Human and the Environment One of the most pressing challenges that the United States and indeed the world will face in the n

admin2011-01-05  41

问题                      Human and the Environment
    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 (减轻点)the growing stress that human activities are placing on the environment. The consequences are just too great to ignore. Wildlife habitats (栖息地)are being degraded(使退化) or disappearing altogether as new developments take up more land. (46) As many as 30 percent of the world’s fish stocks are over-exploited. And the list goes on.
     (47) Advances in computing power and molecular biology(分子生物学) are among the trem endows 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(及时的) actions that would improve our understanding of how human activities affect the environment.
    One priority for research is improving hydrological(水文学的)forecasting. (48) 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 (造成损失)on freshwater(淡水)ecosystems (生态体系)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 or extinct. Using a variety of new remote sensing tools scientists can learn more about how precipitation(降水量)affects water levels, how surface water is generated and transported, and how changes in the landscape affect water supplies.
    To prevent outbreaks of infectious(传染性的)diseases in plants, animals, and humans, more study is needed on how pathogens (病原体), parasites(寄生生物), and disease-carrying species-as well as humans and other species they infect-are affected by changes in the environment. (49) 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 changes to earth’s surface, such as tropical deforestation(砍伐森林), reduction of surface and ground water, and massive development, so dramatic that they approach the levels of transformation that occurred during glacial periods(冰川期). (50) Recent advances in data collection and analysis should be used to record and better understand the causes and consequences of changes in land cover and use.
A. It has been estimated that the world’s water use could triple in the next two decades.
B. Plant and animal species are becoming extinct at a greater rate now than at any time in earth’s history.
C. The overuse of antibiotics (抗生素) both in humans and in farm animals has contributed to the growth of antibiotic resistant micro-organisms (微生物).
D. Yet, there is reason to have hope for the future.
E. Until recently, very little information was documented about changes and consequences of land usage.
F. Such changes cause changes in local and regional climate, and will determine the future of agriculture.

选项

答案B

解析 本题考查的是对上下文之间的意义关系以及文章细节的把握。空格(46)所在的段落的主题句是第一句,该句主要是说美国乃至全世界都面临着如何正确处理人与环境关系的紧迫问题。而主题句后面的句群是对这个主题句的扩展和解释,后三个句子是并列关系,共同说明人与环境关系恶化的严重后果。根据这一线索,我们发现选项B符合题意,它与另外两句一起描绘了物种快速灭绝这一严重后果,故选B。
转载请注明原文地址:https://kaotiyun.com/show/Y9Qd777K
0

最新回复(0)