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) Ehleringers research proved successful in China.
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.
B) Animal hair may help detectives to solve crimes.
C) Detectives watch hairy criminals closely.
D) Most detectives are hair specialists.
答案与题解：
1.B第三段和第六段谈到tap water.A、C、D均是文中提到的内容。8是错误的，因为文章第六段说，我们饮用的牛奶和软饮料都含有大量水分，而没有说tap water是软饮料。
2.C第四段的问句针对第三段的内容。these watery quirks指的是上段中的unique proportions of the heavier and lighter isotopes of hydrogen and oxygen.所以C是正确答案。
3.A第六段和第七段提供了答案。科学家发现头发能反映出当地自来水中氢、氧同位素的含量；科学家也已经研究出不同地区水成分是不同的，并且在此基础上来确定来自不同地区的人的头发成分。
4.C选项A、B、D与原文均有出入。尽管在一个较大的范围内，人们使用成分较为相同的水，但是水的成分组成提供的信息可以帮助官方缩小破案线索范围。
5.A题目的意思是：人的头发可以帮助侦探破案。