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.
The last paragraph implies that

选项 A、local and regional climates have not fluctuated so much since the glacial periods.
B、the future of agriculture depends on how land usages affect climate.
C、until recently, very little information was documented about changes and consequences of land usage.
D、current human transformations of the land surface is of almost unprecedented scale.

答案D

解析 推断题。选项A、B与最后一段内容不符,原文说地球表面状况的改变引起地方性和地区性的气候变化,并将决定未来的农业走向。C项(直到最近,还几乎没有关于土地利用的变化和结果的记录)与最后一句不符,原文说最近取得的数据收集和分析进展应当用于如实记录和更好的认识地表变化的起因和结果以及土地利用的情况。D项符合本段第一句的意思:人类改变了地球表面的情况…,变化之大接近于冰川时期出现的改变程度。因此,D项正确(其中unprecedented“空前的”和原文的dramatic“巨大的”是同义表达)。
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