What do you do when a charismatic marine mammal is wreaking havoc by gorging on a threatened species that humans also find delic

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问题     What do you do when a charismatic marine mammal is wreaking havoc by gorging on a threatened species that humans also find delicious? That’ s the awkward problem faced by wildlife managers along the Columbia River in Washington and Oregon states, where sea lions have been congregating for the past decade to feast on salmon waiting to climb the fish ladders at the base of the Bonneville Dam on their spring voyage upriver to spawn.
    To protect the Chinook salmon and steelhead in the river, some of which are listed as threatened populations, in 2008 the states of Washington and Oregon obtained permission from the National Oceanic and Atmospheric Administration in Silver Spring, Maryland, to kill California sea lions(which are normally protected)seen feeding repeatedly at the dam, after attempts to frighten the animals away proved ineffective.
    In response, the Humane Society of the United States, based in Washington DC, and others filed a lawsuit to stop the practice and their legal challenges have continued. A US district court in Portland, Oregon, is expected to hear full arguments for a final ruling in the next few weeks. In the meantime, more than 40 California sea lions have been killed and 11 transferred to aquaria and zoos.
    Survey data collected by the US Army Corps of Engineers during the years of the killing show that numbers of California sea lions are decreasing at the dam, along with the amount of salmon they eat. The corps and others attribute this to the removal program.
    But the killing may have been too successful. Last year, the larger Steller sea lions, which arrived in earnest at the dam in 2005 and have returned in greater numbers each year, outnumbered California sea lions for the first time and ate fully half of the predated salmon.
    The problem with this shift is that Steller sea lions are themselves listed as a threatened species, meaning that "hazing"—disturbing them with, for example, rubber bullets—is the only option for dealing with them.
    A key issue is exactly how much the sea lions are affecting the salmon, particularly the species that are listed as threatened. This is a difficult question to answer. Yet the Humane Society says that the killing focuses on the wrong problem—sea lions—instead of reducing the allowable fishing catch, improving habitat, and reducing losses from hydropower, which it maintains are greater threats to the fish.
According to the passage, what is most important in solving this awkward problem?

选项 A、Reducing the number of the sea lions.
B、Recognizing whether the sea lions are the main threats to the salmon.
C、Banning the catch of the fish in the Columbia River.
D、Forming a good habit of catching fish.

答案B

解析 根据题干关键词定位至最后一段第一句,a key issue是“关键问题”的意思,即题干most important的同义再现。即解决这一尴尬问题的关键是弄清楚海狮对鲑鱼的影响到底有多大,故B项为正确答案。第三句明确表示海豹的捕杀解决不了问题,reducing theallowable fishing catch是减少允许捕杀量,不是禁止捕鱼,habitat是“栖息地”的意思,不能和habit混淆,因此排除A项、C项和D项。
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