One of the most pressing challenges that the United States—and indeed, the world—will face in the next few decades is how to all

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问题     One of the most pressing challenges that the United States—and indeed, the world—will face in the next few decades is how to alleviate the growing stress that human activities are placing on the environment. The consequences are just too great to ignore. Wildlife habitats are being degraded or disappearing altogether as new developments take up more land. Plant and animal species are becoming extinct at a greater rate now than at any time in Earth’s history. As many as 30 percent of the world’s fish stocks are overexploited. And the list goes on.
    Yet, there is reason to have hope for the future. Advances in computing power and molecular biology are among the tremendous increases in scientific capability that are helping researchers gain a better understanding of these problems. Recent developments in science and technology could provide the basis for some major, and timely actions that would improve our understanding of how human activities affect the environment.
    One priority for research is improving hydrological forecasting. It has been estimated that the world’ s water use could triple in the next two decades. Already, widespread water shortages have occurred in parts of China, India, North Africa, and the Arabian Peninsula. The need for water also is taking its toll on freshwater ecosystems in the United States. Only 2 percent of the nation’ s streams are considered in good condition, and close to 40 percent of native fish species are rare to extinct. Using a variety of new remote sensing tools, scientists can learn more about how precipitation affects water levels, how surface water is generated and transported, and how changes in the landscape affect water supplies.
    To prevent outbreaks of infectious diseases in plants, animals, and humans, more study is needed on how pathogens, parasites, and disease-carrying species—as well as humans and other species they infect— are affected by changes in the environment. The overuse of antibiotics both in humans and in farm animals has contributed to the growth of antibiotic-resistant microorganisms. Researchers can take advantage of new technologies in genetics and computing to better monitor and predict the effects that environmental changes might have on disease outbreaks.
    Humans have made alterations to Earth’ s surface—such as tropical deforestation, reduction of surface and ground water, and massive development—so dramatic that they approach the levels of transformation that occurred during glacial periods. Such alterations cause changes in local and regional climate, and will determine the future of agriculture. Recent advances in data collection and analysis should be used to document and better understand the causes and consequences of changes in land cover and use.
Throughout the text, the author mainly emphasizes

选项 A、the need for more federal funding of environmental scientific research.
B、the role of science in alleviating environmental degradation.
C、the role technology could play in environmental research.
D、the extent of damage humans have wrought on the environment.

答案C

解析 主旨题。文章第一段指出“将来的几十年中,全人类要关注如何减轻人类活动对环境施加的越来越大的压力”。第二段表明“我们有理由对未来抱有希望,因为最近取得的科学技术进展对认识和解决这一问题有帮助”。第三、四段介绍具体的研究项目、重点及其所需技术。最后一段说明研究进展及成绩。由此看来,全文的重点是C项“技术在环境中发挥着很大的作用”。A项文中没有涉及;B项中science一词范围太大;D项只是作者在文中用来引出有必要解决问题的铺垫,不是中心思想,故排除。
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