理工类考试辅导：补全对话Cell Phone
Your cell phone holds secrets about you. Besides the names and 1 that youve programmed into it， traces of your DNA2linger on the device， according to a new study.
DNA is genetic material that 2 in every cell. Like your fingerprint， your DNA is unique to you 3 you have an identical twin. Scientists today routinely analyze DNA in blood， saliva， or hair left 4 at the scene of a crime. The results often help detectives identify 5 and their victims. Your cell phone can reveal more about you 6 you might think.
Meghan J. McFadden， a scientist at McMaster University1in Hamilton， Ontario， heard about a crime in which the suspect bled onto a cell phone and later dropped the 7 This made her wonder whether traces of DNA lingered on cell phones--even when no blood was involved. 8 she and colleague Margaret Wallace of the City University of New York analyzed the flip-open phones3 of 10 volunteers. They used swabs to collect 9 traces of the users from two parts of the phone： the outside， where the user holds it， and the 10 ， which is placed at the users ear.
The scientists scrubbed the phones using a solution made mostly 11 alcohol. The aim of washing was to remove all detectable traces of DNA. The owners got their phones 12 for another week. Then the researchers collected the phones and repeated the swabbing of each phone once more.
The scientists discovered DNA that 13 to the phones speaker on each of the phones. Better samples were collected from the outside of each phone， but those swabs also picked up DNA that belonged to other people who had apparently also handled the phone. 14 ， DNA showed up even in swabs that were taken immediately after the phones were scrubbed. That suggests that washing wont remove all traces of evidence from a criminals device. So cell phones can now be added to the 15 of clues that can clinch a crime-scene investigation.
词汇：
linger v.逗留 flip-open phone 翻盖手机
genetic adj.遗传的 swab n. 药签
saliva n. 涎，唾液 scrub v. 用力擦洗；擦净
bleed v. 流血 clinch v.确定，决定
注释：
1.McMaster University：麦克马斯特大学，位于加拿大安大略省汉密尔顿市，成立于1887年。
2.DNA：脱氧核糖核酸。系deoxyribonucleic acid的缩写。 .
3.flip—open phones：翻盖手机。又可作flip phones.
练习：
1. A numbers B music C secrets D films
2. A appeals B appoint C appears D applies
3. A because B unless C although D still
4. A about B in C for D behind
5. A criminals B people C men D policemen
6. A when B until C before D than
7. A device B paper C file D document
8. A However B So C But D Nevertheless
9. A invisible B non-existent C visible D apparent