Read the passage below and decide whether the statements are TRUE or FALSE?
Autonomous weapons are artificial intelligence systems that are programmed to kill. In the hands of the wrong person, these weapons could easily cause mass casualties. Moreover, an AI arms race could inadvertently lead to an AI war that also results in mass casualties. To avoid being thwarted by the enemy, these weapons would be designed to be extremely difficult to simply “turn off,” so humans could plausibly lose control of such a situation. This risk is one that’s present even with narrow AI, but grows as levels of AI intelligence and autonomy increase.
These weapons would be designed to be extremely complicated
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Lời giải:
Báo saiGiải thích: Dựa vào câu: “, these weapons would be designed to be extremely difficult”.
Dịch nghĩa: những vũ khí này sẽ được thiết kế cực kỳ khó khăn
Câu hỏi liên quan
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Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks.
Finding Beauty in the City
Cities are known to have lives of their own, and photographers are able to (1).............. some of it. Whether taking shots of people walking on a crowded street or time-lapse shots of cars driving at night, the (2).......photos can be breathtaking. Because many of the shots taken are of man-made objects like architecture, many emotions that come into (3)........ wouldn’t be found in nature photography. Photos can show the wonder of a child staring at a fountain as water shoots upward in the sunlight. They can also show the sadder side, such as a camp of homeless people living in terrible poverty. (4)............ of what they show, there is always beauty to be found, even if it is beauty in something that is showing an ugly truth. Depending on the time of the day, photos taken in an urban environment can change drastically. To see the (5)............ of a building as its shadow is cast on the lawn of a park is always amazing to see.
(2)......................... -
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George Washington Carver showed that plant life was more than just food for animals and humans. Carver’s first step was to analyze plant parts to find out what they were made of. He then combined these simpler isolated substances with other substances to create new products.
The branch of chemistry that studies and finds ways to use raw materials from farm products to make industrial products is called chemurgy. Carver was one of the first and greatest chemurgists of all time. Today the science of chemurgy is better known as the science of synthetics. Each day people depend on and use synthetic materials made from raw materials. All his life Carver battled against the disposal of waste materials and warned of the growing need to develop substitutes for the natural substances being used up by humans.
Carver never cared about getting credit for the new products he created. He never tried to patent his discoveries or get wealthy from them. He turned down many offers to leave Tuskegee Institute to become a rich scientist in private industry. Thomas Edison, inventor of the electric light, offered him a laboratory in Detroit to carry out food research. When the United States government made him a collaborator in the Mycology and Plant Disease Survey of the Department of Agriculture, he accepted the position with the understanding that he wouldn’t have to leave Tuskegee. As an authority on plant diseases – especially of the fungus variety – Carver sent hundreds of specimens to the United States Department of Agriculture. At the peak of his career, Carver’s fame and influence were known on every continent.With what topic is the passage mainly concerned?
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The pain of a migraine headache can virtually disable a person who suffers from it. Millions and millions of people suffer from migraines, although many of them do not even recognize that a migraine is different from a regular headache. A migraine is not at all the same as a normal headache, and it seems to have a very physical cause.
One symptom of a migraine is a precursor, which is a visual aura before an attack. Yet only about a third of patients actually experience that, and it is therefore not a requirement in the diagnosis. Other symptoms include increased pain when a person moves, nausea, and sensitivity to light and sound. Scientists now believe that migraines are caused, not by abnormal blood vessels as previously believed, but instead by a unique electrical disorder of brain cells. Physicians used to treat migraines with medicine to constrict blood vessels because of the belief that dilated blood vessels were the cause.
The new research has been enhanced by imaging devices that allow scientists to watch patients' brains during an attack. The results show that sufferers have abnormally excitable neurons, or brain nerve cells. Prior to the attack, the neurons suddenly fire off electrical pulses at the back of the brain, which ripple like waves on a lake after a stone hits the water. They ripple across the top and then the back of the brain, ultimately affecting the brain stem where the pain centers are located. The pain then generates possibly from the brain stem itself or from blood vessels inflamed by the rapidly changing blood flow, or perhaps from both.
Scientists have experimented by applying a powerful magnet to stimulate the neurons and discovered that some people's brains react differently than others'. When stimulation was applied to the brains of people who had suffered migraines, they saw the initial aura, and some actually suffered migraines. When the same stimulation was applied to the brains of people who had never suffered migraines, they realized no effect and the neurons showed no change.
Scientists and doctors continue to work on the research in an attempt to find the perfect treatment. It is considered important to treat migraines because it is believed that prolonged untreated attacks could cause physical changes in the brain leading to chronic pain.The best title for this passage would be what?
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In the exploration of the linguistic life cycle, it is apparent that it is much more difficult to learn a second language in adulthood than a first language in childhood. Most adults never completely master foreign language, especially in phonology - hence the ubiquitous foreign accent. Their development often "fossilizes" into permanent error patterns that no teaching or correction can do. Of course, there are great individual differences, which depend on effort, attitudes, amount of exposure, quality of teaching and plain talent, but there seems to be a cap for the best adults in the best circumstances.
Many explanations have been advanced for children's superiority: they exploit Motherless (the simplified, repetitive conversation between parents and children), make errors oneself- consciously, are more motivated to communicate, like to conform, are not set in their ways, and have no first language to interfere. But some of these accounts are unlikely, based on what is known about how language acquisition works. Recent evidence is calling these social and motivation explanations into doubt. Holding every other factor constant, a key factor stands out: sheer age.
Systematic evidence comes from the psychologist Elisa Newport and her colleagues. They tested Korean and Chinese-born students at the University of Illinois who had spent at least ten years in the United States. The immigrants were given a list of 276 simple English sentences, half of them containing some grammatical errors. The immigrants who came to the United States between the ages of 3 and 7 performed identically to American bom students. Those who arrived between the ages of 8 and 15 did worse the later they arrived, and those who arrived between 17 and 39 did the worst of all, and showed huge variability unrelated to their age of arrival.According to the second paragraph, children learn languages better than adults because of the following reasons EXCEPT.................
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You might be surprised to know that bicycles have existed for less than two hundred years. Though the earliest comes from a sketch said to be from 1534 and attributed to Gian Giacomo, there are several early but unverified claims for the invention of the modem bicycle. No one is sure who invented this popular two- wheeled machine, but it was probably either the German Karl von Drais, in 1817, or the American W K Clarkson, in 1819. The early models didn't look much like the bicycles of today. The front wheel was much bigger than the back one, and also there weren't any pedals - riders had to move themselves forward by pushing their feet against the ground. Pedals finally arrived in the 1840s, and in 1879 an Englishman named Henry Lawson had the idea of connecting them to the back wheel with a chain. Gears, which made things much easier for those cycling uphill, first appeared in the 1890s.
There are now approximately one billion bicycles in the world - more than twice the total number of cars - and they are the main form of transport in some developing countries. They have to compete with cars on the streets of all the world’s cities, and the two forms of transport don't always mix well. In London in 2005, for example, over 300 cyclists were either killed or seriously injured in accidents involving cars. Even though bicycles are much more environmentally friendly than cars, most governments don't do much to encourage people to ride rather than drive. In China, which is famous for having a huge number of bicycles (about 200 million), the authorities in the city of Shanghai even banned cycling for a while in 2003.
Cycling is on the rise is the United Kingdom, and the number of annual journeys made by bike in London has increased 50% over the last five years. Experts say there is a mixture of reasons for this boom: concerns about the environment, the desire to keep fit, and also the fact that cycling is often not only cheaper but also quicker than travelling by car.
However, although one in three British adults owns a bicycle, they still don't use them nearly as much as they could. Bikes are used for a mere 2% of journeys in the UK, while the figure for the Netherlands is an impressive 27%.
Cycling is becoming more popular as a competitive sport, and the most famous race is of course the three-week Tour de France, which takes place every July. American Lance Armstrong won it every year from 1999 to 2005 - one of the greatest individual sporting achievements of all time.What was Lance Armstrong’s amazing achievement?
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Geothermal energy is natural heat from the interior of the Earth that is converted to heat buildings and generate electricity. The idea of harnessing Earth’s internal heat is not new. As early as 1904 , geothermal power was used in Italy . Today, Earth’s natural internal heat is being used to generate electricity in 21 countries , including Russia, Japan, New Zealand, Iceland, Mexico, Ethiopia, Guatemala, EI Salvador, the Philippines, and the United States .Total worldwide production is approaching 9,000 MW (equivalent to nine large modern coal-burning or nuclear power plants)-double the amount in 1980 .Some 40 million people today receive their electricity from geothermal energy at a cost competitive with that of other energy sources. In EI Salvador , geothermal energy is supplying 30% of the total electric energy used.
However, at the global level, geothermal energy supplies less than 0,15%of the total energy supply.
Geothermal energy may be considered a nonrenewable energy source when rates of extraction are greater than rates of natural replenishment. However, geothermal energy has its origin in the natural heat production within Earth , and only a small fraction of the vast total resource base is being utilized today. Although most geothermal energy production involves the tapping of high heat sources, people are also using the low-temperature geothermal energy of groundwater in some applications.Geothermal Systems
The average heat flow from the interior of the Earth is very low, about 0,06% W/m2.This amount is trivial compared with the 177 W/m2from solar heat at the surface in the United States. However, in some areas, heat flow is sufficiently high to be useful for producing energy . For the most part, areas of high heat flow are associated with plate tectonic boundaries. Oceanic ridge systems (divergent plate boundaries) and areas where mountains are being uplifted and volcanic island arcs are forming (convergent plate boundaries) are areas where this natural heat flow is anomalously high. One such region is located in the western, United States, where recent tectonic and volcanic activity has occurred.
On the basis of geological criteria, several types of hot geothermal systems (with temperatures greater than about 800C , or 1760F)have been defined, and the resource base is larger than that of fossil fuels and nuclear energy combined. A common system for energy development is hydrothermal convection, characterized by the circulation of steam and / or hot water that transfers heat from depths to the surface.Geothermal Energy and the Environment
The environmental impact of geothermal energy may not be as extensive as that of other sources of energy , but it can be considerable. When geothermal energy is developed at a particular site, environmental problems include on-site noise, emissions of gas, and disturbance of the land at drilling sites, disposal sites, roads and pipelines, and power plants. Development of geothermal energy does not require large-scale transportation of raw materials or refining of chemicals, as development of fossil fuels does. Furthermore, geothermal energy does not produce the atmospheric pollutants associated with burning fossil fuels or the radioactive waste associated with nuclear energy. However, geothermal development often does produce considerable thermal pollution from hot waste-waters, which may be saline or highly corrosive, producing disposal and treatment problem.
Geothermal power is not very popular in some locations among some people. For instance, geothermal energy has been produced for years on the island of Hawaii, where active volcanic processes provide abundant near surface heat. There is controversy, however, over further exploration and development .Native Hawaiians and other -
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What unusual or unique biological train led to the remarkable diversification and unchallenged success of the ants for over 50 million years? The answer appears to be that they were the first group of predatory eusocial insects that both lived and foraged primarily in the soil and in rotting vegetation on the ground. Eusocial refers to a form of insect society characterized by specialization of tasks and cooperative care of the young; it is rare among insects. Richly organized colonies of the land made possible by eusociality enjoy several key advantages over solitary individuals.
Under most circumstances groups of workers are better able to forage for food and defend the nest, because they can switch from individual to group response and back again swiftly and according to need. When a food object or nest intruder is too large for one individual to handle, nestmates can be quickly assembled by alarm or recruitment signals. Equally important is the fact that the execution of multiple- step tasks is accomplished in a series-parallel sequence. That is, individual ants can specialize in particular steps, moving from one object (such as a larva to be fed) to another (a second larva to be fed). They do not need to carry each task to completion from start to finish - for example, to check the larva first, then collect the food, then feed the larva. Hence, if each link in the chain has many workers in attendance, a sense directed at any particular object is less likely to fail. Moreover, ants specializing in particular labor categories typically constitute a caste specialized by age or body form or both. There has been some documentation of the superiority in performance and net energetic yield of various castes for their modal tasks, although careful experimental studies are still relatively few.
What makes ants unusual in the company of eusocial insects is the fact that they are the only eusocial predators (predators are animals that capture and feed on other animals) occupying the soil and ground litter. The eusocial termites live in the same places as ants and also have wingless workers, but they feed almost exclusively on dead vegetation.The word "unique" in paragraph 1 is closest in meaning to .
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Quite different from storm surges are the giant sea waves called tsunamis, which derive their name from the Japanese expression for “high water in a harbor.” These waves are also referred to by the general public as tidal waves, although they have relatively little to do with tides.
Scientists often referred to them as seismic sea waves, far more appropriate in that they do result from undersea seismic activity.
Tsunamis are caused when the sea bottom suddenly moves, during an underwater earthquake or volcano for example, and the water above the moving earth is suddenly displaced. This sudden shift of water sets off a series of waves. These waves can travel great distances at speeds close to 700 kilometers per hour. In the open ocean, tsunamis have little noticeable amplitude, often no more than one or two meters. It is when they hit the shallow waters near the coast that they increase in height, possibly up to 40 meters.
Tsunamis often occur in the Pacific because the Pacific is an area of heavy seismic activity.
Two areas of the Pacific well accustomed to the threat of tsunamis are Japan and Hawaii. Because the seismic activity that causes tsunamis in Japan often occurs on the ocean bottom quite close to the islands, the tsunamis that hit Japan often come with little warning and can, therefore, prove disastrous. Most of the tsunamis that hit the Hawaiian Islands, however, originate thousands of miles away near the coast of Alaska, so these tsunamis have a much greater distance to travel and the inhabitants of Hawaii generally have time for warning of their imminent arrival.
Tsunamis are certainly not limited to Japan and Hawaii. In 1755, Europe experienced a calamitous tsunami, when movement along the fault lines near the Azores caused a massive tsunami to sweep onto the Portuguese coast and flood the heavily populated area around Lisbon. The greatest tsunami on record occurred on the other side of the world in 1883 when the Krakatoa volcano underwent a massive explosion, sending waves more than 30 meters high onto nearby Indonesian islands; the tsunami from this volcano actually traveled around the world and was witnessed as far away as the English Channel.The possessive “their” refers to ..............
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The problem of cardiac arrest has become a major problem these days. A lot of patients have acute pain after suffering from a stroke. There are plenty of medicines, surgical methods developed in the field of medicine to treat such cardiac problems. These solutions are time consuming and costly. In the process of rehabilitation, the medicines also have a lot of side effects on the human body and take time to give relief. Therefore, a lot of people go for alternative therapies that help in rehabilitation of patients who suffer from cardiac stroke. The alternative therapies help in relieving pain, stress and make the body healthy and fit through exercise, yoga as well as meditation.
Those who have the cardiac complaint have to take a good care of their diet.
Also, they must look after their regular exercise in order to stay fit and make sure that they do not take undue stress. These are some of the precautions that you need to take while you are in the process of rehabilitation. The cardiac rehabilitation can be carried out at the rehabilitation centers as well as at the residence of the patients. Once the patient learns all the exercise and techniques of meditation and understands what diet he or she should include in their meals as the instructions of the doctor’s and dieticians, then it is possible to accomplish the rehabilitation process at home with little guidance and monitoring. But the best results are seen at the center, where the program is given to a group of patients together.
The alternative therapies used for cardiac rehabilitation are stress management, physical exercises and diet. Stress management is very much essential in the rehabilitation process because it has a lot of effects on the patient’s body. A lot of relaxation techniques are taught to the patients that helps them in stress management, among them meditation is one of the main focuses.
The various rehabilitation programs also give you information on how to have a stress free lifestyle. The patients are supported and encouraged to discuss their problems with the counselor or fellow patients. This helps them to vent their feelings and feel comforted. Breathing exercises are also of great help for the patients who are undergoing cardiac rehabilitation.
In addition to stress management, physical exercises are also given a lot of importance in the rehabilitation program. The patients are asked to perform various forms of physical exercise which are suitable to them depending on their age and the severity of their problems. These activities include activities like walking, jogging, cycling, and some other sports like badminton, tennis etc., to maintain their health and keep their muscles, bones, and body tissues in a good state. Cardio exercise in a gymnasium is also encouraged. This helps in strengthening the muscles and managing weight.
The diet of these patients also needs to be looked upon very carefully. Such people should stay away from alcohol and tobacco consumption in order to improve their health. Make sure that their meals include plenty of organic foodstuffs as well as fruits and juices. Do not include junk and oily foodstuffs in your diet because they are very difficult to digest. The intake of calories should also be done at required level. It is a significant fact that the patients have to understand and work accordingly.Which of the following is NOT supported by the passage?
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Theresa May, the second female Britain’s prime minister following Margaret Thatcher, revealed in 2013 that she had been given a diagnosis of Type 1 diabetes, a condition that requires daily insulin injections. Asked later how she felt about the diagnosis, she said her approach to it was the same as toward everything in her life: “Just get on and deal with it.” That kind of steeliness brought her to center stage in the aftermath of Britain’s vote to leave the European Union and the feuding that erupted in the Conservative Party over who would succeed David Cameron.
Ms” May, 59 years old, is the country’s longest-serving home secretary in half a century, with a reputation for seriousness, hard work and above all, determination. She is one of a growing number of women in traditionally male-dominated British politics rising to the upper position of leadership.
Bom in 1956, Ms. May grew up mainly in Oxford shire, an only child who was first drawn to the Conservative Party at age 12. As a conscientious student, she never rebelled against her religious upbringing and remains a regular churchgoer. Tellingly, her sports hero was Geoffrey Boycott, a solid, stubborn cricketer who specialized in playing the long game.
Like many other Britain’s prime minister including Tony Blair, Sir Robert Peel and Margaret Thatcher, she won a place at Oxford. But while almost every other political leader got there by way of Eton College and joined Oxford’s hedonistic Bullingdon Club, she attended a state secondary school and had a more sedate university career. After unsuccessful attempts to be elected to the House of Commons in 1992 and 1994, she finally became an MP in 1997 general election.
May is known for a love of fashion and in particular distinctive shoes. She even wore leopard-print shoes to her final Cabinet meeting as Home Secretary in early 2016. However, she has been quite critical of the media focusing on her fashion instead of her achievement as a politician. May also describes cooking and walking as primary hobbies, and if someone is raising questions about why walking can be classified as a hobby, she elaborates in a column for Balance magazine, in which she wrote of her battle with diabetes.Her reason to consider walking as one of her main hobbies is ..................
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Cyclones in India, hurricanes in the Caribbean - severe weather events make news headlines almost weekly. Yet even in Britain, which has comparatively few climate extremes, the country is still governed by weather. If it’s pouring with rain the British might stay indoors or go to the cinema; if it’s fine they’ll have a picnic.
Most people nervously study the weather forecast the evening before if they’ve got an important appointment the following day. Even if they have nothing planned, the weather often affects their mood.
For individuals, the worst that can usually happen if the weather catches them on the hop is that they get wet. For business, the effects are far more serious. Airlines and shipping companies need to avoid severe weather and storm-force conditions. Power companies need to make sure they can supply the demand for electricity in cold weather; farmers plan their harvests around the forecast and food manufacturers increase their production of salads and other summer foods when fine weather is promised.
So who or what do meteorologists - weather forecasters as they are more commonly known - rely on when it comes to producing a forecast? Ninety percent of the information comes from weather satellites, the first of which was launched into space nearly forty years ago and was a minor revolution in the science of forecasting. Up until then, forecasters had relied on human observers to provide details of developing weather systems. As a result, many parts of the world where there were few humans around, especially the oceans, were information-free weather areas. Today, however, satellites can watch weather patterns developing everywhere.
In the UK meteorologists have also relied on releasing four weather balloons a day from eight fixed sites. These balloons measure wind, temperature and humidity as they rise upwards to a height of about 26,000 metres.
Some commercial aircraft can also be fitted with a range of forecasting instruments although this system has certain disadvantages. For example, it can provide a great deal of information about the weather on popular routes, such as London to New York, but little about the weather on more out-of-the way routes.
Instruments aboard ships can also supply basic weather information as well as important data on wave height. Generally, the range of these instruments is fairly limited but they can indicate which direction rain is coming from, how low the cloud is and give an idea of when the weather system will reach land.
One forecaster who has made a name for himself is a man called Piers Corbyn, who bases his forecasts on watching the Sun. Most forecasters will offer forecasts for only 10 days ahead, but Corbyn’s forecasts are for 11 months. Although most meteorologists believe that there is no scientific basis for his work, Corbyn’s forecasts are used by insurance companies who want to plan months in advance.What does ‘it’ in paragraph 6 refer to?
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When another old cave is discovered in the south of France, it is not unusual news. Rather, it is an ordinary event. Such discoveries are so frequent these days that hardly anybody pays heed to them. However, when the Lascaux cave complex was discovered in 1940, the world was amazed. Painted directly on its walls were hundreds of scenes showing how people lived thousands of years ago. The scenes show people hunting animals, such as bison or wild cats. Other images depict birds and, most noticeably, horses, which appear in more than 300 wall images, by far outnumbering all other animals.
Early artists drawing these animals accomplished a monumental and difficult task. They did not limit themselves to the easily accessible walls but carried their painting materials to spaces that required climbing steep walls or crawling into narrow passages in the Lascaux complex.
Unfortunately, the paintings have been exposed to the destructive action of water and temperature changes, which easily wear the images away. Because the Lascaux caves have many entrances, air movement has also damaged the images inside.
Although they are not out in the open air, where natural light would have destroyed them long ago, many of the images have been deteriorated and are barely recognizable. To prevent further damage, the site was closed to tourists in 1963, 23 years after it was discovered.Which title best summarizes the main idea of the passage?
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Being aware of one's own emotions - recognizing and acknowledging feelings as they happen - is at the very heart of Emotional Intelligence. And this awareness encompasses not only moods but also thoughts about those moods. People who are able to monitor their feelings as they arise are less likely to be ruled by them and are thus better able to manage their emotions.
Managing emotions does not mean suppressing them; nor does it mean giving free rein to every feeling. Psychologist Daniel Goleman, one of several authors who have popularized the notion of Emotional Intelligence, insisted that the goal is balance and that every feeling has value and significance. As Goleman said, "A life without passion would be a dull wasteland of neutrality, cut off and isolated from the richness of life itself." Thus, we manage our emotions by expressing them in an appropriate manner. Emotions can also be managed by engaging in activities that cheer us up, soothe our hurts, or reassure us when we feel anxious.
Clearly, awareness and management of emotions are not independent. For instance, you might think that individuals who seem to experience their feelings more intensely than others would be less able to manage them. However, a critical component of awareness of emotions is the ability to assign meaning to them - to know why we are experiencing a particular feeling or mood. Psychologists have found that, among individuals who experience intense emotions, individual differences in the ability to assign meaning to those feelings predict differences in the ability to manage them. In other words, if two individuals are intensely angry, the one who is better able to understand why he or she is angry will also be better able to manage the anger.
Self-motivation refers to strong emotional self-control, which enables a person to get moving and pursue worthy goals, persist at tasks even when frustrated, and resist the temptation to act on impulse. Resisting impulsive behavior is, according to Goleman, "the root of all emotional self- control."
Of all the attributes of Emotional Intelligence, the ability to postpone immediate gratification and to persist in working toward some greater future gain is most closely related to success - whether one is trying to build a business, get a college degree, or even stay on a diet. One researcher examined whether this trait can predict a child's success in school. The study showed that 4-year-old children who can delay instant gratification in order to advance toward some future goal will be "far superior as students" when they graduate from high school than will 4-year-olds who are not able to resist the impulse to satisfy their immediate wishes.The word "them" in paragraph 3 refers to .............
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DESERTIFICATION
Desertification is the degradation of once-productive land into unproductive or poorly productive land. Since the first great urban-agricultural centers in Mesopotamia nearly 6,000 years ago, human activity has had a destructive impact on soil quality, leading to gradual desertification in virtually every area of the world.
It is a common misconception that desertification is caused by droughts. Although drought does make land more vulnerable, well-managed land can survive droughts and recover, even in arid regions. Another mistaken belief is that the process occurs only along the edges of deserts. In fact, it may take place in any arid or semiarid region, especially where poor land management is practiced. Most vulnerable, however, are the transitional zones between deserts and arable land; wherever human activity leads to land abuse in these fragile marginal areas, soil destruction is inevitable.
[1] Agriculture and overgrazing are the two major sources of desertification. [2] Large-scale farming requires extensive irrigation, which ultimately destroys lands by depleting its nutrients and leaching minerals into the topsoil. [3] Grazing is especially destructive to land because, in addition to depleting cover vegetation, herds of grazing mammals also trample the fine organic particles of the topsoil, leading to soil compaction and
erosion. [4] It takes about 500 years for the earth to build up 3 centimeters of topsoil. However, cattle ranching and agriculture can deplete as much as 2 to 3 centimeters of topsoil every 25 years - 60 to 80 times faster than it can be replaced by nature.
Salination is a type of land degradation that involves an increase in the salt content of the soil. This usually occurs as a result of improper irrigation practices. The greatest Mesopotamian empires- Sumer, Akkad and Babylon- were built on the surplus of the enormously productive soil of the ancient Tigris- Euphrates alluvial plain. After nearly a thousand years of intensive cultivation, land quality was in evident decline. In response, around 2800 BC the Sumerians began digging the huge Tigris-Euphrates canal system to irrigate the exhausted soil. A temporary gain in crop yield was achieved in this way, but over-irrigation was to have serious and unforeseen consequences. From as early as 2400 BC we find Sumerian documents referring to salinization as a soil problem. It is believed that the fall of the Akkadian Empire around 2150 BC may have been due to a catastrophic failure in land productivity; the soil was literally turned into salt. Even today, four thousand years later, vast tracks of salinized land between the Tigris and Euphrates rivers still resemble rock-hard fields of snow.
Soil erosion is another form of desertification. It is a self reinforcing process; once the cycle of degradation begins, conditions are set for continual deterioration. As the vegetative cover begins to disappear, soil becomes more vulnerable to raindrop impact. Water runs off instead of soaking in to provide moisture for plans. This further diminishes plan cover by leaching away nutrients from the soil. As soil quality declines and runoff is increased, floods become more frequent and more severe. Flooding washes away topsoil, the thin, rich, uppermost layer of the earth’s soil, and leaves finer underlying particles more vulnerable to wind erosion. Topsoil contains the earth’s greatest concentration of organic matter and microorganisms, and is where most of the earth’s land-based biological activity occurs. Without this fragile coat of nutrient-laden material, plan life cannot exist. An extreme case of its erosion is found in the Sahel, a transitional zone between the Sahara Desert and the tro -
Before the 1500’s, the Western plains of North America were dominated by farmers. One group, the Mandans, lived in the upper Missouri River country, primarily in present-day North Dakota. They had large villages of houses built close together. The tight arrangement enabled the Mandans to protect themselves more easily from the attacks of others who might seek to obtain some of the food these highly capable farmers stored from one year to the next.
The women had primary responsibility for the fields. They had to exercise considerable skill to produce the desired results, for their northern location meant fleeting growing seasons. Winter often lingered; autumn could be ushered in by severe frost. During the spring and summer, drought, heat, hail, grasshoppers, and other frustrations might await the wary grower.
Under such conditions, Mandan women had to grow maize capable of weathering adversity. They began as early as it appeared feasible to do so in the spring, clearing the land, using fire to clear stubble from the fields and then planting. From this point until the first green corn could be harvested, the crop required labor and vigilance. Harvesting proceeded in two stages. In August the Mandans picked a smaller amount of the crop before it had matured fully. This green corn was boiled, dried, and shelled, with some of the maize slated for immediate consumption and the rest stored in animal-skin bags. Later in the fall, the people picked the rest of the corn. They saved the best of the harvest for seeds or for trade, with the remainder eaten right away or stored for later use in underground reserves. With appropriate banking of the extra food, the Mandans protected themselves against the disaster of crop failure and accompanying hunger.
The women planted another staple, squash, about the first of June, and harvested it near the time of the green corn harvest. After they picked it, they sliced it, dried it, and strung the slices before they stored them. Once again, they saved the seed from the best of the year`s crop. The Mandans also grew sunflowers and tobacco; the latter was the particular task of the older men.Which of the following processes does the author imply was done by both men and women?
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Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks
Choosing clothes can be difficult. Some people want to be fashionable, but they don’t want to look exactly like everybody else. Not all clothes are (1)........ for work or school, perhaps because they are not formal enough, or simply not comfortable. It is easy to buy the (2).......... size, and find that your trousers are too tight, especially if you are a little bit overweight. Very (3)........clothes make you feel slim, but when they have shrunk in the washing machine, then you have the same problem! If you buy light cotton clothes, then they might not be (4)........ enough for winter. If your shoes are not waterproof and if you aren’t (5)....... for the cold, you might look good, but feel terrible!
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Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions:
“ Calcite- containing dust particles blow into the air and combine with nitric acid in polluted air from factories to form an entirely new particle – calcium nitrate , ” said Alexander Laskin, a senior research scientist at the Department of Energy’s Pacific Northwest National Laboratory in Richland, Washington .These nitrates have optical and chemical properties that are completely different from those of the originally dry dust particles . Due to this, climate models need to be updated to reflect this chemistry. Calcite dust is common in arid areas such as Israel, where scientists collected particles for analysis.
Working from a mountaintop, the team collected dust that had blown in from the northern shores of Egypt, Sinai,and southern Israel. The particles had combined with air containing pollutants that came from Cairo.They analyzed nearly 2,00 individual particles and observed the physical and chemical changes at the W.R Wiley Environmental Sciences Laboratory.
A key change in the properties of the newly formed nitrate particles is that they begin to absorb water and retain the moisture .These wet particles can scatter and absorb sunlight-presenting climate modelers, who need to know where the energy is going , a new wild card to deal with . Companion studies of dust samples from the Sahara and the Saudi coast and loess from China show that the higher the calcium in the mineral , the more reactive they are in with nitric acid .And once the particle is changed , it stays that way.
“When dust storms kick up these particles and they enter polluted areas , the particles change ,” Laskin said . “To what extent this is happening globally, as more of the world becomes industrialized , we don’t know . But now we have the laboratory and field evidence that shows it is definitely happening . The story is much more complicated than anybody thought .”Which of the following may be true ?
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Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions:
The ocean bottom - a region nearly 2.5 times greater than the total land area of Earth - is a vast frontier that even today is largely unexplored and uncharted. Until about a century ago, the deep-ocean floor was completely inaccessible, hidden beneath waters averaging over 3,600 meters deep. Totally without light and subjected to intense pressures hundreds of times greater than at the Earth's surface, the deep-ocean bottom is a hostile environment to humans, in some ways as forbidding and remote as the void of outer space.
Although researchers have taken samples of deep-ocean rocks and sediments for over a century, the first detailed global investigation of the ocean bottom did not actually start until 1968, with the beginning ofthe National Science Foundation's Deep Sea Drilling Project (DSDP). Using techniques first developed for the offshore oil and gas industry, the DSDP's drill ship, the Glomar Challenger, was able to maintain a steady position on the ocean's surface and drill in very deep waters, extracting samples of sediments and rock from the ocean floor.
The Glomar Challenger completed 96 voyages in a 15-year research program that ended in November 1983. During this time, the vessel logged 600,000 kilometers and took almost 20,000 core samples of seabed sediments and rocks at 624 drilling sites around the world. The Glomar Challenger's core samples have allowed geologists to reconstruct what the planet looked like hundreds of millions of years ago and to calculate what it will probably look like millions of years in the future. Today, largely on the strength of evidence gathered during the Glomar Challenger's voyages, nearly all earth scientists agree on the theories of plate tectonics and continental drift that explain many of the geological processes that shape the Earth.
The cores of sediment drilled by the Glomar Challenger have also yielded information critical to understanding the world's past climates. Deep-ocean sediments provide a climatic record stretching back hundreds of millions of years, because they are largely isolated from the mechanical erosion and the intense chemical and biological activity that rapidly destroy much land-based evidence of past climates. This record has already provided insights into the patterns and causes of past climatic change - information that may be used to predict future climates.Which of the following is true of the Glomar Challenger?
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Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions:
In the late 1960’s, many people in North America turned their attention to environmental problems and new steel-and-glass skyscrapers were widely criticized. Ecologists pointed out that a cluster of tall buildings in a city often overburdens public transportation and parking lot capacities.
Skyscrapers are also lavish consumers, and waster, of electric power. In one recent year, the addition of 17 million square feet of skyscraper office space in New York City raised the peak daily demand for electricity by 120,-000 kilowatts- enough to supply the entire city of Albany, New York, for a day.
Glass-walled skyscrapers can be especially wasteful. The heat loss (or gain) through a wall of half-inch plate glass is more than ten times that through a typical masonry wall filled with insulation board. To lessen the strain on heating and air- conditioning equipment, builders of skyscrapers have begun to use double glazed panels of glass, and reflective glasses coated with silver or gold mirror films that reduce glare as well as heat gain. However, mirror-walled skyscrapers raise the temperature of the surrounding air and affect neighboring buildings.
Skyscrapers put a severe strain on a city’s sanitation facilities, too. If fully occupied, the two World Trade Center towers in New York City would alone generate 2.25 million gallons of raw sewage each year-as much as a city the size of Stamford, Connecticut, which has a population of more than 109,000.
Skyscrapers also interfere with television reception, block bird flyways, and obstruct air traffic. In Boston, in the late 1960’s some people even feared that shadows from skyscrapers would kill the grass on Boston Common.
Still, people continue to build skyscrapers for all the reasons that they have always built them – personal ambition, civic pride, and the desire of owners to have the largest possible amount of rentable space.The main purpose of the passage is to
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The election of Andrew Jackson to the presidency in 1928 marked the political ascendancy of the “common man” in American politics. Whereas all previous presidents had been Easterners from well-to-do families, Jackson was a self-made man of modest wealth from the West. Born in 1767, Jackson fought in the American Revolution, in which many of his relatives died.
Afterwards, he studied law and moved to the Western District of North California. When that territory became the state of Tennessee, Jackson was elected the state’s first congressman. His name became a household word during the war of 1812, when, as a U.S Army major general, he led troops against the Creek Indians in the Mississippi Territory and later defeated the British at New Orleans.
After his presidential inauguration, Jackson rode on horseback to the White House to attend a private party. Crowds of well-wishers suddenly appeared at the reception and nearly destroyed the White House as they tried to glimpse the new president. The common man had made a dramatic entrance onto the national political scene.
Jackson’s two terms moved American society toward truer democracy. Many states abandoned property requirements for voting. Elected officials began to act more truly as representatives of the people than as their leaders. As president of the common man, Jackson waged a war against the Bank of the United States, vetoing the bill that re-chartered the institution, declaring it a dangerous monopoly that profited the wealthy few.
Although he had built his reputation as an Indian fighter during the War of 1812, Jackson was not an Indian hater. He adopted what was at the time considered an enlightened solution to the Indian problem-removal. Many tribes submitted peacefully to being moved to the West. Others were marched by force to the Indian Territory, under brutal conditions, along what the Cherokees called the Trail of Tears.
One of Andrew Jackson’s most enduring legacies was the Democratic Party, which under him became a highly organized political party. In opposition to the Democrats were the Whigs, a party that attracted supporters of the Bank of the United States and opposed the tyranny of the man called “King Andrew”. A less specific but more basic legacy is the populist philosophy of politics that still bears the name “Jacksonian Democracy.”The word “institution” in paragraph 3 refers to ..............