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  3. Most people think of zoos as safe places for animals, where struggles such as difficulty finding food and avoiding predators (猛兽

Most people think of zoos as safe places for animals, where struggles such as difficulty finding food and avoiding predators (猛兽

admin2012-01-27  102
问题     Most people think of zoos as safe places for animals, where struggles such as difficulty finding food and avoiding predators (猛兽) don’t exist. Without such problems, animals in zoos should live to a ripe old age.
    But that may not be true for the largest land animals on Earth. Scientists have known that elephants in zoos often suffer from poor health. They develop diseases, joint problems and behavior changes. Sometimes, they even become infertile.
    To learn more about how captivity (圈养) affects elephants, a team of international scientists compared the life spans of female elephants born in zoos with female elephants living outdoors in their native lands. Zoos keep detailed records of all the animals in their care. These records made it possible for the researchers to analyze 40 years of data on 800 African and Asian elephants in zoos across Europe.
    The team found that female African elephants bora in zoos lived an average of 16.9 years. Their wild counterparts who died of natural causes lived an average of 56 years — more than three times as long. Female Asian elephants followed a similar pattern. In zoos, they lived 18.9 years, while those in the logging camps lived 41.7 years.
    Scientists don’t yet know why wild elephants seem to fare so much better than their zoo-raised counterparts. Georgia Mason, a biologist at the University of Guelph in Canada who led the study, thinks stress and obesity (肥胖) may be to blame. Zoo elephants don’t get the same kind of exercise they would in the wild, and most are very fat. Social lives of elephants are also much different in zoos than in the wild, where they live in large herds and family groups.
    Another finding from the study showed that Asian elephants born in zoos were more likely to die early than Asian elephants captured in the wild and brought to zoos. Mason suggests stress in the mothers in zoos might cause them to have babies that are less likely to survive.
    The study raises some questions about acquiring more elephants to keep in zoos. While some threatened and endangered species living in zoos reproduce successfully and maintain healthy populations, that doesn’t appear to be the case with elephants. "Currently, zoos are net consumers of elephants, not net producers," Mason says.
What do we learn about the international scientists’ research?
选项 A、They kept detailed records of all the elephants.
B、They compared zoo-born elephants with wild ones.
C、They explain clearly why wild elephants are healthier.
D、They focus on female elephants captured in the wild.
答案B
解析 根据题干中的international scientists将本题出处定位到第3段首句。该句提到，……一队国际科学家刘比了在动物园出生的雌象与生活在自然环境中的雌象的寿命。[B]正是对此的同义转述，其中的zoo-born elephants与elephants born in zoos对应，wild ones与elephants living outdoors in their native lands对应，故答案为[B]。文中提到，动物园保留了“所饲养的所有动物”的详细记录，而非“所有大象”的记录，故排除[A]。[C]中的  explain clearly与第5段首句提到的don’t yet know why矛盾。[D]在文中未提及，故排除。
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