2020年6月大学英语六级长篇阅读练习题
2020年6月大学英语六级长篇阅读练习题(三篇)
【导语】锲⽽舍之,朽⽊不折;锲⽽不舍,⾦⽯可镂。
备考需要这样持之以恒的精神。
⽆忧考为您提供了“2020年6⽉⼤学英语六级长篇阅读练习题(三篇)”,欢迎阅读参考!更多相关讯息请关注⽆忧考!2020年6⽉⼤学英语六级长篇阅读练习题篇⼀ How Ozone Pollution Works A) The weather report on the radio or TV tells you that it is going to be sunny and hot and that an orange ozone alert has been issued. What is ozone? What does an orange alert mean? Why should you be concerned about it? In this article, we will examine what ozone is, how it is produced, what health hazards it poses and what you can do to reduce ozone pollution. B) Ozone is a molecule of three oxygen atoms bound together (O3). It is unstable and highly reactive. Ozone is used as a bleach, a deodorizing agent, and a sterilization agent for air and drinking water. At low concentrations, it is toxic. Ozone is found naturally in small concentrations in the stratosphere, a layer of Earth’s upper atmosphere. In this upper atmosphere, ozone is made when ultraviolet light from the sun splits an oxygen molecule (O2), forming two single oxygen atoms. If a freed atom collides with an oxygen molecule, it becomes ozone. Stratospheric ozone has been called “good” ozone because it protects the Earth’s surface from dangerous ultraviolet light. C) Ozone can also be found in the troposphere, the lowest layer of the atmosphere. Tropospheric ozone (often termed “bad ” ozone) is man - made, a result of air pollution from internal combustion engines and power plants. Automobile exhaust and industrial emissions release a family of nitrogen oxide gases (NOx) and volatile organic compounds (VOC), by-products of burning gasoline and coal. NOx and VOC combine chemically with oxygen to form ozone during sunny, high- temperature conditions of late spring, summer and early fall. High levels of ozone are usually formed in the heat of the afternoon and early evening, dissipating during the cooler nights. D) Although ozone pollution is formed mainly in urban and suburban areas, it ends up in rural areas as well, carried by prevailing winds or resulting from cars and trucks that travel into rural areas. Significant levels of ozone pollution can be detected in rural areas as far as 250 miles downwind from urban industrial zones. E) You can make ozone test strips to detect and monitor ozone levels in your own backyard or around your school. You will need corn starch, filter paper (coffee filters work well) and potassium iodide (can be ordered from a science education supplier such as Carolina Biological Supply or Fisher Scientific). Basically, you make a paste from water, corn starch and potassium-iodide, and you paint this paste on strips of filter paper. You then expose the strips to the air for eight hours. Ozone in the air will react with the potassium iodide to change the color of the strip. You will also need to know the relative humidity, which you can get from a newspaper, weather broadcast or home weather station. F) When you inhale ozone, it travels throughout your respiratory tract. Because ozone is very corrosive, it damages the bronchioles and alveoli in your lungs, air sacs that are important for gas exchange. Repeated exposure to ozone can inflame lung tissues and cause respiratory infections. G) Ozone exposure can aggravate existing respiratory conditions such as asthma, reduce your lung function and capacity for exercise and cause chest pains and coughing. Young children, adults who are active outdoors and people with respiratory diseases are most susceptible to the high levels of ozone encountered during the summer. In addition to effects on humans, the corrosive nature of ozone can damage plants and trees. High levels of ozone can destroy agricultural crops and forest vegetation. H) To protect yourself from ozone exposure, you should be aware of the Air Quality Index (AQI) in your area every day—you can usually find it in the newspaper or on a morning weather forecast on TV or radio. You should also be familiar with the U.S. Environmental Protection Agency (EPA) guide for ozone-alert values. I) What do the numbers in the AQI mean? The AQI measures concentrations of five air pollutants: ozone, sulfur dioxide, particulate matter, carbon monoxide and nitrogen dioxide. The EPA has chosen these pollutants as criteria pollutants, but these are not all of the pollutants in the air. These concentrations are compared to a standard set out in federal law. An index value of 100 means that all of the criteria pollutants are at the maximum level that is considered safe for the majority of the population. To reduce your exposure to ozone, you should avoid exercising during afternoon and early evening hours in the summer. J) There are several ways you can help to decrease ozone pollution. Limit using your automobile during afternoon and early evening hours in the late spring, summer and early fall. Do not use gasoline-powered lawn equipment during these times. Do not fuel your car during these times. Do not light fires or outdoor grills during these times. Keep the engine of your car or boat tuned. Make sure that your tires are properly inflated. Use environmentally safe paints, cleaning and office products (some of these chemicals are sources of VOC). K) Besides personal attempts to reduce ozone pollution, the EPA has initiated more stringent air-quality standards (such as the Clean Air Act and its modifications) to reduce air pollution. Compliance with these standards by industries, manufacturers and state and local governments has significantly reduced the levels of many common air pollutants. L) With continued conservation and reduction practices, adherence to ozone-pollution warnings, research and government regulation, ozone-pollution levels should continue to fall. Perhaps future generations will not be threatened by this environmental pollutant. M) The thing that determines whether ozone is good or bad is its location. Ozone is good,when it is in the stratosphere. The stratosphere is a layer of the atmosphere starting at the level of about 6 miles (about 10 kilometers) above sea level. The stratosphere naturally contains about six parts per million of ozone, and this ozone is very beneficial because it absorbs UV radiation and prevents it from reaching us. N) Ozone is “bad” when it is at ground level. Ozone is a very reactive gas that is hard on lung tissue. It also damages plants and buildings. Any ozone at ground level is a problem. Unfortunately, chemicals in car exhaust and chemicals produced by some industries react with light to produce lots of ozone at ground level. In cities, the ozone level can rise to a point where it becomes hazardous to our health. That’s when you hear about an ozone warning on the news. 1. When ultraviolet rays from the sun separate an oxygen molecule into two single oxygen atoms in the stratosphere, the combination of a single oxygen atom and an oxygen molec u l e f o r m s o z o n e . / p > p b d s f i d = " 1 2 6 " > 0 0 2 . Y o u ca n m a k e o z o n e t e s t s t r i p sb y y o u r s e l f t o f i n d o u t a b o u t o z o n e l e v e l s i n y o u r o w n l oc a l e . / p > pb d s f i d = " 1 2 7 " > 0 0 3 . L o n g - t i m e e x p o s u r e t o o z o n e i s b a d l y h a r m f u l t o o u r r e s p i r a t o r y s y s t e m . / p > p b d s f i d = " 1 2 8 " > 0 0 4 . C h e m ic a l s i n i nd u s t r i a l w a s te g a s a n d v e h i c l e e x h a u s t r e a c t w i t h l i g h t t of o r m l o t s o f o z o n e a tg r o u n d l e v e l . / p > p b d s f i d = " 1 2 9 " > 0 0 5 . I n t e r n a l c o m b u s t i o n e n g i n e s a n d p o w e r p l a n t s c a u s e th e a r ti f i c i a l t r o p o s p h e r i c o z o n e , a l s o k n o w n a s b a d o z o n e . / p > p b d s f i d = " 1 3 0 " > 0 0 6 . O z o n e i s v e r y h e l p f u l b e c a u s e i t a b s o r b s U V r a d i a t i o n a n d s e p a r a t e s u s f r o m i t . / p > p b d s f i d = " 1 3 1 " > 0 0 7 . U s i n g g a s o l i n e - p o w e r e d l a w n e q u i p m e n t i n t h e l a t e s p r i n g , s u m m e r a n d e a r l y f a l l m a y i n c r e a s e o z o n e p o l l u t i o n . / p > p b d s f i d = " 1 3 2 " > 0 0 8 . O z o n e p o l l u t i o n o c c u r s i n u r b a n a n d s u b u r b a n a r e a s a s w e l l a s i n r u r a l a r e a s . / p > p b d s f i d = " 1 3 3 " > 0 0 9 . I n o r d e r t o d e c r e a s e o z o n e p o l l u t i o n , t h e E P A h a s s e t u p m o r e r i g o r o u s a i r - q u a l i t y s t a n d a r d s . / p > p b d s f i d = " 1 3 4 " > 0 0 1 0 . P a y c l o s e a t t e n t i o n t o t h e A i r Q u a l i t y I n d e x i n y o u r a r e a e v e r y d a y c a n k e e p y o u a w a y f r o m o z o n e e x p o s u r e . / p >。
2020年六级长篇阅读练习及答案详解(3)
2020年六级长篇阅读练习及答案详解(3) Preparing for Computer DisastersA: Summary: When home office computers go down, many small businesses grind to a halt. Fortunately, taking stepsto recover from disasters and minimize their effects is quite straightforward.B: Fires, power surges, and floods, they're all facts of life. We read about them in the morning paper and see them on the evening news. We sympathize with the victims and commiserate over their bad luck. We also shake our heads atthe digital consequences—melted computers, system failures, destroyed data. Yet, somehow, many of us continue to live by that old mantra of denial: "It won't happen to me." Well,the truth is, at some point you'll probably have to deal with at least one disaster. That's just how it goes, and in most aspects of our lives we do something about it. We buy insurance. We stow away provisions. We even make disasterplans and run drills. But for some reason, computer disaster recovery is a blind spot for many of us. It shouldn't be. Home computers contain some of our most important information, both business and personal, and making certain our data survives a disaster should be a priority. Moreover, even the smallest disaster can be a serious disruption. Personal computers have become an integral part of the smooth-running household. We use them to communicate, shop, and do homework, and they're even more vital to home office users. When home office computers go down, many small businesses grind to a halt. Fortunately, taking steps to recover from disasters and minimize their effects is quite straightforward. With a goodoffsite storage plan and the right tools, you can bounce back quickly and easily from minor computer disasters. And, should a major calamity strike, you can rest assured your data is safe.Offsite Storage: Major DisastersC: House fires and floods are among the most devastating causes of personal computer destruction. That's why a solid offsite backup and recovery plan is essential. Although many home users faithfully back up their hard drives, many would still lose all their data should their house flood our burn. That's because they keep their backups in relatively close to their computers. Their backup disks might not be in the same room as their computers—tucked away in a closet or even the garage—but they're not nearly far enough away should a serious disaster strike. So, it's important to back up your system to a removable medium and to store it elsewhere.D: There are many ways to approach offsite storage. It starts with choice of backup tools and storage medium. Disaster situations are stressful, and your recovery tools shouldn't add to that stress. They must be dependable and intuitive, making it easy to schedule regular backups and to retrieve files in a pinch. They must also be compatible with your choice of backup medium. Depending on your tools, you can back up to a variety of durable disk types—from CDs to Jaz drives to remote network servers. Although many of these storage media have high capacity, a backup tool with compression capabilities is a big plus, eliminating the inconvenience of multiple disks or large uploads.E: Once you select your tools and a suitable medium, you need to find a remote place to store your backups. The options are endless. However, no matter where you choose, be sure the site is secure, easily accessible, and a good distance away from your home. You may also want to consider using an Internet-based backup service. More and more service providers are offering storage space on their servers, and uploading files to a remote location has become an attractive alternative to conventional offsite storage. Of course, before using one of these services, make certain you completely trust the service provider and its security methods. Whatever you do, schedule backups regularly and store them far away from your home.Come What May: Handling the Garden Variety Computer CrisisF: Not all home computer damage results from physical disaster. Many less menacing problems can also hobble your PC or destroy your information. Systems crash, kids "rearrange" data, adults inadvertently delete files. Although these events might not seem calamitous, they can have serious implications. So, once again, it's important to be prepared. As with physical disasters, regular backups are essential. However, some of these smaller issues require a responsethat's more nuanced than wholesale backup and restoration. To deal with less-than-total disaster, your tool set must be both powerful and agile. For example, when a small number of files are compromised, you may want to retrieve those files alone. Meanwhile, if just your settings are affected, you'll want a simple way to roll back to your preferred setup. Yet, should your operating system fail, you'll need a way to boot。
2020年6月英语六级阅读理解模拟题及答案
2020年6月英语六级阅读理解模拟题及答案2020年6月英语六级阅读理解模拟题及答案Which is safer-staying at home, traveling to work on public transport, or working in the office? Surprisingly,each of these carries the same risk, which is very low. However, what about flying compared to working in the chemical industry? Unfortunately, the former is 65 times riskier than the latter! In fact, the accident rate of workers in the chemical industry is less than that of almost any of human activity, and almost as safe as staying at home.The trouble with the chemical industry is that whenthings go wrong they often cause death to those living nearby. It is this which makes chemical accidents so newsworthy. Fortunately, they are extremely rare. The most famous ones happened at Texas City (1947),Flixborough (1974), Seveso (1976), Pemex (1984) and Bhopal (1984)。
大学英语六级长篇阅读练习(5套)
大学英语六级考试阅读要求考生能顺利读懂语言难度中等的一般性题材的文章、掌握中心大意以及说明中心大意的事实和细节,并能进行一定的分析、推理和判断。
下面小编为大家整理了六级长篇阅读练习题及答案解析,希望对您有所帮助,祝大家备考顺利!大学英语六级改革新题型长篇阅读练习(一)英语六级新题型练习之长篇阅读:段落匹配题。
Paper--More than Meets the EyeA) We are surrounded by so much paper and card that it is eas y to forget just how complex it is. There are many varieties and grades of paper materials, and whilst it is fairly easy to spot the variet ies, it is far more difficult to spot the grades.B) It needs to be understood that most paper and card is manu factured for a specific purpose, so that whilst the corn-flake packetmay look smart, it is clearly not something destined for the archives. It is made to look good, but only needs a limited life span. It isalso much cheaper to manufacture than high grade card.C) Paper can be made from an almost endless variety of cellulo se-based material which will include many woods, cottons and grass es or which papyrus is an example and from where we get the word "paper". Many of these are very specialized, but the preponderance of paper making has been from soft wood and cotton or rags, with the bulk being wood-based.Paper from WoodD) In order to make wood into paper it needs to be broken do wn into fine strands. Firstly by powerful machinery and then boiled with strong alkalies such as caustic soda, until a fine pulp of cellulo se fibers is produced. It is from this pulp that the final product is m ade, relying on the bonding together of the cellulose into layers. Th at, in a very small nutshell, is the essence of paper making from wood. However, the reality is rather more complicated. In order to give us our white paper and card, the makers will add bleach and other materials such as china clay and additional chemicals.E) A further problem with wood is that it contains a material th at is not cellulose. Something called lignin. This is essential for the t ree since it holds the cellulose fibres together, but if it is incorporat ed into the manufactured paper it presents archivists with a proble m. Lignin eventually breaks down and releases acid products into th e paper. This will weaken the bond between the cellulose fibers and the paper will become brittle and look rather brown and careworn. We have all seen this in old newspapers and cheap paperback book s. It has been estimated that most paper back books will have a lif e of not greater than fifty years. Not what we need for our archive s.F) Since the lignin can be removed from the paper pulp during manufacture, the obvious question is "why is it left in the paper?" T he answer lies in the fact that lignin makes up a considerable part of the tree. By leaving the lignin in the pulp a papermaker can incr ease his paper yield from a tree to some 95%. Removing it means a yield of only 35%. It is clearly uneconomic to remove the lignin f or many paper and card applications.G) It also means, of course, that lignin-free paper is going to be more expensive, but that is nevertheless what the archivist must look for in his supplies. There is no point whatsoever in carefully pl acing our valuable artifacts in paper or card that is going to hastentheir demise. Acid is particularly harmful to photographic material s, causing them to fade and is some cases simply vanish!H) So, how do we tell a piece of suitable paper or card from o ne that is unsuitable? You cannot do it by simply looking, and rathe r disappointingly, you cannot always rely on the label. "Acid-free" might be true inasmuch as a test on the paper may indicate that it is a neutral material at this time. But lignin can take years before it starts the inevitable process of breaking down, and in the right co nditions it will speed up enormously.I) Added to this, as I have indicated earlier, paper may also c ontain other materials added during manufacture such as bleach, ch ina clay, chemical whiteners and size. This looks like a bleak pictur e, and it would be but for the fact that there are suppliers who will guarantee the material that they sell. If you want to be absolutely sure that you are storing in, or printing on, the correct material th en this is probably the only way.J) Incidentally, acids can migrate from material to material. Lin ing old shoe boxes with good quality acid-free paper will do little to guard the contents. The acid will get there in the end.Paper from RagK) Paper is also commonly made from cotton and rag waste. Th is has the advantage of being lignin-free, but because there is muc h less cotton and rag than trees, it also tends to be much more ex pensive than wood pulp paper. You will still need to purchase from a reliable source though, since even rag paper and card can contai n undesirable additives.L) A reliable source for quality rag papers is a recognized art st ockiest. Many water color artists insist on using only fine quality rag paper and board.M) The main lesson to learn from this information is that you c annot rely on purchasing archival materials from the high street. Th e only safe solution is to purchase from specialist suppliers. It may cost rather more, but in the end you will know that your important and valuable data and images have the best home possible.1. The corn-flake packet is cheaper than high grade card.2. There are a lot of materials which can be used for making pa per, but the superiority ones are soft wood, cotton and rags.3. During the whole manufacturing process, the final product is made from a pulp of cellulose fibres.4. In order to make white paper and card, the makers will add bleach.5. Liguin is essential for the tree but it will make paper easy to break.6. Many paper producers will preserve lignin during manufactur e, because leaving the lignin will make more paper from a tree.7. Acid is particularly harmful to photographic materials.8. If the lignin is removed from the paper, the paper will be mo re expensive.9. Although free of lignin, paper made from cotton and rag was te can also cost more money than wood pulp paper because there i s much less cotton and rag than trees.10. What we can learn from "Paper from Rag" is that you had b etter buy archival materials from specialist suppliers.文章精要本文主要介绍了我们平常所见所用的纸的复杂性,通过介绍用木头和破布料造纸的过程,使我们对纸的类别、属性有了更深入的了解。
2020年六级长篇阅读冲刺练习及解析(5)
2020年六级长篇阅读冲刺练习及解析(5) Passage OneWords: 1,036EarthquakesA) An earthquake is one of the most terrifying phenomena that nature can dish up. We generally think of the ground we stand on as “rock-solid” and completely stable. An earthquake can shatter (粉碎)that perception instantly, and often with extreme violence.B) Up until relatively recently, scientists only had unproven guesses as to what actually caused earthquakes. Even today there is still a certain amount of mystery surrounding them, but scientists have a much clearer understanding. There has been enormous progress in the past century. Scientists have identified the forces that cause earthquakes, and developed technology that can tell us an earthquake"s magnitude and origin. The next hurdle is to find a way of predicting earthquakes, so they don’t catch people by surprise. In this article, we’ll find out what causes earthquakes, and we’ll also find out why they can have sucha devastating effect on us.C) An earthquake is a vibration(震动)that travels through the earth’s crust. Technically, a large truck that rumbles down the street is causing a mini-earthquake, if you feelyour house shaking as it goes by; but we tend to think of earthquakes as events that affect a fairly large area, suchas an entire city. All kinds of things can cause earthquakes:volcanic eruptions, meteor(流星)impacts, underground explosions (an underground nuclear test, for example), collapsing structures (such as a collapsing mine). But the majority of naturally-occurring earthquakes are caused by movements of the earth’s plates.D) We only hear about earthquakes in the news every once in a while, but they are actually an everyday occurrence on our planet. According to the United States Geological Survey, more than 3 million earthquakes occur every year. That’s about 8,000 a day, or one every 11 seconds! The vast majority of these 3 million quakes are extremely weak. The law of probability also causes a good number of stronger quakes to happen in uninhabited places where no one feels them. It is the bigquakes that occur in highly populated areas that get our attention.E) Earthquakes have caused a great deal of property damage over the years, and they have claimed many lives. In the last hundred years alone, there have been more than 1.5 million earthquake-related fatalities. Usual ly, it’s not the shaking ground itself that claims lives; it’s the associated destruction of man-made structures and other natural disasters it causes, such as tsunamis, avalanches (雪崩)and landslides.F) The biggest scientific breakthrough in the history of seismology—the study of earthquakes—came in the middle of the 20th century, with the development of the theory of plate tectonics(筑造学).Scientists proposed the idea of plate tectonics to explain a number of peculiar phenomena on earth,such as the apparent movement of continents over time, the clustering of volcanic activity in certain areas and the presence of huge ridges at the bottom of the ocean.G) The basic theory is that the surface layer of the earth—the lithosphere—is comprised of many plates thatslide over the lubricating (润滑的)asthenosphere layer. At the boundaries between these huge plates of soil and rock, three different things can happen.H) Plates can move apart. If two plates are moving apart from each other, hot, molten rock flows up from the layers of mantle below the lithosphere. This magma (岩浆) comes out on the surface (mostly at the bottom of the ocean), where it is called lava (熔岩).As the lava cools, it hardens to form new lithosphere material, filling in the gap. This is called a divergent plate boundary.I) Plates can push together. If the two plates are moving toward each other, one plate typically pushes under the other one. This plate below sinks into the lower mantle layers, where it melts. At some boundaries where two plates meet, neither plate is in a position to push under the other, so they both push against each other to form mountains. Thelines where plates push toward each other are called convergent plate boundaries.J) Plates slide against each other. At other boundaries, plates simply slide by each other—one moves north and one moves south, for example. While the plates don’t drift directly into each other at these transform boundaries, they are pushed tightly together. A great deal of tension builds at the boundary.。
2020年6月英语六级阅读真题及答案
2020年6月英语六级阅读真题及答案2020年6月英语六级阅读真题及答案Section ADirections:In this section, there is a passage with ten blanks,You are required to select One word for each blank from a list of choices given in a word bank following the passage.Read the passage through carefully before making your choices. Each choice in the bamk is identified by aletter.Please mark the corresponding letter for each item on Answer Sheet 2 with a single line through the centre You may not use any of the words in the bank more than once.For investors who desire low risk and guaranteed income,U.S. Government bonds are a secure investment because these bonds have the financial backing and full faith and credit of the federal government.Municipal bonds,also secure,are offered by local governmengts and oftenhave____36______such as tax-free interest.Some may even be____37______.Corportate bonds are a bit more risky.Two questions often_____38_____first-time corportate bond investors.The first is”If I purchase a corportate bond,do I have to hold it until the matueity date?”The answer isno.Bonds are bought and sold daily on ____39_____securities exchanges.However,if your bond does not have____40_____ that make it attractive to other investors, you may be forced to sell your bond at a____41____i.e., a price less than the bond’s face value. But if your bond is highly valued byother investors, you may be able to sell it at a premium,i.e., a price above its face value. Bond pricesgcncrally____42____ inversely (相反地)with current market interest rates. As interest rates go up, bond pnccs tall, and vice versa (反之亦然).Thus, like all investments,bonds have a degree of risk.The second question is “How can I ___43_______ the investment risk of a particular bond issue?” Sta ndard & Poor’s and Moody’s Investors Service rate the level of risk of many corporate and government bonds. And ____44______, the higher the market risk of a bond,the higher the interest rate. Investors will invest in a bond considered risky only if the _____45_____return is high enough.注意:此部分试题请在答题卡2上作答。
2020年6月英语六级考试阅读真题及答案
2020年6月英语六级考试阅读真题及答案2020年6月英语六级考试阅读真题及答案Section ADirection: In this section, there is a short passage with 5 questions or incomplete stamens. Read the passage carefully. Then answer the questions or complete the statements in the fewest possible words. Please write your answer on Answer Sheet 2.Question 47 to 51 are based on the following passageHighly proficient musicianship is hard won. Althoughit’s often assumed musical ability us inherited, there’s abundant evidence that this isn’t the case. While it seems that at birth virtually everyone has perfect pitch, the reasons that one child is better than another are motivation and practice.Highly musical children were sung to more as infants and more encouraged to join in song games as kids than less musical ones, long before any musical ability could have been evident. Studies of classical musicians prove that the best ones practiced considerably more from childhood onwards than ordinary orchestral players, and this is because their parents were at them to put in the hours from a very young age.The same was true of children selected for entry to specialist music schools, compared with those who were rejected. The chosen children had parents who had very actively supervised music lessons and daily practice fromyoung ages, giving up substantial periods of leisure time to take the children to lessons and concerts.The singer Michael Jackson’s story, although unusually brutal and extreme, is illumination when considering musical prodigy(天才). Accounts suggest that he was subjected to cruel beatings and emotional torture ,and that he was humiliated (羞辱) constantly by his father, What sets Jackson’s family apart is that his father used his reign of terror to train his children as musicians and dancers.On top of his extra ability Michael also had more drive. This may have been the result of being the closest of his brothers and sisters to his mother. “He seemed different to me from the other children —special,”Michael’s mother said of him. She may not have realized that treating her son as special may have been part of the reason be became like that.All in all, if you want to bring up a Mozart or Bach, the key factor is how hard you are prepared to crack the whip. Thankfully, most of us will probably settle for a bit of fun on the recorder and some ill-executed pieces of music-on the piano from our children.注意:此部分试题请在答题卡2上作答。
2020年大学英语六级长篇阅读练习及答案详解(5)
2020年大学英语六级长篇阅读练习及答案详解(5)Passage OneWords: 1,036EarthquakesA) An earthquake is one of the most terrifying phenomena that nature can dish up. We generally think of the ground we stand on as “rock-solid” and completely stable. An earthquake can shatter (粉碎)that perception instantly, and often with extreme violence.B) Up until relatively recently, scientists only had unproven guesses as to what actually caused earthquakes. Even today there is still a certain amount of mystery surrounding them, but scientists have a much clearer understanding. There has been enormous progress in the past century. Scientists have identified the forces that cause earthquakes, and developed technology that can tell us an earthquake"s magnitude and origin. The next hurdle is to find a way of predicting earthquakes, so they don’t catch people by surprise. In this article, we’ll find out what causes earthquakes, and we’ll also find out why they can have sucha devastating effect on us.C) An earthquake is a vibration(震动)that travels through the earth’s crust. Technically, a large truck that rumbles down the street is causing a mini-earthquake, if you feelyour house shaking as it goes by; but we tend to think of earthquakes as events that affect a fairly large area, suchas an entire city. All kinds of things can cause earthquakes:volcanic eruptions, meteor(流星)impacts, underground explosions (an underground nuclear test, for example), collapsing structures (such as a collapsing mine). But the majority of naturally-occurring earthquakes are caused by movements of the earth’s plates.D) We only hear about earthquakes in the news every once in a while, but they are actually an everyday occurrence on our planet. According to the United States Geological Survey, more than 3 million earthquakes occur every year. That’s about 8,000 a day, or one every 11 seconds! The vast majority of these 3 million quakes are extremely weak. The law of probability also causes a good number of stronger quakes to happen in uninhabited places where no one feels them. It is the bigquakes that occur in highly populated areas that get our attention.E) Earthquakes have caused a great deal of property damage over the years, and they have claimed many lives. In the last hundred years alone, there have been more than 1.5 million earthquake-related fatalities. Usual ly, it’s not the shaking ground itself that claims lives; it’s the associated destruction of man-made structures and other natural disasters it causes, such as tsunamis, avalanches (雪崩)and landslides.F) The biggest scientific breakthrough in the history of seismology—the study of earthquakes—came in the middle of the 20th century, with the development of the theory of plate tectonics(筑造学).Scientists proposed the idea of plate tectonics to explain a number of peculiar phenomena on earth,such as the apparent movement of continents over time, the clustering of volcanic activity in certain areas and the presence of huge ridges at the bottom of the ocean.G) The basic theory is that the surface layer of the earth—the lithosphere—is comprised of many plates thatslide over the lubricating (润滑的)asthenosphere layer. At the boundaries between these huge plates of soil and rock, three different things can happen.H) Plates can move apart. If two plates are moving apart from each other, hot, molten rock flows up from the layers of mantle below the lithosphere. This magma (岩浆) comes out on the surface (mostly at the bottom of the ocean), where it is called lava (熔岩).As the lava cools, it hardens to form new lithosphere material, filling in the gap. This is called a divergent plate boundary.I) Plates can push together. If the two plates are moving toward each other, one plate typically pushes under the other one. This plate below sinks into the lower mantle layers, where it melts. At some boundaries where two plates meet, neither plate is in a position to push under the other, so they both push against each other to form mountains. Thelines where plates push toward each other are called convergent plate boundaries.J) Plates slide against each other. At other boundaries, plates simply slide by each other—one moves north and one moves south, for example. While the plates don’t drift directly into each other at these transform boundaries, they are pushed tightly together. A great deal of tension builds at the boundary.。
2020年大学英语六级长篇阅读匹配练习题(2)
2020年大学英语六级长篇阅读匹配练习题(2)Genetically Modified Foods--Feed the World?[A] If you want to spark a heated debate at a dinner party, bring up the topic about genetically modified foods. For many people, the concept of genetically altered, high-tech crop production raises all kinds of environmental, health, safety and ethical questions. Particularly in countries with long agrarian traditions--and vocal green lobbies--the idea seems against nature.[B] In fact, genetically modified foods are already very much a part of our lives. A third of the corn and more than half the soybeans and cotton grown in the U. S. last year were the product of biotechnology, according to the Department of Agriculture. More than 65 million acres of genetically modified crops will be planted in the U. S. this year. The genetic is out of the bottle.[C] Yet there are clearly some very real issues that need to be resolved. Like any new product entering the food chain, genetically modified foods must be subjected to rigorous testing. In wealthy countries, the debate about biotech is tempered by the fact that we have a rich array of foods to choose from--and a supply that far exceeds our needs. In developing countries desperate to feed fast-growing and underfed populations; the issue is simpler and much more urgent: Do the benefits of biotech outweigh the risks?[D] The statistics on population growth and hunger are disturbing. Last year the world's population reached 6 billion. And by 2050, the UN estimates, it will be probablynear 9 billion. Almost all that growth will occur in developing countries. At the same time, the world's available cultivable land per person is declining. Arable land has declined steadily since 1960 and will decrease by half over the next 50 years, according to the International Service for the Acquisition of Agri-Biotech Applications ( ISAAA).How can biotech help?[E] Biotechnologists have developed genetically modified rice that is fortified with beta-carotene(胡萝卜素)--which the body converts into vitamin A--and additional iron, and they are working on other kinds of nutritionally improved crops. Biotech can also improve farming productivity in places where food shortages are caused by crop damage attribution to pests, drought, poor soil and crop viruses, bacteria or fungi ( 真菌 ).[F] Damage caused by pests is incredible. The European corn borer, for example, destroys 40 million tons of the-world's corn crops annually, about 7% of the total. Incorporating pest-resistant genes into seeds can help restore the balance. In trials of pest-resistant cotton in Africa, yields have increased significantly. So far, fears that genetically modified, pest-resistant crops might kill good insects as well as bad appear unfounded.[G] Viruses often cause massive failure in staple cropsin developing countries. Two years ago, Africa lost more than half its cassava (树薯) crop--a key source of calories-to the mosaic virus (花叶病毒).Genetically modified, virus-resistant crops can reduce that damage, as can drought-tolerant seedsin regions where water shortages limit the amount of landunder cultivation. Biotech can also help solve the problem of soil that contains excess aluminum, which can damage roots and cause many staple-crop failures. A gene that helps neutralize aluminum toxicity (毒性) in rice has been identified. Many scientists believe biotech could raise overall crop productivity in developing countries as much as 25% and help prevent the loss of those crops after they are harvested.[H]Yet for all that promise, biotech is far from being the whole answer. In developing countries, lost crops are only one cause ofhunger. Poverty plays the largest role. Today more than 1 billion people around the globe live on less than 1 dollar a day. Making genetically modified crops available will not reduce hunger if farmers cannot afford to grow them or if the local population cannot afford to buy the food those farmers produce.[I] Biotech has its own "distribution" problems. Private-sector biotech companies in the rich countries carry out much of the leading-edge research on genetically modified crops. Their products are often too costly for poor farmers in the developing world, and many of those products won't even reach the regions where they are most needed. Biotech firms have a strong financial incentive to target rich markets first in order to help them rapidly recoup the high costs of product development. But some of these companies are responding to needs of poor countries.[J] More and more biotech research is being carried outin developing countries. But to increase the impact of genetic research on the food production of those countries,。
2020年大学英语六级长篇阅读练习及答案解析
2020年大学英语六级长篇阅读练习及答案解析大学英语六级考试阅读要求考生能顺利读懂语言难度中等的一般性题材的文章、掌握中心大意以及说明中心大意的事实和细节,并能进行一定的分析、推理和判断。
下面小编为大家整理了六级长篇阅读练习题及答案解析,希望对您有所帮助,祝大家备考顺利I大学英语六级长篇阅读练习及答案解析(6)Section B(原快速阅读理解调整为长篇阅读理解,篇章长度和难度不变.篇章后附有10个句子,每句一题.每句所含的信息出自篇章的某一段落,要求考生找出与每句所含信息相匹配的段落.)Directions:In this section,you are going to read a passage with ten statements attached to it.Each statement contains information given in one of the paragraphs.Identify the paragraph from which the information is derived.You may choose a paragraph more than once.Each paragraph is marked with a letter.Answer the questions by marking the corresponding letter on Answer Sheet 2.Why Are Airlines Withholding Seats?Behind the screen indeed[D]An awful plot goes on behind airline and travel booking screens,and nuch of it is strictly off-linits to consumers.What we do know is that for decades now airlines have becone nasters of what the industry calls yield management,offering millions of conbinations of fares based on advance purchase patterns and other booking trends,so nearly everyone pays a different price based on when they buy.But now that paying extra for your seat selection has become cotmon practice, securing your reservation is just half the battle.[E]Some industry experts have connected the dots."They're trying to get people to buy premium seats,"says George Hobica,*s Fly Guy colunnist and the founder of・“They want to increase revenue.And we're getting more complaints about it."He notes that it“really annoys* passengers who want to sit together,particularly when traveling with snail children.[F]He's echoed by Kevin Mitchell,chairnan of the Business Travel Coalition(联盟):“With yield management,consumers are aware and they know that airlines are constantly changing prices on seats.But if this is true,it is unethical—they're grossly misleading us.The thing that I find so offensive is conveying to me that I have no options,but if I wait a week or two then I do have options."[G]According to the airlines,the reason for ancillary(附加的)revenue is unbundling(分类计价)ticket prices,so passengers who desire a given service―say checking a bag or ordering在[M]段出现,该段第五句引用Mitchell的原话,指出这一问题亟待公开、透明.由此可见,题干是对原文的同义改耳,故答案为[M].题干中的urgent need对应原文中的sore need,carriers!seat assignment代指原文中的this.50.[I].题干意为,尽管霍比卡把主要贵任归咎于各大航空公司,他也提到,低成本的运营商们同样使得座位的获得变得困魔.注意抓住题干中的关键词Hobica,the main responsibilities,thenajor airlines和the low-cost carriers.原文段落中,提及Hobica和低成本的运营商使获得座位变得困难的内容在[I]段出现,该段第一句话提到,霍比卡认为各大航空公司是造成这种状况的罪魁祸首,低成本的运营商也起到了推波助澜的作用.由此可见,题干是对原文的同义改写,故答案为[I].题干中的ascribes...to...和nain responsibilities分别对应原文中的cites…as…和prine culprits.51.[明题干意为,一些人认为,为了解决航空公司保留座位的问题,美国交通运输部应该采取一些措施.注意抓住JS干中的关键词the.Departnent of Transportation.文章段落中,论及美国交通运输部的内容在[M]段出现,该段第三、四句话提到,通常作者会就如何应对航空公司的这类政策给出一些策略,但是在这种情况下,可选择的策略非常有限.这就是为什么一些人认为美国交通运输部应该对此类做法进行调查的原因.由此可见,人们认为交通运输部应该有所行动,故答案为[M].52.[N].题干意为,人们在为买机票制定预算的时候,应该把行李的费用和附加的选择座位的费用都考虐在内.注意抓住题干中的关键词budget,airfares,baggage fees和the added cost of seat selection.文章段落中,论及制定机票Bi算的内容在[N]段出现,该段第(1)点提到,预算票价的时候,确保自己不仅格行李费用考虑在内,还要考虑为选择座位而支付的额外费用.由此可见,题干对原文进行了同义改写,故答案为[N].53.[F].题干意为,凯文・米切尔认为所谓的收益管理是不道德且具有误导性的.注意抓住题干中的关键词Kevin Mitchell,yield nanagenent,unethical和misleading.文章段落中,提到Kevin Mitchell 和航空业收益管理的内容在[F]段出现,该段引用米切尔的原话中提到,对于收益管理,消费者心里有数,他们知道航空公司经常改变座位的价格.但是如果情况果真如此的话,航空公司的做法确实是不道德的他们在严重地误导人们.由此可见,题干是对原文的同义转述,故答案为[F].54.[K].题干意为,达美航空公司发言人的话表明,经济舱优等座在飞机起飞前24小时内可获得.注意题干中的关键词the spokesman of Delta,the preferred econony-class tickets,available 和the plane's departure.文章段落中,论及达美航空公司发言人的内容在[K]段出现,该段第二句提到,优等座主要是为奖章成员预留的,在飞机起飞前24小时内无需支付额外费用就可获得.由此可见,题干是对原文的同义转述,故答窠为[K].55.[N]题干意为,应对航空公司这类行为的最后策略是和其它乘客商量调换座位.注意题干中的关键词the last strategy,exchange seats和negotiating.文章段落中,论及与其它乘客商量调换座位的内容在[N]段出现,该段第(4)点提到,量后一个应对策略,即霍比卡所说的讨价还价”,是和其它乘客商量一下调换座位.由此可见,题干是对原文的同义改写,故答案为[N].题干中的the last strategy 和exchange seats with other passengers by negotiating with them分另']对应原文中的the last resort和negotiating seat svaps with other passengers.。
2020年大学英语六级阅读理解试题及答案(卷四)
2020年大学英语六级阅读理解试题及答案(卷四)I lost my sight when I was four years old by falling off a box car in a freight yard in Atlantic City and landing on my head. Now I am thirty two.I can vaguely remember the brightness of sunshine and what color red is. It would be wonderful to see again, but a calamity can do strange things to people. It occurred to me the other day that I might not have come to love life as I do if I hadn't been blind. I believe in life now. I am not so sure that I would have believed in it so deeply, otherwise. I don't mean that I would prefer to go without my eyes. I simply mean that the loss of them made me appreciate the more what I had left.Life, I believe, asks a continuous series of adjustments to reality. The more readily a person is able to make these adjustments, the more meaningful his own private world becomes. The adjustment is never easy.I was bewildered and afraid. But I was lucky. My parents and my teachers saw something in me--a potential to live, you might call it--which I didn't see, and they made me want to fight it out with blindness.The hardest lesson I had to learn was to believe in myself. That was basic. If I hadn't been able to do that, I would have collapsed and become a chair rocker on the front porch for the rest of my life. When I say belief in myself I am not talking about simply the kind of self confidence that helps me down an unfamiliar staircase alone. That is part of it. But I mean something bigger than that: an assurance that I am,despite imperfections, a real, positive person; that somewhere in the sweeping, intricate pattern of people there is a special place where I can make myself fit.It took me years to discover and strengthen this assurance. It had to start with the most elementary things. Once a man gave me an indoor baseball. I thought he was mocking me and I was hurt. "I can't use this." I said. "Take it with you," he urged me, "and roll it around." The words stuck in my head. "Roll it around! "By rolling the ball I could hear where it went. This gave me an idea how to achieve a goal I had thought impossible: playing baseball. At Philadelphia's Overbrook School for the Blind I invented a successful variation of baseball. We called it ground ball.All my life I have set ahead of me a series of goals and then tried to reach them, one at a time. I had to learn my limitations. It was no good to try for something I knew at the start was wildly out of reach because that only invited the bitterness of failure. I would fail sometimes anyway but on the average I made progress.1. We can learn from the beginning of the passage thatA. the author lost his sight because of a car crash.B. the author wouldn't love life if the disaster didn't happen.C. the disaster made the author appreciate what he had.D. the disaster strengthened the author's desire to see.2. What's the most difficult thing for the author?A. How to adjust himself to reality.B. Building up assurance that he can find his place in life.C. Learning to manage his life alone.D. To find a special work that suits the author.3. According to the context, "a chair rocker on the front porch" in paragraph 3 means that the authorA. would sit in a rocking chair and enjoy his life.B. was paralyzed and stayed in a rocking chair.C. would lose his will to struggle against difficulties.D. would sit in a chair and stay at home.4. According to the passage, the baseball and encouragement offered by the manA. hurt the author's feeling.B. gave the author a deep impression.C. directly led to the invention of ground ball.D. inspired the author.5. According to the passage, which of the following is CORRECT?A. The author set goals for himself but only invited failure most of the time.B. The author suggested not trying something beyond one's ability at the beginning.C. The bitterness of failure prevented the author from trying something out of reach.D. Because of his limitations, the author tried to reach one goal at a time.答案解析:1.[C]细节判断题。
2020年六级考试阅读练习题(5)
2020年六级考试阅读练习题(5)2020年六级考试阅读练习题(5)At some time in your life you may have a strong desire to do something strange or terrible. However, chances are that you don't act on your impulse, but let it pass instead. You know that to commit the action is wrong in some way and that other people will not accept your behavior.Perhaps the most interesting thing about the phenomenon of taboo(禁忌的) behavior is how it can change over the years within the same society, how certain behavior and attitudes once considered taboo can become perfectly acceptable and natural at another point in time. Topics such as death, for example, were once considered so upsetting and unpleasantthat it was a taboo to even talk about them. Now with the publication of important books such as On Death and Dying and Learning to Say Goodbye, people have become more aware of the importance of expressing feelings about death and, as a result, are more willing to talk about this taboo subject.One of the newest taboos in American society is the topic of fat. Unlike many other taboos, fat is a topic that Americans talk about constantly. It's not taboo to talk about fat; it's taboo to be fat. The "in" look is thin, not fat. In the work world, most companies prefer youthful-looking, trim executives to sell their image as well as their products to the public. The thin look is associated with youth, vigor, and success. The fat person, on the other hand, is thought of as lazy and lacking in energy, self-discipline, and self-respect. In an image-conscious society like the U. S. , thin is "in", fat is "out".It's not surprising, then, that millions of Americanshave become obsessed (着迷) with staying slim and "in shape". The pursuit of a youthful physical appearance is not, however, the sole reason for America's obsession with diet and exercise. Recent research has shown the critical importance of diet and exercise for personal health. As in most technologically developed nations, the life-style of North Americans has changed dramatically during the course of the last century. Modern machines do all the physical labor that people were once forced to do by hand. Cars and buses transport us quickly from point to point. As a result of inactivity and disuse, people's bodies can easily become weak and vulnerable to disease. In an effort to avoid such a fate, millions of Americans are spending more of their time exercising every day.26. From the passage we can infer taboo is .A. a strong desire to do something strange or terribleB. a crime committed on impulseC. behavior considered unacceptable in society's eyesD. an unfavorable impression left on other people27、Based on the ideas presented in the passage we can conclude "being fat"_______.A. will always remain a tabooB. is not considered ataboo by most peopleC. has long been a tabooD. may no longer be a taboo some day28、The topic of fat is_______many other taboo subjects.A. the same asB. different fromC. more popular thanD. less often talked about than29、In the U. S. , thin is "in", fat is "out", this means_______.A. thin is "inside", fat is "outside"B. thin is "diligent", fat is "lazy"C. thin is "youthful", fat is "spiritless"D. thin is "fashionable", fat is "unfashionable"30、The main reason the passage gives for why so many Americans are exercising regularly is_______.A. their changed life-styleB. their eagerness to stay thin and youthfulC. their appreciation of the importance of exerciseD. the encouragement they have received from their companies26. C 27. D 28. B 29. D 30. B。
2020年6月英语四级阅读真题及答案
2020年6月英语四级阅读真题及答案Section ADirections:In this section, there is a passage with tenblanks. You are required to select one word for each blankfrom a list of choices given in a word bank following thepassage. Read the passage through carefully before makingyour choices. Each choice in the bank is identified by aletter. Please mark the corresponding letter for each item onAnswer Sheet 2 with a single line through the centre. You maynot use any of the words in the bank more than once.Questions 47 to 56 are based on the following passage.Walking, if you do it vigorously enough, is the overallbest exercise for regular physical activity. It requires noequipment, everyone knows how to do it and it carries the 47risk of injury. The human body is designed to walk. You canwalk in parks or along a river or in your neighborhood. Toget 48 benefit from walking, aim for 45 minutes a day, anaverage of five days a week.Strength training is another important 49 of physicalactivity. Its purpose is to build and 50 bone and muscle mass,both of whichshrink with age. In general, you will want todo strength training two or three days a week, 51 recoverydays between sessions.Finally, flexibility and balance training are 52important as the body ages. Aches and pains are high on thelist of complaints in old age. The result of constant muscletension and stiffness of joints, many of them are 53 , andsimple flexibility training can 54 these by making musclesstronger and keeping joints lubricated (润滑). Some of thisyou do whenever you stretch. If you watch dogs and cats,you’ll get an idea of how natural it is. The general 55 issimple:whenever the body has been in one position for awhile, it is good to 56 stretch it in an opposite position.]A) allowing F) helping K) preventB) avoidable G) increasingly L) principleC) briefly H) lowest M) provokeD) component I) maintain N) seriouslyE) determined J) maximum O) topic参考答案47. H. lowest48. J. maximum>49. D. component50. I. maintain51. A. allowing52. G. increasingly53. B. avoidable54. K. prevent55. L. principle56. C. briefly%SectionBDirections:There are 2 passages in this section. Eachpassage is followed by some questions or unfinishedstatements. For each of them there are four choices marked A),B), C) and D). You should decide on the best choice and markthe corresponding letter on Answer Sheet 2 with a single linethrough the centre.Passage OneQuestions 57 to 61 are based on the following passage.Junk food is everywhere. We’re eating way too much of it.Most of us know what we’re doing and yet we do it anyway.So here’s a suggestion offered by two researchers at theRand Corporation:Why not take a lesson from alcohol controlpolicies and apply them to where food is sold and how it’sdisplayed?“Many policy measures to contr ol obesity(肥胖症)assumethat people consciously and rationally choose what and howmuch they eat and therefore focus on providing informationand more access to healthier foods,” note the tworesearchers.“In contrast,” the researchers continue, “manyregulation s that don’t assume people make rational choiceshave been successfully applied to control alcohol, asubstance—like food—of which immoderate consumptionleads to serious health problems.”—The research references studies of people’s behaviorwith food and alcohol and results of alcohol restrictions,and then lists five regulations that the researchers thinkmight be promising if applied to junk foods. Among them:Density restrictions:licenses to sell alcohol aren’thanded out unplanned to all comers but are allotted(分配)based on the number of places in an area that already sellalcohol. These make alcoholless easy to get and reduce thenumber of psychological cues to drink.Similarly, the researchers say, being presented with junkfood stimulates our desire to eat it. So why not limit thedensity of food outlets, particularly ones that sell foodrich in empty calories? And why not limit sale of food inplaces that aren’t primarily food stores?Display and sales restrictions:California has a ruleprohibiting alcohol displays near the cash registers in gasstations, and in most places you can’t buy alcohol at drive-through facilities. At supermarkets, food companies pay tohave their wares in places where they’re easily seen. Onecould remove junk food to the back of the store and ban themfrom the shelves at checkout lines. The other measuresinclude restricting portion sizes, taxing and prohibitingspecial price deals for junk foods, and placing warninglabels on the products.57. What does the author say about junk food?A) People should be educated not to eat too much.B) It is widely consumed despite its ill reputation.C) Its temptation is too strong for people to resist.[D) It causes more harm than is generally realized.58. What do the Rand researchers think of many of thepolicy measures to control obesity?A) They should be implemented effectively.B) They provide misleading information.C) They are based on wrong assumptions.D) They help people make rational choices.59. Why do policymakers of alcohol control place densityrestrictions?A) Few people are able to resist alcohol’s temptations.~B) There are already too many stores selling alcohol.C) Drinking strong alcohol can cause social problems.D) Easy access leads to customers’ over-consumption.60. What is the p urpose of California’s rule aboutalcohol display in gas stations?A) To effectively limit the density of alcohol outlets.B) To help drivers to give up the habit of drinking.C) To prevent possible traffic jams in nearby areas.D) To get alcohol out of drivers’ immediate sight.)61. What is the general guideline the Rand researcherssuggest about junk food control?A) Guiding people to make rational choices about food.B) Enhancing people’s awareness of their own health.C) Borrowing ideas from alcohol control measures.D) Resorting to economic, legal and psychological means.参考答案57.C 58.C 59.D 60.D 61.CSection C Passage One、Questions 62 to 66 are based on the following passage.Kodak’s decision to file for bankruptcy(破产)protectionis a sad, though not unexpected, turning point for a leadingAmerican corporation that pioneered consumer photography anddominated the film market for decades, but ultimately failedto adapt to the digital revolution.Although many attribute Kodak’s downfall to“complacency(骄傲) ,” that explanation doesn’tacknow-ledge the lengths to which the company went to reinventitself. Decades ago, Kodak anticipated that digitalphotography would overtake film—and in fact, Kodakinvented the first digital camera in 1975—but in afatefuldecision, the company chose to shelf its new discovery tofocus on its traditional film business.It wasn’t that Kodak was blind to the future, saidRebecca Henderson, a professor at Harvard Business School,but rather that it failed to execute on a strategy toconfront it. By the time the company realized its mistake, itwas too late.Kodak is an example of a firm that was very much awarethat they had to adapt, and spent a lot of money trying to doso, but ultimately failed. Large companies have a difficulttime switching into new markets because there is a temptationto put existing assets into the new businesses.Although Kodak anticipated the inevitable rise of digitalphotography, its corporate(企业的) culture was too rooted inthe successes of the past for it to make the clean breaknecessary to fully embrace the future. They were a companystuck in time. Their history was so important to them. Nowtheir history has become a liability.Kodak’s downfall over the last several decades wasdramatic. In 1976, the company commanded 90% of the marketfor photographic film and 85% of the market for cameras. Butthe1980s brought new competition from Japanese film companyFuji Photo, which undermined Kodak by offering lower pricesfor film and photo supplies. Kodak’s decision not topursueth e role of official film for the 1984 Los Angeles Olympicswas a major miscalculation. The bid went instead to Fuji,which exploited its sponsorship to win a permanent footholdin the marketplace.62. What do we learn about Kodak?、A) It went bankrupt all of a sudden.B) It is approaching its downfall.C) It initiated the digital revolution in the filmindustry.D) It is playing a dominant role in the film market.63. Why does the author mention Kodak’s invention of thefirst digital camera?A) To show its early attempt to reinvent itself.B) To show its effort to overcome complacency.C) To show its quick adaptation to the digital revolution.>D) To show its will to compete with Japan’s Fuji photo.64. Why do large companies have difficulty switching tonew markets?A) They find it costly to give up their existing assets.B) They tend to be slow in confronting new challenges.C) They are unwilling to invest in new technology.D) They are deeply stuck in their glorious past.65. What does the author say Kodak’s history has become?A) A burden.—B) A mirror.C) A joke.D) A challenge.66. What was Kodak’s fatal mistake?A) Its blind faith in traditional photography.B) Its failure to see Fuji photo’s emergence.C) Its refusal to sponsor the 1984 Olympics.D) Its overconfidence in its corporate culture.参考谜底62. B.63. A.64. D.65. A.。
2020年英语六级长篇阅读练习及答案详解(4)
2020年英语六级长篇阅读练习及答案详解(4)2020年英语六级长篇阅读练习及答案详解(4)Definitions of ObesityA: How does one define when a person is considered to be obese and not just somewhat overweight? Height-weight tables give an approximate guideline as to whether one is simply overweight or has passed into the obese stage.B:The World Health Organization recommends using a formula that takes into account a person's height and weight. The "Body Mass Index" (BMI) is calculated by dividing the person's weight in kilograms by the square of their height in meters, and is thus given in units of kg/m2. A BMI of 18.5-24.9 is considered to be the healthiest. A BMI of between 25 and 29.9 is considered to be overweight, while a BMI of over 30 is considered to be obese.C: However, it is recognized that this definition is limited as it does not take into account such variables as age, gender and ethnic origin, the latter being important as different ethnic groups have very different fat distributions. Another shortcoming is that it is not applicable to certain very muscular people such as athletes and bodybuilders, who can also have artificially high BMIs. Agencies such as the National Cholesterol Education Program (NCEP) in the USA and the International Diabetes Foundation (IDF) are starting to define obesity in adults simply in terms of waist circumference.Health Effects of ObesityD: Over 2000 years ago, the Greek physician Hippocrates wrote that "persons who are naturally very fat are apt to die earlier than those who are slender". This observation remainsvery true today. Obesity has a major impact on a person's physical, social and emotional well-being. It increases the risk of developing diabetes mellitus type 2 ("mature onset diabetes") and also makes Type 2 diabetes more difficult to control. Thus weight loss improves the levels of blood glucose and blood fats, and reduces blood pressure. The association between obesity and coronary heart disease is also well-known.CancerE: Furthermore, in 2001 medical researchers established a link between being overweight and certain forms of cancer, and estimated that nearly 10,000 Britons per year develop cancer as a result of being overweight. This figure was made up of 5,893 women and 3,220 men, with the strongest associations being with breast and colon cancers. However, it is thought that being overweight may also increase the risk of cancer in the reproductive organs for women and in the prostate gland for men.F: The link between breast cancer and nutritional status is thought to be due to the steroid hormones oestrogen and progesterone, which are produced by the ovaries, and govern a woman's menstrual cycle. Researchers have found that the more a woman eats, or the more sedentary her lifestyle, the higher are the concentrations of progesterone. This link could explain why women from less affluent countries have lower rates of breast cancer. Women from less affluent nations tendto eat less food and to lead lifestyles which involve more daily movement. This lowers their progesterone level, resulting in lower predisposition to breast cancer.G: The Times newspaper, in 2002 reported that obesity was the main avoidable cause of cancer among non-smokers in theWestern world!AgingH: Research published by St Thomas' Hospital, London, UK in 2005 showed a correlation between body fat and aging, to the extent that being obese added 8.8 years to a woman's biological age. The effect was exacerbated by smoking, and a non-overweight woman who smokes 20 cigarettes a day for 20 years added 7.4 years to their biological age. The combination of being obese and a smoker added at least ten yea rs to a woman’s biological age, and although the study only involved women, the lead researcher Professor Tim Spector believes the finding would also apply to men.I: The aging effect was determined by measuring the length of telomeres, tiny "caps" on the ends of chromosomes, which help protect the DNA from the ageing process. Indeed, telomeres have been dubbed the "chromosomal clock" because, as an organism ages, they become progressively shorter, and can be used to determine the age of the organism. Beyond a certain point, the telomere becomes so short that it is no longer able to prevent the DNA of the chromosome from falling apart. It is believed that excess body fat, and the chemicals present in tobacco smoke release free radicals which trigger inflammation. Inflammation causes the production of white blood cells which increases the rate of erosion of telomeres.。
2020年6月英语六级阅读真题及答案(1)
2020年6月英语六级阅读真题及答案2020年6月英语六级阅读真题及答案Section ADirections: In this section, there is a short passagewith 5 questions or incomplete statements. Read the passage carefully. Then answer the questions or complete the statements in the fewest possible words. Please write your answers on Answer Sheet 2.Questions 47 to 51 are based on the following passage.How good are you at saying "no"? For many, it'ssurprisingly difficult. This is especially true of editors, who by nature tend to be eager and engaged participants in everything they do. Consider these scenarios:It's late in the day. That front-page package you've been working on is nearly complete; one last edit and it's finished. Enter the executive editor, who makes a suggestion requiring a more-than-modest rearrangement of the design and the addition of an information box. You want to scream: "No! It's done!" What do you do?The first rule of saying no to the boss is don't say no. She probably has something in mind when she makes suggestions, and it's up to you to find out what. The second rule is don't raise the stakes by challenging her authority. That issue is already decided. The third rule is to be ready to citeoptions and consequences. The boss's suggestions might be appropriate, but there are always consequences. She might not know about the pages backing up that need attention, or aboutthe designer who had to go home sick. Tell her she can have what she wants, but explain the consequences. Understand what she's trying to accomplish and propose a Plan B that will make it happen without destroying what you've done so far.Here's another case. Your least-favorite reporter suggests a dumb story idea. This one should be easy, but it's not. If you say no, even politely, you risk inhibitingfurther ideas, not just from that reporter, but from others who heard that you turned down the idea. This scenario is common in newsrooms that lack a systematic way to filter story suggestions.Two steps are necessary. First, you need a system for how stories are proposed and reviewed. Reporters can tolerate rejection of their ideas if they believe they were given a fair hearing. Your gut reaction (本能反应) and dismissive rejection, even of a worthless idea, might not qualify as systematic or fair.Second, the people you work with need to negotiate a "What if ...?" agreement covering "What if my idea is turned down?" How are people expected to react? Is there an appeal process? Can they refine the idea and resubmit it? By anticipating "What if...?" situations before they happen, you can reach understanding that will help ease you out of confrontations.47. Instead of directly saying no to your boss, you should find out __________.48. The author's second warning is that we should avoid running a greater risk by __________.49. One way of responding to your boss's suggestion is to explain the __________ to her and offer an alternative solution.50. To ensure fairness to reporters, it is important toset up a system for stories to __________.51. People who learn to anticipate "What if...?"situations will be able to reach understanding and avoid__________.参考答案47. what is in your boss's mind48. challenging our boss's anthority49. possible consequences50. be proposed and reviewed51. feeling uneasy about the confrontationsSection BDirections: There are 2 passages in this section. Each passage is followed by some questions or unfinished statements. For each of them there are four choices marked A), B), C) and D). You should decide on the best choice and mark the corresponding letter on Answer Sheet 2 with a single line through the centre.Passage OneQuestions 52 to 56 are based on the following passage.At the heart of the debate over illegal immigration lies one key question: are immigrants good or bad for the economy? The American public overwhelmingly thinks they're bad. Yetthe consensus among most economists is that immigration, both legal and illegal, provides a small net boost to the economy. Immigrants provide cheap labor, lower the prices ofeverything from farm produce to new homes, and leave consumers with a little more money in their pockets. So whyis there such a discrepancy between the perception of immigrants' impact on the economy and the reality?There are a number of familiar theories. Some argue that people are anxious and feel threatened by an inflow of new workers. Others highlight the strain that undocumented immigrants place on public services, like schools, hospitals, and jails. Still others emphasize the role of race, arguing that foreigners add to the nation's fears and insecurities. There's some truth to all these explanations, but they aren't quite sufficient.To get a better understanding of what's going on,consider the way immigration's impact is felt. Though its overall effect may be positive, its costs and benefits are distributed unevenly. David Card, an economist at UC Berkeley, notes that the ones who profit most directly from immigrants' low-cost labor are businesses and employers – meatpacking plants in Nebraska, for instance, or agricultural businessesin California. Granted, these producers' savings probably translate into lower prices at the grocery store, but howmany consumers make that mental connection at the checkout counter? As for the drawbacks of illegal immigration, these, too, are concentrated. Native low-skilled workers suffer mostfrom the competition of foreign labor. According to a study by George Borjas, a Harvard economist, immigration reduced the wages of American high-school dropouts by 9% between 1980-2000.Among high-skilled, better-educated employees, however, opposition was strongest in states with both high numbers of immigrants and relatively generous social services. What worried them most, in other words, was the fiscal (财政的)burden of immigration. That conclusion was reinforced by another finding: that their opposition appeared to soften when that fiscal burden decreased, as occurred with welfare reform in the 1990s, which curbed immigrants' access to certain benefits.The irony is that for all the overexcited debate, the net effect of immigration is minimal. Even for those most acutely affected – say, low-skilled workers, or California residents – the impact isn't all that dramatic. "The unpleasant voices have tended to dominate our perceptions," says Daniel Tichenor, a political science professor at the University of Oregon. "But when all those factors are put together and the economists calculate the numbers, it ends up being a net positive, but a small one." Too bad most people don't realize it.注意:此部分试题请在答题卡2上作答。
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2020年6月大学英语六级长篇阅读练习题(1)10 Ways Obama Could Fight Climate Change[A] One of the biggest surprises of President Barack Obama's inaugural address,on Monday was how much he focused on fighting climate change, spending more time on that issue than any other. "We will respond to the threat of climate change, knowing that the failure to do so would betray our children and future generations," Obama said. The President pointed out that recent severe weather supplied an urgent impetus for energy innovation and staked the nation's economic future on responding to a changing climate. "We cannot cede to other nations the technology that will power new jobs and new industries--we must claim its promise," Obama said. '" That's how we will maintain our economic vitality and our national treasure--our forests and waterways; our croplands and snowcapped (山顶积雪的) peaks. That is how we will preserve our planet, commanded to our care by God. " so what could the President reasonably do to deliver on that vow? Here are ten of their suggestions:Sunset coal with new incentives and regulations.[B] "Provide incentives to phase out the oldest, most polluting power plants," said Robert Jackson, a climate scientist at Duke University. It's already happening, to some degree, as more of the nation transitions to natural gas. Earth scientist Bill Chameides, dean of Duke's Nicholas School of the Environment and a former chief scientist at the Environmental Defense Fund, urges the administration to use its Clean, Air Act authority to promulgate (颁布)carbon regulations for existing power plants like it has for new ones: "Doing that will force fuel switching from coal to natural gas. "Invest federal stimulus money in nuclear power.[C] It's hardly a perfect fuel, as accidents like Japan's Fukushima fallout have shown, but with safety precautions new nuclear plants can meaningfully offset dirtier types of energy, supporters say."Nuclear is the only short-to medium-term way to really get away from fossil fuels," said Peter Raven. President emeritus of the Missouri Botanical Garden. He said the damage done by relentless global warming will far exceed the damage done by faults in the nuclear system.Kill the Keystone pipeline.[D] The controversial Keystone XL oil pipeline is up for review again by the White House this year. "The font thing he should do to set the tone to a lowercarbon economy is to reject the Keystone pipeline, “said Raymond Pierrehum Bert, a geophysical scientist at the University of Chicago. The pipeline was never going to be a major driver of global emissions, but Pierre humbert and some other environmentalists say that by killing it the President would send a clear message about America's intent to ramp down fossil fuels.Protect the oceans by executive order.[E] Land use is complicated, but large swaths of oceans can be protected by executive order. Just as President George W. Bush designated the world's largest marine monument northwest of Hawaii in 2006. Obama could single-handedly protect other areas. National Geographic Explorer-in-Residence Sylvia Earle said the President should focus on parts of the Arctic that are under U. S. control, putting them off limits to energy production, commercial fishing, and mineral exploration. Marine sanctuaries (禁捕区) won't stop climate change, but they can give marine species a better chance of adapting to it by reducing the other man-made threats the animals face.Experiment with capturing carbon.[F] Huge untapped reserves of natural gas and oil make it unlikely that the U. S. will transition away from fossil fuels in the immediate future. Instead, said Wallace Broecker, geology professor at Columbia University's Lamont-Doherty Earth Observatory, we should attack the atmosphere's carbon surplus directly. "Obama could make available funds to build and test prototype air capture units" to capture and store CO2, said Broecker. Removing some carbon from the atmosphere could buy valuable time as policy makers and scientists explore more permanent solutions.Grow government research for new energy sources.[G] The Department of Energy has a nimble program that's tasked with innovative energy research—the Advanced Research Projects Agency-Energy. The ARPA-E funds research in biofuels, transmission,and battery storage, with an annual budget of $ 275 million. Last year, DOE officials requested at least $ 75 million more. Increasing funding for ARPA-E, said Rare Pomerance, former deputy assistant secretary of state for environment and development and currently an environmental consultant, "you get new technologies that undercut coal, oil, and gas. " Plus, he said, yon get a competitive advantage if American researchersuncover the next big idea in new energy.Tax carbon.[H] Congress would have to agree, but many climate experts say that the most meaningful way to tackle emissions is to set a price on carbon. "We should be asking people to pay the cost of putting carbon into the atmosphere as they buy the fuel," said Josh Willis, climate scientist and oceanographer at NASA's Jet Propulsion Laboratory. To gain political support for the idea, Obama would probably have to show that the tax wonld help accelerate technology, grow new industries, and pay down the deficit.Dial back the federal government's energy use.[I] With more than I. 8 million employees, $ 500 billion in annual purchasing power, and 500,000 buildings to operate, the federal government has been a leader in reducing energy use since Obama signed a 2009 executive order to cut waste. "I would urge him to keep using the power of government to promote energy conservation," said Syndonia Bret-Harte, an Arctic biologist who studies climate change at the University of Alaska, Fairbanks.Build a scientific clearinghouse for climate information.[J] "I advocate for building a better information system on what is happening and why," said Kevin Tren berth, head of the Climate Analysis Section at the U. S. National Center for Atmospheric Research. That involves compiling observations related to climate change from around the world and using the data to refine climate modeling. Think of it as a one-stop, user-friendly website that clearly demonstrates how weather data from around the globe are influenced by broader shifts in the planet's climate.Keep talking. Despite a consensus among top scientists, the world still needs some convincing on climate change.[K] A CNN poll last week found that just 49 percent of Americans agree that global warming is real and is due to human activities. "The most important thing the President can do is to build on his inaugural comments to heighten the sense of urgency about rapid climate destabilization and clarify its connection to virtually every other issue on the national agenda," said David Orr, environmental studies professor at Oberlin College. That means using the bully clergymen to show how a more volatile climate affects everything from agriculture totransportation to 21st-century warfare.46. The urge to promulgate carbon regulations is aimed at pushing power plants to replace coal by natural gas.47. Marine sanctuaries should be preserved because they help sea species adapt to climate alteration.48. The government should take the responsibility to raise Americans' awareness about climate change.49. Many climate experts believe that the most effective way to lower emission is to tax on carbon.50. Nuclear supporters argue that nuclear system failures are less challenging than global warming.51. Recent extreme weather made President Obama feel it is urgent to address climate change.52. Keystone pipeline should be rejected because it is a signal to reduce fossil fuels.53. Since Obama signed a 2009 executive order to cut waste, the federal government has taken the lead in saving energy.54. Lower carbon emission will be most likely to happen if research in new energy resources succeeds.55. Compared with turning to new energy, America prefers carbon capture and store as a temporary measure.2020年6月大学英语六级长篇阅读练习题(2)How to Make Attractive and Effective PowerPoint PresentationsA) Microsoft PowerPoint has dramatically changed the way in which academic and business presentations are made. This article outlines few tips on making more effective and attractive PowerPoint presentations.The TextB) Keep the wording clear and simple. Use active, visual language. Cut unnecessary words—a good rule of thumb is to cut paragraphs down to sentences, sentences into phrases, and phrases into key words.Limit the number of words and lines per slide. Try the Rule of Five-five words per line, five lines per slide. If too much text appears on one slide, use the AutoFit feature to split it between two slides. Click within the placeholder to display the AutoFit Options button (its symbol is two horizontal lines with arrows above and below), then click on the button and choose Split Text between Two Slides from the submenu.C) Font size for titles should be at least 36 to 40, while the text body should not be smaller than e only two font styles per slide—one for the title and the other for the text. Choose two fonts that visually contrast with each other. Garamond Medium Condensed and Impact are good for titles, while Garamond or Tempus Sans can be used for the text body.D) Embed the fonts in your presentation, if you are not sure whether the fonts used in the presentation are present in the computer that will be used for the presentation. To embed the fonts: (1) On the File menu, click Save As. (2) On the toolbar, click Tools, click Save Options, select the Embed TrueType Fonts check box, and then select Embed characters in use only.E) Use colors sparingly; two to three at most. You may use one color for all the titles and another for the text body. Be consistent from slide to slide. Choose a font color that contrasts well with the background.F) Capitalizing the first letter of each word is good for the title of slides and suggests a more formal situation than having just the first letter of the first word capitalized. In bullet point lines, capitalize the first word and no other words unless they normally appear capped. Upper and lower case lettering is more readable than all capital letters. Moreover, current styles indicate that using allcapital letters means you are shouting. If you have text that is in the wrong case, select the text, and then click Shift+F3 until it changes to the case style that you like. Clicking Shift+F3 toggles the text case between ALL CAPS, lower case, and Initial Capital styles.G) Use bold or italic typeface for emphasis. Avoid underlining, it clutters up the presentation.Don’t center bulleted lists or text. It is confusing to read. Left align unless you have a good reason not to. Run “spell check” on your show when finished.The BackgroundH) Keep the background consistent. Simple, light textured backgrounds work well. Complicated textures make the content hard to read. If you are planning to use many clips in your slides, select a white background. If the venue of your presentation is not adequately light-proof, select a dark-colored background and use any light color for text. Minimize the use of “bells and whistles” such as sound effects, “flying words” and multiple transitions. Don’t use red in any fonts or backgrounds. It is an emotionally overwhelming color that is difficult to see and read.The ClipsI) Animations are best used subtly; too much flash and motion can distract and annoy viewers. Do not rely too heavily on those images that were originally loaded on your computer with the rest of Office. You can easily find appropriate clips on any topic through Google Images. While searching for images, do not use long search phrases as is usually done while searching the web-use specific words.J) When importing pictures, make sure that they are smaller than two megabytes and are in a .jpg format. Larger files can slow down your show. Keep graphs, charts and diagrams simple, if possible. Use bar graphs and pie charts instead of tables of data. The audience can then immediately pick up the relationships.The PresentationK) If you want your presentation to directly open in the slide show view, save it as a slide show file using the following steps. Open the presentation you want to save as a slide show. On the File menu, click Save As. In the Save astype list, click PowerPoint Show. Your slide show file will be saved with a ppt file extension. When you double-click on this file, it will automatically start your presentation in slide show view. When you’re done, PowerPoint automatically closes and you return to the desktop. If you want to edit the slide show file, you can always open it from PowerPoint by clicking Open on the File menu.L) Look at the audience, not at the slides, whenever possible. If using a laser pointer, don’t move it too fast. For examp le, if circling a number on the slide, do it slowly. Never point the laser at the audience. Black out the screen (use “B” on the keyboard) after the point has been made, to put the focus on you. Press the key again to continue your presentation.M) You can use the shortcut command [Ctrl]P to access the Pen tool during a slide show. Click with your mouse and drag to use the Pen tool to draw during your slide show. To erase everything you’ve drawn, press the E key. To turn off the Pen tool, press [Esc] once.MiscellaneousN) Master Slide Set-Up: The “master slide” will allow you to make changes that are reflected on every slide in your presentation. You can change fonts, colors, backgrounds, headers, and footers at the “master slide” level. First, go to the “View” menu. Pull down the “Master” menu. Select the “slide master” menu. You may now make changes at this level that meet your presentation needs.1. The ways in which academic and business presentations are made have been changed by Microsoft PowerPoint.2. When making the PowerPoint, the wording of the text should not be complicated.3. In each slide, the font styles for the title and the text should contrast with each other.4. A more formal situation is capitalizing the first letter of the first word.5. Centering bulleted lists or text can not help to read.6. Sound effects should be used as less frequently as possible.7. When importing pictures, make sure that they are smaller than two megabytes.8. When making the presentation, you should look at the audience as possible as you can.9. Pressing the E key can help you to erase everything you've drawn.10. In order to meet your presentation needs, you can make changes at the “slide master”level.2020年6月大学英语六级长篇阅读练习题(3)Paper--More than Meets the EyeA) We are surrounded by so much paper and card that it is easy to forget just how complex it is. There are many varieties and grades of paper materials, and whilst it is fairly easy to spot the varieties, it is far more difficult to spot the grades.B) It needs to be understood that most paper and card is manufactured for a specific purpose, so that whilst the corn-flake packet may look smart, it is clearly not something destined for the archives. It is made to look good, but only needs a limited life span. It is also much cheaper to manufacture than high grade card.C) Paper can be made from an almost endless variety of cellulose-based material which will include many woods, cottons and grasses or which papyrus is an example and from where we get the word "paper". Many of these are very specialized, but the preponderance of paper making has been from soft wood and cotton or rags, with the bulk being wood-based.Paper from WoodD) In order to make wood into paper it needs to be broken down into fine strands. Firstly by powerful machinery and then boiled with strong alkalies such as caustic soda, until a fine pulp of cellulose fibers is produced. It is from this pulp that the final product is made, relying on the bonding together of the cellulose into layers. That, in a very small nutshell, is the essence of paper making from wood. However, the reality is rather more complicated. In order to give us our white paper and card, the makers will add bleach and other materials such as china clay and additional chemicals.E) A further problem with wood is that it contains a material that is not cellulose. Something called lignin. This is essential for the tree since it holds the cellulose fibres together, but if it is incorporated into the manufactured paper it presents archivists with a problem. Lignin eventually breaks down and releases acid products into the paper. This will weaken the bond between the cellulose fibers and the paper will become brittle and look rather brown and careworn. We have all seen this in old newspapers and cheap paperback books. It has been estimated that most paper back books will have a life of not greaterthan fifty years. Not what we need for our archives.F) Since the lignin can be removed from the paper pulp during manufacture, the obvious question is "why is it left in the paper?" The answer lies in the fact that lignin makes up a considerable part of the tree. By leaving the lignin in the pulp a papermaker can increase his paper yield from a tree to some 95%. Removing it means a yield of only 35%. It is clearly uneconomic to remove the lignin for many paper and card applications.G) It also means, of course, that lignin-free paper is going to be more expensive, but that is nevertheless what the archivist must look for in his supplies. There is no point whatsoever in carefully placing our valuable artifacts in paper or card that is going to hasten their demise. Acid is particularly harmful to photographic materials, causing them to fade and is some cases simply vanish!H) So, how do we tell a piece of suitable paper or card from one that is unsuitable? You cannot do it by simply looking, and rather disappointingly, you cannot always rely on the label. "Acid-free" might be true inasmuch as a test on the paper may indicate that it is a neutral material at this time. But lignin can take years before it starts the inevitable process of breaking down, and in the right conditions it will speed up enormously.I) Added to this, as I have indicated earlier, paper may also contain other materials added during manufacture such as bleach, china clay, chemical whiteners and size. This looks like a bleak picture, and it would be but for the fact that there are suppliers who will guarantee the material that they sell. If you want to be absolutely sure that you are storing in, or printing on, the correct material then this is probably the only way.J) Incidentally, acids can migrate from material to material. Lining old shoe boxes with good quality acid-free paper will do little to guard the contents. The acid will get there in the end.Paper from RagK) Paper is also commonly made from cotton and rag waste. This has the advantage of being lignin-free, but because there is much less cotton and rag than trees, it also tends to be much more expensive than wood pulp paper. You will still need to purchase from a reliable source though, since even rag paperand card can contain undesirable additives.L) A reliable source for quality rag papers is a recognized art stockiest. Many water color artists insist on using only fine quality rag paper and board.M) The main lesson to learn from this information is that you cannot rely on purchasing archival materials from the high street. The only safe solution is to purchase from specialist suppliers. It may cost rather more, but in the end you will know that your important and valuable data and images have the best home possible.1. The corn-flake packet is cheaper than high grade card.2. There are a lot of materials which can be used for making paper, but the superiority ones are soft wood, cotton and rags.3. During the whole manufacturing process, the final product is made froma pulp of cellulose fibres.4. In order to make white paper and card, the makers will add bleach.5. Liguin is essential for the tree but it will make paper easy to break.6. Many paper producers will preserve lignin during manufacture, because leaving the lignin will make more paper from a tree.7. Acid is particularly harmful to photographic materials.8. If the lignin is removed from the paper, the paper will be more expensive.9. Although free of lignin, paper made from cotton and rag waste can also cost more money than wood pulp paper because there is much less cotton and rag than trees.10. What we can learn from "Paper from Rag" is that you had better buy archival materials from specialist suppliers.2020年6月大学英语六级长篇阅读练习题(4)Definitions of ObesityA: How does one define when a person is considered to be obese and not just somewhat overweight? Height-weight tables give an approximate guideline as to whether one is simply overweight or has passed into the obese stage.B: The World Health Organization recommends using a formula that takes into account a person's height and weight. The "Body Mass Index" (BMI) is calculated by dividing the person's weight in kilograms by the square of their height in meters, and is thus given in units of kg/m2. A BMI of 18.5-24.9 is considered to be the healthiest. A BMI of between 25 and 29.9 is considered to be overweight, while a BMI of over 30 is considered to be obese.C: However, it is recognized that this definition is limited as it does not take into account such variables as age, gender and ethnic origin, the latter being important as different ethnic groups have very different fat distributions. Another shortcoming is that it is not applicable to certain very muscular people such as athletes and bodybuilders, who can also have artificially high BMIs. Agencies such as the National Cholesterol Education Program (NCEP) in the USA and the International Diabetes Foundation (IDF) are starting to define obesity in adults simply in terms of waist circumference.Health Effects of ObesityD: Over 2000 years ago, the Greek physician Hippocrates wrote that "persons who are naturally very fat are apt to die earlier than those who are slender". This observation remains very true today. Obesity has a major impact on a person's physical, social and emotional well-being. It increases the risk of developing diabetes mellitus type 2 ("mature onset diabetes") and also makes Type 2 diabetes more difficult to control. Thus weight loss improves the levels of blood glucose and blood fats, and reduces blood pressure. The association between obesity and coronary heart disease is also well-known.CancerE: Furthermore, in 2001 medical researchers established a link between being overweight and certain forms of cancer, and estimated that nearly 10,000 Britons per year develop cancer as a result of being overweight. This figure was made up of 5,893 women and 3,220 men, with the strongest associations beingwith breast and colon cancers. However, it is thought that being overweight may also increase the risk of cancer in the reproductive organs for women and in the prostate gland for men.F: The link between breast cancer and nutritional status is thought to be due to the steroid hormones oestrogen and progesterone, which are produced by the ovaries, and govern a woman's menstrual cycle. Researchers have found that the more a woman eats, or the more sedentary her lifestyle, the higher are the concentrations of progesterone. This link could explain why women from less affluent countries have lower rates of breast cancer. Women from less affluent nations tend to eat less food and to lead lifestyles which involve more daily movement. This lowers their progesterone level, resulting in lower predisposition to breast cancer.G: The Times newspaper, in 2002 reported that obesity was the main avoidable cause of cancer among non-smokers in the Western world!AgingH: Research published by St Thomas' Hospital, London, UK in 2005 showed a correlation between body fat and aging, to the extent that being obese added 8.8 years to a woman's biological age. The effect was exacerbated by smoking, and a non-overweight woman who smokes 20 cigarettes a day for 20 years added 7.4 years to their biological age. The combination of being obese and a smoker added at least ten years to a woman’s biological age, and although the study only involved women, the lead researcher Professor Tim Spector believes the finding would also apply to men.I: The aging effect was determined by measuring the length of telomeres, tiny "caps" on the ends of chromosomes, which help protect the DNA from the ageing process. Indeed, telomeres have been dubbed the "chromosomal clock" because, as an organism ages, they become progressively shorter, and can be used to determine the age of the organism. Beyond a certain point, the telomere becomes so short that it is no longer able to prevent the DNA of the chromosome from falling apart. It is believed that excess body fat, and the chemicals present in tobacco smoke release free radicals which trigger inflammation. Inflammation causes the production of white blood cells which increases the rate of erosion of telomeres.DementiaJ: Recent research (2005) conducted in the USA shows that obesity in middle age is linked to an increased risk of dementia, with obese people in their40s being 74% more likely to develop dementia compared to those of normal weight. For those who are merely overweight, the lifetime risk of dementia risk was 35% higher.K: Scientists from the Aging Research Centre at the Karolinska Institute in Sweden have been able to take information such as age, number of years in education, gender, body mass index, blood pressure level, physical activity and genetic factors, assigning each a risk score. They then used this information to devise a predictive test for dementia. This test will enable people at risk, for the first time, to be able to affect lifestyle changes which will reduce their risk ofcontracting dementia.Other ProblemsL: The world-wide upsurge in obesity, particularly in children, is of major economic concern, liable to drain economies. Of further concern is that research conducted in Australia and published in 2006, shows that up to one third of breech pregnancies were undetected by the traditional "palpation" examination, the danger being greatest for those women who are overweight or obese—a growing proportion of mothers. This means that such women are not getting the treatment required to turn the baby around in time for the birth, and in many cases require an emergency Caesarean section.M: This is a true health-care crisis, far bigger than Severe Acute Respiratory Syndrome (SARS) and ultimately, even bigger than AIDS.1. You can judge whether one is simply overweight or has passed into the obese stage according to the height-weight table.2. Using the "Body Mass Index"to define a person's weight ideal is limited, because it does not takes into account many variables such as age, gender and ethnic origin.3. A person's emotional well-being would be affected by obesity.4. Obesity has something to do with cancer in the prostate gland for man.5. Women from less affluent nations tend to have much less breast cancer.6. A non-overweight woman who smokes 20 cigarettes a day for 20 years added7.4 years to her biological age.7. The excess body fat, like the chemicals present in tobacco smoke, can lead to inflammation.8. Obese people in middle age run an increased risk of dementia .9. The predictive test for dementia will help people to affect lifestyle changes that will reduce their risk of contracting dementia.10. The world-wide upsurge in obesity, particularly in children, will possibly drain economies.。