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Sir Anthony Van Dyck, one of the world’s greatest masters of portraiture, was born in Antwerp and was the seventh of twelve children. His affluent father apprenticed him to a painter when he was just a little over ten. Having become a member of the Antwerp Guild of painters before he was nineteen, he worked in the studio of Peter Paul Rubens for several years. In Italy, Van Dyck studied the great Venetian masters and painted flattering portraits of gorgeous ladies and haughty nobles in gilded velvet robes with lace and pearls. While he was sought after by the aristocracy for his acclaimed loose brushwork, his engravings and etchings also evinced his outstanding talent. Upon his return to Antwerp in 1628, he was influenced by Rubens’s interpretation of the artistic form and produced numerous religious paintings while holding an appointment as the court painter. During his tenure, he proved that his use of color, his sensitive elegance, and his remarkable insight were unexcelled.
His fame preceded him to England, where he was invited by King Charles I. After years of faithful service, he was knighted in recognition of his achievements in painting countless portraits of the king, the queen, the royal children, and the titled nobility of England.
However, Van Dyck’s greatest piece is one of his religious works, a true masterpiece displayed in the Antwerp gallery. This group scene exhibits his artful polish in painting the folds of fabric, the delicacy of human skin, landscape, and other externals, and puts him above other accomplished contemporary masters. Although Charles paid Van Dyck a salary and granted him a pension, the painter’s extravagant life-style and penchant for luxuries led him into debt, and he died without means.

It can be inferred from the passage that Van Dyck was raised

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Perhaps it was his own lack of adequate schooling that inspired Horace Mann to work so hard for the important reforms in education that he accomplished. While he was still a boy, his father and older brother died, and he became responsible for supporting his family. Like most of the children in his town, he attended school only two or three months a year. Later, with the help of several teachers, he was able to study law and became a member of the Massachusetts bar, but he never forgot those early struggles.
While serving in Massachusetts legislature, he signed a historic education bill that set up a state board of education. Without regret, he gave up his successful legal practice and political career to become the first secretary of the board. There he exercised an enormous influence during the critical period of reconstruction that brought into existence the American graded elementary school as substitute for the older distinct school system. Under his leadership, the curriculum was restructured, the school year was increased to a minimum of six months, and mandatory schooling was extended to age sixteen. Other important reforms included the establishment of state normal schools for teacher training, institutes for in- service teacher education, and lyceums for adult education. He was also instrument in improving salaries for teachers and creating school libraries.
Mann’s ideas about school reform were developed and distributed in twelve annual reports to the state of Massachusetts that he wrote during his tenure as secretary of education. Considered quite radical at the time, the Massachusetts reforms later served as a model for the nation. Mann was recognized as the farther of public education.

Which of the following describes Horace Mann’s early life?

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!
(5).................................

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On the tiny island of Flores, east of Bali and midway between Asia and Australia, the scientists have discovered the remains of a small, hobbit-like species of humans. These people grew no larger than the modern three-year-old child. They lived about 18,000 years ago and are completely different species of human.
This discovery has taught scientists a lot about the human species. This remarkable discovery shows that the human species is more varied and flexible in its ability to adapt than previously thought. These hobbit-like people join a short list of other type of humans that lived with modern humans.
The researchers believe that these hobbits evolved from a normal size, human population that reached Flores around 840,000 years ago. One likely explanation is that, over thousands of years, the species became smaller because the environmental conditions favored a smaller body size. The dwarfing of mammals on islands occurs frequently. Islands limit food supply and predators and species compete for the same environmental space. Survival would depend on minimizing energy requirements.a

Which of the following best favors a smaller body size?

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 paragraph preceding this passage most probably discusses  ............

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Our eyes and ears might be called transformers because they send the light and sound around us and turn them into electrical impulses that the brain can interpret. These electrical impulses that have been transformed by the eyes and ears reach the brain and are turned into massages that we can interpret. For the eye, the process begins as the eye admits light waves, bends them at the cornea and lens, and then focuses them on the retina. At the back of each eye, nerve fibers bundle together to form optic nerves, which join and then split into optic tracts. Some of the fibers cross so that part of the input from the right visual field goes into the left side of the brain, and vice versa. The process in the ear is carried out through sensory cells that are carried in fluid-filled canals and that are extremely sensitive to vibration. Sound that is transformed into electricity travels along nerve fibers in the auditory nerve. These fibers form a synapse with neurons that carry the massages to the auditory cortex on each side of the brain.

What does the word “them” in line 2 refers to?

Fill in each numbered blank with one suitable word or phrase.

In 1986 Vietnam (1)_____ a political and economic innovation campaign (Doi Moi) that introduced reforms intended to facilitate the transition from a centralized economy to a “socialist-oriented market economy”. Doi Moi combined government planning with free-market incentives. The program abolished agricultural (2) _____, removed price controls on agricultural goods, and enabled farmers to sell their goods in the marketplace. It encouraged the establishment of private businesses and foreign investment, including foreign-owned (3) _____.

By the late 1990s, the success of the business and agricultural (4) _____ ushered in under Doi Moi was evident. More than 30,000 private businesses had been (5) _____, and the economy was growing at an annual rate of more than 7 percent. From the early 1990s to 2005, poverty (6) _____ from about 50 percent to 29 percent of the population. However, progress varied geographically, with most prosperity concentrated in urban areas, (7) _____ in and around Ho Chi Minh City. In general, rural areas also made progress, as rural households (8) _____ in poverty declined from 66 percent of the total in 1993 to 36 percent in 2002. (9) _____ contrast, concentrations of poverty remained in (10) _____ rural areas, particularly the northwest, north-central coast, and central highlands. Government control of the economy and a nonconvertible currency have protected Vietnam from what could have been a more severe impact resulting from the East Asian financial crisis in 1997.

(8)_____

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Welcome to the Netherlands, a tiny country that only extends, at its broadest, 312 km north to  south, and 264 km east to west - (1) ......... the land area increases slightly each year as a result of continuous land reclamation and drainage. With a lot of heart and much to offer, ‘Holland,’ as it is (2).......known to most of us abroad - a name stemming from its once most prominent provinces - has more  going  on  per  kilometer  than  most  countries,  and  more  English-speaking  natives.  You’ll  be impressed by its (3).....cities and charmed by its countryside and villages, full of contrasts. From the exciting variety on offer, you could choose a romantic canal boat tour in Amsterdam, a Royal Tour by coach in The Hague, or a hydrofoil tour around the biggest harbour in the world - Rotterdam. In season you could visit the dazzling bulb fields, enjoy a full day on a boat, or take a bike tour through the pancake-flat countryside spiced with windmills. The possibilities are countless and the nationwide tourist office is on hand to give you information and help you (4)...... reservations.  You’ll  have (5)........language problems here, as the Dutch are true linguists and English is spoken here almost universally.
(4)...........................

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

"Quite apart from the economic similarity between present-day automation and the mechanization which has been proceeding for centuries, it must also be stressed that even in the United States automation is by no means the only factor (1)….. people from existing jobs.
 The increasing number of unneeded workers in (2)…. years has been the result of much more simple and old-fashioned influences: farm labourers have been (3)…. out of work by bigger tractors, miners by the cheapness of oil, and railwaymen by better roads.
 It is quite wrong, therefore, to think of automation as some new monster whose arrival (4)…. the existence of employment in the same way that the arrival of myxomatosis threatened the existence of the rabbit. Automation is one (5)….. of technological change, which itself is only one of the several changes (changes in tastes, changes in social patterns, changes in organization) which (6)…. in certain jobs disappearing and certain skills ceasing to be required. And even in America, which has a level of technology and output per (7)…. much in (8)….. of Britain’s, there is no (9)…. that the (10)….  of change is actually speeding up.
 Nevertheless changes in the amount of labour needed to produce a certain output are proceeding fairly rapidly in America - and in other countries - and my proceed more rapidly in future. Indeed it is one of the main objects of economic policy."

10. that the (10)….  of change is actually speeding up.

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Living things include both the visible world of animals, plants, and fungi as well as the invisible world of bacteria and viruses. On a basic level, we can say that life is ordered. Organisms have an enormously complex organization. We're all familiar with the intricate systems of the basic unit of life, the cell. Life can also "work." Living creatures can take in energy from the environment. This energy, in the form of food, is transformed to maintain metabolic processes and for survival. Life grows and develops. This means more than just replicating or getting larger in size. Living organisms also have the ability to rebuild and repair themselves when injured. Life can reproduce. Think about the last time you accidentally stubbed your toe. Almost instantly, you moved back in pain. Finally, life can adapt and respond to the demands placed on it by the environment. There are three basic types of adaptations that can occur in higher organisms.
Reversible changes occur as a response to changes in the environment. Let's say you live near sea level and you travel to a mountainous area. You may begin to experience difficulty breathing and an increase in heart rate as a result of the change in altitude. These symptoms go away when you go back down to sea level. Body-related changes occur as a result of prolonged changes in the environment. Using there previous example, if you were to stay in the mountainous area for a long time, you would notice that your heart rate would begin to slow down and you would begin to breath normally. These changes are also reversible. Genotypic changes (caused by genetic mutation) take place within the genetic makeup of the organism and are not reversible. An example would be the development of resistance to pesticides by insects and spiders.

In what way is life organized?

Are organically grown foods the best food choices? The advantages claimed for such foods over conventionally grown and marketed food products are now being debated. Advocates of organic foods - a term whose meaning varies greatly - frequently proclaim that such products are safer and more nutritious than others.
The growing interest of consumers in the safety and nutritional quality of the typical North American diet is a welcome development. However, much of this interest has been sparked by sweeping claims that the food supply is unsafe or inadequate in meeting nutritional needs.
Although most of these claims are not supported by scientific evidence, the preponderance of written material advancing such claims makes it difficult for the general public to separate fact from fiction. As a result, claims that eating a diet consisting entirely of organically grown foods prevents or cures disease or provides other benefits to health have become widely publicized and form the basis for folklore.
Almost daily the public is besieged by claims for “no-aging” diets, new vitamins, and other wonder foods. There are numerous unsubstantiated reports that natural vitamins are superior to synthetic ones, that fertilized eggs are nutritionally superior to unfertilized eggs, that untreated grains are better than fumigated grains, and the like.
One thing that most organically grown food products seem to have in common is that they cost more than conventionally grown foods. But in many cases consumers are misled if they believe organic foods can maintain health and provide better nutritional quality than conventionally grown foods. So there is real cause for concern if consumers, particularly those with limited incomes, distrust the regular food supply and buy only expensive organic foods instead.

According to the first paragraph, which of the following is true about the term “organic foods”?

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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.

Why didn't early bicycles look much like today's models?

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Our eyes and ears might be called transformers because they send the light and sound around us and turn them into electrical impulses that the brain can interpret. These electrical impulses that have been transformed by the eyes and ears reach the brain and are turned into massages that we can interpret. For the eye, the process begins as the eye admits light waves, bends them at the cornea and lens, and then focuses them on the retina. At the back of each eye, nerve fibers bundle together to form optic nerves, which join and then split into optic tracts. Some of the fibers cross so that part of the input from the right visual field goes into the left side of the brain, and vice versa. The process in the ear is carried out through sensory cells that are carried in fluid-filled canals and that are extremely sensitive to vibration. Sound that is transformed into electricity travels along nerve fibers in the auditory nerve. These fibers form a synapse with neurons that carry the massages to the auditory cortex on each side of the brain.

Which of the following is closest in meaning to the word “admits” in line 4?

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word for each of the blanks
One of the most important (1)........of a standardized test is time. You’ll only be allowed a certain number of minutes for each section, so it is very important that (2)....... . The most important time strategy is pacing yourself. Before you begin, take just a few seconds to survey the test, noting the number of questions and the sections that looks easier than the rest. Then, make a rough time schedule based on the amount of time available to you. Mark the half-way point on your test and make a note beside that mark of the time when the testing period is half over.
Once you begin the test, continue moving. If you work slowly in an attempt to make fewer mistakes, your mind will become bored and begin to wander. You’ll end up making far more mistakes if you’re not concentrating. If you take too long to answer questions that stump you, you may end up (3).........    out of    time before you finish. So don’t stop for difficult questions. Skip them and move on. You can come back to them later if you have time. A question that takes you five seconds to answer counts as much as one that takes you several minutes, so pick up the easy points first. (4)...... , answering the easier questions first helps build your confidence and gets you in the testing groove. If you are a little ahead, you know you are on track and may even have a little time left to check your work. If you are a little behind, you have 4 several choices. You can pick up the pace a little, but do this (5) ..........if you can do it comfortably.
(4).........................

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In the United States, friendship can be close, constant, intense, generous and real, yet fade away in a short time if circumstances change. Neither side feels hurt by this. Both may exchange Christmas greetings for a year or two, perhaps a few letters for a while - then no more. If the same two people meet again by chance, even years later, they pick up the friendship where they left off and are delighted.
In the United States, you can feel free to visit people's homes, share their holidays, or enjoy their lives without fear that they are taking on a lasting obligation. Do not hesitate to accept hospitality because you can’t give it in turn. No one will expect you to do so for they know you are far from home. Americans will enjoy welcoming you and be pleased if you accept their hospitality easily.
Once you arrived there, the welcome will be fun, warm, and real. Most visitors find themselves readily invited into many homes there. In some countries it is considered inhospitable to entertain at home, offering what is felt as only home cooked food, not doing something for your guests." It is felt that restaurant entertaining shows more respect and welcome. Or for other different reasons, such as crowded space, language difficulties, or family customs, outsiders are not invited into homes.
In the United States, both methods are used, but it is often considered friendlier to invite a person to one's home than to go to a public place, except in purely business relationship. So, if your host or hostess brings you home, do not feel that you are being shown inferior treatment.
Don't feel neglected if you do not find flowers awaiting you in your hotel room, either. Flowers are very expensive there; hotel delivery is uncertain; arrival times are delayed, changed or cancelled - so flowers are not customarily sent as a welcoming touch. Please do not feel unwanted! Outward signs vary in different lands; the inward welcome is what matters, and this will be real.

The word “it” in paragraph 2 refers to .................

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 In recent years there have been many articles on air pollution in newspapers and magazines. Scientists all over the world have warned that our atmosphere is (1).....more and more contaminated, and that Man, through his carelessness, may run out of pure air to breathe.
Automobiles and industries mainly account (2).... air pollution in most cities. They pour into the air such gases as carbon monoxide, sulfur and nitrogen oxides, (3)...... are very harmful to humans. (4)......still, these gases, a series of chemical changes, turn into toxic acids. They fall down in “acid rains”, raising the acidity in the air, soil and water to dangerous levels and affecting not only tress but also fish and other wildlife. Many industrial countries in Europe and North America have suffered bad effects (5)......those “rains”.
Surely, Man faces no more urgent problem than that of saving his own survival. Scientists, social organizations and governments shout sit down together to solve the air pollution problem.
(4).........................

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Vitamins, taken in tiny doses, are a major group of organic compounds that regulate the mechanisms by which the body converts food into energy. They should not be confused with minerals, which are inorganic in their makeup. Although in general the naming of vitamins followed the alphabetical order of their identification, the nomenclature of individual substances may appear to be somewhat random and disorganized. Among the 13 vitamins known today, five are produced in the body. Because the body produces sufficient quantities of some but not all vitamins, they must be supplemented in the daily diet. Although each vitamin has its specific designation and cannot be replaced by another compound, a lack of one vitamin can interfere with the processing of another. When a lack of even one vitamin in a diet is continual, a vitamin deficiency may result.
The best way for an individual to ensure a necessary supply of vitamins is to maintain a balanced diet that includes a variety of foods and provides adequate quantities of all the compounds. Some people take vitamin supplements, predominantly in the form of tablets. The vitamins in such supplements are equivalent to those in food, but an adult who maintains a balanced diet does not need a daily supplement. The ingestion of supplements is recommended only to correct an existing deficiency due to unbalanced diet, to provide vitamins known to be lacking in a restricted diet, or to act as a therapeutic measure in medical treatment. Specifically, caution must be exercised with fat-soluble substances, such as vitamins A and D, because, taken in gigantic doses, they may present a serious health hazard over a period of time.

How many vitamins must be derived from nourishment?

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.

(27) _____

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Vitamins, taken in tiny doses, are a major group of organic compounds that regulate the mechanisms by which the body converts food into energy. They should not be confused with minerals, which are inorganic in their makeup. Although in general the naming of vitamins followed the alphabetical order of their identification, the nomenclature of individual substances may appear to be somewhat random and disorganized. Among the 13 vitamins known today, five are produced in the body. Because the body produces sufficient quantities of some but not all vitamins, they must be supplemented in the daily diet. Although each vitamin has its specific designation and cannot be replaced by another compound, a lack of one vitamin can interfere with the processing of another. When a lack of even one vitamin in a diet is continual, a vitamin deficiency may result.
The best way for an individual to ensure a necessary supply of vitamins is to maintain a balanced diet that includes a variety of foods and provides adequate quantities of all the compounds. Some people take vitamin supplements, predominantly in the form of tablets. The vitamins in such supplements are equivalent to those in food, but an adult who maintains a balanced diet does not need a daily supplement. The ingestion of supplements is recommended only to correct an existing deficiency due to unbalanced diet, to provide vitamins known to be lacking in a restricted diet, or to act as a therapeutic measure in medical treatment. Specifically, caution must be exercised with fat-soluble substances, such as vitamins A and D, because, taken in gigantic doses, they may present a serious health hazard over a period of time.

With which of the following statements would the author be most likely to agree?

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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.