職稱英語理工類考試完形填空： 重點文章Secret

　　Your cell phone holds secrets about you. Besides the names and numbers that youve programmed into it， traces of your DNA linger on the device， according to a new study.

　　DNA is genetic material that appears in every cell. Like your fingerprint， your DNA is unique to you-- unless you have an identical twin. Scientists today routinely analyze DNA in blood， saliva， or hair left behind at the scene of a crime. The results often help detectives identify criminals and their victims. Your cell phone can reveal more about you than you might think.

　　Meghan J. McFadden， a scientist at McMaster University in Hamilton， Ontario， heard about a crime in which the suspect bled onto a cell phone and later dropped the device This made her wonder whether traces of DNA lingered on cell phones--even when no blood was involved. So she and colleague Margaret Wallace of the City University of New York analyzed the flip-open phones of 10 volunteers. They used swabs to collect invisible traces of the users from two parts of the phone： the outside， where the user holds it， and the speaker ， which is placed at the users ear.

　　The scientists scrubbed the phones using a solution made mostly of alcohol. The aim of washing was to remove all detectable traces of DNA. The owners got their phones back for another week. Then the researchers collected the phones and repeated the swabbing of each phone once more.

　　The scientists discovered DNA that belongs 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. Surprisingly ， 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 list of clues that can clinch a crime-scene investigation.

　　手機泄露了你的秘密

　　你的手機承載著你的秘密。一項新研究發現，手機里除了存有你輸入的名字和號碼外，還留有你的微量DNA(脫氧核糖核酸)。

　　DNA(脫氧核糖核酸)是基因物質，出現在每個細胞里，如同指紋，你的DNA是獨一無二的——除非你是同卵雙生雙胞胎之一。今天科學家一般可以在犯罪現場遺留的血液、唾液、毛發中分析出DNA.分析結果經常能幫偵探識別罪犯和受害人。你的手機能透露出比你想象的要多得多的信息。

　　安大略省漢密爾頓McMaster大學的科學家Meghan J．McFadden聽說了在一起犯罪中嫌疑人的血流到了手機上，后來還丟掉了手機。這讓她想到手機上是否留下了犯罪嫌疑人的DNA——即使血不流到手機上。所以，她和紐約城市大學的同事Margaret Wallace分析了10個志愿者的翻蓋手機。他們使用藥簽從手機的兩個部位，即使用者把持的外殼，靠近使用者耳部的聽筒部分，采集到了肉眼看不到的手機使用者的微量DNA.

　　科學家們用一種主要由酒精構成的溶液擦洗手機。擦洗的目的是去除所有易被察覺的DNA.之后，機主拿回手機使用一周。接著，研究者又把手機收回來，重復了用藥簽采取每部手機遺留微量DNA的步驟。

　　科學家們在每部手機的聽筒部分都發現了DNA，從手機外殼的取樣更為明顯，但手機外殼的取樣中還發現了那些曾擺弄過該手機的其他人的DNA．令人稱奇的是，DNA甚至出現在擦洗手機之后的藥簽中，這意味著清洗不會完全去掉罪犯手機上的微量DNA證據。因此，現在手機可以作為協助犯。