Longer Lives for Wild Elephants(B級)

Most people think of zoos as safe places for animals, where straggles such as difficulty finding food and avoiding predators don't exist. Without such problems, animals in zoos should live to a ripe old age1.

But that may not be true for2 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 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 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 camps3, 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 may be to blame4. 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. "Currently, zoos are net consumers of elephants ,not net producers." Mason says.

1. According to the first two paragraphs, unlike other zoo animals, zoo elephants根據(jù)前面2段，和其它動物不同， 動物園的大象_____________

A. have difficulty eating food.吃東西有困難。

B. live to a ripe old age.能過活到高齡。

C. are not afraid of predators.不害怕食肉捕食者。

D. develop health problems. 面臨一些健康問題。(正確答案)

2. Which of the following about the international scientists' research on the life spans of elephants is NOT true? (See paragraph 3)? 國際科學(xué)家對于大象的生命周期的研究，______________是不對的?

A. They compared zoo elephants with wild elephants.他們把動物園的大象和野生大象作比較。

B. They kept detailed records of all the elephants in their care. 他們保留了飼養(yǎng)大象的詳細記錄。(正確答案)

C. They analyzed the records of the elephants kept in zoos.他們分析動物園里的大象的生活記錄。

D. The zoo-born elephants they studied are kept in European zoos.他們研究的動物園出生的大象在歐洲動物園飼養(yǎng)。

3. What do the scientist find in their research? 科學(xué)家們在他們的研究中發(fā)現(xiàn)了______________。

A. Female elephants live longer than male elephants.雌象比雄象活得更長。

B. Female zoo elephants live longer than their wild counterparts.動物園雌象比野生的活得更長。

C. Female zoo elephants die much earlier than their wild counterparts. 動物園雌象比起它們的野生的同伴來說要死得早。(正確答案)

D. Elephants in zoos and those in the wild enjoy the same long life spans.動物園大象和野生大象有一樣的壽命。

4. What are the possible causes of stress and obesity Zoo-raised elephants generally suffer from? 動物園中飼養(yǎng)的大象遭受壓力和肥胖的可能的原因是______________。

A. They do not like living in herds.它們不喜歡在畜群中生活。

B. They do not get enough exercise.它們沒有得到充分的鍛煉。

C. They do not live with their families.它們沒有和它們的家人一起生活。

D. Both B and C. B 和C都對。(正確答案)

5. Which of the following does the author suggest in the last paragraph? 在最后一段，作者暗示了______________。

A. It may not be a wise policy to keep elephants in the zoo. 把動物養(yǎng)在動物園里是不明智的做法。(正確答案)

B. Elephants are no longer an endangered species.大象不再是瀕臨滅絕的物種。

C. Zoo-born elephants should be looked after more carefully.照顧動物園里出生的大象應(yīng)該更仔細。

D. Zoos should keep more animals except elephants.除了大象，動物園里應(yīng)該飼養(yǎng)其他更多的動物。

6. Do scientists know why wild elephants seem to fare so much better than their zoo-raised counterparts.? 科學(xué)家是否清楚野生大象比動物園大象更好的原因?

A.uncertain不確定(正確答案)

B.positive 明確的、肯定的

C.clear清楚的

D.biased片面的