The topic of cloning has been a politically and ethically controversial one since its very beginning. While the moral and philos

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问题     The topic of cloning has been a politically and ethically controversial one since its very beginning. While the moral and philosophical aspects of the issues are entirely up to the interpretation of the individual, the application of cloning technology can be studied objectively. Many in the scientific community advocate the use of cloning for the preservation and support of endangered species of animals, which aside from cloning, have no other practical hope for avoiding extinction.
    The goal of the use of cloning to avoid extinction is the reintroduction of new genes into the gene pool of species with few survivors, ensuring the maintenance and expansion of genetic diversity. Likely candidates for this technique are species known to have very few surviving members, such as the African Bongo Antelope, the Sumatran Tiger, and the Chinese Giant Panda. In the case of Giant Panda, some artificial techniques for creating offspring have already been performed, perhaps paving the way for cloning as the next step in the process.
    With the estimated population of only about 1, 000 Giant Pandas left in the world, the urgency of the situation has led to desperate measures. One panda was born through the technique of artificial insemination in the San Diego Zoo in the United States. "Hua Mei" was born in 1999 after her parents, Hsing-Hsing and Ling-Ling, had trouble conceiving naturally.
    The plan to increase the Giant Panda population through the use of cloning involves the use of a species related to the Giant Panda, the American Black Bear. Egg cells will be removed from female black bears and then fertilized with Panda cells such as those from Ling-Ling or Hsing-Hsing. The fertilized embryo will then re-implanted into the black bear, where it will grow and mature, until a new panda is delivered from the black bear host.
    Critics of cloning technology argue that the emphasis on cloning as a method by which to preserve species will draw funding away from other methods, such as habitat preservation and conservation. Proponents of cloning counter that many countries in which many endangered species exist are too poor to protect and maintain the species’ habitats anyway, making cloning technology the only practical way to ensure that those species survive to future generations. The issue is still hotly debated, as both sides weigh the benefits that could be achieved against the risks and ethical concerns that constantly accompany any argument on the issue.
Based on the information in this text, the best candidate for cloning would be

选项 A、pandas.
B、an endangered species with many living related species.
C、the species in which previous techniques of artificial reproduction have been successfully applied.
D、those for which cloning is the only feasible method by which to reproduce the species.

答案B

解析 推断题。题目问:根据文意提供的信息,克隆的最佳对象可能是什么?第一段最后一句指出:很多科学界人士支持使用克隆技术来保护及扶持濒临灭绝的动物物种,除此以外,这些物种没有任何实际希望来避免绝种。第三段第一句以大熊猫为例,说明“通过使用克隆技术来增加大熊猫种群的计划涉及使用另一种与大熊猫有关的物种——美国黑熊。”由此可知,使用克隆技术来拯救濒临灭绝的物种必须有相关物种的支持。因此,B项正确。A项过于片面;C、D项都没有概括到重点。
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