Hair Detectives (C) 理工

 

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.转自环 球 网校edu24ol.com转自环 球 网校edu24ol.com转自环 球 网校edu24ol.com

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? That’s 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.转自环 球 网校edu24ol.com转自环 球 网校edu24ol.com转自环 球 网校edu24ol.com

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. That’s probably because people usually cook their food in the local water. What’s 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 Ehleringer’s 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 can’t 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.

练习:转自环 球 网校edu24ol.com转自环 球 网校edu24ol.com转自环 球 网校edu24ol.com

1. 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.

 

2. James R. Ehleringer tried to find out _______.

A) if our bodies break water down into its parts.

B) of 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.

 

3.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) Ehleringer’s research proved successful in China.转自环 球 网校edu24ol.com转自环 球 网校edu24ol.com转自环 球 网校edu24ol.com

 

4.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.

 

5. Which of the following is closest in meaning to the title?

A) Human hair may help detectives to solve crimes.转自环 球 网校edu24ol.com转自环 球 网校edu24ol.com转自环 球 网校edu24ol.com

B) Animal hair may help detectives to solve crimes.

C) Detectives watch hairy criminals closely.

D) Most detectives are hair specialists.

 

第6篇                                            Hair Detectives侦探  

试听外教课

相关推荐

职称英语复习资料综合类AB级概括大意精选(4)

Museums in the modern world Museums have changed. They are no longer places for the privileged few or for bored vacationers to visit on rainy days. Action and democracy are words used in descriptions of museums now. At a science museum in

大连外国语学院英语专业考研初试经验分享

我是2013年参与的大外英语文学专业的研究生考试,成果:政治69;日语83;语言学119;文学138;总分409,2013年大外英语文学专业研究生的复试分数线是378分。复试后总分为588,计划内(即公费

公共英语二级考试复习资料:工作

(一)杜松子酒 由于起原料运用杜松子而得名。 杜松子原为缓解疼痛所分配的药物,后来于17世纪由一名医生作为药酒开发胜利的。作为解热剂,有利尿解热的效用。杜松子酒源于荷

2011年英语四级阅读备考材料(3)

Gary Finkle had his backbone severely 11 in a swimming-pool accident seven years ago. A heavy-set, bearded man of 27, he is one of thousands of Americans who have lost 12 all feeling and movement from their shoulders down. He lives with h

2014年12月英语四六级考试作文必备资料

① 凡本站注明“稿件来源:中国教育在线”的一切文字、图片和音视频稿件,版权均属本网一切,任何媒体、网站或个人未经本网协议受权不得转载、链接、转贴或以其他方式复制发