Read the following passage and choose the best answer (A, B, C, D):
Most households in the UK will have a broadband connection and a lot of those  houses will also have experienced connection or speed issues. But what if there was a way to connect to the internet and benefit from a direct connection with much faster speeds? Enter Li-Fi.  Li-Fi stands for Light Fidelity and is a Visible Light Communications (VLC) system which runs wireless communications that travel at very high speeds. With Li-Fi, your light blub is essentially your router. It uses common household LED light bulbs to enable data transfer, boasting speeds of up to 224 gigabits per second.  Li-Fi and Wi-Fi are quite similar as both transmit data electromagnetically. However, Wi-Fi uses radio waves, while Li-Fi runs on visible light waves. This means that it accommodates a photo-detector to receive light signals and a signal processing element to convert the data into “streamable” content. For example, data is fed into an LED light bulb, it then sends data at rapid speeds to the photo-detector. The tiny changes in the rapid dimming of LED bulbs is then converted by the “receiver” into electrical signal. The signal is then converted back into a binary data stream that we would recognise as web, video and audio applications that run on internet-enabled devices.  While some may think that Li-Fi with its 224 gigabits per second leaves Wi-Fi in the dust, Li-Fi’s exclusive use of visible light could halt a mass uptake. Li-Fi signals cannot pass through walls, so in order to enjoy full connectivity, capable LED bulbs will need to be placed throughout the home. Not to mention, Li-Fi requires the light bulb is on at all times to provide connectivity, meaning that the lights will need to be on during the day. Additionally, where there is a lack of light bulbs, there is a lack of Li-Fi internet so Li-Fi does take a hit when it comes to public Wi-Fi networks.  However, using Li-Fi instead of Wi-Fi, you’ll negate lots of security problems associated with shared and often overloaded broadband networks. It will also be advantageous in areas where radio frequency waves do not reach. Due to its impressive speeds, Li-Fi could make a huge impact on the internet of things too, with data transferred at much higher levels with even more devices able to connect to one another. 
3. According to paragraph 3, what form does the transferred data from Li-Fi system take?

Read the following passage and choose the best answer (A, B, C, D):
The International Ecotourism Society (TIES), a non-profit organization committed to promoting sustainable tourism, states that ecotourism unites conservation and communities with sustainable travel. With that being said, they offer six core principles of ecotourism that vacationers should follow: minimize impact, build environmental and cultural awareness and respect, provide positive experiences for both visitors and hosts, provide direct financial benefits for conservation, provide financial benefits and empowerment for local people, and raise sensitivity to host countries’ political, environmental, and social climate. Ecotourism offers the opportunity to help protect and maintain our planet. Beginning with responsible travel, sustainable tourism promotes green practices such as recycling and using organic products. There are also many environmental programs and initiatives made available so that people can get involved with sustainability. For example, in Kenya, tourists can get involved with the Basecamp Foundation, which has a monitoring program for big cats and elephants. These kinds of experiences try to demonstrate the positive impact of tourism and teach tourists about the significance of maintaining the environment. However, the simple act of being a tourist in a fragile, natural area helps a great deal, as the money spent there assists in raising funds to protect those areas for generations. Sustainable tourism supports local communities by allowing their economy to grow. Tourism alone employs a large number of local staff. This in turn empowers communities to fight against poverty and encourages the support of local events, festivals, and organizations. As a result the community and its local businesses thrive.  Not only is ecotourism an environmentally fun experience, but it’s also educational. By embarking on an ecotourism vacation, people gain an awareness and understanding of the social and economic conditions of the place they visit. In addition, vacationers learn to appreciate the area’s environment through conservation and also to respect the culture of the local people. While tourists are normally unaware of a country’s poverty or ill conditions, ecotourism strives to expose tourists to the realities of these areas. Ecotourism is a new holiday experience that mixes together vacation fun with conservation and education. Sustainable tourism creates environmentally aware individuals and helps develop their appreciation of nature and local culture. Not only do vacationers go home with new knowledge, but also a worthwhile experience.  
2. The word “sensitivity” in paragraph 1 is closest in meaning to _______

Choose the best answer:
My parents are glad ____ my success in finding a job after graduation.

Most Americans still get married at some point in their lives, but even that group is shrinking. Among current generations of adult American - starting with those bom in 1920s - more than 90 percent have married or will marry at some point in their lives. However, based on recent patterns of marriage and mortality, demographers calculate that a growing share of the younger generations are postponing marriage for so long that an unprecedented number will never marry at all.

More Americans are living together outside of marriage. Divorced and widowed people are waiting longer to remarry. An increasing number of single women are raising children. Put these trends together with our increasing life expectancy, and the result is inevitable. Americans are spending a record low proportion of their adult lives married.

Married rates for unmarried men and women have dropped from their post-195Os high to record lows. Part of this fall is due to the change in the age at which people first marry. The median age at first marriage is the age by which half the men or women who will ever marry have done so. It fell almost continuously from the time it was first measured, in 1890, at 22.0 years for women and 26.1 for men, to a low of 20.3 for women and 22.6 for men between 1947 and 1962. Since then, it has risen at a rapid pace, to a record high for 23.8 for women and 26.2 for men in 1994.

The length of time between marriages is also increasing, and more divorced people are choosing not to remarry. In 1990, divorced men had waited an average of 3.8 years before remarrying, and divorced women had waited an average of 3.5 years, an increase of more than one year over the average interval in 1970.

Data on cohabitation and unmarried childbearing suggest that marriage is becoming less relevant to Americans. 2.8 million of the nation's households are unmarried couples, and one-third of them are caring for children, according to the Census Bureau

 The word “those" in paragraph 1 refers to ________

Read the following passage and choose the best answer (A, B, C, D):
Most researchers agree that artificial intelligence (AI) peaked around 1985. A public (1)  _______ science-fiction movies and excited by the growing power of computers had high expectations. For years, Al researchers had implied that a breakthrough was just (2) ____ the corner. Marvin Minsky said in 1967 that within a generation the problem of creating AI would be (3) ____ solved. Prototypes of medical-diagnosis programs and speech recognition software appeared to be making progress. It proved to be a false dawn. Thinking computers and household robots failed to (4) ______, and a backlash ensued. "There was undue optimism in the early 1980s’, says David Leaky, a researcher at Indiana University. “Then when people realised these were hard problems, there was retrenchment’. By the late 1980s, the term AI was being avoided by many researchers, who opted instead (5) ____ themselves with specific subdisciplines such as neural networks, agent technology, case-based reasoning

Read the following passage and choose the best answer (A, B, C, D):
Scientists believe that something very serious is happening to the Earth. It is becoming warmer. Scientists predict that there will be major changes in the climate during the 21st century. Coastal waters will have higher temperatures. This will have a serious effect on agriculture. Farmers will have trouble producing good crops. In warm regions, the weather will be too dry. The amount of water could decrease by 50 per cent. This would cause a large decrease in agricultural production. World temperatures could increase from 1.5 to 5.6 degrees Celsius by the middle of the 21st century. And the increase in temperature could be even greater in the Arctic and Antarctic regions. A rise in temperature could cause the great ice sheets to melt, which, in turn would raise the level of oceans by one to two meters. Many coastal cities would be underwater. Why is all this happening? The Earth and its atmosphere are kept warm by the Sun. The atmosphere lets most of the light from the Sun pass through to warm the Earth. The Earth is warmer by the sunlight and sends heat energy back into the atmosphere. Much of this energy escapes from the Earth’s atmosphere. However, some of it remains. Gases such as carbon dioxide, ozone and water vapor absorb this energy and create more heat. Then, this heat is sent back down to Earth, and the Earth becomes warmer. Recently, however, an increase of carbon dioxide in the atmosphere is causing serious problems. Too much carbon dioxide in the atmosphere prevents heat energy from escaping. Too much heat is sent back down to the Earth, and the amount of carbon dioxide in the atmosphere continues to increase. When oil, gas, and coal burn, they create large amounts of carbon dioxide. The destruction of rain forests that absorb carbon dioxide also helps to increase the amount of carbon dioxide in our atmosphere. Some scientists believe that the amount of carbon dioxide in the air will double by the late 2000s. Scientists call this warming of the Earth and its atmosphere “the greenhouse effect”. A greenhouse, made of glass and plastic, is a special place where plants are grown. The sunlight passes through the glass or plastic and warms the air inside. The heat inside escapes very slowly, so the greenhouse remains very warm. This is exactly what is happening on the Earth. Another reason why the Earth is growing warmer is because of the amount of ozone in our atmosphere. Ozone is a form of oxygen. In the upper atmosphere, very far from the Earth, a layer of ozone helps to protect the Earth from 95 percent of the harmful light that comes from the sun. If your skin receives too much of this light, you would develop skin cancer. We need the ozone layer to protect ourselves. But the ozone layer is in trouble. Scientists have observed that the ozone layer is becoming thin, and above Antarctica there is a hole. This allows too much of the sun’s dangerous light into our atmosphere and makes the Earth warmer. Scientists say we must start making changes and planning now. We need to continue to do research, so we can predict what will happen in the future. We must burn less coal, oil, and gas. Other scientists believe that the problem is not so serious. They think that the Earth is growing warmer naturally, that we don’t need to worry about it now, and that we should just get ready for life in the warmer climate. Most scientists agree that the causes of the world’s climate are very complicated. They say that we must continue to measure the amount of carbon dioxide and ozone in the atmosphere. Scientists also encourage people to learn about the changes that are occurring in the world and how we can all help protect our atmosphere  
6. How useful is the ozone layer?

Choose the best answer:
Concord used to be _______ passenger plane in the world

Read the following passage and choose the best answer (A, B, C, D):
When people marry, they’re usually in love and happy to be tying the (1) ____. But after that, things tend to change. (2) __________ average, couples’ satisfaction with their marriage declines during the first years of marriage and, if the decline is particularly steep, divorce may follow. The course of true love runs downhill. For around 30 years, researchers have studied how having children affects a marriage, and the results are (3) ______: the relationship between spouses suffers once kids come along. Comparing couples with and (4) ______ children, researchers found that the rate of the decline in relationship satisfaction is nearly twice as steep for couples who have children than for childless couples. In the (5) ______ that a pregnancy is unplanned, the parents experience even greater negative impacts on their relationship. The irony is that even as the marital satisfaction of new parents declines, the likelihood of them divorcing also declines. So, having children may make you miserable, but you’ll be miserable together

Read the following passage and choose the best answer (A, B, C, D):
Hardcover and paperback are two types of books and bookbinding processes. A hardcover book is also called a hardback or hardbound. On the other hand, a paperback also goes by the names softback and soft cover. Paperbacks can be further classified as trade paperbacks and mass-market paperbacks. Paperback book, as its name implies, has a soft card or a thick paper cover over the pages. This type of covering is less heavy but prone to folding, bending, and wrinkles with use and over time. Hardcover books are characterized with a thick and rigid covering. This covering allows protection for the pages and makes the book durable and usable for a long time. Oftentimes, a hardcover book has a dust that protects the books from dust and other wear and tear. Some books are even made durable by using leather or calfskin as a book covering. In terms of manufacturing and purchasing books, hardcover books are more expensive due to the materials and processes. Pages of hardcover books are acid-free paper. This type of paper allows preservation of the ink and is ideal for books in use and preserving them for a long time. On the other hand, paperbacks use cheap paper, usually newsprint. The reason for this is to lower production costs and being readily made available for the masses. The paper in a hardcover book is usually stitched together before being glued, stapled, or sewn to the book’s spine. Due to the stitches, a hardcover book can have signatures, a place where the binding threads are visible. Meanwhile, a paperback book’s pages are glued together and glued again to the spine. This makes the pages loose or separated while being in use. Hardcover books are often applied to academic books, references books, commercial, and bestsellers that have enjoyed financial success. Other books in the hardcover version are books of collectible value. Publishers often release a hardcover version of the book to show investment so that they can project a high return of investment. This is a large contrast regarding paperbacks. Paperback books are done for new or succeeding editions, reprinting of books or books with little profit margin. Publishers use the paperback editions to stretch the profit for the book. The first release or first edition of a literary work is purposefully done as a hardcover book followed by paperback versions.
6. The word “they” in paragraph 4 refers to _____

Each sentence has a mistake. Findit by chosing A B C or D

The United States uses many of energy – nearly a million dollars worth each minute

Read the following passage and choose the best answer (A, B, C, D):
All birds have feathers, and feathers are unique to birds. No other major group of animals is so easy to categorize. All birds have wings, too, but wings are not (1) ___________ to birds. Many adaptations are found in both feathers and wings. Feathers form the soft down of geese and ducks, the long showy plumes of ostriches and egrets, and the strong flight feathers of eagles and condors. Wings (2) _____________ from the short, broad ones of chickens, who seldom fly, to the long slim ones of albatrosses, who spend almost all their lives soaring on air currents. In penguins, wings have been modified (3) ________ flippers, and feathers into a waterproof covering. In kiwis, the wings are almost impossible to detect. Yet diversity among birds is no so striking as it is among mammals. The (4) ___________ between a hummingbird and a penguin is immense, but hardly as startling as that between a bat and a whale. It is variations in details rather than in fundamental patterns (5) _____________ have been important in the adaptation of birds to many kinds of ecosystems

Choose the best answer:
The most important thing is that we ……… foreign tourists come back to Viet Nam again .

Read the following passage and choose the best answer (A, B, C, D):
Seeing the glass as half full may mean a longer life, according to research suggesting that optimists not only live longer in general, but have a better chance of reaching 85 or older. People of an upbeat disposition have previously been found to have a lower risk of heart conditions and premature death. Researchers now say it could also play a role in living a long life. “A lot of evidence suggests that exceptional longevity is usually accompanied by a longer span of good health and living without disability, so our findings raise an exciting possibility that we may be able to promote healthy and resilient ageing by cultivating psychosocial assets such as optimism,” said Lewina Lee, the lead author of the study at Boston University School of Medicine. Writing in the Proceedings of the National Academy of Sciences, Lee and colleagues report how they analysed data from two previous long-term research projects, one involving female nurses and the other focused on a cohort of men. The former team compared lifespan for the most optimistic with the least, taking into account factors including age, sex, race, education, depression and other health conditions present at the outset. The results show the most optimistic group of women had a lifespan almost 15% longer than the least. As for the other project, when the team compared the fifth of men boasting the highest optimism scores with the least optimistic, they found the most positive men had lifespans almost 11% longer. But being optimistic was not only linked to a longer lifespan. For men and women it was also linked more specifically to living to 85 or older when health behaviours were taken into account, with the most optimistic group of women having 20% better odds of reaching age 85 than the least. Lee said it was not yet clear why optimism is linked to longevity. “In our study, healthier behaviours, fewer depressive symptoms, and more social ties only partially accounted for the association from optimism to exceptional longevity,” Lee said, adding there are likely to be other mechanisms at play, such as optimistic people coping better with stress. Dr Catherine Hurt, an expert in health psychology at City, University of London, said the study highlighted the importance of psychological wellbeing alongside physical wellbeing for living a long and healthy life.
8. Which of the following can be inferred from the passage?

Read the following passage and choose the best answer (A, B, C, D):
Without regular supplies of some hormones our capacity to behave would be seriously impaired; without others we would soon die. Tiny amounts of some hormones can modify our moods and our action, our inclination to eat or drink, our aggressiveness or submissiveness, and our reproductive and parental behavior. And hormones do more than influence adult behavior; early in life they help to determine the development of bodily form and may even determine an individual’s behavioral capacities. Later in life the changing outputs of some endocrine glands and the body’s changing sensitivity to some hormones are essential aspects of the phenomena of aging. Communication within the body and the consequent integration of behavior were considered the exclusive province of the nervous system up to the beginning of the present century. The emergence of endocrinology as a separate discipline can probably be traced to the experiments of Bayliss and Starling on the hormone secretion. This substance is secreted from cells in the intestinal walls when food enters the stomach; it travels through the bloodstream and stimulates the pancreas to liberate pancreatic juice, which aids in digestion. By showing that special cells secrete chemical agents that are conveyed by the bloodstream and regulate distant target organs or tissues, Bayliss and Starling demonstrated that chemical integration can occur without participation of the nervous system. William Bayliss and Ernest Henry Starling, two British physiologists, discovered and introduced the word hormone. In 1979, The Bayliss and Starling Society was founded as a forum for research scientists with specific interest in the chemistry, physiology and function of central and autonomic peptides. The Society also offered the travelling fellowship award for members who wanted to attend national and international academic conferences. Sometimes, the Society help schools to organize science fairs for secondary students and give them incentives to fall for related subjects. The term “hormone” was first used with reference to secretion. Starling derived the term from the Greek hormone, meaning “to excited or set in motion.” The term “endocrine” was introduced shortly thereafter, “Endocrine” is used to refer to glands that secrete products into the bloodstream. The term “endocrine” contrasts with “exocrine” which is applied to glands that secrete their products through ducts to the site of action. Examples of exocrine glands are the tear glands, the sweat glands, and the pancreas, which secretes pancreatic juice through a duct into intestine. Exocrine glands are also called duct glands, while endocrine glands are called ductless.
1. Which of the following is NOT mentioned as an effect of hormones?

Read the following passage and choose the best answer (A, B, C, D):
There is still no consensus about how the Neanderthals were driven to extinction,  leaving our Homo sapien ancestors without any competition. The disappearance of the native European Neanderthals is odd partly because their shorter, stockier bodies must have made them better able to withstand the colder temperatures that prevailed when their cousins from Africa entered Europe. With a smaller surface area the Neanderthal body would have been able to retain more heat. The once common assumption that the key was the inferior vocal abilities of the Neanderthal has since been disproved by research on the Neanderthal hyoid bone, located in the throat. The larger skull capacity and brain is another respect in which they do not seem to have been inferior.  It was once thought that proof of a superior intellect was to be found in the narrower Homo sapien stone tools known as “blades”, which were assumed to be more efficient than the broader “flakes” used by the Neanderthals. In a number of important respects, including durability, this idea has proved to be unfounded. However, the blades would have been more effective as tips for throwing spears whereas the stone flakes would have been limited to the kind of thrusting spears the Neanderthals are believed to have used. This could have combined with the greater agility of the Homo sapiens to give them a distinct advantage in hunting on open terrain. Crucial in this respect were the larger canals in the Homo sapien inner ear, providing a more acute sense of balance, in addition to the longer limbs and lighter build. The Neanderthal technique of hiding and lying in wait for passing animals ceased to be viable when the dense forests of Europe began to recede. After a period of co-existence with their cousins, the Neanderthals were slowly eradicated.
5. According to the passage, which of the following is NOT an older assumption that has now been cast in doubt?

Mark the letter A, B, C, or D on your answer sheet to indicate the undelined part that needs correction in each of the following questions:
Being aware of one's own emotions - recognizing and acknowledging feelings as they happen - is at the very heart of Emotional Intelligence. And this awareness encompasses not only moods but also thoughts about those moods. People who are able to monitor their feelings as they arise are less likely to be ruled by them and are thus better able to manage their emotions.
Managing emotions does not mean suppressing them; nor does it mean giving free rein to every feeling. Psychologist Daniel Goleman, one of several authors who have popularized the notion of Emotional Intelligence, insisted that the goal is balance and that every feeling has value and significance. As Goleman said, "A life without passion would be a dull wasteland of neutrality, cut off and isolated from the richness of life itself." Thus, we manage our emotions by expressing them in an appropriate manner. Emotions can also be managed by engaging in activities that cheer us up, soothe our hurts, or reassure us when we feel anxious.
Clearly, awareness and management of emotions are not independent. For instance, you might think that individuals who seem to experience their feelings more intensely than others would be less able to manage them. However, a critical component of awareness of emotions is the ability to assign meaning to them - to know why we are experiencing a particular feeling or mood.
Psychologists have found that, among individuals who experience intense emotions, individual differences in the ability to assign meaning to those feelings predict differences in the ability to manage them. In other words, if two individuals are intensely angry, the one who is better able to understand why he or she is angry will also be better able to manage the anger.
Self-motivation refers to strong emotional self-control, which enables a person to get moving and pursue worthy goals, persist at tasks even when frustrated, and resist the temptation to act on impulse. Resisting impulsive behavior is, according to Goleman, "the root of all emotional self- control."
Of all the attributes of Emotional Intelligence, the ability to postpone immediate gratification and to persist in working toward some greater future gain is most closely related to success - whether one is trying to build a business, get a college degree, or even stay on a diet. One researcher examined whether this trait can predict a child's success in school. The study showed that 4-year-old children who can delay instant gratification in order to advance toward some future goal will be “far superior as students” when they graduate from high school than will 4-year-olds who are not able to resist the impulse to satisfy their immediate wishes.

The word “them” in paragraph 3 refers to     .

Read the following passage and choose the best answer (A, B, C, D):
The Forbidden City is the former imperial palace in the center of Beijing, China. Construction began in 1406, and the emperor’s (1)_______ officially moved in by 1420. The Forbidden City got its name because most people were barred (2) _______ entering the 72- hectare site, surrounded by walls. Even government officials and the imperial family were permitted only limited access. Only the emperor could enter any section at (3)_______. The architecture of the Forbidden City conforms rigidly to traditional Chinese principles. All buildings within the walls follow a north-south line and the most important ones face south to honor the sun. The designers arranged the other buildings, and the ceremonial spaces between them, to impress all visitors with the great power of the Emperor, while reinforcing the (4)_____ of the individual. This architectural concept was carried out to the smallest detail. For example, the importance of a building was determined not only by its height or width but also by the style of its roof and the quantity of statuettes placed on the roof’s ridges. In (5)_____ of the importance of its unparalleled architecture, UNESCO added the palace to its World Heritage List in 1987. Today, visitors from all over the world do not wait for an imperial invitation to walk about this palace, now a museum of imperial art

Read the following passage and choose the best answer (A, B, C, D):
Electronic devices are becoming increasingly common in educational environments. The term most commonly used for such devices is “educational technology”. This is not actually a new idea, as the rewritable wax tablets, often with lined surfaces to guide novice writers used in antiquity or the blackboard itself are both instances of technological innovations to support pedagogy. There are many different ways in which electronic devices are used in education. For example, students in STEM (science, technology, engineering medicine) fields have been making extensive use of sophisticated calculators for many years (the abacus and slide rule were non-electronic predecessors to calculators). In humanities as well as sciences, students use computers or equivalent devices to do research and write papers. In all fields, courses are now likely to have websites, and many instructors use course management software such as Blackboard, to post information for students, record grades, set up online discussions, and check for plagiarism. In lecture classes, many instructors project slides or notes on a screen and may even upload lecture notes so that students can review them. Some courses are hybrid, meaning that they have a strong online component, or offered entirely online. Many courses taught in conventional lecture halls are streamed online, and may use devices such as clickers to become more interactive. Any device (including tablets or cell phones) that instructors incorporate into a learning environment functions as educational technology.  
2. The word "instances" mostly means ___

Read the following passage and choose the best answer (A, B, C, D):
You get off your plane and make your way to the Baggage Reclaim area. After quite some time spent waiting, their is no sign of your bags and you begin to consider the possibility that they may have gone (1) _________. What should you do? Firstly, don’t panic. The most likely (2) _________ is that your bags simply didn’t make it onto the flight, perhaps because they were mislaid at the departure airport, or perhaps because the aircraft had already (3) _________ its weight allowance. If they fail to appear on the carousel, report the loss before you leave the baggage hall and go through customs. Recovering your luggage should be no problems, (4) ______ you’ve kept hold of your baggage checks – those little barcodes stuck to the back of your tickets at check-in. Go to the handling agent’s desk and complete a Property Irregularity Report (PIR) form, (5) _________ describes the checked bag and its contents. Then, ask the baggageservices manager for a contact telephone number and confirm that your bags will be forwarded to your final destination

Read the following passage and choose the best answer (A, B, C, D):
The Colosseum was constructed over a short decade, between 70-80 AD, by up to  100,000 slaves. Its building was overseen by different emperors who ruled under the Imperial Flavian dynasty, lending the structure its original name. Emperor Vespasian began the construction of the Flavian Amphitheater and his son Titus oversaw the construction of an additional tier after his death in 79 AD. His youngest son Domitian constructed the underground tunnels and added an extra level to increase its seating capacity. The amphitheater takes its more commonly attributed name from the Colossus of Nero, an enormous bronze statue of the Emperor which was located beside the structure.  The Colosseum was a recreational and gathering space that was used for gladiatorial contests, public spectacles, historical re-enactments, mythological theatrical performances and of course, executions. It could hold between 50,000 to 80,000 spectators and the seating arrangements reflect the stratification of Roman society: senators were seated closest to the stage while the poorest Roman citizens (and women) stood at the highest level. Its skilled architects developed an ingenious design which included 80 entrances and exits with a numbering system to allow access in and out of the structure. Unlike most ancient amphitheaters which were built into hillsides for support, the Colosseum is so impressive because it is a freestanding structure: it is made of travertine stone that was sourced from the nearby Tivoli area and held together with iron clamps.  The Colosseum is most closely associated with its gladiatorial shows, although often the combatants were not skilled professionals but rather unlucky slaves and criminals pitted against each other for the enjoyment of the public. In fact the venatio, or animal hunt, was one of the most popular shows for its novelty and shock appeal. Always in pursuit of ostentatious displays of wealth and power, the Romans procured exotic animals such as elephants, giraffes, lions, bears and crocodiles from the far reaches of the empire and sent them out into the pit, often along with unfortunate souls who would be torn to pieces. During the inaugural games of the Colosseum, most likely held in 80 AD, over 9,000 animals are believed to have been killed. The Romans also constructed elaborate stage sets on the arena floor, simulating forests and other natural environments, as backdrops to the events taking place. 
2. The word “tier” in paragraph 1 can be replaced by_______