Cell Phone Lets YourSecret Out

Your cell phoneholds secrets about you.Besides the names and _____________(51)that you've pro-

grammed intoit,traces of your DNA linger on the device,according to a new study.

DNA is geneticmaterial that______________(52)in every cell.Like your fingerprint,your DNA isunique

to you一 _____________（53)you have an identical twin.Scientists today routinely analyze DNAin blood,

saliva,or hair left_____________(54)at the scene of a crime.The results often help detectivesidentify

_____________(55)andtheir victims.Your cell phone can reveal more about you _____________(56)youmight

think.

Meghan J.McFadden,ascientist at McMaster University in Hamilton,Ontario,heard about a crime in

which the suspectbled onto a cell phone and later dropped the______________(57).This made herwonder

whether traces ofDNA lingered on cell phones even when no blood wasinvolved.______________(58)she and

colleague MargaretWallace of the City University of New York analyzed the flip-open phones of 10volun-

teers.They usedswabs to collect______________(59)traces of the users from two parts of thephone.the

outside,where theuser holds it,and the______________(60),which is placed at the user's ear.

The scientistsscrubbed the phones using a solution made mostly______________(61)alcohol.Theaim of

washing was toremove all detectable traces of DNA.The owners got theirphones______________(62)for

another week.Thenthe researchers collected the phones and repeated the swabbing of each phoneonce

more.

The scientistsdiscovered DNA that _____________(63)to the phone's speaker on each of thephones.

Better samples werecollected from the outside of each phone,but those swabs also picked up DNAthat be-

longed to otherpeople who had apparently also handled the phone.______________(64),DNA showedup even

in swabs that weretaken immediately after the phones were scrubbed.That suggests that washingwon't remove

all traces ofevidence from a criminal's device.So cell phones can now be added to the

______________(65)ofclues

that can clinch acrime-scene investigation._________(55)

A.criminals

B.people

C.men

D.policemen