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Cloning,Unit 2,In the movie Jurassic Park, scientists clone dinosaurs by using the DNA that was preserved for millions of years. However, there is trouble when the cloned dinosaurs turn out fiercer and smarter than expected. Can dinosaurs really be cloned? Theoretically, they can; all that would be required is DNA from an extinct dinosaur and a currently living closely related species which would act as a surrogate mother(代孕母亲). In fact, there is continuing research to clone the Woolly Mammoth by extracting (提取) the DNA from frozen animals.,Actually, cloning is a phenomenon that occurs naturally in a wide variety of species. Whenever you see a pair of identical twins, they are examples of natures clones. Although scientists have been cloning certain plants like the carrot quite successfully for decades, attempts at cloning animals have not been as successful. However, they began long before the birth of Dolly, the sheepthe first mammal to be successfully cloned.,Cloning humans does give rise to some misgivings,_raising a number of moral problems involved. In fact, the social influences of producing humans artificially were brilliantly explored in the famous novel Brave New World by Aldous Huxley, and also in the movie The Island.,Human cloning is basically about creating a genetically(基因地) identical copy of a previously existing person.Why would some people choose to clone human beings？Well, generally, it could make couples unable to have babies have their own children. Replacing a dead child is also another reason why some people have expressed interest in the technology.,文章大意：本文是说明文。介绍了克隆的相关情况。 1The purpose of the first paragraph is to _. Agive us an introduction to a movie Banalyse the possibility of cloning Cgive an introduction to the text Dtell us the importance of cloning 答案：C 从后文内容可知，第一段主要是为了引出下文。,2We can infer from the second paragraph that _. Amore and more people are interested in cloning Bcloning has saved many animals from dying out Ccloning has a very short history Dcloning plants is much easier 答案：D 第二段说明，人们已经成功克隆了植物，而动物还不太成功，说明克隆植物要比克隆动物简单得多。,3In what way is human cloning useful? AIt can bring a dead person back to life. BIt makes it possible to replace a dead child. CIt can help cure some human diseases. DIt can help people have more healthy children. 答案：B 从最后一段可知，克隆人可以替代一个死了的孩子或者帮助不孕夫妻受孕。,4What does the underlined word“misgivings” in the third paragraph mean? AWorries. BAims. CRegulations. DPrinciples. 答案：A 从该词后的raising a number of moral problems involved可知，克隆人引起了很多担忧。,5What attitude do people have towards human cloning? AThey think human cloning is useless. BThey believe it can help humans in many ways. CThey believe it can cause many moral problems. DThey doubt whether it can succeed or not. 答案：C 从第三段可知，克隆人一直是一个存在争议的问题，涉及很多道德问题。,
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