Asweknow,DNAtestingisveryusefulforcrimefighting.Butnowc...

问题详情：

As we know, DNA testing is very useful for crime fighting. But now crime fighters could have a new tool at hand. Researchers have developed a cutting-edge (前沿的) technique to identify human hair. Their test is quicker than DNA analysis techniques currently used by the police.

DNA testing is commonly used for identification because DNA is unique to each individual. However, environmental and chemical processes can degrade(降解) DNA, limiting its usefulness over time. Protein (蛋白质) in hair, on the other hand, is more stable than DNA but can also have variations (变异体) that may be unique to the individual.

“Our analysis process can be used universally, ”says Ms. Huang, “One of our samples even included dyed hair and the test was 100 per cent accurate. The test was able to distinguish East Asians, Caucasians and South Asians.”

Dr. Beauchemin says she has got in touch with law enforcement agencies about using the new technology. She is also planning to collect more hair samples and continue her research with a goal of finding where exactly in the world hair sample is from, to look for more races and determine specific age.

“We are in a very similar place with protein-based identification to where DNA testing was during the early days of development,” said chemist Brad Hart. “This method will be a game-changer, and while we’ve made a lot of progress toward improving it, there are steps to go before this new technique is able to reach its full potential.”

44. What’s the main purpose of the text?

A. To analyze crime scenes.

B. To distinguish different races.

C. To show the usefulness of DNA testing.

D. To introduce a new identification method.

45. Which will be the most useful in identifying a person according to Brad Hart?

A. Chemical materials.    B. Protein in hair.

C. DNA variations.    D. Blood sample.

46. What’s the advantage of the protein-based identification over DNA testing?

A. Stability.    B. Popularity.

C. Security.    D. Convenience.

47. What can be inferred from the last paragraph of the text?

A. DNA testing will soon reach its full potential.

B. Protein-based identification remains to be improved.

C. Protein-based identification has replaced DNA testing.

D. DNA testing develops as rapidly as protein-based identification.

【回答】

DBAB

知识点：阅读理解

题型：阅读理解