第三篇 DNA testing

DNA testing reveals the genes of each individual person. Since the early twentieth century, scientists have known that all human characteristics are contained in a person's genes and are passed from parents to children. Genes work as a chemical instruction manual for each part and each function of the body. Their basic chemical element is called DNA, a copy of which can be found in every cell. The existence of genes and the chemical structure of DNA were understood by the mid-1900s, but scientists have only recently been able to identify a person from just a drop of blood or a single hair.

One of the most important uses of DNA testing is in criminal investigation. The very first use of DNA testing in a criminal case was in 1985 in Great Britain, when a man confessed to killing a young woman in the English countryside. Because police had found samples of the killer’s DNA at the scene of the crime, a biologist suggsstod that it might be possible to compare that DNA to some from the confessor’ s blood. To everyone's surprise, the tests showed that he was not the killer. Nor was he guity of a similar murder that had happened some time earlier. At that point he acdmitted that he had confessed to the crimes out of fear and police pressure. The police then asked 5, 000 locaI men for samples of their blood,and DNA testing revealed that one of them was the real murderer, so- the first man was set free.

In 1992, two law professors, Peter Neufeld and Barry Scheck, decided to use DNA evidence to help set free such mistakenly convicted prisoners. With the help of their students, they created a not-for-profit organization called the lnnocence Project. Most of their clients are poor men, many from racial and ethnic minorities. In fact, studies have shown that U. S. judges and juries are often influenced by racial and ethnic background,and that people from minority groups are more likely to be convicted. Some of these men had been sentenced to death, a form of punishment used in thirty-eight states out of fifty ( as of 2006). For most of these prisoners, their only hope was another trial in which DNA testing could be used to prove their innocence.

Between 1992 and 2006, the Innocence Project helped free 100 men. Some of these prisoners had been in jail for ten, twenty years or more for crimes they did not commit.  However, the goal of the Innocence Project is not simply to set free those who are wrongfully in jail. They also hope to bring about real changes in the criminal justice system.

In Illinois in the late 1990s, a group of journalism students at Northwestern University were able to bring about such a change in that state. They began investigating some Illinois prisoners who claimed to be innocent.Through DNA testing,the students were able to prove that in fact  the prisoners were not guilty of the crimes they had been accused of. Thirteen of these men were set free, and in 2000, Governor Ryan of IIIinois decided to stop carrying out death stentences until further study could be made of the prisoners' cases.

The use of DNA in criminal cases is still being debated around the world. Some fear that governments will one day keep records of everyone's DNA,which could put limits on the privacy and freedom of citizens. Other people mistrust the science of DNA testing and think that lawyers use it to get their clients free whether'or not they are guilty. But for those whose innocence has been proven and who are now free men, DNA testing has meant nothing less than a return to life. And with the careful use of DNA testing, no innocent person should ever be convicted again.

41. What is the main idea of this passage?

A.　DNA testing has changed the American legal system.

B.　DNA testing has helped innocent men go free in Illinois.

C.　DNA testing uses genetics to identify a person.

D.　DNA testing has played a key role in criminal investigation.

42. DNA testing was first used in a criminal case by

A.　a lawyer in New York

B.　students in Illinois

C.　doctors in the United States

D.　police in Great Britain

43. The innocence project uses DNA testing to

A.　set free innocent prisoner

B.　help the police put people in prison

C.　find out which lawyer are incompetent

D.　prove that suspects are guilty

44. Some students in Northwestern University

A.　proved some prisoners were not guilty

B.　believed some suspects were from ethnic groups

C.　told the governors of Illinois not to free the prisoners

D.　showed DNA testing was not always reliable

45. What is the author’s attitude toward DNA testing?

A.　Negative

B.　Positive

C.　Suspicious

D.　Indifferent

41  C  本文的題目是DNA testing但除了第一段對DNA testing做了一個簡單的介紹外，文章其他各段主要講的是DNA testing在對罪犯做調(diào)查時所起的作用。第二段的第一句話One of the most important uses of DNA testing is in criminal investigation點明了全文的中心。

42  D  從第二段可以得到答案。第一次把DNA testing用于犯罪調(diào)查的是英國的警察。

43  D  第三段介紹了Innocence Project的來由和目的，1992年，丙位法律教授Peter Neufeld和Barry Scheck創(chuàng)立了這個非盈利的項目，目的是通過DNA testing來幫助被誤判的犯人重獲自由（help set free such mistakenly convicted prisoners）。

44  A  在第五段里可以找到答案：Through DNA testing, the students were able to prove that in fact the prisoners were not guilty of the crimes they had been accused of.

45  B  縱觀全文，作者對DNA testing明顯是持肯定態(tài)度的。

（責(zé)任編輯：vstara）

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