In 1995, after an absence of nearly 70 years, wolves were reintroduced into Yellowstone National Park. During the wolf-free era,

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问题     In 1995, after an absence of nearly 70 years, wolves were reintroduced into Yellowstone National Park. During the wolf-free era, heavy browsing of aspen trees by elk populations spelled doom not only for trees themselves but for a host of other creatures dependent on them, such as beavers, whose population in Yellowstone crashed after wolves were removed. Without beavers to create ponds, wetland ecosystems—aquatic plants, amphibians, birds— were devastated. When wolves returned, grazers and browsers resumed normal patterns of behaviors, preferring safer, open areas over the dense cover and streamsides where carnivores can lurk. Keeping elk wary and on the move, wolves gave aspen and other young trees the opportunity to grow and become reestablished.
The author would most likely agree with which of the following claims about the reintroduction of wolves to Yellowstone?

选项 A、It indirectly harmed some of the park’s amphibian habitats.
B、It reduced the number of elk feeding along streamsides.
C、It led to greater species diversity among the park’s grazers and browsers.
D、It significantly increased competition for food among the park’s carnivores.
E、It fostered the resurgence of tree species that once flourished in the park’s open areas.

答案B

解析 根据第二句可知,麋鹿是食嫩叶的动物的一种。根据第四句的resume (resume表明做某件事情中断后再继续做)可知,狼消失之前,食嫩叶的动物喜欢在安全的地方觅食,而狼消失之后,它们在河边觅食,狼回来以后,食嫩叶的动物又会离开河边,因此麋鹿在河边觅食的数量会减少。因此选项B正确。A项文中未提及。C项文章只讨论这些食草动物的觅食行为受到了怎样的影响,没有提及物种多样性。D项文中未提及。E项从文中看不出重新繁荣的白杨树是否生活在开阔的地方。
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