TEXT G

　　First read the question. 54. Who is Dolly? A. A scientist in Chicago. B. A member of the U.S. National Bioethics Advisory Committee. C. A Scottish researcher at Edinburghs Roslin Institute. D. The first animal cloned from the cells of an adult. Now go through TEXT G quickly to answer question 54.

　　From the slave drones of Huxleys Brave New World to the hollow-headed replicates of Helenes Time Enough for Love and the production-line Hitler of The Boys from Brazil, clones get a bad press. Yet, in the real world, we encounter clones al the time. Identical twins are genetic replicas of each other. And so, for that matter, are some oranges. All the worlds navel oranges come from a single cutting. 　 But it is the laboratory-made clones that upset people. Chicagos Dr Richard Seed found that out when he proposed establishing a chain of fertility clinics that would clone man in His image, such man-made creation was merely our latest step towards becoming God. Howls of outrage echoed from Washington to China. It was the latest eruption in a debate that has been simmering ever since Scottish researchers at Edinburghs Roslin Institute announced the cloning of a lamb called Dolly. 　 Scientists have been cloning frogs and mice since 1952, but Dolly was the first animal to be cloned from the cells of an adult, rather than an embryo or fetus. This was a necessary step in the institutes plan to mass-produce transgenic animals. These include cows and sheep that have been implanted with human genes for such medically useful items as ant thrombin III, an anti-cloning protein genes for heart patients, or Factor IX, a clotting protein for hemophiliacs. The proteins are discharged in their milk. The animals also include donor organ pigs whose tissues are compatible with human tissue. 　 To many non-scientists, Dollys cloning raised the specter of human cloning. The Pope promptly called for a worldwide ban on human cloning. The U.S. National Bioethics Advisory Committee also recommended a ban —— for safety reasons, such as the risk to clone children from cancer-causing mutations in government-funded research on human cloning and put a bill before Congress proposing to outlaw such research for five years. A U.S. opinion poll found 90 percent opposition to human cloning. By the end of 1997, the 40-nation Council of Europe had imposed the first legal binding international ban on human cloning. 　 Cloning had also been criticized for its effects on the experimental animals. At birth, lambs and calves cloned from embryos can be twice the usual size, creating considerable stress on the surrogate mother. Transgenic animals can experience unpleasant in their growth rates, physical condition or behavior. The "Beltsville pig", for instance, was created by the U.S. Department of Agriculture at Beltsville, Maryland, to produce human growth hormone. The pig grew all right, but suffered severely from bone and joint problems. There is also the question of premature ageing. Do cloned animals wear out faster? Genes trend to accumulate wear and tear with age. This may mean that 18-month-old Dolly really had the genes and physiology of an eight-year-old. If so, will she age and die faster than her non-cloned pals? The scientists are watching closely. 　 Right now, cloning research is continuing at speed. Researchers know how to grow human tissue cloned from aborted fetuses, keeping it alive in laboratories as a potentially inexhaustible source of replacement tissue to graft onto sick people. One U.S. company, Reprogenesis, claims to have induced the growth of nipples on breast tissue. It aims to make silicon implants obsolete within five years. Some gene therapy researchers are even predicting that, within 10 to 20 years, the biggest taboo for genetic researchers——permanent alternation of human gene line —— will be an accepted medical practice. "Gremlin intervention" is already used on mice to alter genes in the sperm and egg cells. It is dome by implanting cloned tissue in the developing embryo. 　 For all frenzied activity and gung-ho talk, it may be some time before we see the promise of the new techniques. And those hordes of identical people swarming across the continents? They are unlikely to happen. Right now, the techniques are still very costly and very inefficient. Noting that Dolly was the only one of 277 cloned eggs to survive, Jim Mc Whir of the Roslin Institute says that, for now, human cloning "is completely impracticable, especially considering that its much pleasanter making children in the classical way". And, even if it does become less costly and more efficient in future, who could really want to change that?

　　54. Who is Dolly?

　　A) A scientist in Chicago.

　　B) A member of the U.S. National Bioethics Advisory Committee.

　　C) A Scottish researcher at Edinburgh's Roslin Institute.

　　D) The first animal cloned from the cells of an adult.