Each sentence has a mistake. Find it bychosing A B C or D

Food addictive is any chemical that food manufacturers intentional add to their products

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

Over the past 60 years, starting right after World War II, American society became  richer

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:
When another old cave is discovered in the south of France, it is not usually news.
Rather, it is an ordinary event. Such discoveries are so frequent these days that hardly anybody pays heed to them. However, when the Lascaux cave complex was discovered in 1940, the world was amazed. Painted directly on its walls were hundreds of scenes showing how people lived thousands of years ago. The scenes show people hunting animals, such as bison or wild cats.
Other images depict birds and, most noticeably, horses, which appear in more than 300 wall images, by far outnumbering all other animals.
Early artists drawing these animals accomplished a monumental and difficult task. “They” did not limit themselves to the easily accessible walls but carried their painting materials to spaces that required climbing steep walls or crawling into narrow passages in the Lascaux complex.
Unfortunately, the paintings have been exposed to the destructive action of water and temperature changes, which easily wear the images away. Because the Lascaux caves have many entrances, air movement has also damaged the images inside. Although they are not out in the open air, where natural light would have destroyed them long ago, many of the images have deteriorated and are barely recognizable. To prevent further damage, the site was closed to tourists in 1963, 23 years after it was discovered.

What does the passage say happened at the Lascaux caves in 1963?

Read the following passage and choose the best answer (A, B, C, D):
Nowadays, dozens of interventions are known that extend the lifespan of various living organisms ranging from yeast to mammals. They include chemical compounds, genetic interventions, and diets. Some targets of these interventions have been discovered. However, there is still no clear understanding of the systemic molecular mechanisms leading to lifespan extension. A group of scientists from Skoltech, Moscow State University and Harvard University decided to fill this gap and identify crucial molecular processes associated with longevity. To do so, they looked at the effects of various lifespan-extending interventions on the activity of genes in a mouse, a commonly used model organism closely related to humans. “In our lab, we subjected mice of different sexes and ages to 8 longevity interventions and analyzed gene expression changes induced by these treatments. After aggregating our data with the datasets published by other groups, we obtained gene activity profiles of 17 interventions. Although in general the effects produced by individual treatments turned out to be rather specific, a certain group of genes changed its expression in a similar way in response to different lifespan-extending interventions,” says the first author of the study, Alexander Tyshkovskiy. The scientists then applied the discovered biomarkers to search for other interventions with the same effect on their activity and, therefore, high potential for lifespan extension "Currently, we are validating these hits by testing their effect on the mouse lifespan. We hope that our biomarkers will significantly facilitate the search for new longevity interventions and help improve the healthspan and lifespan in rodents and, in the long term, in humans," says Alexander. 
5. The word “validating” in paragraph 4 is closest in meaning to ______

Read the following passage and choose the best answer (A, B, C, D):
Birds are even more disrupted by their noisy neighbours than had been thought  previously, researchers have found. And human activities could be preventing birds from reproducing and even developing normal social behaviour and keeping the peace.  A study by Queen’s University Belfast found that when European robins were subjected to human produced noises their behaviour changed. Background noise appeared to mask the communication of crucial information between birds. While aggressive communication is common and birds respond to it, interference through noise can lead to the birds mistaking the signals.  Birds can end up in situations all too familiar to humans. “The birds receive incomplete information on their opponent’s intent and do not appropriately adjust their response,” explained Arnott. “Where song is disguised by background noise, in some cases the male ends up fighting more vigorously than he should, but at other times gives in too easily.”Arnott said the purpose of birdsong was twofold – to attract mates and defend territory. Birds already face an array of human-made dangers, from pesticides and intensive farming to shooting and poisoning. But noise had often been overlooked, the paper in Biology Letters found. A spokesperson for the RSPB said: “Everyone is becoming increasingly concerned that nature is in crisis in the UK, with one in 10 of our wildlife species at threat of extinction. Many of our birds’ populations are already facing a serious crisis as a result of habitat loss, climate change and other human activities. This report is a good reminder that the way we live and our lifestyle has an impact on our natural world, and that we need to protect our natural world if we want to let nature sing.”  For birds, the extra burden of noise pollution adds to extraordinary decline in species, including among once common birds, in recent decades due to such activities as agricultural practice and pesticide use. In the experiment the team used playbacks of robin song to stimulate responses from birds who were territory holders. Simple or complex songs were used in either the presence or absence of noise. The researchers found that song complexity  was used as a signal of aggressive intent; birds demonstrated higher aggressive intent towards complex rather than simple song. This process was disrupted by the presence of added noise.
6. According to paragraph 5, what did the research find out from the experiment?

Rewrite the sentence:
Do you have a food processor at your house?

Read the following passage and choose the best answer (A, B, C, D):
Bagpipe music played, wreaths were sent and Amazing Grace was sung. A  black shroud was laid upon a makeshift urn. It was a funeral, of course, for which such displays of respect are common. But in this case, the people living in a small Nova Scotia community had gathered to pay their respects not to a person who had died, but to a post office.  The grief might have been hard for outsiders to understand, but not for those living in Head of St. Margaret’s Bay, N.S., where the post office run by Verna Dunlop was a big part of their small, tight-knit community. The post office, which had been located in the back of Dunlop’s home, was not just a utilitarian service kiosk where residents had to go to pick up their mail. According to locals, it was also a community hub where people gathered to catch up on the town gossip, or to enjoy a cup of the coffee the postmaster had been brewing for them. “It’s really the centre of the village,” said one woman, explaining what the post office meant to the people living there.  There had been a post office located in Head of St. Margaret’s Bay since before Confederation. And local residents spent months fighting to keep the one they had. But Canada Post made the decision to close it, as it was losing money. It was replacing the post office with sets of newly installed super mailboxes.  Many people in town weren’t convinced the coming changes were for the better. “We do not want those super mailboxes. We want to have a community life,” he said. At the mock funeral, Dunlop choked up as she said she hoped “this is going to stop,” alluding to the fact that it wasn’t just Head of St. Margaret’s Bay that was losing its post office. “We hope that the way of life that we’re used to we can keep,” she added. Canada Post had closed 40 such rural post offices that year and had long-term plans to close more than 5,000 of them across the country. “Just as Verna Dunlop’s post office came to symbolize for these people the best qualities of rural life, so does its passing remind them of the steady erosion of that way of life,” said Evans.
4. According to paragraph 2, what was NOT the reason for the locals to keep visiting the post office?

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:
Clara Barton became known as “The Angel of the Battlefield” during the American Civial War. Born in Oxford, Massachusetts in 1821, Clara Barton’s interest in helping soldiers on the battlefield began when she was told army stories from her father. Another event that influenced her decision to help soldiers was an accident her brother had. His injuries were cared for by Barton for 2 years. At the time, she was only 11 years old. Barton began teaching school at the age of 15. She taught for 18 years before she moved to Washington, D.C. in 1854.
The civil war broke out 6 years later. Immediately, Barton started was service by helping the soldiers with their needs. At the battle of Bull Run, Clara Barton received permission from the government to take care of the sick and hurt. Barton did this with great empathy and kindness. She acknowledged each soldier as a person. Her endurance and courage on the

battlefield were admired by many. When the war ended in 1865, she used 4 years of her life to assist the government in searching for soldiers who were missing during the war.
The search for missing soldiers and years of hard work made her feeble physically. In 1869, her doctors recommended a trip to Europe for a rest. While she was on vacation, she became involved with the International Red Cross, an organization set up by the Geneva Convention in 1864. Clara Barton realized that the red Cross would be a big help to the United States. After she returned to the United States, she worked very hard to create an American red Cross. She talked to government leaders and let American people know about the Red Cross. In 1881, the Notional Society of the Red Cross was finally established with its headquarters in Washington, D.C. Clara Barton managed its activities for 23 years.
Barton never let her age stop her from helping people. At the age of 79, she helped flood victims in Galveston, Texas. Barton finally resigned from the Red Cross in 1904. She was 92 years old and had truly earned her titled “The Angel of the Battlefield”.

What does the author mention about the American Red Cross?

Read the following passage and choose the best answer (A, B, C, D):
Although the “lie detectors” are being used by governments, police departments, and businesses that all want guaranteed ways of detecting the truth, the results are not always accurate. Lie detectors are properly called emotion detectors, for their aim is to measure bodily changes that contradict what a person says. The polygraph machine records changes in heart rate, breathing, blood pressure, and the electrical activity of the skin (galvanic skin response, or GSR). In the first part of the polygraph test, you are electronically connected to the machine and asked a few neutral questions (“What is your name?”, “Where do you live?”). Your physical reactions serve as the standard (baseline) for evaluating what comes next. Then you are asked a few critical questions among the neutral ones (“When did you rob the bank?”). The assumption is that if you are guilty, your body will reveal the truth, even if you try to deny it. Your heart rate, respiration, and GSR will change abruptly as you respond to the incriminating questions. That is the theory; but psychologists have found that lie detectors are simply not reliable. Since most physical changes are the same across all emotions, machines cannot tell whether you are feeling guilty, angry, nervous, thrilled, or revved up form an exciting day. Innocent people may be tense and nervous about the whole procedure. They may react physiologically to a certain word (“bank”) not because they robbed it, but because they recently bounced a check. In either case the machine will record a “lie”. The reverse mistake is also common. Some practiced liars can lie without flinching, and others learn to beat the machine by tensing muscles or thinking about an exciting experience during neutral questions
5. The word “it” in paragraph 1 refers to ______

Choose the best answer:
He asked the children ............... too much noise.

Read the following passage and choose the best answer (A, B, C, D):
Elephants need a large amount of habitat because they eat so much. Humans have become their direct competitors for living space. Human populations in Africa and Asia have quadrupled since the turn of the century, the fastest growth rate on the planet. Forest and savanna habitat has been converted to cropland, pastureland for livestock, and timber for housing and fuel. Humans do not regard elephants as good neighbors. When humans and elephants live close together, elephants raid crops, and rogue elephants rampage through villages. Local people shoot elephants because they fear them and regard them as pests. Some countries have established culling programs: park officials or hunters kill a predetermined number of elephants to keep herds manageable and minimize human-elephant conflicts. Hunting has been a major cause of the decline in elephant populations. Elephants became prized trophies for big-game hunters after Europeans arrived in Africa. More recently, and more devastatingly, hunters have slaughtered elephants for their ivory tusks. The ivory trade became a serious threat to elephants in the 1970s. A sudden oil shortage caused the world economy to collapse, and ivory became more valuable than gold. In fact, ivory has been called “white gold” because it is beautiful, easily carved, durable, and pleasing to the touch. Most of the world’s ivory is carved in Japan, Hong Kong, and other Asian countries, where skilled carvers depend on a supply of ivory for their livelihoods  Hunting elephants is no longer legal in many African countries, but poaching was widespread until very recently. For many the high price of ivory, about $100 a pound in the 1980s, was too tempting to resist. Local people often had few other ways to make a living, and subsistence farmers or herders could make more by selling the tusks of one elephant than they could make in a dozen years of farming or herding. As the price of ivory soared, poachers became more organized, using automatic weapons, motorized vehicles, and airplanes to chase and kill thousands of elephants. To governments and revolutionaries mired in civil wars and strapped for cash, poaching ivory became a way to pay for more firearms and supplies. Poaching has caused the collapse of elephants’ social structure as well as decimating their numbers. Poachers target the biggest elephants because their tusks are larger. They often kill all the adults in the group, leaving young elephants without any adults to teach them migration routes, dry-season water sources, and other learned behavior. Many of Africa’s remaining elephant groups are leaderless subadults and juveniles.
5. Which of the following is NOT mentioned as a reason why ivory is valuable?

Read the following passage and choose the best answer (A, B, C, D):
We all want to live in a clean and green world and breathe pollution free air. For this kind of environment we desperately need a fossil fuel free world. Scientists are toiling hard to come up (1)______ alternative fuels which can replace conventional fuels. One such study was presented at the 237th National Meeting of the American Chemical Society. This study throws interesting light on the first economical, eco-friendly process to (2)______ algae oil into biodiesel fuel. The scientists are quite hopeful that one day America will become independent (3)______ fossil fuels. Ben Wen is the (4)______ researcher and vice president of United Environment and Energy LLC, Horseheads, N.Y. According to him, “This is the first economical way to produce biodiesel from algae oil. It costs much less than conventional processes because you would need a much smaller factory, there (5)______ no water disposal costs, and the process is considerably faster.”

Read the following passage and choose the best answer (A, B, C, D):
Human’s avarice for ivory has resulted in thousands of unfathomable elephant atrocities and senseless suffering that has pushed the species to the brink of extinction. In 2015, the U.S. and China announced they will work together to enact a near complete ban on the import and export of ivory. As an industry that has largely been driven by China and, if substantiated, these claims could be a ray of light for one of the most endangered animals in the kingdom. However, as the famous saying goes, “for every action, there is an equal and opposite reaction.” With the worldwide attention on elephant ivory, hippo teeth, which can grow up to three-feet-long, have become the next target. Since the United Nations Convention on International Trade in Endangered Species officially imposed a ban on ivory trading in 1990, about 30,000 pounds per year of hippo teeth have been exported from Africa. On a recent trip to Kenya, I had the unfortunate displeasure of meeting these facts face-to-face. On the banks of the Mara River, the infamous transient point of the great wildebeest migration, I met a Conservancy Ranger, a local Kenyan, named Ivan. He led me along a narrow path above the riverbed to view pods of hippos. They clumped together in the river, every few minutes lifting their heads above the waterline to welcome my arrival. Despite their label as one of the most dangerous animals in Africa, they were playful to watch. Their tiny ears and eyes would appear from the murky river and then, with a splash, they would disappear. The river is everything to the hippo, Ivan explained, it is their lifeline. The only real time they leave the river is during their nightly ritual of traveling to nearby plains to consume grasses. Contrary to their aggressiveness, they are vegetarians. As we neared the end of our trek, we reached the Mara Bridge, spanning the divide between Kenya and Tanzania. An undeniable stench filled the air. Our gaze fell to the water beneath the structure, and as if to mark the metaphorical significance of the passage, lay a poached hippo. It had been killed the previous night, probably as it grazed unsuspectingly under the cover of darkness. They had found spear punctures in its body, and its teeth were missing. It had somehow, in unthinkable pain, made its way back to the river, its home, to die.
4. What does the word “which” in the second paragraph refer to?

Read the following passage and choose the best answer (A, B, C, D):
Coal, oil and gas get more than $370bn a year in support, compared with $100bn for renewables, the International Institute for Sustainable Development (IISD) report found. Just 10-30% of the fossil fuel subsidies would pay for a global transition to clean energy, the IISD said. Ending fossil fuel subsidies has long been seen as vital to tackling the climate emergency, with the G20 nations pledging in 2009 to phase them out, but progress has been limited. The new analysis shows how redirecting some of the fossil fuel subsidies could decisively tip the balance in favour of green energy, making it the cheapest electricity available and instigating a rapid global rollout. The transition from polluting fossil fuels to clean energy is already under way. Annual investment in renewables has been greater than that in fossil fuel electricity generation since 2008 and new renewable capacity has exceeded fossil fuel power each year since 2014. But progress is slow compared with the urgency required, said Bridle. “There is no question that renewables can power the energy system,” he said. “The question now is can we transit quickly enough away from fuels like coal, and subsidy reform is a very obvious step towards that.  Reform of fossil fuel subsidies could have a significant impact on global heating. An earlier IISD study of 20 countries with large fossil fuel subsidies found that a 30% swap to renewables would lead to emissions reductions of between 11% and 18%. Most experts define fossil fuel subsidies as financial or tax support for those buying fuel or the companies producing it. The IMF also includes the cost of the damage fossil fuel burning causes to climate and health, leading to an estimate of $5.2tn of fossil fuel subsidies in 2017, or $10m a minute. Ending the subsidies would cut global emissions by about a quarter, the IMF estimates, and halve the number of early deaths from fossil fuel air pollution. Bridle said funding fossil fuel subsidies was “madness”, but said ending them could cause short-term price rises and political difficulties, as the benefits of lower costs in the future and reduced air pollution are less obvious. “There are political problems but it is worth persevering because the prize is so big,” he said. “You have to bring people along with you.” Gençsü said governments must ensure that the most vulnerable people were not adversely affected by changes. 
3. According to paragraph 3, what is the only problem left in the progress of green transition?

Rewrite the sentence:
You needn’t have opened a bank account.

Choose the best answer:
Please don’t ___________ when I am studying.

Read the following passage and choose the best answer (A, B, C, D):
Despite the fact that humans haven’t returned to the Moon since the cancellation of the Apollo program in 1972, there have nonetheless been incredible advances in space exploration in recent years. All across the world, human time is the most valuable commodity – particularly when it comes to solving problems. Far from stealing jobs, the majority of advances in artificial intelligence and machine learning are designed to automate relatively “simple” processes and free up time for humans to do what they do best. Already we have had a taste of what AI can achieve from space, even as far back as the early 2000s with the launch of the Earth Observing-1 (EO-1) satellite, which helps analyse and inform the appropriate response in the event of a disaster, such as hurricanes and volcanic eruptions. In some cases, the systems in place on EO-1 began capturing satellite images of disaster zones before ground personnel were even aware that a disaster had occurred. More recently, AI has been used on the Mars Curiosity rover, where AEGIS software is able to identify intriguing rock or soil patches that should be targeted for analysis. This significantly expedites the process of collecting data from the surface of Mars as the robot isn’t relying solely on human commands. Richard Branson’s Virgin Galactic – which hopes to soon begin conducting commercial flights – charges between $200,000 to $250,000 per ticket for a flight where passengers will experience just several minutes of weightlessness beyond the Karman line where space officially begins. Therefore, previous space missions have always needed to consider very carefully which astronauts they send to space, with the ultimate decision often coming down to an astronaut’s ability to act as a ‘jack-of-all-trade’. In future, it should be possible to automate the computing and engineering tasks that historically astronauts have had to train for. This would mean sending individuals with specialised expertise in science and research in place of the all-rounder astronauts of yesteryear. For success in space exploration in the years to come, we will need to continue along the exponential curve of open source uptake and see advances in the approach to how spacecraft software, hardware and infrastructure is developed and deployed. With this baseline in place, advances in AI-driven scientific research have the potential to propel us forwards.
2. The word “they” in paragraph 1 refers to _____

Read the following passage and choose the best answer (A, B, C, D):
OPEC was established at a conference held in Baghdad Sept. 10–14, 1960, and was  formally constituted in January 1961 by five countries: Saudi Arabia, Iran, Iraq, Kuwait, and Venezuela. Members admitted afterward include Qatar (1961), Indonesia and Libya (1962), Abū Ẓabī (1967), Algeria (1969), Nigeria (1971), Ecuador (1973), and Angola (2007). The United Arab Emirates assumed Abū Ẓabī’s membership in the 1970s. Gabon, which had joined in 1975, withdrew in January 1995, but it had relatively insignificant oil reserves. Ecuador suspended its membership from OPEC from December 1992 until October 2007, while Indonesia suspended its membership beginning in January 2009.  OPEC’s headquarters, first located in Geneva, was moved to Vienna in 1965. OPEC members coordinate policies on oil prices, production, and related matters at semiannual and special meetings of the OPEC Conference. The Board of Governors, which is responsible for managing the organization, convening the Conference, and drawing up the annual budget, contains representatives appointed by each member country; its chair is elected to a one-year term by the Conference. OPEC also possesses a Secretariat, headed by a secretary – general appointed by the Conference for a three-year term; the Secretariat includes research and energy-studies divisions.  OPEC members collectively own about two-thirds of the world’s proven petroleum reserves and account for two-fifths of world oil production. Members differ in a variety of ways, including the size of oil reserves, geography, religion, and economic and political interests. Four members – Kuwait, Qatar, Saudi Arabia, and the United Arab Emirates – have very large per capita oil reserves; they also are relatively strong financially and thus have considerable flexibility in adjusting their production. Saudi Arabia, which has the largest reserves and a relatively small (but fast-growing) population, has traditionally played a dominant role in determining overall production and prices Because OPEC has been beset by numerous conflicts throughout its history, some experts have concluded that it is not a cartel – or at least not an effective one – and that it has little, if any, influence over the amount of oil produced or its price. Other experts believe that OPEC is an effective cartel, though it has not been equally effective at all times. The debate largely centers on semantics and the definition of what constitutes a cartel. Those who argue that OPEC is not a cartel emphasize the sovereignty of each member country, the inherent problems of coordinating price and production policies, and the tendency of countries to renege on prior agreements at ministerial meetings. Those who claim that OPEC is a cartel argue that production costs in the Persian Gulf are generally less than 10 percent of the price charged and that prices would decline toward those costs in the absence of coordination by OPEC.  The influence of individual OPEC members on the organization and on the oil market usually depends on their levels of reserves and production. Saudi Arabia, which controls about one-third of OPEC’s total oil reserves, plays a leading role in the organization. Other important members are Iran, Iraq, Kuwait, and the United Arab Emirates, whose combined reserves are significantly greater than those of Saudi Arabia. Kuwait, which has a very small population, has shown a willingness to cut production relative to the size of its reserves, whereas Iran and Iraq, both with large and growing populations, have generally produced at high levels relative to reserves. Revolutions and wars have impaired the ability of some OPEC members to maintain high levels of production. 
3. According to paragraph 2, how to identify representatives in the Board of Governors?

Read the following passage and choose the best answer (A, B, C, D):
The relationship between Britain and the US has always been a close one. Like all close relationship it has had difficult times. The US was first a British colony, but between 1775 and 1783 the US fought a war to become independent. The US fought the British again in the War of 1812. In general, however, the two countries have felt closer to each other than to any other country, and their foreign policies have shown this. During World War I and World War II, Britain and the US supported each other. When the US looks for foreign support, Britain is usually the first country to come forward and it is sometimes called “the 51st state of union”. But the special relationship that developed after 1945 is not explained only by shared political interests. An important reason for the friendship is that the people of the two countries are very similar. They share the same language and enjoy each other’s literature, films and television. Many Americans have British ancestors, or relatives still living in Britain. The US government and political system is based on Britain’s, and there are many Anglo-American businesses operating on both sides of the Atlantic. In Britain some people are worried about the extent of US influence, and there is some jealousy of its current power. The special relationship was strong in the early 1980s when Margaret Thatcher was Prime Minister in Britain and Ronald Reagan was President of the US.  
1. What is the passage mainly about?

Read the following passage and choose the best answer (A, B, C, D):
Advertising helps people recognize a particular brand, persuades them to try it, and tries to keep them loyal to it. Brand loyalty is perhaps the most important goal of consumer advertising. Whether they produce cars, canned foods or cosmetics, manufacturers want their customers to make repeated purchases. [2] The quality of the product will encourage this, of course, but so, too, will affect advertising. Advertising relies on the techniques of market research to identify potential users of a product. [3] Are they homemakers or professional people? Are they young or old? Are they city dwellers or country dwellers? Such questions have a bearing on where and when ads should be placed. By studying readership breakdowns for newspapers and magazines as well as television ratings and other statistics, an advertising agency can decide on the best way of reaching potential buyers. Detailed research and marketing expertise are essential today when advertising budgets can run into thousands of millions of dollars. [4] Advertising is a fast-paced, high-pressure industry. There is a constant need for creative ideas that will establish a personality for a product in the public’s mind. Current developments in advertising increase the need for talented workers. In the past, the majority of advertising was aimed at the traditional white family - breadwinner father, non-working mother, and two children. Research now reveals that only about 6 percent of American households fit this stereotype. Instead, society is fragmented into many groups, with working mothers, single people and older people on the rise. To be most successful, advertising must identify a particular segment and aim its message toward that group. Advertising is also making use of new technologies. Computer graphics are used to grab the attention of consumers and to help them see products in a new light. The use of computer graphics in a commercial for canned goods, for instance, gave a new image to the tin can  
7. The word “fragmented” in the fourth paragraph is closest in meaning to __________

Read the following passage and choose the best answer (A, B, C, D):
The aviation industry, especially the commercial aviation sector, is constantly striving to improve both the way it works and its customer satisfaction. It has begun using artificial intelligence. Though AI in the aviation industry is still in the nascent stage, some progress has been made already as certain leading carriers invest in AI. To make a long story short, AI can redefine how the aviation industry goes about its work. In 2017, American Airlines conducted an app development competition with the goal of having an app developed for making baggage screening easier for passengers. The competition, named HackWars, was themed upon artificial intelligence, drones and augmented and virtual reality. The winner, known as “Team Avatar,” developed an app that would not only allow passengers determine their baggage size before arriving at the airport, but also prepay any potential baggage-related expenses. United Airlines is using Amazon’s Alexa to have certain common customer queries answered. In September 2017, United announced a collaboration with Alexa. The feature is known as the United skill. To get started, all passengers need to do is to  add the United skill to their Alexa app and then start asking questions. Alexa answers common queries correctly, such as the status of a flight by number, check-in requests and availability of Wi-Fi on a flight. The reviews so far have been mixed, which points to the fact that there is a learning curve, and it is still a long way to go before AI can fully handle customer assistance. Tracking progress is an enormous challenge that airlines will face. The first thing they need to do is to develop analytics that will help them develop and process accurate data. However, that in itself is a challenge. What kind of analytics will help? For example, customer satisfaction is going to be one of the most important factors in success. What kind of analytics will determine that airlines have been improving on customer satisfaction parameters? AI needs huge investments, and probably the biggest risk in this is smaller, especially budget airlines are going to miss out on reaping the benefits of AI fully. Does that mean that the performance of the smaller carriers will be impacted? That might not be the case, because we might be moving toward more acquisitions and mergers. Bigger airlines will have a massive appetite for acquiring smaller airlines with an eye on the market. It is not all gloom and doom though, because smaller airlines like Southwest have already shown some initiatives toward embracing AI. It is surprising that a sector as important as aviation has woken up to AI so late. As AI in aviation picks up its pace, there could probably be a few mergers, acquisitions or even closure of small airlines which will not be able to afford the investments. Now, AI seems the best option to take aviation to the next level.
2. The word “carriers” in paragraph 1 probably means ______