Iron production was revolutionized in the early eighteenth century when coke was first used instead of charcoal for refining iron ore. Previously the poor quality of the iron had restricted its use in architecture to items such as chains and tie bars for supporting arches, vaults, and walls. With the improvement in refining ore, it was now possible  to  make  cast-iron beams, columns, and girders. During the nineteenth century further advances were made, notably Bessemer’s process for converting iron into steel, which made the material more commercially viable.
Iron was rapidly adopted for the  construction  of  bridges,  because  its  strength was far greater  than that of stone or timber, but its use in the architecture of buildings developed more slowly. By 1800 a complete internal iron skeleton for buildings had been developed in industrial architecture replacing traditional timber beams, but it generally remained concealed. Apart from its low cost, the appeal of iron as a building material lay in its strength, its resistance to fire, and its potential to span vast areas. As a result, iron became increasingly popular as a structural material for more traditional styles of architecture during the nineteenth century, but it was invariably concealed.
Significantly, the use  of  exposed  iron  occurred  mainly  in  the  new  building types spawned by the Industrial Revolution: in factories, warehouses, commercial offices, exhibition hall, and railroad stations, where its  practical  advantages  far  outweighed  its  lack of status. Designers of the railroad stations of the new age explored the potential of iron, covering huge areas with spans that surpassed the great vaults of medieval churches and cathedrals. Paxton’s Crystal Palace, designed to house the Great Exhibition of 1851, covered an area of 1.848 feet by 408 feet in prefabricated units of glass set in iron frames. The Paris Exhibition of 1889 included both the widest span and the  greatest height achieved so far with the Halle Des Machines, spanning 362 feet, and the Eiffel Tower 1,000 feet high. However, these achievements were mocked by the artistic elite of Paris as expensive and ugly follies. Iron, despite its structural advantages, had little aesthetic status. The use of an exposed iron structure in the more traditional styles of architecture was slower to develop.

What does the passage mainly discuss?

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.

According to the passage, all of the following are true about tidal waves except that .............

Read the following passage and choose the best answer for each blank.

Vietnam is considered a third world country, its people live (26) _____ poverty by the millions. After the (27) _____, Vietnam's economy remained dominated by small-scale production, low labor productivity, (28) _____, material and technological shortfalls, and insufficient food and (29) _____ goods. The Doi Moi reforms that were instated in 1986 have shed new light and added new features to the Vietnamese economy. (30) ____ Vietnamese Communist Party plays a leading role in establishing the foundations and principles of communism, mapping strategies for economic development, setting growth targets, and (31) _____ reforms. Doi Moi combined government planning with free-market incentives and (32) _____ the establishment of private businesses and foreign investment, including foreign-owned enterprises. By the late 1990s, the success of the business and agricultural reforms ushered in under Doi Moi was evident. (33) _____ than 30,000 private businesses had been created, and the economy was growing at an annual (34) _____ of more than 7 percent. Farming systems research and the international development projects are a source of new hope for the people of Vietnam. If these recent projects are successful and Doi Moi continues on its current path the Vietnamese people may (35) _____ a new standard of living. More reforms like Doi Moi need to take place in order to create a more stable Vietnamese future.

(32) _____

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Fifty-five delegates representing all thirteen states except Rhode Island attended the Constitutional Convention in Philadelphia from May to September 1787. The delegates had been instructed by the Continental Congress to revise the old Articles of Confederation, but most believed that a stronger central government was needed. There were differences, however, about what structure the government should take and how much influence large states should have.
Virginia was by far the most populous state, with twice as many as people as New York, four times as many as New Jersey, and ten times as many as Delaware. The leader of the Virginia delegation, James Madison, had already drawn up a plan for government, which became known as the Large State Plan. Its essence was that congressional representation would be based on population. It provided for two or more national executives. The smaller states feared that under this plan, a few large states would lord over the rest. New Jersey countered with the Small State Plan. It provided for equal representation for all states in a national legislature and for a single national executive. Angry debate, heightened by a stifling heat wave, led to deadlock.
A cooling of tempers seemed to come with lower temperatures. The delegates hammered out an agreement known as the Great Compromise- actually a bundle of shrewd compromises. They decided that Congress would consist of two houses. The larger states were granted representation based on population in the lower house, the House of Representatives. The smaller states were given equal representation in the upper house, the Senate, in which each state would have two senators regardless of population. It was also agreed that there would be a single executive, the president. This critical compromise broke the logjam, and from then on, success seemed within reach.

Which of the following is NOT given in the passage as one of the provisions of the Great Compromise?

No educational medium better as means of spatial communication than the atlas. Atlases deal with such invaluable information as population distribution and density. One of the best, Pennycooke's World Atlas, has been widely accepted as a standard owing to the quality of its maps and photographs, which not only show various settlements but also portray them in a variety of scales. In fact, the very first map in the atlas is a cleverly designed population cartogram that projects the size of each country if geographical size were proportional to population. Following the proportional layout, a sequence of smaller maps shows the world’s population density, each country’s birth and death rates, population increase or decrease, industrialization, urbanization, gross national product in terms of per capita income, the quality of medical care, literacy, and language. To give readers a perspective on how their own country fits in with the global view, additional projections depict the world's patterns in nutrition, calorie and protein consumption, health care, number of physicians per unit of population, and life expectancy by region. Population density maps on a subcontinental scale, as well as political maps. Convey the diverse demographic phenomena of the world in a broad array of scales.

The author of the passage implies that ...........

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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.

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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!
(1).................................

Choose the word or phrase that best fits each space in the following passage

 Many people love boats. Going out on the water on a warm summer day is a lot of fun. (1) _______ ,different people like different kinds of boats. Two of the most popular kinds of boat are sailboats and speedboats. Sailboats use the (2) _______to give them power. They only have small engines. In contrast, speedboats have large engines and go very fast. Furthermore, speedboats are usually not as (3) _______ as sailboats. Speedboats are small so that they can go fast. Sailboats, on the other hand, are big so that they are more comfortable. ( 4) _______, sailboats can travel into the ocean, but this would be very dangerous in a speedboat. You can only use speedboats on rivers or lakes.

(1) _______

All mammals feed their young. Beluga whale mothers, for example, nurse their calves for some twenty months, until they are about to give birth again and their young are able to find their own food. The behavior of feeding of the young is built into the reproductive system. It is a nonselective part of parental care and the defining feature of a mammal, the most important thing that mammals-- whether marsupials, platypuses, spiny anteaters, or placental mammals -- have in common.
But not all animal parents, even those that tend their offspring to the point of hatching or birth, feed their young. Most egg-guarding fish do not, for the simple reason that their young are so much smaller than the parents and eat food that is also much smaller than the food eaten by adults. In reptiles, the crocodile mother protects her young after they have hatched and takes them down to the water, where they will find food, but she does not actually feed them. Few insects feed their young after hatching, but some make other arrangement, provisioning their cells and nests with caterpillars and spiders that they have paralyzed with their venom and stored in a state of suspended animation so that their larvae might have a supply of fresh food when they hatch.
For animals other than mammals, then, feeding is not intrinsic to parental care. Animals add it to their reproductive strategies to give them an edge in their lifelong quest for descendants. The most vulnerable moment in any animal's life is when it first finds itself completely on its own, when it must forage and fend for itself. Feeding postpones that moment until a young animal has grown to such a size that it is better able to cope. Young that are fed by their parents become nutritionally independent at a much greater fraction of their full adult size. And in the meantime those young are shielded against the vagaries of fluctuating of difficult-to-find supplies. Once a species does take the step of feeding its young, the young become totally dependent on the extra effort. If both parents are removed, the young generally do not survive.

What does the passage mainly discuss?

Choose the item among A, B, C or D that best answers the question about the passage:

"In recent years many countries of the world have been with the problem of how to make their workers more productive. Some experts claim the answer is to make jobs more varied. But do more various jobs lead to greater productivity? There is evidence to suggest that while variety certainly makes the workers’ life more enjoyable, it does not actually make him work harder. As far as increasing productivity is concerned, then variety is not an important factor.
 Other experts feel that giving the worker freedom to do his job in his own way is important, and there is no doubt that this is true. The problem is that this kind of freedom cannot easily be given in the modern factory with its complicated machinery which must be used very little that can be done to create it.
 Another very important consideration is how each worker contributes to the product he is making. In most factories the worker sees only one part of the product. Some car factories are now experimenting with having many small production lines rather than one large one, so that each worker contributes more to the production of the cars on his line, it would seem that not only is degree of the worker contribution an important factor, therefore, but it is also one we can do something about.
 To what extent does more money lead to greater productivity? The workers themselves certainly think this is important. But perhaps they want more money only because the work they do is boring. Money just lets them enjoy their spare time more. A similar argument may explain demands for shorter working hours. Perhaps if we succeed in making their jobs more interesting, they will neither want more money, nor will shorter working hours be so important to them."

2. The reason why a worker cannot have freedom in doing the job in his own way is that …….

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Puerto Rico, a Caribbean island rich in history and remarkable natural beauty, has a cuisine all its own. Immigration to the island has helped to shape its cuisine, with people from all over the world making various contributions to it. However, before the arrival of these immigrants, the island of Puerto Rico was already known as Borikén and was inhabited by the Taíno people. Taíno cuisine included such foods as rodents with sweet chili peppers, fresh shellfish, yams, and fish fried in corn oil.
Many aspects of Taíno cuisine continue today in Puerto Rican cooking, but it has been heavily influenced by the Spanish, who invaded Puerto Rico in 1508, and Africans, who were initially brought to Puerto Rico to work as slaves. (2)Taíno cooking styles were mixed with ideas brought by the Spanish and Africans to create new dishes. (3) Africans also added to the island’s food culture by introducing powerful, contrasting tastes in dishes like piñon–plantains layered in ground beef. In fact, much of the food Puerto Rico is now famous for—plantains, coffee, sugarcane, coconuts, and oranges—was actually imported by foreigners to the island. (4)
A common assumption many people make about Puerto Rican food is that it is very spicy. It’s true that chili peppers are popular; ajícaballero in particular is a very hot chili pepper that Puerto Ricans enjoy. However, milder tastes are popular too, such as sofrito. The 25 base of many Puerto Rican dishes, sofrito is a sauce made from chopped onions, garlic, green bell peppers, sweet chili peppers, oregano, cilantro, and a handful of other spices. It is fried in oil and then added to other dishes.

The word "cuisine" in paragraph 1 is closest in meaning to      

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.
              THE FUTURE OF WATER
Many of us often wonder what the future holds; some believe major advances in technology will occur which will result in improvements to our everyday lives. Scientists have predicted shortages in fossil fuels and changes in the weather patterns of the world. (1).......... , one significant change that will have an alarming impact on all of us is the global water shortage. Analysts have forecast that some of the consequences of this will be mass migration from Africa to Europe and wars between countries over clean water. The main causes of this disturbing water shortage are global warming, climate change and the increasing world population. The supply of fresh water (2)....... comes from mountain glaciers and  flows  into  lakes  and  rivers  is  diminishing,  and  this also (3).......... to the shortage. Water analysts and government leaders need to start making radical changes to the way water use is managed and they need to find new sources that will be able to meet the demands of an ever-growing population.  In addition, more things need to be done to control global warming as this will help to reduce water shortages.   People   should   be made  (4)......... of the situation and warned not to waste water. Multinational companies should invest in developing better water management systems. In summary, if we start (5) ............. action now, we might be able to prevent a world disaster.
(4).................................

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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.

The author refers to the ocean bottom as a “frontier” because it      

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“ 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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In this modern world where closed-circuit television (CCTV) cameras are everywhere and smartphones in every pocket, the routine filming of everyday life is becoming pervasive. A number of countries are rolling out body cams for police officers; other public-facing agencies such as schools, councils and hospitals are also experimenting with cameras for their employees. Private citizens are getting in on the act too: cyclists increasingly wear headcams as a deterrent to aggressive drivers. As camera technology gets smaller and cheaper, it isn't hard to envisage a future where we're all filming everything all the time, in every direction.
Would that be a good thing? There are some obvious potential upsides. If people know they are on camera, especially when at work or using public services, they are surely less likely to misbehave. The available evidence suggests that it discourages behaviours such as vandalism. Another upside is that it would be harder to get away with crimes or to evade blame for accidents.
But a world on camera could have subtle negative effects. The deluge of data we pour into the hands of Google, Facebook and others has already proved a mixed blessing. Those companies would no doubt be willing to upload and curate our body-cam data for free, but at what cost to privacy and freedom of choice?
Body-cam data could also create a legal minefield. Disputes over the veracity and interpretation of police footage have already surfaced. Eventually, events not caught on camera could be treated as if they didn't happen. Alternatively, footage could be faked or doctored to dodge blame or incriminate others.
Of course, there's always the argument that if you're not doing anything wrong, you have nothing to fear. But most people have done something embarrassing, or even illegal, that they regret and would prefer they hadn't been caught on film. People already censor their social media feeds – or avoid doing anything incriminating in public – for fear of damaging their reputation. Would ubiquitous body cams have a further chilling effect on our freedom?
The always-on-camera world could even threaten some of the attributes that make us human. We are natural gossips and backbiters, and while those might not be desirable behaviours, they oil the wheels of our social interactions. Once people assume they are being filmed, they are likely to clam up.
The argument in relation to body-cam ownership is a bit like that for guns: once you go past a critical threshold, almost everyone will feel they need one as an insurance policy. We are nowhere near that point yet – but we should think hard about whether we really want to say "lights, body cam, action." 

The word "they" in paragraph 6 refers to     .

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For many American university students, the weeklong spring break holiday means on endless party on a sunny beach in Florida or Mexico. In Panama City Beach in Florida, a city with permanent population of around 36.000, more than half a million university students arrive during the month of March to play and party, making it the number one spring break destination in the United States
A weeklong drinking binge is not for everyone, however and a growing number of American university students have found a way to make spring break matter. For them, joining or leading a group of volunteers to travel locally or internationally and work to alleviate problems such as poverty, homelessness, or environmental damage makes spring break a unique learning experience that university students can feel good about.
During one spring break students at James Madison University in Virginia participated in 15 alternative spring break" trips to nearby states, three others to more distant parts of the United States and five international trips. One group of JMU students travelled to Bogalusa, Louisiana to help rebuild homes damaged by Hurricane Katrina. Another group traveled to Mississippi to organize creative activities for children living in homeless shelter. One group of students did go to exhausting physical labor such Florida. but not to lie on the sand. They performed as maintaining hiker rails and destroying invasive plant species that threaten the native Florida ecosystem.
Students who participate in alternative spring break projects find them very rewarding. While most university students have to get their degrees before they can start helping people, students volunteers are able to help people now. On the other hand, the accommodations are far from glamorous. Students often sleep on the floor of a school or church, or spend the week camping in tents. But students only pay around
$250 for meals and transportation, which is much less than some their peers spend to travel to more traditional spring break hotspots
Alternative spring break trips appear to be growing in popularity at universities across the United States. Students cite a number of reasons for participating. Some appreciate the opportunity to socialize and meet new friends. Others want to exercise their beliefs about peoples obligation to serve humanity and make the world a better place. Whatever their reasons, these students have discovered something that gives them rich rewards along with a break from school work.

The article is mainly about     .

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What geologists call the Basin and Range Province in the United States roughly coincides in its northern portions with the geographic province known as the Great Basin. The Great Basin is hemmed in west by the Sierra Nevada and on the east Line by the Rocky Mountains; it has no outlet to the sea. The prevailing winds in the Great Basin are from the west. Warm, moist air from the Pacific Ocean is forced upward as it crosses the Sierra Nevada. At the higher altitudes it cools and the moisture it carries is precipitated as rain or snow on the western slopes of the mountains. That which reaches the Basin is air wrung dry of moisture. What little water falls there as rain or snow, mostly in the winter months, evaporates on the broad, flat desert floors. It is, therefore, an environment in which organisms battle for survival. Along the rare watercourses, cottonwoods and willows eke out a sparse existence. In the upland ranges, pinion pines and junipers struggle to hold their own.
But the Great Basin has not always been so arid. Many of its dry, closed depressions were once filled with water. Owens Valley, Panamint Valley, and Death Valley were once a string of interconnected lakes .The two largest of the ancient lakes of the Great Basin were Lake Lahontan and Lake Bonneville. The Great Salt Lake is all that remains of the latter, and Pyramid Lake is one of the last briny remnants of the former. There seem to have been several periods within the last tens of thousands of years when water accumulated in these basins. The rise and fall of the lakes were undoubtedly linked to the advances and retreats of the great ice sheets that covered much of the northern part of the North American continent during those times.
Climatic changes during the Ice Ages sometimes brought cooler, wetter weather to mid latitude deserts worldwide, including those of the Great Basin. The broken valleys of the Great Basin provided ready receptacles for this moisture.

Why does the author mention cottonwoods and willows?

Since the dawn of time, people have found ways to communicate with one another. Smoke signals and tribal drums were some of the earliest forms of communication. Letters, carried by birds or by humans on foot or on horseback, made it possible for people to communicate larger amounts of information between two places. The telegram and telephone set the stage for more modern means of communication. With the invention of the cellular phone, communication itself has become mobile.
For you, a cell phone is probably just a device that you and your friends use to keep in touch with family and friends, take pictures, play games, or send text message. The definition of a cell phone is more specific: it is a hand- held wireless communication device that sends and receives signals by way of small special areas called cells.
Walkie - talkies, telephones and cell phones are duplex communication devices: They make it possible for two people to talk to each other. Cell phones and walkie- talkies are different from regular phones because they can be used in many different locations. A walkie- talkie is sometimes called a half- duplex communication device because only one person can talk at a time. A cell phone is a full- duplex device because it uses both frequencies at the same time. A walkie-talkie has only one channel. A cell phone has more than a thousand channels. A walkie- talkie can transmit and receive signals across a distance of about a mile. A cell phone can transmit and receive signals over hundreds of miles. In 1973, an electronic company called Motorola hired Martin Cooper to work on wireless communication. Motorola and Bell Laboratories (now AT& T) were in a race to invent the first portable communication device.
Martin Cooper won the race and became the inventor of the cell phone. On April 3, 1973, Cooper made the first cell phone call to his opponent at AT& T while walking down the streets of New York city. People on the sidewalks gazed at cooper in amazement. Cooper's phone was called A Motorola Dyna- Tac. It weighed a whopping 2.5 pounds (as compared to today's cell phones that weigh as little as 3 or 4 ounces)
After the invention of his cell phone, Cooper began thinking of ways to make the cell phone available to the general public. After a decade, Motorola introduced the first cell phone for commercial use. The early cell phone and its service were both expensive. The cell phone itself cost about $ 3, 500. In 1977, AT & T constructed a cell phone system and tried it out in Chicago with over 2, 000 customers. In 1981, a second cellular phone system was started in the Washington,D.C and Baltimore area. It took nearly 37 years for cell phones to become available for general public use. Today, there are more than sixty million cell phone customers with cell phones producing over thirty billion dollars per years.

What definition is true of a cell phone?

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Scientists have experimented with a new procedure for alleviating the damage caused by strokes. Strokes are frequently caused by a blood clot lodging in the tree of arteries in the head, choking the flow of blood. Some brain cells die as a direct result of the stroke, but others also die over several hours because the proteins spilling out of the first cells that die trigger a chemical chain reaction that kills the neighboring cells.
The current method of reducing the amount of damage is to give a clot dissolver, known as TPA, as soon as possible. But generally TPA is not given to the patient until he or she reaches the hospital, and it still does not immediately stop the damage.
The new technology, still in the research stage, involves chilling the area or the entire patient. It is already known that when an organ is cooled, damage is slowed. This is why sometimes a person who has fallen into an icy pond is not significantly harmed after being warmed up again. The biggest issue is the method of cooling. It is not feasible to chill the head alone. Doctors have chilled the entire body by wrapping the patient in cold materials, but extreme shivering was a problem.
The new idea is to cool the patient from the inside out. Several companies are studying the use of cold-tipped catheters, inserted into the artery in the groin and threaded up to the inferior vena cava, which is a large vein that supplies blood to the abdomen. The catheter is expected to cool the blood that flows over it, thus allowing cooler blood to reach the area of the stroke damage.
It is not expected that the cooling will be substantial, but even a slight decrease in temperature is thought to be helpful. In effect, the patient is given a kind of forced hypothermia. And doctors believe it is important to keep the patient awake so that they can converse with the patient in order to ascertain mental condition.
Studies continue to determine the most effective and least damaging means of cooling the patient in order to reduce this damage.

According to the passage, all of the following are true except that    .

Choose the word or phrase among A, B, C or D that best fits the blank space in the following passage.

We won't have robot doctors for a long time, (1) ____ the human doctors we have now are beginning to learn on specialized artificial intelligence to help save time.

Google Deep Mind has just announced a partnership with University College London Hospital(UCLH) which will explore (2) ____ artificial intelligence to treat patients with head and neck cancers. The goal is to develop tools to automatically identify cancerous cells for radiology machines.

Currently, radiologists employ a manual process, called image (3) ____, to make CT and MRI scans and use them to create a map of the patient's anatomy with clear guidelines of where to direct the (4) ____.

Avoiding healthy areas of the head and neck requires that map to be extraordinarily detailed; typically it takes four hours to create. Google believes it can do the same job or better in one hour.

Deep Mind, Google's research arm, works primarily in deep learning, a form of artificial intelligence that learns to identify patterns from looking at large amount of data. In this case, DeepMind researchers will (5) ____ access to anonymized radiology scans from up to 700 former UCLH patients, and then feed them into (6) ____ that would process the scans to learn the visual difference between healthy and cancerous tissue.

The partnership will (7) ____ researchers to train their algorithms with highly-specialized, high- quality data, which theoretically will enable the algorithm to (8) ____ at a higher rate of success than if they had been using publicly available scans.

For those concerned about machines making health (9) ____ decisions, UCLH made it clear in a statement to the newspaper Guardian that clinicians will be in complete control of diagnoses and treatment.

DeepMind isn't the first care. Samsung Medison, the South Korean (10) ____ company's medical device arm, recently released an ultrasound machine that uses deep learning to quickly recommend whether breast tissue is cancerous or benign. The machine's algorithm was trained on 9,000 breast tissue scans, and is pending FDA approval in the US.

(9) ____

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:
For many American university students, the weeklong spring break holiday means on endless party on a sunny beach in Florida or Mexico. In Panama City Beach in Florida, a city with permanent population of around 36.000, more than half a million university students arrive during the month of March to play and party, making it the number one spring break destination in the United States
A weeklong drinking binge is not for everyone, however and a growing number of American university students have found a way to make spring break matter. For them, joining or leading a group of volunteers to travel locally or internationally and work to alleviate problems such as poverty, homelessness, or environmental damage makes spring break a unique learning experience that university students can feel good about.
During one spring break students at James Madison University in Virginia participated in 15 alternative spring break" trips to nearby states, three others to more distant parts of the United States and five international trips. One group of JMU students travelled to Bogalusa, Louisiana to help rebuild homes damaged by Hurricane Katrina. Another group traveled to Mississippi to organize creative activities for children living in homeless shelter. One group of students did go to exhausting physical labor such Florida. but not to lie on the sand. They performed as maintaining hiker rails and destroying invasive plant species that threaten the native Florida ecosystem.
Students who participate in alternative spring break projects find them very rewarding. While most university students have to get their degrees before they can start helping people, students volunteers are able to help people now. On the other hand, the accommodations are far from glamorous. Students often sleep on the floor of a school or church, or spend the week camping in tents. But students only pay around
$250 for meals and transportation, which is much less than some their peers spend to travel to more traditional spring break hotspots
Alternative spring break trips appear to be growing in popularity at universities across the United States. Students cite a number of reasons for participating. Some appreciate the opportunity to socialize and meet new friends. Others want to exercise their beliefs about peoples obligation to serve humanity and make the world a better place. Whatever their reasons, these students have discovered something that gives them rich rewards along with a break from school work.

Which of the following is NOT mentioned as a problem that alternative spring break trips try to help solve?