WASHINGTON—Two-thirds of the world’s polar bear population could be gone by 2050 if predictions of melting sea ice hold true, the US Geological Survey reported on Friday.
The fate of polar bears could be even worse than that estimate, because sea ice in the Arctic might be disappearing faster than the available computer models predict, the geological survey said in a report aimed at determining whether the big white bear should be listed as a threatened species.
“There is a definite link between changes in the sea ice and the welfare of polar bears,” said Steve Amstrup, who led the research team. He says Arctic sea ice is already at the lowest this year and is expected to retreat(退却) farther this month.
That means that polar bears—some 16,000 of them -- will disappear by 2050 from parts of the Arctic where sea ice is melting most rapidly, along the north coasts of Alaska and Russia, researchers said in a telephone briefing(简报).
Other polar bears could survive beyond that date but many of those could be gone by 2100, Amstrup said. By this century’s end, the only polar bears left might live in the Canadian Arctic islands and along the west coast of Greenland.
“It is likely to result in loss of approximately two-thirds of the world’s current polar bear population by the mid 21st century,” the report’s executive summary said.
“Because the observed trajectory(轨迹)of Arctic sea ice decline appears to be underestimated by currently available models, this assessment of future polar bear status may be conservative(保守的).”
In January, the US Fish and Wildlife Service proposed listing the polar bear as a threatened species, noting polar bears depend on sea ice as a platform to hunt seals, their main food.
Without enough sea ice, polar bears would be forced onto land, but they are poor hunters once they get out of the water and ice, the researchers said. The bears’ disappearance would probably take place as young cubs(幼兽)failed to survive to adulthood and females were unable to reproduce successfully.What was the US Geological Survey intended to do?
| A．To determine whether the polar bear was in danger. |
| B．To measure how fast the sea ice melts in the Arctic. |
| C．To check the predictions of the computer models. |
| D．To find out the exact number of the polar bear. |
What causes the polar bears to disappear by 2050?
| A．The pollution of the Arctic region. | B．The sea ice melting at high speed |
| C．Fewer food sources being left. | D．The temperature getting colder. |
The key to preventing polar bears dying out seems to _______________.
| A．help young polar bears to survive the cold winter |
| B．have large number of seals living in the oceans |
| C．make sure there is enough sea ice in the Arctic |
| D．provide chances for adult polar bears to reproduce |
Britons stranded（搁浅）at sea or in flooded homes could find a real-life prince riding to their rescue. Prince William announced on Monday that he is to train to be a full-time pilot with the Royal Air Force's Search and Rescue Force (SARF).
William, who is currently a Lieutenant（中尉）in the Army's Household Cavalry Regiment（皇家骑兵团）, will transfer to the RAF and begin an 18-month training course in January 2009.
If successful, he will become a fully operational Search and Rescue pilot in 2010, flying Sea King helicopters at one of the six SARF units based in Britain.
"The time I spent with the RAF earlier this year made me realize how much I love flying," the prince, who spent two weeks with a SARF team while on work experience in 2005, said in a statement.
"Joining Search and Rescue is a perfect opportunity for me to serve in the Forces operationally, while contributing to a vital part of the country's Emergency Services."
It means he will follow a similar career to that of his uncle, Prince Andrew, who was a Sea King helicopter pilot during the 1982 Falklands war.
The Search and Rescue teams' main duty is to recover RAF personnel but in peacetime they mainly respond to civilian emergencies, dealing with more than 1,000 calls a year.
The units deal with incidents ranging from helping those trapped by sudden major floods to rescuing people lost while out walking on hills.
William, who has spent the last year on secondment（借调）to the various branches of the military to prepare for his future role as head of the armed forces, received his RAF wings （飞行勋章）following a four-month stint（持续的工作）with the service earlier this year.
However, his time with the RAF was clouded when the Defense Ministry was forced to fend off (挡开) criticism for allowing the prince to f
ly military helicopters to a bachelor party for his cousin and to the family home of his girlfriend Kate Middleton.
49. Prince William wanted to be a full-time pilot because _______.
A. he liked flying
B. he would like to do something in the country’s Emergency Services
C. many Britons were in danger at sea waiting for rescue
D. he had much experience in flying
50. According to the passage, _______.
A. the Falklands war broke out in 2005
B. Prince William served in the Army’s Household Cavalry Regiment in 1982
C. Prince Andrew is serving in SARF now
D. William would finish his training course in June 2010
51. The author’s opinion on William’s joining RAF is _______.
A. enthusiastic B. doubtful C. negative D. pessimistic
52. What is the purpose of the author by mentioning what the prince had done before in the last
paragraph?
A. The author wants to say that Prince William pays much attention to his family and friends
B. The author suggests that the Defense Ministry was criticized when William flew for his
private business
C. William had a hard time when he went against his leaders
D.The author has the worry that Prince William is likely to get the Defense Ministry into
trouble again.
Energy-saving Finns invented the first ice skate more than 5,000 years ago, as a practical method of transport to make getting across frozen lakes less of a struggle.
The earliest skates would have been blades made from bones and are one of the oldest means of transport ever discovered —they may even have been essential survival tools.
Researchers at Manchester Metropolitan University have calculated that ice skates would have saved energy by 10 percent, and suggest that they were developed for practical use and were not used for recreation, as they are today.
They think the most likely birthplace of skating is southern Finland, where there are many icy lakes.
The scientists have put their theory to the test and made replica（复制品） skates modeled after examples held at the British Museum and the Fitzwilliam Museum in Cambridge.
Volunteers on ice rinks in the Alps had their heart rates, oxygen intake and skating speeds measured while they skated with the replica skates. From this experiment, re-searchers were able to calculate energy co
nsumption and the efficiency of their skating. They discovered that skating over the land in ancient Fin-land would have saved 10 percent of people’s energy. The result is based on the fact that Finland has the highest concentration of lakes in the world. The ancient Finnish people could benefit more than others from developing this tool for transport.
In a time and environment in which the balance between energy taken from food and energy required to live was crucial; the least cost of energy might have helped humans survive in extreme conditions.
45. The first ice skate invent
ed by the Finns was used for _____.
A. recreationB. transportation across lakesC. saving energyD. Sports
46. The birthplace of skating might be southern Finland because _____.
A. there are many icy lakes there
B. people need more oxygen to breathe in there
C. people feel tired easily there
D. transportation there is more difficult
47. Scientists have experimented with replica skates and found that with those skates the ancient
Finnish people would have _____.
A. crossed a lot of lakes
B. saved 10 percent of energy when crossing the lakes
C. climbed the Alps easily
D. otherwise wasted a lot of food and energy
48. It can be inferred from the story that _____.
A. the Finnish people were clever enough to invent the practical skates
B. there were a lot of lakes in ancient Finland
C. the living conditions were very hard for the ancient Finnish people
D. it was very cold in ancient times in Finland
III、阅读理解（共20小题；每小题2分，满分40分）
阅读下列短文，从每题所给的四个选项（A、B、C、D）中，选出最佳选项。
Do dogs understand us?
Be careful what you say around your dog. It might understand more than you think.
A border collie named Rico recognizes the names of about 200 objects, say researchers in Germany. The dog also appears to be able to learn new words as easily as a 3-year-old child. Its word-learning skills are as good as those of a parrot or chimpanzee(黑猩猩).
In one experiment, the researchers took all 200 items that Rico is supposed to know and divided them into 20 groups of 10 objects. Then the owner told the dog to go and fetch one of the items and bring it back. In four tests, Rico got 37 out of 40 commands right. As the dog couldn't see anyone to get clues, the scientists believe Rico must understand the meanings of certain words.
In another experiment, the scientists took one toy that Rico had never seen before and put it in a room with seven toys whose names the dog already knew. The owner then told Rico to fetch the object, using a word the dog had never heard before.
The correct object was chosen in seven out of l0 tests, suggesting that the dog had worked
out the answer by process of elimination(排除法). A month later, Rico remembered half of the new names, which is even more impressive.
Rico is thought to be smarter than the average dog. For one thing, Rico is a border collie, a breed (品种)known for its mental abilities. In addition, the 9-year-old dog has been trained to fetch toys by their names since the age of nine months.
It's hard to know if all dogs understand at least some of the words we say. Even if they do, they can't talk back. Still, it wouldn't hurt to sweet-talk your dog every now and then. You might just get a big, wet kiss in return!
41. From paragraph 3 we know that _________.
A. animals are as clever as human beings
B. dogs are smarter than parrots and chimpanzees
C. chimpanzees have very good word-learning skills
D. dogs have the same learning abilities as 3-year-old children
42. Both experiments show that .
A. Rico is smart enough to get all commands right
B. Rico can recognize different things including toys
C. Rico has developed the ability of learning mathematics
D. Rico won't forget the names of objects once recognizing them
43. Which of the following statements is true?
A. The purpose of the experiments is to show the border collie's mental abilities.
B. Rico has a better memory partly because of its proper early training.
C. The Border collie is world-famous for recognizing objects.
D. Rico is born to understand its owner's commands.
44. What does the writer want to tell us?
A. To train your dog. B. To talk to your dog.
C. To be friendly to your dog. D. To be careful with your dog.
Do you want to live forever? By the year 2050, you might actually get your wish — if you are willing to leave your biological body and live in silicon circuits (半导体电路). But long before then, perhaps as early as 2010, some measures will begin offering a semblance of immortality (虚拟的永生).
Researchers are confident that technology will soon be able to track every waking moment of your life. Whatever you see and hear, all that you say and write, can be recorded, analyzed and added to your personal chronicles (履历). By the 2030, it may be possible to catch your nervous (神经) systems through electrical activities, which would also keep your thoughts and emotions. Researchers at the laboratories of British Telecommunications have given the name of this idea as Soul Catcher.
Small electronic equipment will make preparation for Soul Catcher. It would use a wearable supercomputer, perhaps in a wristwatch, with wireless links to micro sensors under your scalp (头皮) and in the nerves that carry all five sensory signals. So wearing a video camera would no longer be required.
At first, the Soul Catcher’s companion system — the Soul Reader — might have trouble copying your thoughts in complete details. Even in 2030, we may still be struggling to understand how the brain is working inside, so reading your thoughts and understanding your emotions might not be possible. But these signals could be kept for the day when they can be transferred to silicon circuits to revitalize minds everlasting entities (永生实体). Researchers can only wonder what it will be like to wake up one day and find yourself alive inside a machine.
For people who choose not to live in silicon semblance of immortality, it would not be as useless as they thought. People would know their lives would not be forgotten, but would be kept a record of the human race forever. And future generations would have a much fuller understanding of the past. History would not be controlled by just the rich and powerful, Hollywood stars, and a few thinkers in the upper society.
57．The main idea of this passage is that .
A. human beings long for living forever
B. there are many difficulties in making the Soul Catcher
C. people can live forever as technology develops
D. the invention of Soul Catcher has great importance
58．According to this passage, a Soul Catcher will be .
A. a new machine on which research measures have already been made
B. a new invention in order to catch and keep human’s thoughts
C. made by British scientists to offer something that looks like living forever
D. made of silicon circuits which can catch people’s nervous activity
59．We can infer from the passage that semblance of immortality is .
A. to be a reality sooner or later B. far from certain
C. just an idea that couldn’t t be realized at all D. a fading hope
60．The meaning of the underlined word “revitalize” in the fourth paragraph is close to .
A. make dead B. make famous
C. make known D. make active
Originally from tropical South America, the red fire ant gained entry to the United States through the port of Mobile, Alabama in the late 1930s on cargo ships, but the first colony of the red ants was not found until 1942 by a 13-year-old boy in his backyard.
It immediately began to thrive in the new land and colonies spread quickly throughout the southeastern states. By 1975 the red imported fire ant had colonized over 52 million hectares of the United States. Now, it has infested more than 275 million hectares in the country.
Red imported fire ants build mounds in any type of soil. They also make mounds indoors. Each nest used to have but one queen, but now many mounds are often found with multiple queens. With multiple queens at work, its population increases rapidly. It’s common to find a nest with over 25,000 workers.
Red imported fire ants can cause a number of problems. They construct their colonies on precious farmland, invading crops while searching for insects underground. They also like to make their mounds in sunny areas, heavily infesting lawns and pastures. They can quickly strip fruit trees of their fruit. Small birds such as baby quails are fair game to the expanding colony. They appear to be attracted to electromagnetic fields and attack electrical insulation or wire connections. They can cause electrical shorts, fires, and other damage to electrical equipment. Worst of all, their stings can be deadly to livestock and humans.
53. When was the first nest of the red ant found in the United States?
(A) In 1930s. (B) In 1942. (C) In 1975. (D) After 1975.
54. Which of the following is TRUE according to the article?
(A) Each nest of the red ant has one queen.
(B) The red ant was originally found in North America.
(C) The red ant can reproduce young ants very quickly.
(D) The red ant does not build mounds inside the house.
55. What kinds of problems can the red ant cause?
(A) Health, social, and agricultural. (B) Health, social, and environmental.
(C) Social, environmental, and agricultural. (D) Health, agricultural, and environmental.
56. What is the purpose of the article?
(A) To ask for help to kill the red ant.
(B) To urge people to protect the red ant.
(C) To provide information about the red ant.
(D) To seek help from the government to control the red ant.