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.

   Orchids are unique in having the most highly developed of all blossoms, in which the usual male and female reproductive organs are fused in a single structure called the column. The column is designed so that a single pollination will fertilize hundreds of thousands, and in some cases millions, of seeds, so microscopic and light they are easily carried by the breeze. Surrounding the column are three sepals and three petals, sometimes easily recognizable as such, often distorted into gorgeous, weird, but always functional shapes. The most noticeable of the petals is called the labellum, or lip. It is often dramatically marked as an unmistakable landing strip to attract the specific insect the orchid has chosen as its pollinator.

   To lure their pollinators from afar, orchids use appropriately intriguing shapes, colors, and scents. At least 50 different aromatic compounds have been analyzed in the orchid family, each blended to attract one, or at most a few, species of insects or birds. Some orchids even change their scents to interest different insects at different times.

   Once the right insect has been attracted, some orchids present all sorts of one-way obstacle courses to make sure it does not leave until pollen has been accurately placed or removed. By such ingenious adaptations to specific pollinators, orchids have avoided the hazards of rampant crossbreeding in the wild, assuring the survival of species as discrete identities. At the same time they have made themselves irresistible to collectors.

The word "fused" in line 2 is closest in meaning to......................

Read the passage and choose the correct answer:

The proverb 'A friend in need is a friend indeed.' means that we shall know who our real friends are when we are in need. Those who desert us when we are in difficulty are just unfaithful friends.

A true friend would remain with us whether we are rich or poor. Some people be friend the rich, simply for the sake of getting benefits from them.

It is useless to have insincere friends because these friends remain with us as long as we are rich or powerful. It is better to have one or two good friends rather than having hundreds of insincere ones.

A true friend will stand by us in our trials and tribulations. He will be a great source of consolation and comfort in our troubles. So we must be careful in choosing our friends. It is difficult to choose a sincere friend overnight; it takes years for us to find a sincere friend.

Real friends share everything we need.

Certain birds are, more often than not, considered bad luck, or even a sign of impending death. For example, all over the world, both crows and ravens have some connection to war, and death. In early times, crows and ravens were thought to accompany the gods of war, or be signs of the gods’ approaching arrival. This idea later changed. Crows in particular were thought to be harbingers of ill fortune or, in some cases, guides to the afterlife. Woe be it to the person who saw a single crow or raven flying overhead, for this was most certainly a portent of death in the near future.
 Interestingly, though potentially bad luck for people individually, the raven is considered to be good luck for the crown of England. So much so, in fact, that a “raven master” is, even today, an actual government position in London. He takes care of the ravens there and also clips their wings, ensuring that these birds can never fly far from the seat of the British government. This way, the kingdom will never fall to ill fortune.
 Another bird that is thought to play a part in forecasting the fortunes of people is the swallow. Depending on how and when it is seen, the swallow can be a harbinger of either good or ill fortune. Perhaps inspired by the swallow’s red-brown breast, Christian people initially related the swallow to the death of Jesus Christ. Thus, people who saw a swallow fly through their house considered it a portent of death. Later, however, farmers began to consider swallows signs of good fortune. Any barn that has swallows living in it is sure to be blessed in the following year. Farmers also have to beware of killing a swallow; that would be certain to end any good luck they might have had.
 Though many people think these superstitions are old wives’ tales, there is actually some evidence to support them. For example, crows and ravens, being scavengers, appear at the aftermath of battles. Thus, large numbers of crows and ravens could be good indications of war in an area. As well, swallows feed on insects that can cause infections in cattle. Thus, a farmer who has many swallows in his barn may actually have healthier animals on his farm. Therefore, the next time you feel inclined to laugh at an old wives’ tale, maybe you had better find out if there is any truth to it first!.

The word "old wives’ tales" in paragraph 4 is closest in meaning to ___________.

Read the text again. Decide whether the following statements are true (T), false (F), or not given (NG).

Changing lifestyles for better health

As a way of living, lifestyle is everyday behaviours, activities, and diet. It involves your work, leisure activities, food and drink consumption, and interaction with people. That is why it is important to have a healthy lifestyle. Although it is often difficult to change your habits, reorganising your daily activities to achieve a healthy lifestyle is not impossible. Here are some steps you need to take to have a better life and health.

Become more active

Scientists have proved that regular exercise can help to reduce cholesterol and the risk of heart disease. Remember that you do not need to do too much exercise - just a 30-minute walk a day will bring health benefits. But it is important that you do it regularly and safely. Simple things like walking or cycling to school, using the stairs instead of the lift, doing the housework and gardening can all contribute to good health.

Moreover, hobbies such as dancing, reading, listening to music, playing chess, and solving crossword or sudoku puzzles are also good ways to keep your body and mind engaged, and increase life expectancy. No matter where you are - at home, at work, or at play - always look for opportunities to be more active and energetic.

Eat healthily

‘Eat to live, not live to eat’ is the advice to follow.The food and drink we consume can dramatically affect our health. Bad nutrition based on fast food, and meals high in fat and sugar can lead to obesity, diabetes, some types of cancer and other chronic diseases. Planning and following a healthy and balanced diet is not difficult at all. Eat the right amount of calories to balance the energy you get from food and the energy you use. Make sure you have a wide range of foods to receive all the nutrients you need. Remember to eat less saturated fat, sugar and salt, and more fish, fruit, and vegetables.

Stay positive and be happy

Once you have started to be more active and eat more healthily, you can notice that you also feel happier. There is no doubt that daily worrying and stress can damage your heart and brain. When you are under a lot of stress, you may get angry easily. Anger and hostility have negative effects on the cardiovascular system. Recent research has confirmed that angry, hostile people live a shorter life. Try to control your anger, always look at the positive side of every situation and be optimistic. If necessary, practise sor-e meditation and yoga to help you to relieve your stress and anger, and enjoy life more.

Question 29. Stress and anger can affect people's life expectancy negatively.

Children all around the world love to read comic books. Maybe they like to read the kind of comic books that come out once a month, like Spiderman or Batman, or maybe they like manga-style comic books. That means that publishers who make comic books need to keep in touch with the things young people like to do. One thing that many young people today are interested in is technology, so of course kids want to read digital comic books on electronic devices.

Let's take Japanese manga as an example. There are lots of people around the world who enjoy reading manga. However, in the past, it was difficult to find translated versions of manga in comic bookstores. But that did not stop manga fans. Some fans who could translate Japanese into their own language started translating manga themselves. Then they scanned the pages of manga books and uploaded the scanned pages to the Internet with their translation. This practice has become so popular. People in the comic book industry made up a name for it. By combining the words scan and translation, they call it "scanlation", and it is a big problem today. The people who do scanlation usually share their manga for free, so readers do not buy manga books. Writers, artists, and publishers all end up losing money because of scanlation. Another problem is piracy in the comic book industry. Illegal copies of old and brand new comics alike have been hurting comic book sales.

Despite the progress made in converting comics to digital formats, hardcopy comic books are still by far the most popular format among fans. In the meantime, comic book publishers and stores will just have to keep an eye on their buyers' habits. As the popularity of digital books for e-readers and tablets grows, the popularity of digital comic books will grow as well.

According to paragraph 2, the practice of "scanlation" mostly involves ______.

Identify the one underlined word or phrase - A, B, C or D - that must be changed for the sentence to be correct.

 Clay that has been heated or fired in a kiln cannot to be softened again.

Read the following passage and choose the best answer (A, B, C, D):
Amid the hum and heat of Berlin’s Reuter thermal power station stands a shining contraption that looks out of place in the decades-old machine hall. Its silver pipes and vats contain a substance that the company Vattenfall, the plant’s operator, says could become a key ingredient for a fossil fuel-free future. The energy company, together with a Swedish start-up, is testing the use of salt to store heat, which accounts for more than half the power consumed in Germany. If it works well, the system could help solve a problem posed by renewable energy sources like wind and solar: unreliability, meaning they sometimes generate too much, and sometimes too little power. “Germany currently has enough installed renewable energy capacity to produce twice as much as it needs, it’s just not constant,” says Hendrik Roeglin, who oversees the salt storage project for Vattenfall. At the Reuter power plant in Berlin, which supplies 600,000 households in the capital with heat, the solution involves the use of calcium oxide, also known as quicklime. Vattenfall and Swedish start-up SaltX have been taking advantage of a simple chemical reaction that occurs when quicklime becomes wet: the salt-like grains soak up the water, becoming calcium hydroxide and releasing large amounts of heat in the process. By removing the water again, the substance turns back into calcium oxide. The process essentially mirrors how batteries work, except that instead of electricity, the system stores heat. Roeglin says the process can absorb ten times more energy than water, which is currently used for power- to-heat facilities. And unlike tanks of hot water, which slowly cool down over time, the system can retain the chemically-trapped energy for far longer. Need heat? Just add water. The pilot project in Berlin can currently store enough energy to heat about 100 large houses. But SaltX says the facility could easily be scaled up and provide heat to any of the homes or offices already connected to the capital’s district heating system. Such networks — consisting of pipes pumping hot water or steam from power plants to consumers — exist in many European countries, Canada, the United States, Japan and China. SaltX also notes that the calcium oxide currently mined in Finland could be safely recycled, giving it an edge over some battery technologies that use rare or toxic materials. “If your ambition is to be fossil-free within a generation, you have to consider various alternatives to reach that,” a representative of SaltX, Simon Ahlin, said during a visit to the facility. “This is an effective solution that’s available in a short time frame.”
7. As mentioned in paragraph 1, if the new heat-retaining system operates effectively, it can: 

Read the following passage and choose the best answer (A, B, C, D):
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.
4. According to the passage, in 1787 which of the following states had the FEWEST people?

Choose the correct answer to complete the  following passage.

"In a healthy relationship, both partners respect, trust and embrace (1) ____ differences. Both partners are able to communicate (2) ____ their needs and listen to their partner, and work to resolve conflict in a rational and (3) ____ way. But maintaining a healthy relationship (4) ____ for skills many young people are never taught. A lack of these skills, and (5) ____ up in a society that sometimes celebrates violence or in a community that experiences a high (6) ____ of violence, can lead to unhealthy and even violent relationships among youth.

Dating violence (7) ____ psychological or emotional violence, such as controlling behaviours or jealousy; physical violence, such as hitting or punching. More than 20 per cent of all adolescents report having experienced (8) ____ psychological or physical violence from an intimate partner - and underreporting remains a concern.

Adolescents, (9) ____ older adolescents, often have romantic relationships, which are long-term, serious, and intimate. Society has a responsibility to provide young people with the resources, skills, and space (10) ____ to safeguard their physical and emotional well being in these relationships. Youth-serving professionals, educators, and parents can help young people in need access services to (11) ____ dating abuse victimisation. Research also has shown that programmes intended to prevent dating violence can be (12) ____."

10. Society has a responsibility to provide young people with the resources, skills, and space (10) ____ to safeguard their physical and emotional well being in these relationships.

Read the following passage and choose the best answer (A, B, C, D):
The United Nations is an international organization founded in 1945. It is currently made up of 193 member countries. Its main goal is to bring different nations together to promote peace and justice in the world. The UN also works to make the world a safe and secure place. It is important to remember that the UN is not a “world government”. This means that the UN does not make laws for different countries to follow. However, the UN does hold regular votes on global policies and issues. The main branch of the UN is called the “General Assembly”. All members of the United Nations are represented and have their votes. If there is a problem in a certain area of the world or a particular country, the UN will vote on how to best solve the problem. At least two-thirds of all member countries must agree on how to resolve the problem in order for the UN to take action. If less than two-thirds of the voting countries agree, no immediate action is taken. Another branch is the Security Council. Its main purpose is to maintain international peace and keep the world secure. This branch has only fifteen members, five of which are permanent, including China, France, Russia, the United Kingdom, and the United States. The other ten members are elected by the General Assembly for two-year terms. IF the council feels that international peace is being threatened, the fifteen members will try to outline a way to resolve the situation in a peaceful manner. The third important branch is the Economic and Social Council. This branch works to help monitor the world economy and resolve social issues around the world such as violations of human rights, the fight against international crime and destruction of the environment. There are 54 government representatives serving on this council. They are elected by the General Assembly to serve for three-year terms. Council members are elected to represent certain areas of the world. 
7. It can be inferred from the passage that: 

Read the following passage and choose the best answer (A, B, C, D):
Fiberscopes are one of the most are one of the most important outcomes of he science of fiber optics. Fibers made of glass and transparent acrylic plastic are capable of conveying light energy, and when thousands of these fibers are combined in what is called a fiberscope, they can transmit images. The most common fiberscopes contain about 750,000 fibers, each 0.001 centimeter, or 10 microns, in diameter. For certain uses, the diameter of the fiber may be as small as 5 microns. Fiberscopes have a wide range of applications. In the medical field, physicians use fiberscopes to examine internal organs and as an aid in delicate surgeries. Miniature probes have also been developed to view muscle fiber, skin tissue, and blood cells. Fiberscopes have also found varied uses in industry, particularly to inspect or control operations in inaccessible areas. Bundles of fiberscopes fused together in a solid plate, called a faceplate, are being used in the manufacture of television tubes and other cathode- ray tube devices. The most far reaching applications of fiber-optic technology are in communication. Optical fibers carry voice messages for telephone service. The sound of the voice is electronically broken down into thousands of pulses per second, which causes a transmitting laser to send coordinated pulses of light through the optical fibers. At the receiving end, the light pulses are converted to electrical signals and the voice message is reconstructed. Light-wave communication systems can handle an immensely greater number of telephone calls and television programs than the current system, and they will form the basis of the “electronic superhighway” expected to crisscross the nation in the near future of the information age.
3. It can be inferred from the passage that fiberscopes .

Read the following passage and choose the best answer (A, B, C, D):
The word "laser" was coined as an acronym for Light Amplifiation by the Stimulated Emission of Radiation. Ordinary light, from the Sun or a light bulb, is emitted spontaneously, when atoms or molecules get rid of excess energy by themselves, without any outside intervention. Stimulated emission is different because it occurs when an atom or molecule holding onto excess energy has been stimulated to emit it as light. Albert Einstein was the first to suggest the existence of stimulated emission in a paper published in 1917. However, for many years physicists thought that atoms and molecules always were much more likely to emit light spontaneously and that stimulated emission thus always would be much weaker. It was not until after the Second World War that physicists began trying to make stimulated emission dominate. They sought ways by which, one atom or molecule could stimulate many others to emit light, amplifying it to much higher powers. The first to succeed was Charles H. Townes, then at Colombia University in New York. Instead of working with light, however, he worked with microwaves, which have a much longer wavelength, and built a device he called a "maser", for Microwave Amplifiation by the Stimulated Emission of Radiation. Although he thought of the key idea in 1951, the first maser was not completed until a couple of years later. Before long, many other physicists were building masers and trying to discover how to produce stimulated emission even shorter wavelength. The key concepts emerged about 1957. Townes and Arthur Schawlow, then at Bell Telephone Laboratories, wrote it long paper outlining the conditions needed to amplify stimulated emission of visible light waves. At about the same time, similar ideas crystallized in the mind of Gordon Gould, then a 37-year-old graduate student at Columbia, who wrote them down in a series of notebooks. Townes and Schawlow published their ideas in a scientific journal, Physical Review Letters, but Gould filed a patent application. Three decades later, people still argue about who deserves the credit for the concept of the laser.
9: The word "outlining" in paragraph 4 is closest in meaning to .

Read the text again. Decide whether the following statements are true (T), false (F), or not given (NG).

Changing lifestyles for better health

As a way of living, lifestyle is everyday behaviours, activities, and diet. It involves your work, leisure activities, food and drink consumption, and interaction with people. That is why it is important to have a healthy lifestyle. Although it is often difficult to change your habits, reorganising your daily activities to achieve a healthy lifestyle is not impossible. Here are some steps you need to take to have a better life and health.

Become more active

Scientists have proved that regular exercise can help to reduce cholesterol and the risk of heart disease. Remember that you do not need to do too much exercise - just a 30-minute walk a day will bring health benefits. But it is important that you do it regularly and safely. Simple things like walking or cycling to school, using the stairs instead of the lift, doing the housework and gardening can all contribute to good health.

Moreover, hobbies such as dancing, reading, listening to music, playing chess, and solving crossword or sudoku puzzles are also good ways to keep your body and mind engaged, and increase life expectancy. No matter where you are - at home, at work, or at play - always look for opportunities to be more active and energetic.

Eat healthily

‘Eat to live, not live to eat’ is the advice to follow.The food and drink we consume can dramatically affect our health. Bad nutrition based on fast food, and meals high in fat and sugar can lead to obesity, diabetes, some types of cancer and other chronic diseases. Planning and following a healthy and balanced diet is not difficult at all. Eat the right amount of calories to balance the energy you get from food and the energy you use. Make sure you have a wide range of foods to receive all the nutrients you need. Remember to eat less saturated fat, sugar and salt, and more fish, fruit, and vegetables.

Stay positive and be happy

Once you have started to be more active and eat more healthily, you can notice that you also feel happier. There is no doubt that daily worrying and stress can damage your heart and brain. When you are under a lot of stress, you may get angry easily. Anger and hostility have negative effects on the cardiovascular system. Recent research has confirmed that angry, hostile people live a shorter life. Try to control your anger, always look at the positive side of every situation and be optimistic. If necessary, practise sor-e meditation and yoga to help you to relieve your stress and anger, and enjoy life more.

Question 25. In order to reduce cholesterol, you need to exercise a lot and work out more than 30 minutes every day.

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 Asian Games owes its origins to small Asian multi-sport competitions. The Far Eastern Championship Games were created to show unity and cooperation among three nations: Japan, the Philippines and China. The first games were held in Manila, the Philippines in 1931. Other Asian nations participated after it was organized. After World War II, a number of Asian countries became independent. Many of the new independent Asian countries wanted to use a new type of competition where Asian dominance should not be shown by violence and should be strengthened by mutual understanding. In August 1948, during the 14th Olympic Game in London, India representative Guru Dutt Sondhi proposed to sports leaders of the Asian teams the idea of having discussions about holding the Asian Games. They agreed to form the Asian Athletic Federation. A preparatory was set up to draft the charter for the Asian amateur athletic federation. In February 1949, the Asian athletic federation was formed and used the name Asian Games Federation. It was formed and used the name Asian Games Federation. It was decided to hold the first Asian Games in 1951 in New Delhi the capital of India. They added that the Asian Games would be regularly held once every four years.

The text is about the ____.

Read the following passage and choose the best answer (A, B, C, D):
A survey is a study, generally in the form of an interview or a questionnaire, which provides information concerning how people think and act. In the United States, the best-known surveys are the Gallup poll and the Harris poll. As anyone who watches the news during campaigns presidential knows, these polls have become an important part of political life in the United States. North Americans are familiar with the many “person on the street” interviews on local television news shows. While such interviews can be highly entertaining, they are not necessarily an accurate indication of public opinion. First, they reflect the opinions of only those people who appear at a certain location. Thus, such samples can be biased in favor of commuters, middle-class shoppers, or factory workers, depending on which area the news people select. Second, television interviews tend to attract outgoing people who are willing to appear on the air, while they frighten away others who may feel intimidated by a camera. A survey must be based on a precise, representative sampling if it is to genuinely reflect a broad range of the population.
In preparing to conduct a survey, sociologists must exercise great care in the wording of questions. An effective survey question must be simple and clear enough for people to understand it. It must also be specific enough so that there are no problems in interpreting the results. Even questions that are less structured must be carefully phrased in order to elicit the type of information desired. Surveys can be indispensable sources of information, but only if the sampling is done properly and the questions are worded accurately. There are two main forms of surveys: the interview and the questionnaire. Each of these forms of survey research has its advantages. An interviewer can obtain a high response rate because people find it more difficult to turn down a personal request for an interview than to throw away a written questionnaire. In addition, an interviewer can go beyond written questions and probe for a subject’s underlying feelings  and reasons. However, questionnaires have the advantage of being cheaper and more consistent.
3. According to the passage, the main disadvantage of person-on-the-street interviews is that they

Read the following passage and choose the best answer (A, B, C, D):
The word "laser" was coined as an acronym for Light Amplifiation by the Stimulated Emission of Radiation. Ordinary light, from the Sun or a light bulb, is emitted spontaneously, when atoms or molecules get rid of excess energy by themselves, without any outside intervention. Stimulated emission is different because it occurs when an atom or molecule holding onto excess energy has been stimulated to emit it as light. Albert Einstein was the first to suggest the existence of stimulated emission in a paper published in 1917. However, for many years physicists thought that atoms and molecules always were much more likely to emit light spontaneously and that stimulated emission thus always would be much weaker. It was not until after the Second World War that physicists began trying to make stimulated emission dominate. They sought ways by which, one atom or molecule could stimulate many others to emit light, amplifying it to much higher powers. The first to succeed was Charles H. Townes, then at Colombia University in New York. Instead of working with light, however, he worked with microwaves, which have a much longer wavelength, and built a device he called a "maser", for Microwave Amplifiation by the Stimulated Emission of Radiation. Although he thought of the key idea in 1951, the first maser was not completed until a couple of years later. Before long, many other physicists were building masers and trying to discover how to produce stimulated emission even shorter wavelength. The key concepts emerged about 1957. Townes and Arthur Schawlow, then at Bell Telephone Laboratories, wrote it long paper outlining the conditions needed to amplify stimulated emission of visible light waves. At about the same time, similar ideas crystallized in the mind of Gordon Gould, then a 37-year-old graduate student at Columbia, who wrote them down in a series of notebooks. Townes and Schawlow published their ideas in a scientific journal, Physical Review Letters, but Gould filed a patent application. Three decades later, people still argue about who deserves the credit for the concept of the laser.
3: The word "it" in line 5 refers to .

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.

   Technology has utterly transformed our ability to communicate with each other. Linking to each other both literally and figuratively, many of us connect through cell phones, email, instant messaging, blogs, and networking web sites, yet we may be less connected to each other than we think.

   According to a study, Americans are becoming increasingly socially isolated. The study reveals, for example, that one quarter of Americans say that they have no one to discuss important personal issues with, and that the number of close friends that American have has dropped from three to two. Meanwhile, the Boston Globe reports that this spreading isolation is experienced more sharply among those with less education, people of color, and older Americans. Unsurprisingly, those who are young, white, and well educated tend to have stronger social networks.

   From my own experience I have to say that I’ve never felt more connected, thanks to a web of friends, family, and colleagues. One of my closest friends is someone I met through an online discussion group who lives hundreds of miles away from me. We have met face-to-face only twice, yet our regular electronic correspondence and cell phone calls sustain our close friendship. And, speaking of blogging, my blog has introduced me to people I would never have met otherwise and has led to enduring and important friendships.

   On the other hand, I recently saw a scene unfold that proved to me how deeply disconnected we as Americans have become. I had just wrapped up a presentation on mediation at a family therapy center. As I was leaving, I noticed a mother and her teenage son who had just completed their session with their family therapist. After making their next appointment, they both took out their cell phones, placed calls, and began loud conversations with whoever was on the other end. I walked out behind them to the parking lot to my car. They both jumped into their SUV, and, as I saw them drive off, they were still talking on their cell phones. But, alas, not to each other.

Which of the following has nothing to do with the isolation among Americans?

Read the following passage and choose the best answer (A, B, C, D):
The word "laser" was coined as an acronym for Light Amplifiation by the Stimulated Emission of Radiation. Ordinary light, from the Sun or a light bulb, is emitted spontaneously, when atoms or molecules get rid of excess energy by themselves, without any outside intervention. Stimulated emission is different because it occurs when an atom or molecule holding onto excess energy has been stimulated to emit it as light. Albert Einstein was the first to suggest the existence of stimulated emission in a paper published in 1917. However, for many years physicists thought that atoms and molecules always were much more likely to emit light spontaneously and that stimulated emission thus always would be much weaker. It was not until after the Second World War that physicists began trying to make stimulated emission dominate. They sought ways by which, one atom or molecule could stimulate many others to emit light, amplifying it to much higher powers. The first to succeed was Charles H. Townes, then at Colombia University in New York. Instead of working with light, however, he worked with microwaves, which have a much longer wavelength, and built a device he called a "maser", for Microwave Amplifiation by the Stimulated Emission of Radiation. Although he thought of the key idea in 1951, the first maser was not completed until a couple of years later. Before long, many other physicists were building masers and trying to discover how to produce stimulated emission even shorter wavelength. The key concepts emerged about 1957. Townes and Arthur Schawlow, then at Bell Telephone Laboratories, wrote it long paper outlining the conditions needed to amplify stimulated emission of visible light waves. At about the same time, similar ideas crystallized in the mind of Gordon Gould, then a 37-year-old graduate student at Columbia, who wrote them down in a series of notebooks. Townes and Schawlow published their ideas in a scientific journal, Physical Review Letters, but Gould filed a patent application. Three decades later, people still argue about who deserves the credit for the concept of the laser.
5: Why has Towne's early work with stimulated emission done with microwaves?

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.

   A rather surprising geographical feature of Antarctica is that a huge freshwater, one of the world’s largest and deepest, lies hidden there under four kilometers of ice. Now known as Lake Vostok, this huge body of water is located under the ice block that comprises Antarctica. The lake is able to exist in its unfrozen state beneath this block of ice because its waters are warned by geothermal heat from the earth’s core. This thick glacier above Lake Vostok actually insulates it from frigid temperatures (the lowest ever recorded on Earth) on the surface.

   The lake was first discovered in the 1970s while a research team was conducting an aerial survey of the area. Radio waves from the survey equipment penetrated the ice and revealed a body of water of indeterminate size. It was not until much more recently that data collected by satellite made scientists aware of the tremendous size of the lake; satellite-borne radar detected an extremely flat region where the ice remains level because it is floating on the water of the lake.

   The discovery of such a huge fresh water lake trapped under Antarctica is of interest to the scientific community because of the potential that the lake contains ancient microbes that have survived for thousands upon thousands of years, unaffected by factors such as nuclear fallout and elevated ultraviolet light that have conducting research on the lake in such a harsh climate and in the problems associated with obtaining uncontaminated sampled from the lake without actually exposing the lake to contamination. Scientists are looking for possible ways to accomplish this.

The passage mentions which of the following as a reason for the importance of Lake Vostok to scientists?

Read the following passage and choose the best answer (A, B, C, D):
Tulips are Old World, rather than New World, plants, with the origins of the species lying in Central Asia. They became an integral part of the gardens of the Ottoman Empire from the sixteenth century onward, and, soon after, part of European life as well. Holland, in particular, became famous for its cultivation of the flowers. A tenuous line marked the advance of the tulip to the New World, where it was unknown in the wild. The first Dutch colonies in North America had been established in New Netherlands by the Dutch West India Company in 1624, and one individual who settled in New Amsterdam (today's Manhattan section of New York City) in 1642 described the flowers that bravely colonized the settlers' gardens. They were the same flowers seen in Dutch still-life paintings of the time: crown imperials, roses, carnations, and of course tulips. They flurished in Pennsylvania too, where in 1698 William Penn received a report of John Tateham's "Great and Stately Palace," its garden full of tulips. By 1760, Boston newspapers were advertising 50 different kinds of mixed tulip "roots." But the length of the journey between Europe and North America created many difficulties. Thomas Hancock, an English settler, wrote thanking his plant supplier for a gift of some tulip bulbs from England, but his letter the following year grumbled that they were all dead. Tulips arrived in Holland, Michigan, with a later wave of early nineteenth-century Dutch immigrants who quickly colonized the plains of Michigan. Together with many other Dutch settlements, such astheone at Pella, Iowa, they established a regular demand for European plants. The demand was bravely met by a new kind of tulip entrepreneur, the traveling salesperson. One Dutchman, Hendrick van de Schoot, spent six months in 1849 traveling through the United States taking orders for tulip bulbs. While tulip bulbs were traveling from Europe to the United States to satisfy the nostalgic longings of homesick English and Dutch settlers, North American plants were traveling in the opposite direction. In England, the enthusiasm for American plants was one reason why tulips dropped out of fashion in the gardens of the rich and famous 
5. The author mentions tulip growing in New Netherlands, Pennsylvania and Michigan in order to illustrate how

Read the following passage and choose the best answer (A, B, C, D):
Light from a living plant or animal is called bioluminescence, or cold light, to distinguish it from incandescence or heat-generating light. Life forms could not produce incandescent light without being burned. Their light is produced in chemicals combining in such a way that little or no measurable heat is produced, and the life forms generating it are unharmed. Although bioluminescence is a relatively complicated process, it can be reduced to simple terms. Living light occurs when luciferin and oxygen combine in the presence of luciferase. In a few cases, fireflies the most common, an additional compound called ATP is required. The earliest recorded experiments with bioluminescence in the late 1800s are attributed to Raphael Dubois, who extracted a luminous fluid from a clam, observing that it continued to glow in the test tube for several minutes. He named the substance luciferin, which means “the bearer of life”. In further research, Dubois discovered that several chemicals were required for bioluminescence to occur. In his notes, it was recorded that a second important substance, which he called luciferase, was always present. In later study of small, luminous sea creatures, Newton Harley concluded that luciferin was composed of carbon, hydrogen, and oxygen, which are the building blocks of all living cells. He also proved that there are a variety of luciferin and luciferase, specific to the plants and animals that produce them. Much remains unknown, but many scientists who are studying bioluminescence now believe that the origin of the phenomenon may be traced to a time when there was no oxygen in the Earth’s atmosphere. When oxygen was gradually introduced to the atmosphere, it was actually poisonous to life forms, plants and animals produced light to use up the oxygen in a gradual but necessary adaptation. It is speculated that millions of years ago, all life may have produced light to survive. As the millennia passed, life forms on Earth became tolerant of, and finally dependent on oxygen, and the adaptation that produced bioluminescence was no longer necessary, but some primitive plants and animals continued to use the light for new functions such as mating or attracting prey.
2: According to the author, why has bioluminescence continued in modern plants and animals?