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  3. The population of African forest elephants plummeted 62% in the past decade. The figure comes as policymakers discuss ways to cu

The population of African forest elephants plummeted 62% in the past decade. The figure comes as policymakers discuss ways to cu

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问题     The population of African forest elephants plummeted 62% in the past decade. The figure comes as policymakers discuss ways to curb the ivory market at the Convention on International Trade in Endangered Species of Wild Fauna and Flora(CITES)meeting.
    Forest elephants, which often live closer to human populations, have been particularly hard-hit by ivory poachers. After declines in the elephant population last century, a 1989 international ban on ivory initially led to signs of a resurgence in the animals. Since then, anecdotal evidence and surveys taken in individual parks suggested that heightened demand for ivory in China has once again led an uptick in elephant slaughters.
    To get a more complete picture, Maisels and a team of 60 researchers from around the world helped coordinate and assemble data from 80 individual surveys taken from 2002 through 2011 in central African locales. When the team crunched(进行大量运算)the numbers, it found that just during the 10-year span covered in the new surveys, the elephant population declined by 62% and the land area inhabited by elephants dropped by 30%. Areas lacking guards, closest to roads and in countries with high levels of corruption had the most elephant population decline.
    These numbers are a bit conservative. Because many of the surveys took place in protected areas, they could overestimate elephant populations—elephants often flee into the protected zones to escape nearby poaching.
    Estimates on the absolute population of elephants at any given time must be taken with a grain of salt, but overall trends seen over years of sampling the same areas in a standardized way are generally more accurate.
    The new numbers are not surprising to conservationists who work in the area, but are needed to convince others of the problems and provide a starting point to see the effect of future conservation efforts.
    The challenge now is for those countries represented at the CITES meeting, to put together new policies to curb the ivory trade. The key will be to stop the trade within China, lowering the demand for ivory and the price. Previous programs aimed at this aspect of the market have been more successful than those specifically aiming to stop the poaching.
Why are these numbers in previous surveys a bit conservative?
选项 A、Because some surveys underestimate the numbers of elephants in the protected areas.
B、Because elephants often flee into the protected areas to look for food.
C、Because researchers could overestimate elephant populations in the protected areas.
D、Because estimates on the absolute population of elephants must be doubtful.
答案C
解析 细节辨认题。由定位段可知，这些数字是有些保守的。因为许多调查是在保护区进行的，他们可能高估了大象的数量——大象经常逃到保护区来逃脱附近的偷猎，故本题答案为C)。
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大学英语四级

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