（C）
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 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(伐木场), 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 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 elephants _______ .
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)?
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?
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. 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. 

Section C
Directions: Read the following text and choose the most suitable heading from A—F for each paragraph. There is one extra heading which you do not need.

An interview with Benno Nigg, the sports scientist

A. What kind of technology might we see in sports shoes of the future?
B. What should people look out for when buying a new pair of sports shoes?
C. Will a more expensive shoe make me run faster or jump higher, as the ads suggest?
D. Is it true that expensive shoes are no better at preventing injury than cheap ones?
E. Some people say we should run just as well without shoes. What’s your opinion?
F. You helped develop the unstable Masai MBT shoes. Does this design actually work?

76.

Nigg’s Answer: That is a little bit overstated. But the literature shows that shoes are a minor player in injury development. If you take a group of people and want to injure them, send them out every day for a 20-kilometre run. A lot of them will be injured in three weeks. The major factors are the distance run, the intensity and recovery time, not the shoes.

77.

Nigg’s Answer: The problem is that if you go to a store and want to find your best shoes, you don’t know what to do. Things that are sometimes done, like video analysis of your rear foot movement, may not help. The only way to assess whether a shoe is right for you is how it feels. If you feel comfortable in a shoe, it’s likely to be good for you.

78.

Nigg’s Answer: A shoe may act as a training device, making some muscles to function more effectively for a majority of users. Or it may use materials that last longer. That may have something to do with its price. However, for the average runner it is difficult to distinguish between actual functional designs and unnecessary features. Generally, the more a shoe controls movement, the more it acts like a cast, which means you lose some muscle strength, and your feet are more likely to be injured.

79.

Nigg’s Answer: Yes, for about 80 per cent of people. The major benefits are training the small muscles crossing the ankle joint, and a reduction of knee and lower back pain. However, some claims for these unstable shoes are overstated, such as the general muscle strengthening that they are claimed to produce.

80.

Nigg’s Answer: There are claims that there are fewer injuries when you run barefoot, but there is not yet enough evidence, or enough research, to prove that. If you look at performance, most papers suggest an advantage of 3 to 4 per cent. With a few exceptions, people don’t run barefoot, so it may be that it’s not an advantage, or it may be that we’re just not used to it.

Section D
Directions: Read the passage carefully and answer the questions or complete the statements in no more than 12 words.

Planting trees around poultry(家禽) farms can improve air and water quality – and relations with neighbors. Research has shown that just three rows of trees near poultry houses can reduce the release of dust and ammonia (氨). They can also reduce the strong smell of ammonia gas.
The trees capture dust, ammonia and smells in their leaves. They can also reduce energy use. They also provide shade from the sun, so they reduce cooling costs in summer. And they act as a windbreak, so they reduce heating costs in winter. Trees can also improve water quality around farms by removing pollutions from soil and groundwater.

Several years ago, people were objecting to the smell of poultry farms on the Delmarva Peninsula in the eastern United States. Delmarva is where the states of Delaware, Maryland and Virginia come together. Two thousand farms there can each house an average of seventy-five thousand chickens.
Traditionally the farms used windows to provide fresh air in the chicken houses. Farmers rarely planted trees or tall crops around the buildings, so there would be no barrier to the airflow.

But then in the 60s, farms began to use mechanical ventilation(通风) systems. Instead of windows, the mechanical systems used tunnel fans to circulate(使…循环) air. The fans directed airflow from the poultry houses toward the homes of neighbors.

Researchers began dealing with the problem in 2000. They found that over a period of six years, planting three rows of trees reduced total dust and ammonia by more than half. And they found that smells were reduced by 18%.

Farmers may think trees will take too long to grow and be effective. But some trees can grow quickly. At least one-third of the Delmarva farms have planted trees, technically known as vegetative environmental buffers. The idea offers a way to cut pollution, save money and energy, and make the neighbors happy.

81. How did the mechanical ventilation system work?

82. The number of chickens raised on the poultry farms in Delmarva is up to __________.

83. The benefits of planting trees around poultry farms are _________.

84. What is the main topic of the passage?