职称英语理工类考试完形填空： 重点文章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.
手机泄露了你的秘密
你的手机承载着你的秘密。一项新研究发现，手机里除了存有你输入的名字和号码外，还留有你的微量DNA(脱氧核糖核酸)。
DNA(脱氧核糖核酸)是基因物质，出现在每个细胞里，如同指纹，你的DNA是独一无二的——除非你是同卵双生双胞胎之一。今天科学家一般可以在犯罪现场遗留的血液、唾液、毛发中分析出DNA.分析结果经常能帮侦探识别罪犯和受害人。你的手机能透露出比你想象的要多得多的信息。
安大略省汉密尔顿McMaster大学的科学家Meghan J．McFadden听说了在一起犯罪中嫌疑人的血流到了手机上，后来还丢掉了手机。这让她想到手机上是否留下了犯罪嫌疑人的DNA——即使血不流到手机上。所以，她和纽约城市大学的同事Margaret Wallace分析了10个志愿者的翻盖手机。他们使用药签从手机的两个部位，即使用者把持的外壳，靠近使用者耳部的听筒部分，采集到了肉眼看不到的手机使用者的微量DNA.
科学家们用一种主要由酒精构成的溶液擦洗手机。擦洗的目的是去除所有易被察觉的DNA.之后，机主拿回手机使用一周。接着，研究者又把手机收回来，重复了用药签采取每部手机遗留微量DNA的步骤。
科学家们在每部手机的听筒部分都发现了DNA，从手机外壳的取样更为明显，但手机外壳的取样中还发现了那些曾摆弄过该手机的其他人的DNA．令人称奇的是，DNA甚至出现在擦洗手机之后的药签中，这意味着清洗不会完全去掉罪犯手机上的微量DNA证据。因此，现在手机可以作为协助犯。