Hair Detectives
Scientists have found a way to use hair to figure out where a person is from and where that person has been. The finding could help solve crimes, among other useful applications.
Water is central to the new technique. Our bodies break water down into its parts: hydrogen and oxygen. Atoms of these two elements end up in our tissues and hair.
But not all water is the same. Hydrogen and oxygen atoms can vary in how much they weigh. Different forms of a single element are called isotopes. And depending on where you live, tap water contains unique proportions of the heavier and lighter isotopes of hydrogen and oxygen.
Might hair record these watery quirks? Thats what James R. Ehleringer, an environmental scientist at the University of Utah in Salt Lake City, wondered.
To find out, he and his colleagues collected hair from barbers and hair stylists in 65 cities in 18 states across the United States. The researchers assumed that the hair they collected came from people who lived in the area.
Even though people drink a lot of bottled water these days, the scientists found that hair overwhelmingly reflected the concentrations of hydrogen and oxygen isotopes in local tap water. Thats probably because people usually cook their food in the local water. Whats more, most of the other liquids people drink including milk and soft drinks contain large amounts of water that also come from sources within their region.
Scientists already knew how the composition of water varies throughout the country. Ehleringer and colleagues combined that information with their results to predict the composition of hair in people from different regions. One hair sample used in Ehleringers study came from a man who had recently moved from Beijing, China, to Salt Lake City. As his hair grew, it reflected his change in location.
The new technique cant point to exactly where a person is from, because similar types of water appear in different regions that span a broad area. But authorities can now use the information to analyze hair samples from criminals or crime victims and narrow their search for clues.
36. What does the writer say about tap water? Which of the following is NOT correct?
A Tap water reflects the concentrations of hydrogen and oxygen isotopes in different regions.
B Tap water is a kind of soft drink in the United States.
C Tap water contains unique proportions of isotopes of hydrogen and oxygen.
D Tap water is used to cook food.
37. James R. Ehleringer tried to find out
A if our bodies break water down into its parts.
B if it is possible to collect hair samples across the country.
C if tap water contains unique proportions of isotopes of hydrogen and oxygen.
D if the composition of hair can indicate exactly where people are from.
38. Which of the following statements is meant by the writer?
A Ehleringer was successful in his research.
B Ehleringer failed in his research.
C Ehleringer can be a successful detective.
D Ehleringers research proved successful in China.
39. What does the last paragraph tell you?
A The new technique can tell precisely where a person lives.
B Water supplied in different regions all come from the same source.
C Types of water used in different regions provide useful information for the police.
D Hair samples provide the most important clues to identify crimes.
40. Which of the following is closest in meaning to the title?
A Human hair may help detectives to solve crimes.
B Animal hair may help detectives to solve crimes.
C Detectives watch hairy criminals closely.
D Most detectives are hair specialists.
丝绸之路与欧亚经济联盟对接
《一步之遥》获“脏烟灰缸奖”
The Coming of Thanksgiving Day 感恩节的由来
“导盲犬”可乘坐北京地铁
政协座谈会建言“媒体融合”
体坛英语资讯:Rios Maracana stadium to host 2020 Copa Libertadores final
东莞建第一座“无人工厂”
国际英语资讯:BRI ideal platform to tackle emerging intl, regional challenges: experts
人类命运共同体里的中国担当
见钱就收“蚁贪”也是蛮拼的
“胡萝卜加大棒”战略
“自贸区战略”倒逼金融改革
沙特阿美,全世界最能赚钱的公司要上市了
商界大佬眼中的“互联网+”
“非行政许可审批”成历史
国际英语资讯:Israeli PM Netanyahu indicted for corruption
国际英语资讯:EPP congress adopts climate policies
深改组:“改革促进派”将获重用
体坛英语资讯:ANALYSIS: Four things to look out for in Spains matchday 9
美国囚犯心跳停止后被救活,说自己终身监禁已结束
Oppo旗下的Realme手机席卷印度,声势惊人
国际英语资讯:AIIB membership complements Irelands development programs: minister
无奈的“万能居委会”
一周热词回顾
国际英语资讯:UN urges for patience on South Sudan parties to implement outstanding issues
什么是“抵押补充贷款”?
母女“联名发表”论文引质疑
女司机“变道”遭暴打
国际英语资讯:UKs Labour Party launches election manifesto
庆安官场被“链式举报”
| 不限 |
| 英语教案 |
| 英语课件 |
| 英语试题 |
| 不限 |
| 不限 |
| 上册 |
| 下册 |
| 不限 |