第三篇 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 (猛獸) don't exist. Without such problems, animals in zoos should live to a ripe (成熟的) old age1.

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, or unable to have babies.

To learn more about how captivity (圈養(yǎng)) 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 me researchers to analyze 40 years of data on 800 African 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(伐木場),over approximately the same time period.

The team found that female African elephants born 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 (肥胖癥) 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.

The study raises some questions about acquiring more elephants to keep in zoos. While some threatened and endangered species living in zoos reproduce (生殖) successfully and maintain healthy populations, that doesn't appear to be the case with elephants. 41 Unlike other animals in zoos, zoo-raised elephants

A live a long life

B give birth to many babies

C develop poor health

D have difficulty getting food

42 Which of the following about the international scientists' study is NOT true?

A They compared zoo elephants with wild elephants.

B They analyzed the records of the elephants kept in zoos.

C The zoo-born elephants they studied are kept in European zoos.

D They kept detailed records of all the elephants in their care.

43 It was found that, compared with female wild elephants, female zoo-born elephants

A lived longer.

B grew up faster.

C died much earlier.

D enjoyed the same life spans.

44 One of the possible reasons for the Zoo-raised elephants' problems is that

A they do not get enough exercise.

B they do too much exercise.

C they live in large herds.

D they do not live in family groups.

45 It can be inferred from the last paragraph that

A Zoo-born elephants should be looked after more carefully.

B Zoos should keep more animals except elephants.

C It may not be a wise policy to keep elephants in the zoo.

D Elephants are no longer an endangered species.

本題分數(shù)（15）

41 C 第二段第二句話 "Scientists have known that elephants in zoos often suffer from poor health"，說明"生活在動物園的大象經(jīng)常會有不良的健康狀態(tài)"。答案為C。

42 D 第三段第二句話"Zoos keep detailed records of all the animals in their care, documenting factors such as birth dates, illnesses, weight and death"，說明是動物園記錄了有關(guān)大象生活的各個方面，而不是科學家做的，所以選項 D 不符合文章本意。其余選項的內(nèi)容在文中都有體現(xiàn)。

43 C 第四段中作者向讀者講述了野生雌大象存活的時間是生活在動物園的雌大象存活時間的三倍，所以答案為 C。

44 D 第五段最后一句話"Social lives of elephants are a1so much different in zoos than in the wild, where they live in large herds and family groups"，說明"生活在動物園里的雌大象與野生雌大象不同之處是后者是群居并以家族的方式生活"。答案為D。

45 C 文章最后一段主要講述大象不適宜動物園的生活，尤其是最后一句話 "that doesn't appear to be the case with elephant"，說明"那不適宜大象的情況"。答案為 C。

（責任編輯：vstara）

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