历年考研英语模拟试题及答案:阅读篇.doc
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1、如有侵权,请联系网站删除,仅供学习与交流历年考研英语模拟试题及答案:阅读篇【精品文档】第 4 页历年考研英语模拟试题及答案:阅读篇 Scientists have known since 1952 that DNA is the basic stuff of heredity. Theyve known its chemical structure since 1953. They know that human DNA acts like a biological computer program some 3 billion bits long that spells out the in
2、structions for making proteins, the basic building blocks of life.But everything the genetic engineers have accomplished during the past half-century is just a preamble to the work that Collins and Anderson and legions of colleagues are doing now. Collins leads the Human Genome Project, a 15-year ef
3、fort to draw the first detailed map of every nook and cranny and gene in human DNA. Anderson, who pioneered the first successful human gene-therapy operations, is leading the campaign to put information about DNA to use as quickly as possible in the treatment and prevention of human diseases.What th
4、ey and other researchers are plotting is nothing less than a biomedical revolution. Like Silicon Valley pirates reverse-engineering a computer chip to steal a competitors secrets, genetic engineers are decoding lifes molecular secrets and trying to use that knowledge to reverse the natural course of
5、 disease. DNA in their hands has become both a blueprint and a drug, a pharmacological substance of extraordinary potency that can treat not just symptoms or the diseases that cause them but also the imperfections in DNA that make people susceptible to a disease.And thats just the beginning. For all
6、 the fevered work being done, however, science is still far away from the Brave New World vision of engineering a perfect humanor even a perfect tomato. Much more research is needed before gene therapy becomes commonplace, and many diseases will take decades to conquer, if they can be conquered at a
7、ll.In the short run, the most practical way to use the new technology will be in genetic screening. Doctors will be able to detect all sorts of flaws in DNA long before they can be fixed. In some cases the knowledge may leadto treatments that delay the onset of the disease or soften its effects. Som
8、eone with a genetic predisposition to heart disease, for example, could follow a low-fat diet. And if scientists determine that a vital protein is missing because the gene that was supposed to make it is defective, they might be able to give the patient an artificial version of the protein. But in o
9、ther instances, almost nothing can be done to stop the ravages brought on by genetic mutations. (409 words)1. It can be inferred from the text that Collins and Anderson and legions of colleagues _.A know that human DNA acts like a biological computer programB have found the basic building blocks of
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