Movies about ghosts and monsters and crazy killers are _____.
Movies about ghosts and monsters and crazy killers are _____.
AIDS has become one of the first killers to human beings. Despite their lack of success so far, scientists have ________ in their research for a cure for AIDS.
AIDS has become one of the first killers to human beings. Despite their lack of success so far, scientists have ________ in their research for a cure for AIDS.
According to the passage why is online love dangerous? A: Because there are many killers on the net. B: Because there are many hikers on the net. C: Because there are many cheaters on the net. D: Because there are many stealers on the net.
According to the passage why is online love dangerous? A: Because there are many killers on the net. B: Because there are many hikers on the net. C: Because there are many cheaters on the net. D: Because there are many stealers on the net.
What do we know about Alcatraz prison? A: It has been in use since 1934. B: It was considered a strong prison. C: It only kept killers and bank robbers. D: It was considered the worst prison in America.
What do we know about Alcatraz prison? A: It has been in use since 1934. B: It was considered a strong prison. C: It only kept killers and bank robbers. D: It was considered the worst prison in America.
People in the third world countries are now facing a serious problem that ______. A: infectious diseases are becoming big killers B: more people are becoming the victim of cancer C: smallpox and typhoid are spreading widely D: some middle- and old-aged people are getting sick easily
People in the third world countries are now facing a serious problem that ______. A: infectious diseases are becoming big killers B: more people are becoming the victim of cancer C: smallpox and typhoid are spreading widely D: some middle- and old-aged people are getting sick easily
Directions: There are ten sentences removed from the text marked A, B, C.... Find their proper places in the text and mark the choices A, B, C... on the answer sheet.Efforts to combat aging and extend human life date at least as far back as 3500 B.C., and self-proclaimed experts have touted anti-aging elixirs ever since.__1___, spurring Alexander the Great and Ponce de León to search for the legendary Fountain of Youth and feeding alchemists’ desire to manufacture gold (once believed to be the most potent anti-aging substance in existence). But the hawking of anti-aging “therapies” has taken a particularly troubling turn of late. Disturbingly large numbers of entrepreneurs are luring gullible and frequently desperate customers of all ages to “longevity” clinics, claiming a scientific basis for the anti-aging products they recommend and, often, sell. At the same time, the Internet has enabled those who seek lucre from supposed anti-aging products to new customers with ease. Alarmed by these trends, scientists who study aging have issued a position statement containing this warning: no currently marketed intervention－ none－has yet been proved to slow, stop or reverse human aging, and some can be downright dangerous. __2___. Various definitions have been proposed, but we think of aging as the accumulation of random damage to the building blocks of life－especially to DNA, certain proteins, carbohydrates and lipids (fats)－that begins life early in life and eventually exceeds the body’s self-repair capabilities. This damage gradually impairs the functioning of cells, tissues, organs and organ systems, thereby increasing vulnerability to disease and giving rise to the characteristic manifestations of aging, such as a loss of muscle and bone mass, a decline in reaction time, compromised hearing and vision, and reduced elasticity of skin. Aging, in our view, makes us ever more susceptible to such ills as heart disease, Alzheimer’s disease, stroke and cancer, but these age-related conditions are superimposed on aging, not equivalent to it. Therefore, even if science could eliminate today’s leading killers of older individuals, aging would continue to occur, ensuring that different maladies would take their place. In addition, it would guarantee that one crucial body component or another－say, the cardiovascular system－would eventually experience a catastrophic failure. __3___.Men and women in the developed world typically live longer now (75 and 80 years, respectively) than they did throughout much of history (about 25 years) because human ingenuity－which brought us sanitation systems, vaccines, antibiotics and so on－has had phenomenal success in thwarting the infectious and parasitic diseases responsible for a great deal of premature death. __4___. Though inevitable, aging is not, as some might think, a genetically programmed process, playing itself out on a rigidly predetermined time schedule. The way evolution works makes it impossible for us to possess genes that are specifically designed to cause physiological decline with age or to control how long we live. Just as an automobile does not have a built-in plan for decline written in its blueprints, we do not possess genetic instructions that tell our bodies how to age or when to die. Without a doubt, a host of our genes influence aging, but they do so indirectly, as an inadvertent by-product of processes involved in growth, development, and the maintenance of health and vigor. __5___. A single genetic intervention in an organism as complex as a human being would have little chance of combating the probably vast array of genes and biological activities that play subtle, unpredictable part in the timing of our ultimate demise. On what grounds do we assert so vehemently that no purported anti-aging intervention has been proved to modify aging? To assess whether an intervention has affected a biological process, researchers need a yardstick for measuring that process. In this case, no single or aggregate age-related phenomenon has proved to be a reliable indicator of the rate of aging in humans or other species. __6___. Some people might wonder whether following today's public health recommendations for diet and exercise can serve as a more natural Fountain of Youth. Good nutrition and regular exercise do reduce the risk of various diseases and, in that way, may extend the duration of life for many people－thereby serving as the best current prescription for a long and healthy life. __7___. Another avenue of research may also lead to true aging interventions. Investigators have known for decades that caloric restriction extends life and the duration of good health in all species in which it has been studied, as long as the diet includes enough nutrition for routine maintenance of the body. __8___. Given that few people would ever reduce their food intake enough to lengthen their lives, biologists are now trying to discover the mechanism that underlies the benefits of caloric restriction and to find agents that might mimic those helpful effects in people without forcing them to go hungry. A number of scientists look at current research trends and feel hopeful. They can envision a time when treatments based on an understanding of aging can help slow its progression and when not yet specialized (stem) cells can be coaxed to repair and rejuvenate damaged tissues, enabling people to remain vigorous longer than they would without medical assistance. __9___. Some assert that aging’s complexity will forever militate against the development of anti-aging therapies. One thing is indisputable: the number of elderly people is growing worldwide, and opportunists stand steady to cash in on the burgeoning market for anti-aging products. The public needs to know that the products sold as anti-aging remedies at longevity clinics and elsewhere have no scientifically proven efficacy and may at times be harmful. Systematic investigations into aging and its modification are in progress and could one day provide methods to slow our inevitable decline and extend health and longevity.__10___. People might well recognize the paucity of proof but decide to try a putative anti-aging intervention anyway, thinking they have little to lose. They should think again. 1. A: Not all researchers share that optimism, though. B: Any discussion of aging should first clarify its terms. C: It is an inescapable biological reality that once the engine of life switches on, the body inevitably sows the seeds of its own destruction. D: Indeed, the prospect of immortality has always had universal appeal. E: These findings suggest that caloric restriction might have similar effects in humans. F: We live longer now not because we have altered the way we age but because we have altered the way we live. G: The lack of a specific genetic program for aging and death means that there are no quick fixes that will permit us to treat aging as if it were a disease. H: Without a yardstick, there can be no assurance that an intervention was successful. I: As is true of other interventions, though, no one has shown that diet or exercise, or both, directly influences aging. J: That day, however, has not yet dawned yet.
Directions: There are ten sentences removed from the text marked A, B, C.... Find their proper places in the text and mark the choices A, B, C... on the answer sheet.Efforts to combat aging and extend human life date at least as far back as 3500 B.C., and self-proclaimed experts have touted anti-aging elixirs ever since.__1___, spurring Alexander the Great and Ponce de León to search for the legendary Fountain of Youth and feeding alchemists’ desire to manufacture gold (once believed to be the most potent anti-aging substance in existence). But the hawking of anti-aging “therapies” has taken a particularly troubling turn of late. Disturbingly large numbers of entrepreneurs are luring gullible and frequently desperate customers of all ages to “longevity” clinics, claiming a scientific basis for the anti-aging products they recommend and, often, sell. At the same time, the Internet has enabled those who seek lucre from supposed anti-aging products to new customers with ease. Alarmed by these trends, scientists who study aging have issued a position statement containing this warning: no currently marketed intervention－ none－has yet been proved to slow, stop or reverse human aging, and some can be downright dangerous. __2___. Various definitions have been proposed, but we think of aging as the accumulation of random damage to the building blocks of life－especially to DNA, certain proteins, carbohydrates and lipids (fats)－that begins life early in life and eventually exceeds the body’s self-repair capabilities. This damage gradually impairs the functioning of cells, tissues, organs and organ systems, thereby increasing vulnerability to disease and giving rise to the characteristic manifestations of aging, such as a loss of muscle and bone mass, a decline in reaction time, compromised hearing and vision, and reduced elasticity of skin. Aging, in our view, makes us ever more susceptible to such ills as heart disease, Alzheimer’s disease, stroke and cancer, but these age-related conditions are superimposed on aging, not equivalent to it. Therefore, even if science could eliminate today’s leading killers of older individuals, aging would continue to occur, ensuring that different maladies would take their place. In addition, it would guarantee that one crucial body component or another－say, the cardiovascular system－would eventually experience a catastrophic failure. __3___.Men and women in the developed world typically live longer now (75 and 80 years, respectively) than they did throughout much of history (about 25 years) because human ingenuity－which brought us sanitation systems, vaccines, antibiotics and so on－has had phenomenal success in thwarting the infectious and parasitic diseases responsible for a great deal of premature death. __4___. Though inevitable, aging is not, as some might think, a genetically programmed process, playing itself out on a rigidly predetermined time schedule. The way evolution works makes it impossible for us to possess genes that are specifically designed to cause physiological decline with age or to control how long we live. Just as an automobile does not have a built-in plan for decline written in its blueprints, we do not possess genetic instructions that tell our bodies how to age or when to die. Without a doubt, a host of our genes influence aging, but they do so indirectly, as an inadvertent by-product of processes involved in growth, development, and the maintenance of health and vigor. __5___. A single genetic intervention in an organism as complex as a human being would have little chance of combating the probably vast array of genes and biological activities that play subtle, unpredictable part in the timing of our ultimate demise. On what grounds do we assert so vehemently that no purported anti-aging intervention has been proved to modify aging? To assess whether an intervention has affected a biological process, researchers need a yardstick for measuring that process. In this case, no single or aggregate age-related phenomenon has proved to be a reliable indicator of the rate of aging in humans or other species. __6___. Some people might wonder whether following today's public health recommendations for diet and exercise can serve as a more natural Fountain of Youth. Good nutrition and regular exercise do reduce the risk of various diseases and, in that way, may extend the duration of life for many people－thereby serving as the best current prescription for a long and healthy life. __7___. Another avenue of research may also lead to true aging interventions. Investigators have known for decades that caloric restriction extends life and the duration of good health in all species in which it has been studied, as long as the diet includes enough nutrition for routine maintenance of the body. __8___. Given that few people would ever reduce their food intake enough to lengthen their lives, biologists are now trying to discover the mechanism that underlies the benefits of caloric restriction and to find agents that might mimic those helpful effects in people without forcing them to go hungry. A number of scientists look at current research trends and feel hopeful. They can envision a time when treatments based on an understanding of aging can help slow its progression and when not yet specialized (stem) cells can be coaxed to repair and rejuvenate damaged tissues, enabling people to remain vigorous longer than they would without medical assistance. __9___. Some assert that aging’s complexity will forever militate against the development of anti-aging therapies. One thing is indisputable: the number of elderly people is growing worldwide, and opportunists stand steady to cash in on the burgeoning market for anti-aging products. The public needs to know that the products sold as anti-aging remedies at longevity clinics and elsewhere have no scientifically proven efficacy and may at times be harmful. Systematic investigations into aging and its modification are in progress and could one day provide methods to slow our inevitable decline and extend health and longevity.__10___. People might well recognize the paucity of proof but decide to try a putative anti-aging intervention anyway, thinking they have little to lose. They should think again. 1. A: Not all researchers share that optimism, though. B: Any discussion of aging should first clarify its terms. C: It is an inescapable biological reality that once the engine of life switches on, the body inevitably sows the seeds of its own destruction. D: Indeed, the prospect of immortality has always had universal appeal. E: These findings suggest that caloric restriction might have similar effects in humans. F: We live longer now not because we have altered the way we age but because we have altered the way we live. G: The lack of a specific genetic program for aging and death means that there are no quick fixes that will permit us to treat aging as if it were a disease. H: Without a yardstick, there can be no assurance that an intervention was successful. I: As is true of other interventions, though, no one has shown that diet or exercise, or both, directly influences aging. J: That day, however, has not yet dawned yet.