A recent study of ancient and modern elephants has come up with the unexpected conclusion that the African elephant is divided into two distinct (不同的) species.
The discovery was made by researchers at York and Harvard Universities when they were examining the genetic relationship between the ancient woolly mammoth and mastodon to modern elephants—the Asian elephant,African forest elephant,and African savanna elephant.
Once they obtained DNA sequences (序列) from two fossils (化石),mammoths and mastodons,the team compared them with DNA from modern elephants.They found to their amazement that modern forest and savanna elephants are as distinct from each other as Asian elephants and mammoths.
The scientists used detailed genetic analysis to prove that the African savanna elephant and the African forest elephant have been distinct species for several million years.The divergence of the two species took place around the time of the divergence of Asian elephants and woolly mammoths.This result amazed all the scientists.
There has long been debate in the scientific community that the two might be separate species,but this is the most convincing scientific evidence so far that they are indeed different species.
Previously,many naturalists believed that African savanna elephants and African forest elephants were two populations of the same species,despite the elephants’ significant size differences.The savanna elephant has an average shoulder height of 3.5 metres while the forest elephant has an average shoulder height of 2.5 metres.The savanna elephant weighs between six and seven tons,roughly double the weight of the forest elephant.But the fact that they look so different does not necessarily mean they are different species.However the proof lay in the analysis of the DNA.
Alfred Roca,assistant professor in the Department of Animal Sciences at the University of Illinois,said,“We now have to treat the forest and savanna elephants as two different units for conservation purposes.Since 1950,all African elephants have been conserved as one species.Now that we know the forest and savanna elephants are two very distinctive animals,the forest elephant should become a bigger priority(优先) for conservation purposes.”One of the fossils studied by the researchers is that of .
A.the Asian elephant |
B.the forest elephant |
C.the savanna elephant |
D.the mastodon elephant |
The underlined word “divergence” in Paragraph 4 means “ ”.
A.evolution |
B.exhibition |
C.separation |
D.examination |
The researchers’ conclusion was based on a study of the African elephant’s .
A.DNA |
B.height |
C.weight |
D.population |
What are Alfred Roca’s words mainly about?
A.The conservation of African elephants. |
B.The purpose of studying African elephants. |
C.The way to divide African elephants into two units. |
D.The reason for the distinction of African elephants. |
Which of the following can be the best title for the passage?
A.Naturalists’ Beliefs about Elephants |
B.Amazing Experiments about Elephants |
C.An Unexpected Finding about Elephants |
D.A Long Scientific Debate about Elephants |
New archaeological discoveries suggest that trade between Europe and Asia along the Silk Road probably began in some form many centuries earlier than once thought. The findings, coupled with a widening range of scientific and historical research could add a fascinating new page to the epic (史诗) of the Silk Road.
The most surprising discovery is pieces of silk found in the hair of an Egyptian mummy from about 1000 BC, long before regular traffic on the Silk Road and at least one thousand years before silk was previously thought to be used in Egypt. Other research may extend human activity along this route back even further, perhaps a million years to the migration of human ancestors into eastern Asia.
The official origin of East-West trade along the road is usually placed in the late 2nd century BC when an agent of the Chinese Emperor Wu-di returned from a dangerous secret mission(使命)across the desert into the remote high country of Central Asia. The agent, Zhang Qian, travelled as far as Afghanistan and brought back knowledge of even more distant lands such as Persia, Syria and a place known as Lijien, perhaps Rome. Historians have called this one of the most important journeys in ancient times. His journey opened the way for what have been thought to be the first indirect contacts between the ancient world’s two superpowers, China and Rome. Chinese silk, first traded to central Asian tribes for war horses and to the Parthian for acrobats and ostrich eggs, was soon finding its way through a network of merchants to the luxury (奢侈品) markets in Rome.
But the new discoveries show that Chinese silk was apparently present in the West long before the Han emperor started organized trade over the Silk Road. The research could change thinking about the early history of world trade and provide insights into the mystery of just how and when Europe and the Mediterranean lands first became aware of the glorious culture at the other end of Eurasia. The word “coupled” in the first paragraph could best be replaced by.
A.combined | B.contributed | C.doubled | D.produced |
The silk thread found in the hair of an Egyptian mummy suggests that.
A.Egyptians had probably travelled to China to buy silk |
B.new light can now be thrown on ancient trading pr![]() |
C.historical research often achieves fascinating results |
D.trade along the Silk Road began earlier than once thought |
Until recently historians mostly believed that trade along the Silk Road.
A.began a million years ago |
B.primarily benefited the Egyptians |
C.originated in the 2nd century BC |
D.extended human migration into eastern Asia |
Historians have always considered Zhang Qian’s mission important because they believe .
A.he discovered the Silk Road |
B.he helped establish East-West trade |
C.he travelled as far as Afghanistan |
D.he brought back knowledge of Rome to the emperor |
Have you seen Jurassic Park? In this film, scientists use DNA kept for tens of millions of years to clone dinosaurs. They find trouble, however, when they realize that the cloned creatures are smarter and more dangerous than expected. That’s nothing more than a fiction.
But could we really clone endangered animals?
To date, the most successful attempt to do so was the cloning of a gaur, a rare ox-like animal from southeast Asia. Scientists used a cow to bring the cloned baby gaur, named Noah. Two days after birth, however, Noah died from a common bacterial infection. Other endangered species that may be cloned include the African bongo antelope (羚羊), the Sumatran tiger, the cheetah (猎豹), and the giant panda.
Next, could we really clone extinct animals?
In theory? Yes. To do this, you need a well-kept source of DNA from the extinct animals such as wool mammoth (毛象), Tasmanian tiger, or even dinosaur, and a closely related species, still living, which could serve as a surrogate mother.
In reality? Probably not. On the one hand, it’s not likely that extinct animals’ DNA could survive undamaged for such a long time. Cloning such extinct animals as wool mammoth, Tasmanian tiger, or dinosaur is much more difficult due to the lack of properly well-preserved DNA. On the other hand, for example, a gaur can have a cow as a surrogate mother, definitely not a monkey. But what about an extinct animal as unique as the panda? What species could possibly serve as a surrogate mother?
Cloning presents many exciting possibilities. However, even if extinct animals were brought back, they could not survive in today’s world. Not only do most extinct animals have no habitat to love in, but the other plants and animals they depended on for food may also be gone as well. It can be learned from the text that ________.
A.the gaur is an extinct species |
B.the gaur lives in Asia and is endangered |
C.scientists have cloned the African bongo antelope |
D.both the cheetah and the giant panda live in Asia |
The underlined words “a surrogate mother” probably refer to a female who ______.
A.gives birth to a baby of its own | B.cannot give birth to a baby |
C.gives birth to a baby for another female | D.provides DNA |
The difficulty in cloning an extinct species is the lack of ______.
A.both the well-preserved DNA and a surrogate mother |
B.both the habitat to live in and the well-preserved DNA |
C.both the well-preserved DNA and plants to live on |
D.both the habitat to live in and plants to live on |
In the author’s opinion, it is possible that ______.
A.all the extinct species may be cloned |
B.extinct species may be cloned and easily survive |
C.a gaur can have a monkey as a surrogate mother |
D.some extinct species may be cloned, but not survive |
Welcome to Adventure land!
Everyone loves Adventure land! The Parks and Exhibitions were built for you to explore(探索), enjoy, and admire their wonders. Every visit will be an unforgettable experience. You will go away enriched, longing to come back. What are you going to do this time?
The Travel Pavilion
Explore places you have never been to before, and experience different ways of life. Visit the Amazon jungle(丛林)village, the Turkish market, the Thai floating market, the Berber mountain house and others. Talk to the people there who will tell you about their lives and things they make. You can try making a carpet, making nets, fishing…
The Future Tower
This exhibition shows how progress will touch our lives. It allows us to look into the future and explore the cities of the next century and the way we’ll be living then. Spend some time in our space station and climb into our simulator(模拟装置)for the Journey to Mars!
The Nature Park
This is not really one park but several.
In the Safari Park you can drive among African animals in one of our Range Cruisers: see lions, giraffes, elephants in the wild. Move on to the Ocean Park to watch the dolphins and whales. And then there is still the Aviary to see…
The Pyramid
This is the center of Adventure land. Run out of film, need some postcards and stamps? For all these things and many more, visit our underground shopping center. Come here for information and ideas too.The Travel Pavilion is built to help visitors _______.
A.learn how to make things such as fishing nets |
B.realize the importance of travelling |
C.learn something about different places in the world |
D.become familiar with mountain countries |
If you are interested in knowing about what people’s life will be, you may visit _______.
A.the Safari Park | B.the Travel Pavilion |
C.the Future Tower | D.the Pyramid |
If you want to get a souvenir(纪念品)to take home, where will you most likely go?
A.The Pyramid. | B.The Future Tower. |
C. The Nature Park. | D.The Travel Pavilion. |
Zoe Chambers was a successful PR (Public Relations) consultant (顾问) and life was going well—she had a great job, a beautiful flat and a busy social life in London. Then one evening in June last year, she received a text message telling her she was out of work. “The first two weeks were the most difficult to live through,” she said. “After everything I’d done for the company, they dismissed me by text
! I was so angry and I just didn’t feel like looking for another job. I hated everything about the city and my life.”
Then, Zoe received an invitation from an old school friend, Kathy, to come and stay. Kathy and her husband, Huw, had just bought a farm in northwest Wales. Zoë jumped at the chance to spend a weekend away from London, and now, ten months later, she is still on the farm.
“The moment I arrived at Kathy’s farm, I loved it and I knew I wanted to stay,”said Zoe.“Everything about my past life suddenly seemed meaningless.”
Zoe has been working on the farm since October of last year and says she has no regrets. “It’s a hard life, physically very tiring,” she says.“In London I was stressed and often mentally exhausted. But this is a good, healthy tiredness. Here, all I need to put me in a good mood is a hot bath and one of Kathy’s wonderful dinners.”
Zoe says she has never felt bored on the farm. Every day brings a new experience. Kathy has been teaching her how to ride a horse and she has learnt to drive a tractor. Since Christmas, she has been helping with the lambing—watching a lamb being born is unbelievable, she says,“It’s one of the most moving experiences I’ve ever had. I could never go back to city life now.” When she worked as a PR consultant in London, Zoë thought she lived a life.
A.meaningless | B.tough | C.boring | D.satisfying |
The most important reason why Zoe went to visit Kathy’s farm is that .
A.Kathy persuaded her to do so | B.Zoe lost her job as a PR consultant |
C.Zoe got tired of the city life | D.Zoe loved Wales more than London |
How does Zoe feel about the country life according to the passage?
A.Physically tiring but rewarding. | B.Romantic and peaceful. |
C.Mentally exhausting but healthy. | D.Tiresome and troublesome |
Which of the following is closest to the main idea of the passage?
A.A friend in need is a friend indeed. | B.A misfortune may turn out a blessing. |
C.Kill two birds with one stone. | D.Where there is a will, there is a way. |
On March 5, 2009, Michael Jackson stood in front of crowds of fans.Before screaming fans, he pronounced with pumping arms: "This is it!"
A few months later, Jackson was dead.With the late pop star’s return to radio, television and the cultural events, Forbes judges that Jackson has made $90 million since his death June 25.This figure is based on his royalties(版税) from album sales, radio play, rights to his name and royalties from his stock in the Sony/ATV music catalog (编目权).
Jackson's music was his most easily-seen source in the last months.“Nothing increases the value of an artist than death ...an untimely death,” says Barry Massarsky, a music industry economist.
The music's immediate value was clear.Since June, Jackson has sold more than 5.9 million albums in the U.S.and another 4.5 million overseas.In the first weeks after his death, there were 5.6 million single downloads across North America, Europe and Australia.Jackson recently has three of the top 20 best-selling albums of the year in the US, according to Nielsen SoundScan.His 2003 hits album Number Ones is the best seller of the year, beating Taylor Swift's Fearless.
More than 500,000 Jackson ringtones and 100,000 music videos were sold.In the week following his death, songs by The Jackson 5, The Jacksons and Michael were played over 100,000 times on the radio, according to Nielsen BDS.
Jackson's estate(遗产)will likely see more money by the end of this year, as it has rights to some of the profits from This Is It as well as the two-disc album of the same name.The estate will share 90% of the film profits with AEG.
Ticket sales from an exhibit opening in London will also contribute a likely profit.Hundreds of Jackson's personal belongings-his L.A.Rolls Royce etc-will remain on show for three months at the O2 Arena for fans willing to shell out $25 for a view.
The pop singer bought ATV Publishing, for $47.5 million in 1985.Ten years later, he sold the catalog to Sony for $95 million and took a 50% stock in Sony/ATV, which is now worth about $1.7 to $2 billion.So he still owned half the Sony/ATV catalog at his death.
Jackson's future earning potential is based on his stock in valuable music as well as the value of his image(肖像).As many musicians, actors and artists before him, Jackson's fame could have a long tail on the market with allowable products, advertising and entertainment events.What do Barry Massarsky’s words in Paragraph 3 imply?
A.Jackson died at the time as expected. |
B.Only at death can an artist become famous. |
C.Jackson became more famous at death than when he was alive. |
D.Jackson’s unexpected death raised his value as an artist immediately. |
All the fol
lowing is true EXCEPT that _____.
A.“This is it” is the last concert that Jackson gave
B.Jackson has sold 10.4 million albums since June
C.Jackson’s L.A.Rolls Royce is now for show and will finally be sold
D.Jackson’s stock in music and his image will keep on earning money in the futureWhat can be inferred from the passage?
A.Jackson’s album Number Ones beat Taylor Swift’s Fearless in 2003. |
B.Taylor Swift’s Fearless is the second best seller of music albums of 2009. |
C.AEG takes in more film profits from “This is it” than Jackson’s estate. |
D.More Jackson’s music videos were sold than his ringtones right after his death. |
What is the main idea of the passage?
A.Why Michael Jackson’s music is so popular all over the world. |
B.How Michael Jackson has earned $90 million in the months since his death. |
C.What Michael Jackson's future earning potential is based on. |
D.How much Michael Jackson earned in the first few months after his death. |