题目内容
Zoo elephants don’t live as long as those in the wild, according to a study sure to cause debate about keeping the giant animals on display. Researchers compared the life spans of elephants in European zoos with those living in Amboseli National Park in Kenya and others working on a timber （木材） enterprise in Burma. Animals in the wild or in natural working conditions had life spans twice that or more of their relatives in zoos.
Animal care activists have urged in recent years to discourage keeping elephants in zoos, largely because of the lack of space and small numbers of animals that can be kept in a group.
The researchers found that the median life span for African elephants in European zoos was 16.9 years, compared with 56 years for elephants who died of natural causes in Kenya’s Amboseli Park. Adding in those elephants killed by people in Africa lowered the median life span there to 35.9 years. For the more endangered Asian elephants, the median life span in European zoos was 18.9 years, compared with 41.7 years for those working in the Burma Timber Enterprise. Median means half died younger than that age and half lived longer.
There is some good news, though. The life spans of zoo elephants have improved in recent years, suggesting an improvement in their care and raising, but “Protecting elephants in Africa and Asia is far more successful than protecting them in Western zoos.”
There are about 1,200 elephants in zoos, half in Europe, researchers concentrated on female elephants, which make up 80 percent of the zoo population. One amazing thing was that Asian elephants born in zoos had shorter life spans than those brought to the zoos from the wild.
Zoos usually lack large areas that elephants are used to in the wild, and that zoo animals often are alone or with one or two other unrelated animals, while in the wild they tend to live in related groups of 8 to 12 animals. In Asian elephants, baby death rates are two to three times higher in zoos than in the Burmese logging camps, and then, in adulthood, zoo-born animals die young. People are not sure why.
1．What is argued in this passage?
A．Zoo elephants don’t live as long as those in the wild.
B．Elephants should not be on display.
C．Asian elephants are in danger.
D．Asia is far more successful protecting elephants in zoos.
2．What does the underlined word “median” mean according to the passage?
A．Average. B．Longest. C．Shortest. D．Ordinary.
3．Which of the following is NOT the disadvantage of keeping elephants in zoos?
A．Limited number of relatives. B．Lack of space.
C．Shorter life span. D．Less attention.
4．Who does the writer of the passage expect to pay more attention to the issue addressed?
A．Zoologists. B．Zoo Visitors.
C．Animal care activists. D．The public.
BADD
Most people regard zoos as safe places for animals, where struggles such as difficulty finding food and avoiding predators（捕食性动物） 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 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 led by Mason, a biologist, compared the life spans of female elephants born in zoos with female elephants living outdoors in the wild. 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 elephants in zoos.
The team found that female elephants born in zoos lived an average of 16.9 years. Their wild counterparts（同类事物） who died of natural causes lived an average of 56 years——more than three times as long.
Scientists don't yet know for sure why wild elephants seem to live so much better than their zoo-raised counterparts. Mason thinks stress and obesity(肥胖) may be to blame. Zoo elephants don't get the same kind of exercise as they do 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 groups.
Another finding from the study showed that elephants born in zoos were more likely to die earlier than 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 keep healthy populations, that doesn't appear to be the case with elephants.
【小题1】The text tells us that zoo elephants are different from other zoo animals because they________
| A．develop health problems. |
| B．1ive to a ripe old age. |
| C．are not afraid of predators. |
| D．have difficulty eating food. |
| A．Female elephants live longer than male elephants. |
| B．Female zoo elephants die earlier than their wild counterparts. |
| C．Female zoo elephants live longer than their wild counterparts. |
| D．Both elephants in zoos and those in the wild live in large herds. |
| A．Zoo-born elephants should be attended more carefully |
| B．Elephants are no longer an endangered species. |
| C．It may not be a wise policy to keep elephants in the zoo. |
| D．Zoos should keep more animals except elephants. |
| A．Comparison between two species of elephants |
| B．Longer lives for wild elephants |
| C．Female elephants suffer from poor health. |
| D．Longer lives for zoo animals. |
Researchers at San Diego Zoo have been studying what has been described as the “secret language” of elephants. They have been monitoring（监测） communications between animals that cannot be heard by human ears.
The elephant’s call will be familiar to most people, but the animals also give out growls (低吼). Their growls, however, are only partly audible (听得见的); two-thirds of the call is at frequencies that are too low to be picked up by our hearing. To learn more about the inaudible part of the growl, the team attached (附在……上面) a microphone sensitive to these low frequencies and a GPS tracking system to eight of the zoo’s female elephants. The researchers could then relate the noises the animals were making to what they were doing. Matt Anderson, who led the project, told BBC News, “We’re excited to learn how they interact and contact with one another.”
The team has already learned that pregnant females use this low frequency communication to announce to the rest of their long gestation (妊娠期) of over two years, in the last 12 days we see the low part of the growl, which we can’t hear. This we believe is to announce to the rest of the herd that the baby is upcoming,” said Dr Anderson.
The researchers believe that this also warns the elephants to look out for coming danger. “You may think that a baby calf of about 300 pounds would not be as open to predation (捕食) as other species,” he says. “But packs of hyenas (袋狼) are a big threat in the wild.”
Female elephants are only in season for around four days every four years and these calls can be heard by males more than two miles away.
【小题1】Why some elephants’ call is called “secret language”?
| A．Because it can’t be heard by human ears. |
| B．Because it can only be heard by female elephants. |
| C．Because people don’t know its meanings. |
| D．Because people haven’t studied it completely. |
| A．where the elephants usually go |
| B．what the elephants’ growls really mean |
| C．how mother elephants raise baby calves |
| D．how elephants protect their babies. |
| A．show the location where she is staying |
| B．ask for help when she losses her way |
| C．scare away the enemy |
| D．let others know she will have a baby |
| A．The elephants can speak like people. |
| B．The wild elephants’ ways to fight against enemies. |
| C．The “secret language” between elephants. |
| D．The special life of female elephants. |
Most people regard zoos as safe places for animals, where struggles such as difficulty finding food and avoiding predators（捕食性动物） 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 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 led by Mason, a biologist, compared the life spans of female elephants born in zoos with female elephants living outdoors in the wild. 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 elephants in zoos.
The team found that female elephants born in zoos lived an average of 16.9 years. Their wild counterparts（同类事物） who died of natural causes lived an average of 56 years——more than three times as long.
Scientists don't yet know for sure why wild elephants seem to live so much better than their zoo-raised counterparts. Mason thinks stress and obesity(肥胖) may be to blame. Zoo elephants don't get the same kind of exercise as they do 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 groups.
Another finding from the study showed that elephants born in zoos were more likely to die earlier than 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 keep healthy populations, that doesn't appear to be the case with elephants.
1.The text tells us that zoo elephants are different from other zoo animals because they________
|
A．develop health problems. |
|
B．1ive to a ripe old age. |
|
C．are not afraid of predators. |
|
D．have difficulty eating food. |
2.What do the scientists find in their research?
|
A．Female elephants live longer than male elephants. |
|
B．Female zoo elephants die earlier than their wild counterparts. |
|
C．Female zoo elephants live longer than their wild counterparts. |
|
D．Both elephants in zoos and those in the wild live in large herds. |
3.Which of the following does the author suggest in the last paragraph?
|
A．Zoo-born elephants should be attended more carefully |
|
B．Elephants are no longer an endangered species. |
|
C．It may not be a wise policy to keep elephants in the zoo. |
|
D．Zoos should keep more animals except elephants. |
4.Which of the following can be the best title?
|
A．Comparison between two species of elephants |
|
B．Longer lives for wild elephants |
|
C．Female elephants suffer from poor health. |
|
D．Longer lives for zoo animals. |