题目内容
Who would have believed it After what seems like an eternity of tantalizing hype about "high-definition" television, the first digital sets are actually on their way to the market. This much anticipated debut would seem to be terrific news for tube lovers. As promised, the sets deliver super-sharp digital pictures, wide-format movie-style screens and magnificent stereo surround sound. So should everybody rush out to buy one Well...maybe not. HDTV"s obvious advantages over conventional sets are offset by significant disadvantages. For openers, there"s the price tag. Sony"s small set, with a 34-in screen, lists for a fairly large $8,999. Prices will eventually drop, of course, but Bill Mannion, general manager of Panasonic"s TV division, acknowledges, "It"s going to be a while, maybe years before most consumers can afford HDTV." Even if you"re a gadget freak with deep pockets, you may think twice about buying for another reason: "high definition" will not be equally high. Some programs will be broadcast at 480 lines of resolution (compared with 330 or so on conventional televisions), others at a sharper 720 lines, and still others at the maximum of 1,080. NBC says it plans to start by offering 480-line quality for day-time programming and 1,080 for some prime-time shows and specials. But cable-TV customers—a full two-thirds of American households—may get a sinking feeling of another sort if they try to tune in. Cable companies are refusing, for now, to carry broadcasters" HDTV signals, saying information-rich HDTV channels overtax their systems. Therefore viewers, who want decent reception, will have to buy clumsy, old-fashioned TV antennas if they plan to pull in digital broadcasts. One decision consumers won"t have to make is whether to buy a set that uses one format or another. Back in the days when VCRs were new, you could buy a VHS or a Beta-format machine; neither could read or record on the other"s tapes. Those who chose Beta generally regretted it, as VHS took over the market, video companies stopped releasing Beta-format movies, and Beta sets became essentially useless. Most reassuring of all, the new sets will be able to pick up conventional TV broadcasts. You won"t need two TV sets sitting side by side. Will that be enough to talk consumers into putting down the better part of $10,0007 Manufactures hope that wide-eyed excitement over this genuinely revolutionary new technology will help hide the fact that it"s still a work in progress. Realistically, they expect the revolution to be a slow one. Who does the author intend to write the passage for
查看答案
搜索结果不匹配？点我反馈
更多问题
In a large, air-conditioned room in a conference center located in a city of more than a million people, well-qualified doctors of science discuss the pros and cons of global warming, and debate how the temperature of the sea is being measured. After several hours of discussion, they walk out into the warm sunshine of a summer"s day, heading off to a comfortable restaurant for lunch. On the same day, on the sands of small islands in the middle of the Pacific Ocean, baked hard by the burning sun, Hemi and Naqono look at the water lapping over the place where they once stored their potato plants. They watch the waves dashing gently at the feet of their straw huts which some years ago were many metres from the seashore. Global warming is a problem for theoretical discussion among scientists all over the world. For many Pacific Islanders it is now becoming a practical problem. While international science argues about global warming and climate change, low-lying Pacific Islands are already suffering coastal erosion and crop failures. In places such as Marshall Islands, where much of the land is only a metre above sea-level, villagers face leaving their slowly disappearing homes. Scientists and officials from 13 Pacific Island Countries discussed their concerns in a Pacific conference in Aukland, New Zealand, and examined a New Zealand computer model on climate change that could provide a valuable planning tool. Lack of meteorological and tidal research means Government agencies throughout the Pacific and the world have to rely largely on anecdotal of rising sea levels eroding foreshores, and increasingly severe droughts affecting the vital coconut crop. Australian research commissioned by the South Pacific Regional Environment Programme has already calculated that human greenhouse gas emissions already measured up to 1995 will cause a 5cm to 12cm sea-level rise by 2025. Pacific Island countries fear their vulnerable low-lying homes will be the first to pay the price for the emissions of industrialized nations. A Pacific Islands Climate Change Assistance Programme is already in place and is working on plans to help Pacific Islanders who have few resources to combat the fast-changing environmental circumstances. Yumi Crisostomo, of the Marshall Islands Environmental Protection Authority, said residents of some of the 1,225 islands in the group had reported alarming coastal erosion, forcing them to shift homes inland. Some islands were only about a kilometer across, so residents had little room to move. "We may have to look at the option of internal migration within the island group," he said. Human greenhouse gas emissions which cause low-lying places to disappear are mainly let out by
With the rapid spread of the internet eye where in the world, and the (1)_____ number of users, one of the most exciting developments on the internet is E-commerce—(2)_____ commerce. E-commerce has two forms, (3)_____ business-to-business, or B-to-B, and business-to-consumer, or B-to-C. B-to-C was the first of these developments. It grew (4)_____ from the first days when people started to buy things from their homes without going to a shop. First came "catalogue shopping" (5)_____ you choose what you want from a catalogue (6)_____ pictures and other details of everything that is (7)_____ sale. You then send an order with a check by (8)_____ and the things you have chosen sent to your home. Then (9)_____ "television shopping", where (10)_____ a catalogue, the items for sale are shown or (11)_____ on television to attract the customer. (12)_____, the customer sends a check and the item is delivered to his or her home. B-to-C is the (13)_____ development, where the "catalogue" is (14)_____ on the internet, combining the advantages of both the book catalogue and the television and indeed adding more (15)_____ The customer makes his choice but rather than sending an order and a (16)_____ through the post, he places the order and pays for it using his credit card, all using the (17)_____ Many people worry about giving (18)_____ of their credit card over the internet and the danger that it may be deceitfully used. (19)_____, the general view is that with modern systems of secure measures the dangers of the misuse of credit cards is (20)_____ greater in a shop, garage or restaurant than in using it for shopping on the internet.
In developing a model of cognition, we must recognize that perception of the external world does not always remain independent of motivation. While progress toward maturity is positively correlated with differentiation between motivation and cognition, tension will, even in the mature adult, lead towards a narrowing of the range of perception. Cognition can be seen as the first step in the sequence events leading from the external stimulus to the behavior of the individual. The child develops from belief that all things are an extension of its own body to the recognition that objects exist independent of his perception. He begins to demonstrate awareness of people and things which are removed from his sensory apparatus and initiates goal-directed behaviors. He may, however, refuse to recognize the existence of barriers to the attainment of his goal, despite the fact that his cognition of these objects has been previously demonstrated. In the primitive beings, goal-directed behavior can be very simple motivated. The presence of an attractive object will cause an infant to reach for it; its removal will result in the cease of that action. In adult life, mere cognition can be similarly motivational, although the visible presence of the opportunity is not required as the stimulants of response. The mature adult modifies his reaction by obtaining information, interpreting it, and examining consequences. He formulates a hypothesis and attempts to test it. He searches out implicit relationships, examines all factors, and differentiates among them. Just as the trained artist can separate the value of color, composition, and technique, while taking in and evaluating the whole work, so, too, the mature person brings his cognitive learning strengths to bear in evaluating a situation. Understanding that cognition is separate from action, his reaction is only minimally guided from conditioning, and take into consideration anticipatable events. The impact of the socialization process, particularly that of parental and social group ideology, may reduce cognitively directed behavior. The tension thus produced, as for instance the stress of fear, anger, or extreme emotion, will often be the primary influence. The evolutionary process of development from body schema through cognitive learning is similarly manifested in the process of language acquisition. Every normal infant has the physiological equipment necessary to produce sound, but the child must first master their use for sucking, biting, and chewing before he can control his equipment for use in producing the sounds of language. From the earlier times, it is clear that language and human thought have been intimately connected. Sending or receiving messages, from primitive warnings of danger to explaining creative or reflective thinking, this aspect of cognitive development is also firmly linked to the needs and aspirations of society. The influence of socialization process may
In a large, air-conditioned room in a conference center located in a city of more than a million people, well-qualified doctors of science discuss the pros and cons of global warming, and debate how the temperature of the sea is being measured. After several hours of discussion, they walk out into the warm sunshine of a summer"s day, heading off to a comfortable restaurant for lunch. On the same day, on the sands of small islands in the middle of the Pacific Ocean, baked hard by the burning sun, Hemi and Naqono look at the water lapping over the place where they once stored their potato plants. They watch the waves dashing gently at the feet of their straw huts which some years ago were many metres from the seashore. Global warming is a problem for theoretical discussion among scientists all over the world. For many Pacific Islanders it is now becoming a practical problem. While international science argues about global warming and climate change, low-lying Pacific Islands are already suffering coastal erosion and crop failures. In places such as Marshall Islands, where much of the land is only a metre above sea-level, villagers face leaving their slowly disappearing homes. Scientists and officials from 13 Pacific Island Countries discussed their concerns in a Pacific conference in Aukland, New Zealand, and examined a New Zealand computer model on climate change that could provide a valuable planning tool. Lack of meteorological and tidal research means Government agencies throughout the Pacific and the world have to rely largely on anecdotal of rising sea levels eroding foreshores, and increasingly severe droughts affecting the vital coconut crop. Australian research commissioned by the South Pacific Regional Environment Programme has already calculated that human greenhouse gas emissions already measured up to 1995 will cause a 5cm to 12cm sea-level rise by 2025. Pacific Island countries fear their vulnerable low-lying homes will be the first to pay the price for the emissions of industrialized nations. A Pacific Islands Climate Change Assistance Programme is already in place and is working on plans to help Pacific Islanders who have few resources to combat the fast-changing environmental circumstances. Yumi Crisostomo, of the Marshall Islands Environmental Protection Authority, said residents of some of the 1,225 islands in the group had reported alarming coastal erosion, forcing them to shift homes inland. Some islands were only about a kilometer across, so residents had little room to move. "We may have to look at the option of internal migration within the island group," he said. The author gives the example of Pacific islands climate change to
微信支付 
支付宝支付