16.Longer Lives for Wild Elephants
Most people think of zoos as safe places for animals,where struggles such as difficulty finding food and avoiding predators 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 unable to have babies.
To learn more about how captivity(监禁) 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,documenting factors such as birth dates,illnesses,weight and death.These records made it possible for the researchers to analyze 40years of data on 800African and Asian elephants in zoos across Europe.The scientists compared the life spans of the zoo-born elephants with the life spans of thousands of female wild elephants in Africa and Asian elephants that work in logging camps(伐木场),over approximately the same time period.
The team found that female African elephants born in zoos lived an average of 16.9years.Their wild counterparts who died of natural causes lived an average of 56years--more than three times as long.Female Asian elephants followed a similar pattern.In zoos,they lived 18.9years,while those in the logging camps lived 41.7years.
Scientists don't yet know why wild elephants seem to live 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.Elephant social lives 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.
72.According to the first two paragraphs,unlike other zoo animals,zoo elephantsD.
A.have difficulty eating food. B.1ive to a ripe old age.
C.are not afraid of predators. D.develop health problems.
73.Which of the following about the international scientists'research on the life spans of elephants is NOT true?(See paragraph 3)?B
A.They compared zoo elephants with wild elephants.
B.They kept detailed records of all the elephants in their care.
C.They analyzed the records of the elephants kept in zoos.
D.The zoo-born elephants they studied are kept in European zoos.
74.What do the scientists find in their research?C
A.Female elephants live longer than male elephants.
B.Female zoo elephants live longer than their wild counterparts.
C.Female zoo elephants die much earlier than their wild counterparts.
D.Elephants in zoos and those in the wild enjoy the same long life spans.
75.Which of the following does the author suggest in the last paragraph?A
A.It may not be a wise policy to keep elephants in the zoo.
B.Elephants are no longer an endangered species.
C.Zoo-born elephants should be looked after more carefully.
D.Zoos should keep more animals except elephants.
分析 本文主要讲述了科学家们已经发现动物园里的大象面临着许多健康问题.研究发现,野外生活的大象比动物园饲养的大象活得更好.因此,把大象养在动物园里是不明智的.
解答 72.D细节理解题.根据第二段Scientists have known that elephants in zoos often suffer from poor health.可知科学家们已经发现动物园内的大象面临着很多的健康问题.故选D.
73.B细节理解题.根据第三段Zoos keep detailed records of all the animals in their care,可知动物园保留了所有动物的详细记录,而不是科学家.故选B.
74.C推理判断题.根据第六段Scientists don't yet know why wild elephants seem to live so much better than their zoo-raised counterparts.可知科学家们还不知道野生象为什么会比动物园饲养的象活得更好.由此推知,科学家们发现动物园的雌象会比野生象死得更早.故选C.
75.A细节推断题.根据最后一段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.可知该项研究提出了是否应该把更多的大象关在动物园内的问题.虽然一些受威胁和濒危的物种在动物园里生活,成功的繁殖了后代而且很健康,但似乎大象并非如此.由此推知,把大象养在动物园里或许是不明智的.故选A.
点评 本文考察学生的理解推断能力以及细心程度,只要抓住文章的关键词,采用寻读的方法查找细节,就能找到正确答案.