The thousands of people forced to abandon their homes in recent weeks to flo

游客2023-07-14  25

问题     The thousands of people forced to abandon their homes in recent weeks to floodwaters are victims not just of nature but of human error as well. Years of mismanagement of the vast Mississippi River ecosystem—the continuous and often inadvisable construction of levees (堤坝) and navigation (导航) channels, the paving over of wetlands, the commercial development of flood plains—have made the damage worse than it might otherwise have been.
    The Obama administration is now completing an inspection of the guidelines governing dams, levees and other water-related projects built with federal money.
    Historically, projects had been shaped by two main factors: the Army Corps of Engineers’ conviction that nature can be subdued by levees and dams, and its reflexive green-lighting of any flood control project that encouraged commercial or agricultural development. The new rules, Congress said, should require the Corps and other federal agencies to give equal weight to less easily measurable benefits like wildlife habitat and to "nonstructural" solutions to flood control like preserving wetlands, flood plains and other "natural systems. "
    To give the Corps its due, it has performed nobly in the present emergency. Its main-stem levees have held. Its decision to blow holes in levees guarding the New Madrid floodway in Missouri clearly saved Cairo, Illinois, and other places downstream. These methods had long been part of Corps emergency plans, and they worked.
    The question the environmental community and many in Congress are asking is whether this would have been necessary if the river had been better managed. In populated areas, some levees were built solely to attract more development, while others closed off flood plains that could have acted as a natural safety valve.
    Meanwhile, over the years, the upper Mississippi watershed has lost millions of acres of wetlands that could have served as a natural sponge for floodwaters.
    So-called 100-year floods seemed to be hitting the Mississippi with scary regularity—a $ 16 billion flood in 1993, a bad one in 2001, another in 2008, and now this one. Climate change, which some suspect of causing violent downpours, may be part of the problem, though the connection is unclear. What is clear is that we should learn from our mistakes, let nature help out where it can, and not build or farm in places where it makes no sense to do so. As the saying goes, nobody ever beats the river. [br] What function are flood plains supposed to fulfill?

选项 A、Expanding populated areas.
B、Acting as a natural safety valve.
C、Attracting more development.
D、Closing off some levees.

答案 B

解析 推理判断题。本题考查冲积平原本身具有的功能。定位句后半句的定语从句修饰前面的flood plains,由定语从句可知,这些冲积平原原本可以充当一道自然屏障,保护人们不受洪水的侵害,故B)“发挥自然安全阀门的作用”为答案。A)“扩张人口密集地区”和原文意思不符,故排除;C)“吸引更多发展”是人们建造堤坝的部分原因,文中已进行了批驳,故排除;D)“阻塞平原”是建造堤坝后造成的一个结果,故排除。
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