Glaciers consist of fallen snow that compresses over many years into large, thickened ice masses. Most of the world's glacial ice is found in Antarctica and Greenland, but glaciers are found on nearly every continent, even Africa. Presently, 10% of land area is covered with glaciers. Glacial ice often appears blue because ice absorbs all other colors but reflects blue. Almost 90% of an iceberg is below water; only about 10% shows above water. What makes glaciers unique is their ability to move. Due to sheer mass, glaciers flow like very slow rivers. Some glaciers are as small as football fields, whereas others grow to be over 100 kilometers long. Within the past 750, 000 years, scientists know that there have been eight Ice Age cycles, separated by warmer periods called interglacial periods. Currently, the earth is nearing the end of an interglacial, meaning that another Ice Age is due in a few thousand years. This is part of the normal climate variation cycle. Greenhouse warming may delay the onset of another glacial era, but scientists still have many questions to answer about climate change. Although glaciers change very slowly over long periods, they may provide important global climate change signals. The girth of the ice, combined with gravity's influence, causes glaciers to flow very slowly. Once a mass of compressed ice reaches a critical thickness of about 18 meters thick, it becomes so heavy that it begins to deform and move. Ice may flow down mountains and valleys, fan across plains, or spread out to sea. Movement along the underside of a glacier is slower than movement at the top due to the friction created as it slides along the ground's surface. Most glaciers are found in remote mountainous areas. However, some found near cities or towns present a danger to the people living nearby. On land, lakes formed on top of a glacier during the melt season may cause floods. At the narrow part of a valley glacier, ice falling from the glacier presents a hazard to hikers below. When ice breaks off over the ocean, an iceberg is formed. Glaciers are a natural resource and contain 75% of the world's freshwater. People worldwide are trying to harness the power of these frozen streams. Some towns rely on glacial melting from a nearby ice cap to provide drinking water. Some farmers spread soil or ashes over snow to promote melting, hoping that the melting will provide water to irrigate crops in drought-stricken areas. Others have channeled meltwater from glaciers to their fields. Scientists and engineers have worked together to tap into glacial resources, using electricity that has been generated in part by damming glacial meltwater.

[A] Analyzing your own taste[B] Being cautious when experimenting[C] Finding a model to follow[D] Getting the final look absolutely right[E] Learning to be realistic[F] Making regular conscious choices[G] Following your taste When we meet people for the first time, we often make decisions about them based entirely on how they look. And, of course it's something that works both ways, for we too are being judged on our appearance. When we look good, we feel good, which in turn leads to a more confident and self-assured manner. People then pick up on this confidence and respond positively towards us. Undoubtedly, what's inside is important, but sometimes we can send out the wrong signals simply by wearing inappropriate clothing or not spending enough time thinking about how others see us. 【R1】______For example, people often make the mistake of trying to look like someone else they've seen in a magazine, but this is usually a disaster as we all have our own characteristics. Stand in front of a full-length mirror and be honest with yourself about what you see. There is no need to dwell on your faults—we all have good points and bad points—but think instead about the best way to emphasize the good ones. 【R2】______ When selecting your clothes each day, think about who you're likely to meet, where you're going to be spending most of your time and what tasks you are likely to perform. Clearly, some outfits will be more appropriate to different sorts of activity and this will dictate your choice to an extent. However, there's no need to abandon your individual taste completely. After all, if you dress to please somebody else's idea of what looks good, you may end up feeling uncomfortable and not quite yourself. 【R3】______ But to know your own mind, you have to get to know yourself. What do you truly feel good in? There are probably a few favorite items that you wear a lot—most people wear 20 per cent of their wardrobe 80 per cent of the time. Look at these clothes and ask yourself what they have in common. Are they neat and tidy, loose and flowing? Then look at the things hanging in your wardrobe that you don't wear and ask yourself why. Go through a few magazines and catalogues and mark the things that catch your eye. Is there a common theme? 【R4】______Some colors bring your natural coloring to life and others can give us a washed-out appearance. Try out new colors by all means, but remember that dressing in bright colors when you really like subtle neutral tones, or vice versa, will make you feel self-conscious and uncomfortable. You know deep down where your own taste boundaries lie. And although it's good to challenge those sometimes with new combinations or shades, take care not to go too far all at once. 【R5】______ So, you've chosen an outfit that matches your style, your personality, your shape and your coloring. But does it fit? If something is too tight or too loose, you won't achieve the desired effect, and no matter what other qualities it has, it won't improve your appearance or your confidence. Sometimes, we buy things without thinking. Some people who dislike shopping grab the first thing they see, or prefer to use mail-order or the Internet. In all cases, if it doesn't fit perfectly, don't buy it, because the finer details are just as important as the overall style. Reappraising your image isn't selfish because everyone who comes into contact with you will benefit. You'll look better and you'll feel a better person all round.

A candlelit dinner works wonders for romance. Now scientists say it could also be good for your heart. Breathing in candle smoke causes beneficial【C1】______in your heart rhythm, they claim. It is thought that tiny salt particles released when the candle burns are【C2】______the effect The researchers monitored the hearts of 13 men and women as they breathed in air【C3】______into a small chamber. In some【C4】______the air included smoke from candles in a second room. The volunteers didn't know which type of air they were breathing, but when it included candle smoke, their heart rate variability【C5】______. Everyone's heart rate varies【C6】______all the time, beating a little bit faster when we breathe in than when we breathe out This is perfectly healthy and a sign that the brain is【C7】______and able to regulate the heart But this variation【C8】______as we get older and if we【C9】______heart problems. In the study, it was increased by【C10】______candle smoke. Researcher Christina Isaxon said the concentration of smoke【C11】______during the study was similar to that created by a candlelit dinner. As the volunteers could not see the candles and weren't told what they were breathing, the effect could not be explained【C12】______by the calming effect of candlelight. Dr Isaxon believed that tiny particles of the candle smoke could be responsible for the beneficial effects. These particles are【C13】______regulating the heart's rhythm and in sending messages between cells in the body. More salts are produced when a【C14】______is still. The study did not find any【C15】______health effects of the smoke—【C16】______she admitted she did not 'make a huge effort' to find any. Soot, black powder in the smoke, from lit candles has been【C17】______health problems in the past. The American Chemical Society has warned that common wax candles release【C18】______harmful chemicals linked to cancer and other illnessea It recommends using beeswax. Dr Isaxon used candles made of a natural fat in her study. She recommended using candles that are as natural as possible and avoiding【C19】______and dyes as they may give off【C20】______chemicals when burned.

Consumer products such as shampoos and sunscreens, even ones boosted as safer, may contain potentially harmful chemicals not listed on their labels, according to a study out today that tested dozens of them. Chemicals that【C1】______hormones or affect health were found in all 42 of conventional products sampled, as well as in most—32 of 43—of the alternative products【C2】______as safer, including some by Seventh Generation, the study says. The scientific group studies the【C3】______between the environment and women"s health. "It was【C4】______," says Julia Brody, co-author of the findings. She says consumers using a typical array of products are【C5】______many harmful chemicals. Seventh Generation, which makes six of the alternative products tested, welcomed the study"s goal of e-ducating consumers【C6】______questioned its method. Martin Wolf, its director of product sustainability, says the company【C7】______none of the chemicals the study found in three of its products. "The fact that trace amounts were found raises questions" about possible cross-contamination in either【C8】______or testing, he says. "There are so many【C9】______chemicals in this world that they"re finding their way【C10】______everything." John Spengler, a professor of environmental health at Harvard School of Public Health, who was not【C11】______the study, says the work is "very important" for improving health concerns and【C12】______companies to possible cross-contamination in products, whether from the supply【C13】______or the packaging. "You don"t want to worry people【C14】______a reasonable extent," he says, adding that trace amounts of some chemicals may not pose a problem.【C15】______, he says, there"s an "interactive" accumulating effect from broad use of chemicals, 【C16】______it"s important to look at them as a group. The study, which tested for 66 chemicals and found 55 of them in the products, says sunscreens and fragrant products had the most【C17】______chemicals and some of the highest concentrations. Brody, who says there needs to be a more【C18】______listing and testing of a product"s ingredients,【C19】______consumers to use fewer products, seek plantbased ingredients and rely on【C20】______water, baking soda and vinegar for cleaning.

BPart CDirections: Read the following text carefully and then translate the underlined segments into Chinese./B

A simple idea supports science: "trust, but verify". Results should always be【C1】______to challenge from experiment. That simple but powerful idea has【C2】______a vast body of knowledge.【C3】______its birth in the 17th century, modern science has changed the world【C4】______recognition, and overwhelmingly for the better. But success can【C5】______self-contentment. Modern scientists are doing too much trusting and not enough verifying, which does harm to both the whole of science and humanity. Too many of the【C6】______that fill the academic field are the result of inferior experiments or poor analysis. A rule of thumb among biotechnology venture-capitalists is that half of【C7】______research cannot be reproduced. Even that may be【C8】______. Last year researchers at one biotech firm, Amgen, found they could reproduce just six of 53 "landmark" studies in cancer research. Earlier, a group at Bayer, a drug company,【C9】______to repeat just a quarter of 67 similarly important papers. A leading computer scientist complains that three-quarters of papers in his subfield are nonsense. The reasons might lie in this: researchers are no longer willing to verify hypothesis investigated by other scholars since these papers have rare chance to be published. All this makes a poor foundation for an enterprise dedicated【C10】______discovering the truth about the world What might be done to shore it up? One【C11】______should be for all disciplines to follow the example of those that have done most to tighten standards. 【C12】______research protocols should be registered in advance and monitored in virtual notebooks. This would【C13】______the temptation to distort the experiment's design so as to make the results look more【C14】______than they are.【C15】______possible, trial data also should be open for other researchers to【C16】______and test. Science still【C17】______enormous respect. But its privileged【C18】______is founded on the capacity to be right most of the time and to correct its mistakes when it gets things wrong. And it is not as if the universe is short of【C19】______mysteries to keep generations of scientists hard【C20】______The false trails laid down by inferior research are an unforgivable barrier to understanding.

Write a letter of about 100 words to the customer service center of an online store, complaining about the quality of the new ipad and demanding a prompt solution. You should include the details you think necessary. You should write neatly on the ANSWER SHEET. Do not use your own name. Use "Li Ming" instead. Do not write the address. (10 points)

How best to solve the pollution problems of a city sunk so deep within sulfurous clouds that it was described as hell on earth? Simply answered: Relocate all urban smoke-creating industry and encircle the metropolis of London with sweetly scented flowers and elegant hedges. In fact, as Christine L. Cotton, a Cambridge scholar, reveals in her new book, London Fog, this fragrant anti-smoke scheme was the brainchild of John Evelyn, the 17th-century diarist. King Charles II was said to be much pleased with Evelyn' s idea, and a bill against the smoky nuisance was duly drafted. Then nothing was done. Nobody at the time, and nobody right up to the middle of the 20th century, was willing to put public health above business interests. And yet it's a surprise to discover how beloved a feature of London life these multicolored fogs became. A painter, Claude Monet, fleeing besieged Paris in 1870, fell in love with London's vaporous, mutating clouds. He looked upon the familiar mist as his reliable collaborator. Visitors from abroad may have delighted in the fog, but homegrown artists lit candles and vainly scrubbed the grime from their gloom-filled studio windows. "Give us light!" Frederic Leighton pleaded to the guests at a Lord Mayor' s banquet in 1882, begging them to have pity on the poor painter. The more serious side of Corton' s book documents how business has taken precedence over humanity where London' s history of pollution is concerned. A prevailing westerly wind meant that those dwelling to the east were always at most risk. Those who could afford it lived elsewhere. The east was abandoned to the underclass. Lord Palmerston spoke up for choking East Enders in the 1850s, pointing a finger at the interests of the furnace owners. A bill was passed, but there was little change. Eventually, another connection was established: between London' s perpetual veil of smog and its citizens' cozily smoldering grates. Sadly, popular World War I songs like "Keep the Home Fires Burning" didn't do much to encourage the adoption of smokeless fuel. It wasn't until what came to be known as the "Great Killer Fog" of 1952 that the casualty rate became impossible to ignore and the British press finally took up the cause. It was left to a Member of Parliament to steer the Clean Air Act into law in 1956. Within a few years, even as the war against pollution was still in its infancy, the dreaded fog began to fade. Corton' s book combines meticulous social history with a wealth of eccentric detail. Thus we learn that London' s ubiquitous plane trees were chosen for their shiny, fog-resistant foliage. It' s discoveries like these that make reading London Fog such an unusual and enlightening experience.

BSection I Use of EnglishDirections: Read the following text. Choose the best word(s) for each numbered blank and mark A, B, C or D./B

Most people believe that saving money is quite necessary. But nowadays, many young people like to spend money without thinking of saving it for the future. In this section, you are asked to write an essay on the advantages of saving money. You can provide specific reasons and examples to support your idea. You should write at least 150 words.

The country's inadequate mental health system gets the most attention after instances of mass violence that the nation has seen repeatedly over the past few months. Not all who【C1】______these sorts of cruelties are mentally ill, but 【C2】______ have been. After each, the national discussion quickly, but temporarily, turns toward the mental health services that may have 【C3】______to prevent another attack. Mental illness usually is not as dangerous or dramatic.【C4】_____23 million Americans live with mental disorder, according to the National Institute of Mental Health. Very few of these men and women are【C5】______mass-murderers; they need help for their own well-being and for that of their【C6】______. The Affordable Care Act has significantly increased insurance coverage 【C7】______ mental health care. But that may not be enough to expand 【C8】______ to insufficient mental-health-care resources. Tim Murphy has a bill that would do so. The Helping Families in Mental Health Crisis Act is more 【C9】______ than other recent efforts to reform the system and perhaps has the brightest prospects in a divided Congress. The【C10】______would reorganize the billions the federal government pours into mental health services. It would【C11】______the way Medicaid pays for certain mental health treatments. It would fund mental health clinics that【C12】______certain medical standards. And it would【C13】______states to adopt policies that allow judges to order some severely mentally ill people to undergo treatment. Not everyone is satisfied. Some patients' advocates have【C14】______Mr. Murphy' s approach as coercive and【C15】______to those who need help. The government should not be expanding the system' s capability to hospitalize or impose treatment on those【C16】______severe episodes, they say. It should instead be investing in community care that【C17】______the need for more serious treatment.【C18】______, for a small class who will not accept treatment between hospital visits or repeat arrests, they say, states have good reason to【C19】______them to accept care, under judicial supervision. Mr. Murphy's reform package may not prevent the next Sandy Hook.【C20】______the changes would help relieve a lot of suffering that does not make the front page.

In the Second World War a "blockbuster" was a bomb that could eliminate whole streets. Today it is the kind of hit creation that every media executive prays for. Popular films, books, music albums and sports teams that bring in huge audiences—and vast profits—can determine whether a year is profitable or loss-making, and break a boss"s career. The entertainment industry"s search for the golden release is the focus of " Blockbusters" by Anita Elberse, a professor of business administration at Harvard Business School. Conventional corporate wisdom maintains that spreading resources across many smaller properties is sounder than pushing money into a few big, concentrated bets. Ms Elberse uses case studies from the film, television , music and sporting worlds to argue that, counterintuitively, " the idea of smaller bets being " safer" is a myth. " Nurturing a few choice works and helps firms create superstars and super products , and is the key to far higher profits. Ms Elberse cites Grand Central Publishing as one example: the top 10% of its titles account for 64% of the publisher"s costs, but 126% of its profits. The thesis that popular products earn more money might seem as obvious as the plot of the latest Hollywood film you saw. But it is not what business experts predicted would happen. In 2006 Chris Anderson, the editor of Wired and a former journalist at The Economist, wrote "The Long Tail; Why the Future of Business is Selling Less of More" , in which he argued that the internet would change the demand curve for entertainment products. With unlimited " shelf" space available online and more refined search algorithms to direct people to songs and books they might be interested in, niche products would attract more attention and a greater share of spending. Ms Elberse originally disagreed on Mr Anderson"s work in a 2008 article for the Harvard Business Review, which is the basis for her book. The tail has become longer, but the internet has helped bestsellers become even bigger, because people follow the recommendations of friends and casual consumers choose known quantities. In 2011 just 102 of the 8m digital musical tracks sold generated nearly a sixth of all sales. Blockbusters tend to be self-reinforcing, because firms spend more to promote products they think stand a better chance of becoming popular.

BPart BDirections: Write an essay of 160-200 words based on the following information./B

The immune system is equal in complexity to the combined intricacies of the brain and nervous system. The success of the immune system in defending the body relies on a dynamic regulatory communications network consisting of millions and millions of cells. Organized into sets and subsets, these cells pass information back and forth like clouds of bees swarming around a hive. The result is a sensitive system of checks and balances that produces an immune response that is prompt, appropriate, effective, and self-limiting. At the heart of the immune system is the ability to distinguish between self and non-self. When immune defenders encounter cells or organisms carrying foreign or non-self molecules, the immune troops move quickly to eliminate the intruders. Virtually every body cell carries distinctive molecules that identify it as self. The body's immune defenses do not normally attack tissues that carry a self-marker. Rather, immune cells and other body cells coexist peaceably in a state known as self-tolerance. When a normally functioning immune system attacks a non-self molecule, the system has the ability to remember the specifics of the foreign body. Upon subsequent encounters with the same species of molecules, the immune system reacts accordingly. With the possible exception of antibodies passed during lactation, this so-called immune system memory is not inherited. Despite the occurrence of a virus in your family, your immune system must learn from experience with the many millions of distinctive non-self molecules in the sea of microbes in which we live. Learning entails producing the appropriate molecules and cells to match up with and counteract each non-self invader. Any substance capable of triggering an immune response is called an antigen. Antigens are not to be confused with allergens, which are most often harmless substances ( such as ragweed pollen or cat hair) that provoke the immune system to set off the inappropriate and harmful response known as allergy. An antigen can be a virus, a bacterium, a fungus, a parasite, or even a portion or product of one of these organisms. Tissues or cells from another individual ( except an identical twin, whose cells carry identical selfmarkers) also act as antigens; because the immune system recognizes transplanted tissues as foreign, it rejects them. The body will even reject nourishing proteins unless they are first broken down by the digestive system into their primary, non-antigenic building blocks. An antigen announces its foreignness by means of intricate and characteristic shapes called epitopes, which protrude from its surface. Most antigens, even the simplest microbes, carry several different kinds of epitopes on their surface; some may even carry several hundred. Some epitopes will be more effective than others at stimulating an immune response. Only in abnormal situations does the immune system wrongly identify self as non-self and execute a misdirected immune attack. The result can be a so-called autoimmune disease such as rheumatoid arthritis or systemic lupus erythematosis. The painful side effects of these diseases are caused by a person's immune system actually attacking itself.

Scientists have long argued over the relative contributions of practice and native talent to the development of elite performance. This debate swings back and forth every century, it seems, but a paper in the current issue of the journal Psychological Science illustrates where the discussion now stands and hints—more tantalizingly, for people who just want to do their best—at where the research will go next. The value-of-practice debate has reached a stalemate. In a landmark 1993 study of musicians, a research team led by K. Anders Ericsson found that practice time explained almost all the difference(about 80 percent)between elite performers and committed amateurs. The finding rippled quickly through the popular culture, perhaps most visibly as the apparent inspiration for the "10,000-hour rule" in Malcolm Gladwell's best-selling "Outliers" —a rough average of the amount of practice time required for expert performance. The new paper, the most comprehensive review of relevant research to date, comes to a different conclusion. Compiling results from 88 studies across a wide range of skills, it estimates that practice time explains about 20 percent to 25 percent of the difference in performance in music, sports and games like chess. In academics, the number is much lower—4 percent—in part because it's hard to assess the effect of previous knowledge, the authors wrote. One of those people, Dr. Ericsson, had by last week already written his critique of the new review. He points out that the paper uses a definition of practice that includes a variety of related activities, including playing music or sports for fun or playing in a group. But his own studies focused on what he calls deliberate practice: one-on-one lessons in which an instructor pushes a student continually, gives immediate feedback and focuses on weak spots. "If you throw all these kinds of practice into one big soup, of course you are going to reduce the effect of deliberate practice," he said in a telephone interview. Zach Hambrick, a co-author of the paper of the journal Psychological Science, said that using Dr. Ericsson' s definition of practice would not change the results much, if at all, and partisans on both sides have staked out positions. Like most branches of the nature-nurture debate, this one has produced multiple camps, whose estimates of the effects of practice vary by as much as 50 percentage points.

Does the language we speak determine how healthy and rich we will be? New research by Keith Chen of Yale Business School suggests so. The structure of languages【C1】______our judgments and decisions about the future and this might have【C2】______long-term consequences. There has been a lot of research【C3】______how we deal with the future.【C4】______, the famous marshmallow studies of Walter Mischel and colleagues showed that being able to resist【C5】______is predictive of future success. Four-year-old kids were given a marshmallow and were told that【C6】______they do not eat that marshmallow and wait for the experimenter to come back, they will get two marshmallows instead of one. Follow-up studies showed that the kids who were able to wait for the bigger future【C7】______became more successful young adults. Chen"s recent findings suggest that an unlikely【C8】______, language, strongly influences our future-oriented【C9】______Some languages strongly distinguish the present and the future【C10】______other languages can only weakly tell them apart. Chen"s recent research suggests that people who speak languages that weakly distinguish the present and the future are better【C11】______for the future. They accumulate more wealth and they are better able to【C12】______their health. The way these people conceive the future is similar【C13】______the way they conceive the present. As a result, the future does not feel very【C14】______and it is easier for them to act【C15】______their future interests. Chen analyzed individual-level data from 76 developed and developing countries. The analyses showed that speaking a language that does not have obligatory future markers, such as Mandarin, makes people accumulate more retirement【C16】______smoke less, exercise more, and【C17】______be healthier in older age. Language also has an impact on countries" national savings rates. Chen"s research shows that language【C18】______our future-related thoughts. And the research also points at the possibility that the way we talk about the future can shape our mindsets. Language can【C19】______the future back and forth in our mental space and this might have significant【C20】______on our judgments and decisions.

It only takes ten minutes, but reading your baby a bedtime story could yield benefits for years to come, scientists said today. Research shows that children who are【C1】______to a lot are faster at understanding words. This【C2】______processing helps them do better at school— and could【C3】______help them get a good job, have a happy【C4】______and keep on the right side of the law. Psychologist Anne Fernald said that the effects are so【C5】______that talking to children should be【C6】______as importantly as feeding them. And it is never too【C7】______to start. Dr Fernald said: "【C8】______you want your kid to do well in school, talk to them【C9】______a baby. If you bring a child into the world, we【C10】______the responsibility for feeding them, keeping them clean and keeping them safe. I think we now have enough scientific evidence to add something else to that list—and that is【C11】______learning from infancy on. Long before your baby is speaking, it is【C12】______information about language." In a series of studies on babies, Dr Fernald showed that there are big differences in how quickly children process words. Speedy processing is important【C13】______it frees up the brain to think about the next word—or the world【C14】______. Dr Fernald said: "You are building a mind that can conceptualize and【C15】______and think about the past and think about the future." She also showed that children who are【C16】______at understanding words tend to hear more words at home. In her studies, some【C17】______had as few as 600 words a day directly talked to them. To put this in【C18】______, the average adult speaks around 200 words a minute. Other children heard more than 12,000 words. Dr Fernald has also shown that children who can quickly process words at the age of two do better at school at the age of eight. Other research has shown that children who do well in【C19】______school are more likely to go onto higher education, get a good job, re-mam married and stay out of【C20】______.

BPart BDirections: Write an essay of 160-200 words based on the following information./B

BPart B/B

Warren Buffett, who will host Berkshire Hathaway's annual shareholders' meeting on May 3rd, is an icon of American capitalism. At 83, he also epitomizes a striking demographic【C1】______: for highly skilled people to go on working well into【C2】______was once thought to be old age. Across the rich world,well-educated people【C3】______work longer than the less-skilled. Some 65% of American men aged 62-74 with a professional degree are in the【C4】______, compared with 32% of men with only a high-school certificate. In the European Union the pattern is similar. This【C5】______is part of a deepening divide between the well-educated【C6】______and the unskilled poor that is slicing【C7】______all age groups. Rapid innovation has raised the incomes of the highly skilled while【C8】______those of the unskilled. Those at the top are working longer hours each year than those at the bottom.【C9】______the well-qualified are extending their working lives, compared with those of less-educated people. The【C10】______, for individuals and society,are profound. The world is on the【C11】______rise in the number of old people, and they will live longer than ever before.【C12】______the next 20 years the global population of those aged 65 or more will almost double, from 600m to 1.1 billion. The【C13】______of the 20th century, when greater longevity translated into more years in retirement【C14】______more years at work, has persuaded many observers that this shift will【C15】______slower economic growth and "secular stagnation" , while the【C16】______ranks of pensioners will bust government budgets. But the notion of a sharp division between the working young and the【C17】______old misses a new trend, the【C18】______gap between the skilled and the unskilled. Employment rates are falling among younger unskilled people,【C19】______older skilled folk are working longer. The divide is most extreme in America, where well-educated baby-boomers are【C20】______retirement while many less-skilled younger people have dropped out of the workforce.