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  3. Hungry prehistoric hunters, not climate change, drove elephants to extinction during the Pleistocene era (更新世), new research sug

Hungry prehistoric hunters, not climate change, drove elephants to extinction during the Pleistocene era (更新世), new research sug

admin2012-12-26  68
问题     Hungry prehistoric hunters, not climate change, drove elephants to extinction during the Pleistocene era (更新世), new research suggests.
    At least 12 kinds of elephants【1】to wander about the African, Eurasian, and American continents.
    Today, only two【2】of elephants are left in South Asia and Africa. One theory for this dramatic death holds that rapid climate shifts at the end of the most recent major ice age, some 10,000 years ago,【3】vegetation and broke up habitats (栖息地), causing the death of those unable to adapt to the new conditions. Another【4】blames prehistoric humans, whose improved weapons and hunting techniques allowed them to wipe out whole herds of elephants.
    To help【5】the debate, archaeologist Todd Surovell of the University of Wyoming, and colleagues tested two assumptions. If humans caused the elephant extinction, Surovell reasoned, the timing of the die-off in【6】regions should match human expansion into those regions. On the contrary, if the extinction was【7】to climate change, elephants should remain in regions【8】colonized by humans and would only begin to die off once climate change occurred.
    The team tested both theories by analyzing where and when elephants were killed. In all, the study included 41 archaeological sites on five continents. The researchers found that, as humans【9】out of Africa, they left a trail of dead elephants behind them. The creatures disappear from the fossil record of a region once it became colonized by humans. Modern elephants survived in refu ges【10】to humans, such as tropical forests, says Surovell.
A. uninviting B. migrated C. declined D. due
E. memorial F. specific G. already N. used
I. hypothesis J. endurance K. resolve L. polish
M. altered O. species
【9】
选项
答案B
解析 此处应该是动词，且联系上下文可知应是过去式，作谓语。migrated out of Africa意为“迁移出非洲”。
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