkanalyzedtheflip-openphonesof10volunteers．Theyusedswabs(药签)tocollect(59)tracesoftheusersfromtwopartsofthephone:theoutside,wheretheuserheldit,andthe(60),whichwasplacedattheuser'sear.
Thescientistsscrubbed(擦洗)thephonesusingasolutionmademostly(61)alcohol．TheaimofwashingwastoremovealldetectabletracesofDNA．Theownersgottheirphones(62)foranotherweek．Thentheresearcherscollectedthephonesandrepeatedtheswabbingofeachphoneoncemore.
ThescientistsdiscoveredDNAthat(63)tothephone'sspeakeroneachofthephones.
Bettersampleswerecollectedfromtheoutsideofeachphone,butthoseswabsalsopickedupDNAthatbelongedtootherpeoplewhohadapparentlyalsohandledthephone．(64),DNAshowedupeveninswabsthatweretakenimmediatelyafterthephoneswerescrubbed．Thatsuggeststhatwashingwon'tremovealltracesofevidencefromacriminal'sdevice．Socellphonescannowbeaddedtothe(65)ofcluesthatcandecideacrime-sceneinvestigation.
回答(51)题 A．numbers
B．music
C．secrets
D．films
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