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 Ehleringer's 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.