科普知识类1.doc

科普知识类9601Question 30-40 天气预报 Many of the most damaging and life-threatening types of weather - torrential rains, severe thunderstorms, and tornadoes - begin quickly, strike suddenly, and dissipate rapidly, devastating small regions while leaving neighboring areas untouched. One such event, a tornado, stuck the northeastern section of Edmonton, Alberta, in July 1987. Total damages from the tornado exceeded $250 million, the highest ever for any Canadian storm. Conventional computer models of the atmosphere have limited value in predicting short - lived local storms like the Edmonton tornado, because the available weather data are generally not detailed enough to allow computers to discern the subtle atmospheric changes that precede these storms. In most nations, for example, weather -balloon observations are taken just once every twelve hours at locations typically separated by hundreds of miles. With such limited data, conventional forecasting models do a much better job predicting general weather conditions over large regions than they do forecasting specific local events. Until recently, the observation - intensive approach needed for accurate, very short - range forecasts, or Nowcasts, was not feasible. The cost of equipping and operating many thousands of conventional weather stations was prohibitively high, and the difficulties involved in rapidly collecting and processing the raw weather data from such a network were insurmountable. Fortunately, scientific and technological advances have overcome most of these problems. Radar systems, automated weather instruments, and satellites are all capable of making detailed, nearly continuous observation over large regions at a relatively low cost. Communications satellites can transmit data around the world cheaply and instantaneously, and modern computers can quickly compile and analyzing this large volume of weather information. Meteorologists and computer scientists now work together to design computer programs and video equipment capable of transforming raw weather data into words, symbols, and vivid graphic displays that forecasters can interpret easily and quickly. As meteorologists have begun using these new technologies in weather forecasting offices, Nowcasting is becoming a reality.30. What does he passage mainly discuss?(A) Computers and weather(B) Dangerous storms (C) Weather forecasting (D) Satellites31.Why does the author mention the tornado in Edmonton, Canada?(A)To indicate that tornadoes are common in the summer(B)To give an example of a damaging storm(C)To explain different types of weather(D)To show that tornadoes occur frequently in Canada32.The word subtle in line 8 is closest in meaning to (A)complex(B)regular(C)imagined(D)slight33.Why does the author state in line 10 that observations are taken just once every twelve hours?(A)To indicate that the observations are timely(B)To show why the observations are on limited value(C)To compare data from balloons and computers(D)To give an example of international cooperation34.The word they in line 13 refers to (A)models(B)conditions(C)regions(D)events35.Which of the following is NOT mentioned as an advance in short - range weather forecasting?(A)Weather balloons(B)Radar systems(C)Automated instruments(D)Satellites36.The word compile in line 23 is closest in meaning to (A)put together(B)look up(C)pile high(D)work over37.With Nowcasting, it first became possible to provide information about(A)short-lived local storms(B)radar networks(C)long - range weather forecasts(D)general weather conditions38.The word raw in line 25 is closest in meaning to (A)stormy(B)inaccurate(C)uncooked(D)unprocessed39.With which of the following statements is the author most likely to agree?(A)Communications satellites can predict severe weather.(B)Meteorologists should standardize computer programs.(C)The observation - intensive approach is no longer useful.(D)Weather predictions are becoming more accurate.40.Which of the following would best illustrate Nowcasting?(A)A five-day forecast(B)A warning about a severe thunderstorm on the radio(C)The average rainfall for each month(D)A list of temperatures in major cities9708Question 10-19 科普知识(倒刺金属在栅栏中的应用) Barbed wire, first patented in the United States in 1867, played an important part in the development of American farming, as it enabled the settlers to make effective fencing to enclose their land and keep cattle away from their crops. This had a considerable effect on cattle ranching, since the herds no longer had unrestricted use of the plans for grazing, and the fencing led to conflict between the farmers and the cattle ranchers. Before barbed wire came into general use, fencing was often made from serrated wire, which was unsatisfactory because it broke easily when under strain, and could snap in cold weather due to contraction. The first practical machine for producing barbed wire was invented in 1874 by an Illinois farmer, and between then and the end of the century about 400 types of barbed wire were devised, of which only about a dozen were ever put to practical use. Modern barbed wire is made from mild steel high-tensile steel, or aluminum. Mild steel and aluminum barbed wire have two strands twisted together to form a cable which is stronger than single-strand wire and less affected by temperature changes. Single-strand wire, round or oval, is made from high-tensile steel with the barbs crimped or welded on . The steel wires used are galvanized - coated with zinc to make them rustproof. The two wires that make up the line wire or cable are fed separately into a machine at one end. They leave it at the other end twisted-together and barbed. The wire to make the barbs is fed into the machine from the sides and cut to length by knives that cut diagonally through the wire to produce a sharp point. This process continues automatically, and the finished barbed wire is wound onto reels, usually made of wire in length of 400 meters or in weights of up to 50 kilograms. A variation of barbed wire is also used for military purposes. It is formed into long cojis or entanglements called concertina wire.10.What is the main topic of the passage?(A)Cattle ranching in the United States.(B)A type of fencing(C)Industrial uses of wire(D)A controversy over land use.11.The word unrestricted in line 4 is closest in meaning to(A)unsatisfactory(B)difficult(C)considerable(D)unlimited12.The word snap in line 9 could best be replaced by which of the following?(A)freeze(B)click(C)loosen(D)break13.What is the benefit of using two-stranded barbed wire?(A)Improved rust-resistance(B)Increased strength(C)More rapid attachment of barbs(D)Easier installation.14.According to the author, the steel wires used to make barbed wire are specially processed to(A)protect them against rust(B)make them more flexible(C)prevent contraction in cold weather(D)straighten them.15.The word fed in line 20 is closest in meaning to(A)put(B)eaten(C)bitten(D)nourished16.The knives referred to in line 21 are used to(A)separate double-stranded wire(B)prevent the reel from advancing too rapidly(C)twist the wire(D)cut the wire that becomes barbs17.What is the authors purpose in the third paragraph?(A)To explain the importance of the wire.(B)To outline the difficulty of making the wire(C)To describe how the wire is made(D)To suggest several different uses of the wire.18.According to the passage, concertina wire is used for (A)livestock management(B)international communications(C)prison enclosures(D)military purposes.19.Which of the following most closely resembles the fencing described in the passage?(A) （图）(B) （图）(C) （图）(D) （图）9708Question 20-28 科普知识(人体所承受的压力在潜水中) Under certain circumstance the human body must cope with gases at greater-than-normal atmospheric pressure. For example, gas pressures increase rapidly during a dive made with scuba gear because the breathing equipment allows divers to stay underwater longer and dive deeper. The pressure exerted on the human body increases by 1 atmosphere for every 10 meters of depth in seawater, so that at 30 meters in seawater a diver is exposed to a pressure of about 4 atmospheres. The pressure of the gases being breathed must equal the external pressure applied to the body; otherwise breathing is very difficult. Therefore all of the gases in the air breathed by a scuba diver at 40 meters are present at five times their usual pressure. Nitrogen which composes 80 percent of the air we breathe usually causes a balmy feeling of well-being at this pressure. At a depth of 5 atmospheres nitrogen causes symptoms resembling alcohol intoxication known as nitrogen narcosis. Nitrogen narcosis apparently results from a direct effect on the brain of the large amounts of nitrogen dissolved in the blood. Deep dives are less dangerous if helium is substituted for nitrogen, because under these pressures helium does not exert a similar narcotic effect. As a scuba diver descends, the pressure of nitrogen in the lungs increases. Nitrogen then diffuses from the lungs to the blood and from the blood to body tissues. The reverse occurs when the diver surfaces; the nitrogen pressure in the lungs falls and the nitrogen diffuses from the tissues into the blood and from the blood into the lungs. If the return to the surface is too rapid, nitrogen in the tissues and blood cannot diffuse out rapidly enough and nitrogen bubbles are formed . They can cause severe pains, particularly around the joints. Another complication may result if the breath is held during ascent. During ascent from a depth of 10 meters, the volume of air in the lungs will double because the air pressure at the surface is only half of what it was at 10 meters. This change in volume may cause the lungs to distend and even rupture. This condition is called air embolism. To avoid this event, a diver must ascent slowly, never at a rate exceeding the rise of the exhaled air bubbles, and must exhale during ascent.20.What does the passage mainly discuss?(A)The equipment divers use(B)The effects of pressure on gases in the human body(C)How to prepare for a deep dive(D)The symptoms of nitrogen bubbles in the bloodstream.21.The word exposed to in line 6 are closest in meaning to(A)leaving behind(B)prepared for(C)propelled by(D)subjected to22.The word exert in line 15 is closest in meaning to(A)cause(B)permit(C)need(D)change23.The word diffuses in line 19 is closest in meaning to(A)yields(B)starts(C)surfaces(D)travels24.What happens to nitrogen in body tissues if a diver ascends too quickly.(A)It forms bubbles(B)It goes directly to the brain(C)It is reabsorbed by the lungs.(D)It has a narcotic effect.25.The word They in line 21 refers to(A)joints(B)pains(C)bubbles(D)tissues.26.The word rupture in line 26 is closest in meaning to(A)hurt(B)shrink(C)burst(D)stop27.It can be inferred from the passage that which of the following presents the greatest danger to a diver?(A)Pressurized helium(B)Nitrogen diffusion(C)Nitrogen bubbles(D)An air embolism 28.What should a diver do when ascending?(A)Rise slowly(B)Breathe faster(C)Relax completely(D)Breathe helium.9801Question 10-19 科普知识 Glass is a remarkable substance made from the simplest raw materials. It can be colored or colorless, monochrome or polychrome, transparent, translucent, or opaque. It is lightweight impermeable to liquids, readily cleaned and reused , durable yet fragile, and often very beautiful Glass can be decorated in multiple ways and its optical properties are exceptional. In all its myriad forms as table ware, containers, in architecture and design glass represents a major achievement in the history of technological developments. Since the Bronze Age about 3,000 B.C., glass lias been used for making various kinds of objects. It was first made from a mixture of silica, line and an alkali such as soda or potash, and these remained the basic ingredients of glass until the development of lead glass in the seventeenth century. When heated , the mixture becomes soft and malleable and can be formed by various techniques into a vast array of shapes and sizes. The homogeneous mass thus formed by melting then cools to create glass, but in contrast to most materials formed in this way (metals, for instance), glass lacks the crystalline structure normally associated with solids, and instead retains the random molecular structure of a liquid. In effect, as molten glass cools, it progressively stiffens until rigid, but does so without setting up a network of interlocking crystals customarily associated with that process. This is why glass shatters so easily when dealt a blow. Why glass deteriorates over time, especially when exposed to moisture, and why glassware must be slowly reheated and uniformly cooled after manufacture to release internal stresses Induced by uneven cooling. Another unusual feature of glass is the manner in which its viscosity changes as it turns from a cold substance into a hot, ductile liquid. Unlike metals that flow or freeze at specific temperatures glass progressively softens as the temperature rises, going through varying stages of malleability until it flows like a thick syrup. Each stage of malleability allows the glass to be manipulated into various forms, by different techniques, and if suddenly cooled the object retains the shape achieved at that point. Glass is thus amenable to a greater number of heat-forming techniques than most other materials.10.Why does the author list the characteristics of glass in lines 1-5?(A) To demonstrate how glass evolved(B) To show the versatility of glass(C) To explain glassmaking technology (D) To explain the purpose of each component of glass11.The word durable in hue 3 is closest in meaning to (A)lasting (B) delicate (C) heavy (D) Plain1 2. What does the author imply about the raw materials used to make glass?(A)They were the same for centuries.(B)They arc liquid(C)They are transparent(D)They are very heavy.13.According to the passage, how is glass that has cooled and become rigid different from most other rigid substances?(A)It has an interlocking crystal network.(B)It has an unusually low melting temperature.(C) It has varying physical properties.(D) It has a random molecular structure.14.The word customarily in line 13 is closest in meaning to(A)naturally(B)necessarily(C)usually(D) certainly15.The words exposed to in line 19 are closest in meaning to(A)hardened by(B)chilled with(C)subjected to(D) deprived of16.What must be done to release the internal stresses that build up in glass products during manufacture?(A)the glass must be reheated and evenly cooled.(B) the glass must be cooled quickly.(C) The glass must be kept moist until cooled.(D) The glass must be shaped to its desired form immediately 17.The word induced in line 21 is closest in meaning to(A)joined(B)missed(C)caused(D) lost18.The word it in line 22 refers to(A)feature(B) glass(C) manner(D) viscosity19.According to the passage. why can glass be more easily shaped into specific forms than can metals(A)It resists breaking when heated(B)It has better optical properties.(C)It retains heat while its viscosity changes.(D) It gradually becomes softer as its temperature rises.9801Questions 31-40 科普知识 The livelihood of each species in the vast and intricate assemblage of living things depends on the existences of other organisms. This interdependence is sometimes subtle, sometimes obvious. Perhaps the most straight forward dependence of one species on another occurs with parasites, organisms that live on or in other living things and derive nutrients directly from them. The parasitic way of life is widespread. A multitude of microorganisms( including viruses and bacteria) and an army of invertebrates or creatures lacking a spinal column (including crustaceans, insects, and many different types of worms ) make their livings directly at the expense of other creatures. In the face of this onslaught, living things have evolved a variety of defense mechanisms for protecting their bodies from invasion by other organisms. Certain fungi and even some kinds of bacteria secrete substances known as antibiotics into their external environment. These substances are capable of killing or inhibiting the growth of various kinds of bacteria that also occupy the area, thereby eliminating or reducing the competition for nutrients. The same principle is used in defense against invaders in other groups of organisms. For example, when attacked by disease-causing fungi or bacteria, many kinds of plants produce chemicals that help to ward off the invaders. Members of the animal kingdom have developed a variety of defense mechanisms for dealing with parasites. Although these mechanisms vary considerably, all major groups of animals are capable of detecting and reacting to the presence of foreign cells. In fact, throughout the animal kingdom, from sponges to certain types of worms, shellfish, and all vertebrates (creatures possessing a spinal column), there is evidence that transplants of cells or fragments of tissues into an animal are accepted only if they come from g