17.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 (蛋白質(zhì)) in hair,on the other hand,is more stable than DNA but can also have variations (變異體) 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 percent 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."
64.What's the main purpose of the text?D
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.
65.Which will be the most useful in identifying a person according to Brad Hart?B
A.Chemical materials.
B.Protein in hair.
C.DNA variations.
D.Blood sample.
66.What's the advantage of the protein-based identification over DNA testing?A
A.Stability.B.Popularity.C.Security.D.Convenience.
67.What can be inferred from the last paragraph of the text?B
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.
分析 本文是一篇科教類閱讀,屬于說明文,我們知道,DNA測試對于犯罪行為非常有用.本文以此展開,主要講述了一種新的識別方法.
解答 64.D.主旨大意題.閱讀全文,根據(jù)文章內(nèi)容可知,我們知道,DNA測試對于犯罪行為非常有用.本文以此展開,主要講述了一種新的識別方法.故選D.
65.B.細節(jié)理解題.根據(jù)Protein (蛋白質(zhì)) in hair,on the other hand,is more stable than DNA but can also have variations (變異體) that may be unique to the individual.可知,根據(jù)Brad Hart所說,頭發(fā)中的蛋白質(zhì)將成為識別身份最有用的方法.故選B.
66.A.推理判斷題.根據(jù)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.可以推測出,DNA會降解,而和DNA相比,蛋白質(zhì)的方法會比較穩(wěn)定.故選A.
67.B.推理判斷題.根據(jù)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可知,基于蛋白質(zhì)的鑒定仍有待改進.故選B.
點評 本文是一篇科教類閱讀,題目涉及多道主旨大意題,細節(jié)理解題,推理判斷題.做題時學(xué)生應(yīng)仔細閱讀原文,把握文章主要內(nèi)容,聯(lián)系文章上下文內(nèi)容并結(jié)合所給選項含義,從中選出正確答案,一定要做到有理有據(jù),切忌胡亂猜測.