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The researchers, led by Hwang Woo-suk, insist they cloned an Afghan hound, only to help investigate (研究) human disease, including the possibility of cloning stem cells (干细胞) for treatment purposes.
But others immediately renewed calls for a global ban on human reproductive cloning before the technology moves any farther.
“Successful cloning of an increasing number of species confirms the general impression that it would be possible to clone any species of mammals, including
humans,” said Ian Wilmut, a reproductive biologist at the University of Edinburgh who produced the first cloned mammal, Dolly the sheep, from an adult cell nearly a decade ago.
Researchers have since cloned cats, goats, cows, mice, pigs, rabbits, horses, deer, mules and gaur, a large wild ox of Southeast Asia. So far, efforts to clone a monkey or another primate with the same techniques have failed.
Uncertainties about the health and life span (寿命) of cloned animals continue to exsist; Dolly died at a young age in 2003 after developing cancer and arthritis.
Wilmut and others complimented Hwang’s achievement, reported Wednesday in the journal Nature. But they said politicians and scientists must face the larger issue — how to go on with the research without crossing the moral boundary of copying human life in the lab.
“The ability to use the technology is hopeful,” said Robert Schenken, president of the American Society for Reproductive Medicine. “However, the paper also points out that in dogs as in most species, cloning for reproductive purposes is unsafe.”
The cloned puppy was the lone success from more than 100 dogs implanted (嵌入)with more than 1,000 cloned embryos.
In a news conference in Seoul, the cloning team also condemned the reproductive cloning of humans as “unsafe and inefficient.” Human reproductive cloning already is banned in South Korea. Other nations, including the United States, are divided on whether to ban just human cloning or cloning of all kinds, including the production of stem cells.
43． An Afghan hound is a kind of ______.
A. cat B. dog C. cow D. goat
44． A ______ is a large wild ox of Southeast Asia.
A. horse B. deer C. mules D. gaur
45．Accrding to the passage, scientists haven’t been able to clone a ______ so far.
A. deer B. mule C. monkey D. mouse
46．The underlined word complimented is probably similar in meaning to ______.
A. praised B. doubted C. refused D. gave up
47．The cloning of human beings is banned in ______.
A. South Korea
B. the United States
C. both South Korea and the United States
D. neither South Korea nor the United States
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Everyone has heard of the San Andreas fault （断层）, which constantly threatens California and the West Coast with earthquakes. But how many people know about the equally serious New Madrid fault in Missouri?
Between December of 1811 and February of 1812, three major earthquakes occurred, all centered around the town of New Madrid, Missouri, on the Mississippi River. Property damage was severe. Buildings in the area were almost destroyed. Whole forests fell at once, and huge cracks opened in the ground, releasing some strong smell chemicals.
The Mississippi River itself completely changed character, developing sudden rapids and whirlpools (激流和漩涡). Several times it changed its course, and once, according to some observers, it actually appeared to run backwards. Few people were killed in the New Marid earthquakes, probably simply because few people lived in the area in 1811; but the severity of the earthquakes are shown by the fact that the shock waves rang bells in church towers in Charleston, South Carolina, on the coast. Buildings shook in New York City, and clocks were stopped in Washington, D.C.
Scientists now know that America's two major faults are essentially different. The San Andreas is a horizontal boundary between two major land masses that are slowly moving in opposite directions. California earthquakes result when the two masses make a sudden move.
The New Madrid fault, on the other hand, is a vertical fault; at some points, possibly hundreds of millions of years ago, rock was pushed up toward the surface, probably by volcanoes under the surface. Suddenly, the volcanoes cooled and the rock collapsed, leaving huge cracks. Even now, the rock continues to settle downwards, and sudden sinking motions cause earthquakes in the region. The fault itself, a large crack in this layer of rock, with dozens of other cracks that split off from it, extends from northeast Arkansas through Missouri and into southern Illinois.
Scientists who have studied the New Madrid fault say there have been numerous smaller quakes in the area since 1811; these smaller quakes indicate that larger ones are probably coming, but the scientists say they have no method of predicting when a large earthquake will occur.
64. This passage is mainly about ___________.
A. current scientific knowledge about faults
B. the San Andreas and the New Madrid faults
C. the causes of faults
D. the New Madrid fault in Missouri
65. The New Madrid fault is __________.
A. a vertical fault
B. a horizontal fault
C. a more serious fault than the San Andreas fault
D. responsible for forming the Mississippi River
66. This passage implies that _________. .
A. horizontal faults are more dangerous than vertical faults
B. Vertical faults are more dangerous than horizontal faults
C. The volcanoes that caused the New Madrid fault are still alive
D. A lot of people would die if the 1811 New Madrid earthquakes happened today
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Stephen Hawking, the disabled author of A Brief History of Time is launching his second journey to China in Hangzhou of Zhejiang Province. His first visit was over 10 years ago.
The great theoretical scientist has been invited to attend a state-of-the-art mathematics research institute at Zhejing University, Hangzhou-based Dushi Kuaibao reported.
On Sunday evening, he made his début at a press conference held at Shangri-La hotel, Hangzhou. Hawking appeared at about 5:00 p.m. with his wife.
The 50-year-old man answered a total of nine questions with the help of his computer.
“Experts in theoretical science are dispersed around the world, but we need communication. I am very glad that the world’s first-class conference is being held in China this time,”he said.
“I find the real universe much more interesting than the one in the film Star Wars ,” Hawking joked.“I encourage young people to study theoretical physics first if they are interested in it.”
Stephen Hawking has worked on the basic laws which govern the universe. With Roger Penrose he showed that Einstein’s General Theory of Relativity implied (隐含) space and time would have a beginning in the Big Bang and an end in black holes. These results indicated it was necessary to unify General Relativity with Quantum Theory, the other great scientific development of the first half of the 20th century.
One consequence(结果) of such a unification theory would be that black holes would not be completely black, but emit (放射) radiation and eventually evaporate (蒸发) and disappear. Another conjecture (推 测) is that the universe has no edge or boundary in imaginary time. This would imply that the way the universe began was completely determined by the laws of science.
But the talented man who has produced such rich work suffers serious Amyotrophic Lateral Sclerosis (ALS) (肌萎缩性脊髓索硬化). He is one of the 350,000 sufferers in the world. The disease kills over 100,000 people every year.
“I like life and I love life, my family and music give me the greatest happiness,”smiled Hawking, who can only move three fingers.
In the coming year, Hawking said he is scheduled to write a new edition of A Brief History of Time for young children.
“A Brief History of Time is my first book for common people. But I later found that I could write it in a more simple way,”he answered,“So I decided to rewrite it so that all people can read it easily.”
1．It is obvious that Hawking ________.
[ ]
A．comes to China for the first time
B．has never been to China before
C．has been to China twice
D．hopes to come to visit China one day
2．What do the underlined words“are dispersed”in the fifth paragraph mean?
[ ]
A．Live together.
B．Live far away from.
C．Know each other better.
D．Have connection with each other.
3．From the passage we know the nature of Hawking’s being ________.
[ ]
A．determined and humorous
B．learned and humorous
C．learned and shy
D．disabled
4．It can be inferred that Hawking ________.
[ ]
A．greatly improved Einstein’s General Theory of Relativity
B．knows a lot about Einstein’s theory
C．has A Brief History of Time published recently
D．loves nothing but his study on universe
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