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

 In 1969, the Cuyahoga River in Cleveland, Ohio, was such polluted with hazardous wastes that it caught fire and burned

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They ____ sacrifices so that their only child could have a good education.

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The issue of equality for women in British society first attracted national attention in the early 20th century, when the suffragettes won for women the right to vote. In the 1960s feminism became the subject of intense debate when the women's liberation movement encouraged women to reject their traditional supporting role and to demand the equal right with men in areas such as employment and play. Since then, the gender gap between the sexes has been reduced. The Equal Pay Act of 1970, for instance, made it illegal for woman to be paid less than men for doing the same work, and in 1975 the Sex Discrimination Act aimed to prevent either sex having an unfair advantage when applying forjobs. In the same year the Equal Opportunities Commission was set up to help people claim their rights to equal treatment and to publish research and statistics to show where improvements in opportunities for women need to be made. Women now have much better employment opportunities, though they still tend to get less well-paid jobs than men, and very few are appointed to top jobs in industry. In the US the movement that is often called the"first wave of feminism"began in the 1800s. Susan B. Anthony worked for the right to vote, Margaret Sanger wanted to provide women with the means of contraception so that they could decide whether or not to have children, and Elizabeth Blackwell, who had to fight for the chance to become a doctor, wanted to have greater opportunities to study. Many feminists were interested in other social issues. The second wave of feminism began in 1960s. Women like Betty Friedan and Gloria Steinem became associated with the fight to get equal rights and opportunities for women under law. An important issue was the Equal Rights Amendment (ERA), which was intended to change the Constitution. Although the ERA was not passed, there was progress in other areas. It became illegal for employers, schools, clubs, etc... to discriminate against women. But women still find it hard to advance beyond a certain point in their career, the so-called glass ceiling that prevents them from having high level jobs. Many women also face the problem of the second shift, i.e. the household chores. In the 1980s, feminism became less popular in the US and there was less interest in solving the remaining problems, such as the fact that most women still earn much less than men. Although there is still discrimination, the principle that it should not exist is widely accepted.
7. The phrase "glass ceiling" in paragraph 4 mostly means: 

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

"Face-to-face conversation is a two-way process: you speak to me, I reply to you and so on. Two-way (1)….. depends on having a coding System that is understood by both (2)….. and receiver, and an agreed convention about (3)…. the beginning and end of the (4)… . In speech, the coding System is the language like English or Spanish; the convention that one person speaks at a time may seem too obvious to (5)…. . In fact, the (6)…..that people use in conversations and meetings are often non- verbal. For example, lowering the pitch of voice may mean the end of a sentence; a Sharp intake of breath may signal the desire to (7)….. , catching the chairman’s (8)…. may indicate the desire to speak in a formal setting like a (9)….. , a clenched fist may indicate anger. When these (10)….. signals are not possible, more formal signals may be needed."

9. in a formal setting like a (9)….. , a clenched fist may indicate anger.

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Like the revolutions that preceded it, the Fourth Industrial Revolution has the potential to raise global income levels and improve the quality of life for populations around the world. To date, those who have gained the most from it have been consumers able to afford and access the digital world; technology has made possible new products and services that increase the efficiency and pleasure of our personal lives. Ordering a cab, booking a flight, buying a product, making a payment, listening to music, watching a film or playing a game — any of these can now be done remotely. In the future, technological innovation will also lead to a supply-side miracle, with long-term gains in efficiency and productivity. Transportation and communication costs will drop, logistics and global supply chains will become more effective and the cost of trade will diminish, all of which will open new markets and drive economic growth. At the same time, as the economists Erik Brynjolfsson and Andrew McAfee have pointed out, the revolution could yield greater inequality, particularly in its potential to disrupt labor markets. As automation substitutes for labor across the entire economy, the net displacement of workers by machines might exacerbate the gap between returns to capital  and returns to labor. On the other hand, it is also possible that the displacement of workers by technology will, in aggregate, result in a net increase in safe and rewarding jobs. We cannot foresee at this point which scenario is likely to emerge, and history suggests that the outcome is likely to be some combination of the two. However, I am convinced of one thing — that in the future, talent, more than capital, will represent the critical factor of production. This will give rise to a job market increasingly segregated into “low-skill/low-pay” and “highskill/high-pay” segments, which in turn will lead to an increase in social tensions. In addition to being a key economic concern, inequality represents the greatest societal concern associated with the Fourth Industrial Revolution. The largest beneficiaries of innovation tend to be the providers of intellectual and physical capital — the innovators, shareholders and investors — which explains the rising gap in wealth between those dependent on capital versus labor. Technology is therefore one of the main reasons why incomes have stagnated, or even decreased, for a majority of the population in high-income countries: the demand for highly skilled workers has increased while the demand for workers with less education and lower skills has decreased. The result is a job market with a strong demand at the high and low ends, but a hollowing out of the middle. This helps explain why so many workers are disillusioned and fearful that their own real incomes and those of their children will continue to stagnate. It also helps explain why middle classes around the world are increasingly experiencing a pervasive sense of dissatisfaction and unfairness. A winnertakes-all economy that offers only limited access to the middle class is a recipe for democratic malaise and dereliction.  
6. What does the word “stagnated” in the last paragraph mean?

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Children can learn a lot from doing household chores. Doing chores helps children learn about (1)___________ they need to do to care for themselves, a home and a family. They learn skills they can use in their adult lives, like preparing meals, cleaning, organizing and keeping a garden. (2)________in chores also gives children experience of relationship skills like communicating clearly, negotiating, cooperating and working as a team. When children (3)_________ to family life, it helps them feel competent and responsible. Even if they don’t enjoy the chore, when they keep going they get the feeling of satisfaction that comes with finishing a task. And sharing housework can also help families work better and reduce family stress. When children help out, chores get done sooner, and parents have less to do. This frees up time for the family to spend doing fun things together. The secret for involving children in household chores is asking for contributions that you (4)__________ and that suit your children’s ages and abilities. A chore that’s too hard for a child can be frustrating – or even dangerous – and one that’s too easy might be boring. Even a young child can start to help out if you choose activities that are right for his age. You can start with simple jobs like looking after his own toys. Chores like this send the message to your child that his contribution is important. If your child is old enough, you can have a family discussion (5)___________ chores. This can reinforce the idea that the whole family contributes to how the household runs.

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

 Before the nineteenth century, it was rarely to find organized systems of adult education

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The Moon is the Earth’s only natural satellite and was formed 4.6 billion years ago  around some 30–50 million years after the formation of the solar system. Science has told us so (1) ____ about the Moon that it is fairly easy to imagine what it would be like to go there. It is certainly not a friendly place. As there is no air or water, there can be no (2) ____ of any kind. There is no variety of scenery (3) ____ . For mile after mile there are only flat plains of dust with mountains around them. Above, the Sun and stars shine in a black sky. If you step out of the mountain shadows, it will (4) ____ moving from severe cold into great heat. This extreme (5) ____ continually breaks rocks away from the surface of the mountains. The Moon is also a very silent world, for sound waves can only travel through air. But beyond the broken horizon, you see a friendly sight, our earth is shining more brightly than the stars. From this distance, it looks like an immense ball, colored blue and green and brown.

BODY LANGUAGE AND CULTURAL DIFFERENCES
The body language people use often communicates more about their feelings than the words they are saying. We use body movements, hand gestures, facial expressions, and changes in our voice to communicate with each other. Although some body language is universal, many gestures are culturally specific and may mean different things in different countries. 
If you want to give someone the nod in Bulgaria, you have to nod your head to say no and shake it to say yes – the exact opposite of what we do! In Belgium, pointing with your index finger or snapping your fingers at someone is very rude. 
In France, you shouldn't rest your feet on tables or chairs. Speaking to someone with your hands in your pockets will only make matters worse. In the Middle East, you should never show the soles of your feet or shoes to others as it will be seen as a grave insult. When eating, only use your right hand because they use their left hands when going to the bathroom. 
In Bangladesh, the 'thumbs-up' is a rude sign. In Myanmar, people greet each other by clapping, and in India, whistling in public is considered rude.
In Japan, you should not blow your nose in public, but you can burp at the end of a meal to show that you have enjoyed it. The 'OK' sign (thumb and index finger forming a circle) means 'everything is good' in the West, but in China it means nothing or zero. In Japan, it means money, and in the Middle East, it is a rude gesture.

The word “others” in paragraph 3 refers to __________.

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The era of “smart cities”, controlled by an ecosystem of sensors, cameras and  algorithms, is fast approaching. In China, state media claim 500 are under construction. In Canada, Alphabet has plans for turning parts of Toronto into a timber-framed tech town as a prototype. Incremental steps are also making cities smarter. Last week, Transport for London announced plans to track Tube passengers through WiFi to monitor congestion. In the US, fast-food drive-throughs will trial number plates scanners to make ordering faster. Individually these services can improve daily life. Integrating them will create something more powerful than the sum of its parts.  Though convenience and safety are the end goals, serious questions about how city authorities will both store and share vast bodies of data must be answered. The fact that surveillance is built into key transport infrastructure will also make it increasingly difficult to avoid without disrupting daily life. The smart city risks creating a panopticon in the name of an easier and better life. The risks of anonymity disappearing will be increased by the use of different data sets, making it more likely that identifiable characteristics may appear. Closely linked to this is the question of data storage and sharing. The treasure trove of personal information will be a tempting target for hackers. This information might also be used by law enforcement, feeding into the existing dangers of mass surveillance and profiling, as is already the case in China.  These concerns have long been levelled at social media and internet-enabled home appliances. Smart city surveillance can be even more insidious. Users can avoid Facebook or hardware such as Alexa. Avoiding basic infrastructure will be near impossible without seriously affecting day-to-day life. TfL has put up signs warning customers of the WiFi tracking, yet the only choice is between tracking and having no signal. Reports on the facial recognition at airports in America suggest that avoiding being automatically scanned will be tough as well. As these systems become more closely enmeshed, avoiding snooping will become increasingly tricky.  The inevitable rise of smart cities is not inherently negative. Harnessing the power of technology and data can potentially help urban environments adapt to challenges such as climate change and overcrowding. Politicians, programmers and academics must work to ensure that does not come at the cost of all-seeing, 24-hour surveillance. 
4. According to paragraph 2, what is the mentioned unwanted consequence for the future of high-tech societies?

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Recently scientists have apply new tools of biochemistry and molecular biology to investigate the structure of human hair

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A Tidal Stream Generation system reduces some of the environmental effects of tidal barrages by using turbine generators beneath the surface of the water. Major tidal flows and ocean currents, like the Gulf Stream, can be exploited to extract its tidal energy using underwater rotors and turbines. Tidal stream generation is very similar in principle to wind power generation. Water currents flow across a turbines rotor blades which rotates the turbine, much like how wind currents turn the blades for wind power turbines. In fact, tidal stream generation areas on the sea bed can look just like underwater wind farms. Unlike off-shore wind power which can suffer from storms or heavy sea damage, tidal stream turbines operate just below the sea surface or are fixed to the sea bed. Tidal streams are formed by the horizontal fast flowing volumes of water caused by the ebb and flow of the tide as the profile of the sea bed causes the water to speed up as it approaches the shoreline. As water is much more denser than air and has a much slower flow rate, tidal stream turbines have much smaller diameters and higher tip speed rates compared to an equivalent wind turbine. Tidal stream turbines generate tidal power on both the ebb and flow of the tide. One of the disadvantages of Tidal Stream Generation is that as the turbines are submerged under the surface of the water they can create hazards to navigation and shipping. Other forms of tidal energy include tidal fences which use individual vertical-axis turbines that are mounted within a fence structure, known as the caisson, which completely blocks a channel and force water through them. Another alternative way of harnessing tidal power is by using an “oscillating tidal turbine”. This is basically a fixed wing called a Hydroplane positioned on the sea bed. The hydroplane uses the energy of the tidal stream flowing past it to oscillate its giant wing, similar to a whales flipper, up and down with the movement of the tidal currents. This motion is then used to generate electricity. The angle of the hydroplane to the flow of the tide can be varied to increase efficiency. Tidal energy is another form of low-head hydro power that is completely carbon neutral like wind and hydro energy. Tidal power has many advantages compared to other forms of renewable energy with its main advantage being that it is predictable. However, like many other forms of renewable energy, tidal energy also has its disadvantages such as its inflexible generation times dependant upon the tides and the fact that it operates in the hostile conditions of the oceans and seas
3. What does the word “profile” in paragraph 3 refer to?

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National parks protect the best of our natural heritage: stunning landscapes,  extraordinary wildlife and majestic forests. Together with other protected areas they form the basis of our economic and social wellbeing, attract millions of visitors annually, and help to protect Australia’s unique wildlife by acting as a refuge for threatened species. Future generations deserve the right to see these natural values intact and protected as we do today.  Our national parks form the cornerstone of biodiversity conservation in Australia, containing vital habitat that provides safe havens in which animals and plants can survive and thrive. Together with other protected areas, they provide a ‘backbone’ of core conservation areas that can be linked by conservation efforts across different tenures, supporting a diverse, healthy and resilient environment. A well-connected landscape is essential for saving NSW’s 1,000 threatened species, 70% of which occur in our national parks. In addition our protected areas provide life-sustaining services vital for the wellbeing of our environment and society, such as protection of urban water catchments and climate amelioration.  National Parks provide a major boost to Australia’s economy, with nature-based tourism bringing $23 billion into the country every year. Regional communities in particular benefit from the 35.5 million people who visit NSW’s national parks each year, through job creation and money spent on accommodation, fuel and food. The Great Barrier Reef alone attracts more than $6 billion a year in tourist-spending and supports over 63,000 jobs. Furthermore, from ancient aboriginal rock-art sites, to the buildings left over from early European settlements, our national parks also serve as a natural history book dating back thousands of years. Our national parks protect these vital and fragile places; areas where the traces of a history extending back more than 22,000 years can remain undisturbed.  Natural areas have a profound effect on our physical and emotional health and wellbeing. In our increasingly frenetic world, our national parks are important sanctuaries where people can take time out, enjoy nature, get fit, relax and revitalise, whilst nature’s inherent beauty serves as a source of artistic, creative and spiritual inspiration. Research on the benefits of contact with the natural environment show that it is likely to have a significant positive psychological effect, serving to reduce stress, anger, frustration and aggression, providing an opportunity for social bonding, and serving as a place for learning and mental stimulation. Children in particular display long-term benefits of playing outdoors.
1. Which best serves as the title for the passage?

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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.  
4. The word "they" in the passage refers to ____

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In the last five decades or so, the media and its influence on the societies, has grown (1)_______ with the advance of technology. First there was the telegraph and the post offices, then the radio, the newspaper, magazines, television and now the internet and the new media including palmtops, cell phones etc. There are positive and negative influences of mass media, which we must understand as a responsible person of a society. Before (2)___________ the influence of mass media on society it is imperative to explain the three basic functions of mass media; they are providing news/information, entertainment and education. The first and foremost function of the media in a society is to provide news and information to the masses, that is why the present era is some time termed as the information age (3)__________. People need news/information for various reasons, on one hand it can be used to socialize and on the other to make decisions and formulate opinions. Entertainment would be the other function of the mass media (4)______ it is mostly used by the masses to amuse them in present day hectic environment. Educating the masses about their rights, moral, social and religious obligations is another important function of mass media, which needs no emphasis. In present era of (5)__________ , majority of people in the society depends on information and communication to remain connected with the world and do our daily activities like work, entertainment, health care, education, socialization, travelling and anything else that we have to do

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Population in the world is currently (2018) growing at a rate of around 1.09% per year (down from 1.12% in 2017 and 1.14% in 2016). The current average population increase is estimated (1)________83 million people per year Annual growth rate reached its (2)__________in the late 1960s, when it was at around 2%. The rate of increase has nearly halved since then, and will continue (3)_________in the coming years. It is estimated to reach 1% by 2023, less than 0.5% by 2052, and 0.25% in 2076 (a yearly addition of 27 million people to a population of 10.7 billion). In 2100, it should be only 0.09%, or an addition of only 10 million people to a total population of 11.2 billion. World population will therefore continue to grow in the 21st century, but at a much slower rate (4)___________to the recent past. World population has doubled (100% increase) in 40 years from 1959 (3 billion) to 1999 (6 billion). It is now estimated that it will (5)_________another nearly 40 years to increase by another 50% to become 9 billion by 2037

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 from 36 to 42.

It is estimated that by 2050 more than two-thirds of the world's population will live in cities, up from about 54 percent today. While the many benefits of organized and efficient cities are well understood, we need to recognize that this rapid, often unplanned urbanization brings risks of profound social instability, risks to critical infrastructure, potential water crises and the potential for devastating spread of disease. These risks can only be further exacerbated as this unprecedented transition from rural to urban areas continues.
 How effectively these risks can be addressed will increasingly be determined by how well cities are governed. The increased concentration of people, physical assets, infrastructure and economic activities mean that the risks materializing at the city level will have far greater potential to disrupt society than ever before.
 Urbanization is by no means bad by itself. It brings important benefits for economic, cultural and societal development. Well managed cities are both efficient and effective, enabling economies of scale and network effects while reducing the impact on the climate of transportation. As such, an urban model can make economic activity more environmentally-friendly. Further, the proximity and diversity of people can spark innovation and create employment as exchanging ideas breeds new ideas.
 But these utopian concepts are threatened by some of the factors driving rapid urbanization. For example, one of the main factors is rural-urban migration, driven by the prospect of greater employment opportunities and the hope of a better life in cities. But rapidly increasing population density can create severe problems, especially if planning efforts are not sufficient to cope with the influx of new inhabitants. The result may, in extreme cases, be widespread poverty. Estimates suggest that 40% of the world's urban expansion is taking place in slums, exacerbating socio-economic disparities and creating unsanitary conditions that facilitate the spread of disease.
 The Global Risks 2015 Report looks at four areas that face particularly daunting challenges in the face of rapid and unplanned urbanization: infrastructure, health, climate change, and social instability. In each of these areas we find new risks that can best be managed or, in some cases, transferred through the mechanism of insurance.

What can be inferred from the passage? 

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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  
1. Which of the following will be one of the consequences of a warmer earth?

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In order to stay healthy, make sure you have a balanced intake of vitamins and minerals.

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Whether a species is endangered—meaning at risk of extinction—depends on which definition you use. The International Union for Conservation of Nature’s Red List of Threatened Species classifies an animal as endangered when its numbers in the wild have dropped so low that it’s at “extremely high risk” of extinction. Meanwhile, the United States’ Endangered Species Act of 1973 takes into consideration any destruction to a species’ habitat, whether it has been over-consumed, any disease or predation that threaten it, whether any other man-made factors put it in danger, and what policies currently exist to protect it. When members of the public or a state agency propose to the U.S. Fish & Wildlife Service or the National Marine Fisheries Service that a species be listed as endangered under the law, research and management plans are formed to help those species survive. It is illegal under the Endangered Species Act to capture, hunt, shoot, or otherwise harm an animal that’s listed as endangered. Sometimes, federal agencies decide that although a species could be considered endangered, other species are higher priorities. In those cases, the animal or plant gets limited protections. One animal whose numbers have increased through conservation is the bald eagle. There were only about 500 bald eagles in the continental United States in the 1960s because of pesticides that damaged the shells of their eggs. Conservation efforts including captive breeding programs, habitat protection, and a ban on the insecticide DDT helped the bald eagle’s numbers soar back into the thousands. Another is the giant panda, which was declared no longer endangered in 2016 thanks to 50 years of efforts to save it. U.S. Rep. John Dingell, who wrote the Endangered Species Act, argued that “only natural extinction is part of natural order.” Scientists believe that 227 species - including the grizzly bear, the peregrine falcon and the gray wolf - were saved from extinction in the first 33 years of the law’s existence. Still, critics argue that the act is expensive and ineffective because it protects so many species. Several federal courts have heard and rejected arguments that the Endangered Species Act is unconstitutional, and members of Congress have tried to weaken the law in small ways.
1. Which best serves as the title for the passage?

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Many prehistoric people subsisted as hunters and gatherers. Undoubtedly, game  animals, including some very large species, provided major components of human diets. An important controversy centering on the question of human effects on prehistoric  wildlife concerns the sudden disappearance of so many species of large animals at or near the end of the Pleistocene epoch. Most paleontologists suspect that abrupt changes in climate led to the mass extinctions. Others, however, have concluded that prehistoric people drove many of those species to extinction through overhunting. In their “Pleistocene overkill hypothesis,” they cite what seems to be a remarkable coincidence between the arrival of prehistoric peoples in North and South America and the time during which mammoths, giant ground sloths, the giant bison, and numerous other large mammals became extinct.  Perhaps the human species was driving others to extinction long before the dawn of history. Hunter-gatherers may have contributed to Pleistocene extinctions in more indirect ways. Besides overhunting, at least three other kinds of effects have been suggested: direct competition, imbalances between competing species of game animals, and early agricultural practices. Direct competition may have brought about the demise of large carnivores such as the saber-toothed cats. These animals simply may have been unable to compete with the increasingly sophisticated hunting skills of Pleistocene people.  Human hunters could have caused imbalances among game animals, leading to the extinctions of species less able to compete. When other predators such as the gray wolf prey upon large mammals, they generally take high proportions of each year’s crop of young. Some human hunters, in contrast, tend to take the various age-groups of large animals in proportion to their actual occurrence. If such hunters first competed with the larger predators and then replaced them, they may have allowed younger to survive each year, gradually increasing the populations of favored species. As these populations expanded, they in turn may have competed with other game species for the same environmental niche, forcing the less hunted species into extinction. This theory, suggests that human hunters played an indirect role in Pleistocene extinctions by hunting one species more than another. 
8. The imbalances discussed in paragraph 4 may have resulted from __________