BSection II Reading Comprehension/B

It is not a question so much of what will happen as much as it is a statement of what has already happened and is still happening. Society is falling down all around us. As compared to days gone by, the family structure has weakened so much that people have developed uncaring and self serving attitudes. We see more and more with each passing year, less and less stable homes. Kids are caring for themselves and parents are out working more than ever. Even if they are structured enough to meet around the dinner table at night, it will most likely be the only time they connect with each other for the entire day. Children learn to cope with the world by watching and learning from loving parents that spend time with them. It only makes sense that when the time is not invested, the children grow to adulthood lacking life skills they should have grown up with. Society is already feeling the effects of this sad trend when we see young adults with no set goals or any kind of direction as to which path they should walk in life. Schools counselors try to help these kids decide on a career choice or a direction to look towards, but often this advice is ignored. It is the parents responsibility to guide their children and raise them in homes that are stable and caring. Ninety percent of the time, people who become successful members of society and achieve the most, come from stable, loving homes with adults that cared enough to lead them every day. If this lack of stability in the home continues to increase, then of course, society as a whole, will suffer! As parents and caregivers, we must begin to put our priorities in order if we are to build a better tomorrow. Is it more important to have a gym membership and new car or bigger house at the expense of our child and what they will bring to the future of our society? With our nation in a recession, getting back to the basics seems to be the talk of the day. Many people are realising the value of a dollar again and cutting back on many "extras". This could be the start of building our society back up again and saving the future of it by teaching young people to work together and be together. Maybe by work hours being cut back and layoffs happening everywhere, families will spend more time together and begin to see the value of relationships rather than the value of "things".

Stephen Colbert"s performance at the White House Correspondents Dinner nine days ago has already created a debate over politics, the press and humor. Now, a commercial rivalry has broken out over its rebroadcast. On Wednesday, C-Span, the nonprofit network that first showed Mr. Colbert"s speech, wrote letters to the video sites YouTube.com and ifilm.com, demanding that the clips of the speech be taken off their Web sites. The action was a first for C-Span, whose prime-time schedule tends to feature events like Congressional hearings on auto fuel-economy standards. "We have had other hot—I hate to use that word—videos that generated a lot of buzz", said Rob Kennedy, executive vice president of C-Span, which was founded in 1979. "But this is the first time it has occurred since the advent of the video clipping sites". After the clips of Mr. Colbert"s performance were ordered taken down at You Tube—where 41 clips of the speech had been viewed a total of 2.7 million times in less than 48 hours, according to the site—there were rumblings on left-wing sites that someone was trying to silence a man who dared to speak truth to power. But as became clear later in the week. this was a business decision, not a political one. Not only is the entire event available to be streamed at C-Span"s Web site: c-span.org, but the network is selling DVD"s of the event for $24.95, including speeches and a comedy routine by President Bush with a President Bush imitator. And C-Span gave permission to Google Videos to carry the Colbert speech beginning Friday. The arrangement, which came with the stipulation that Google Videos provide the entire event and a clip of Mr. Bush"s entire routine as well, is a one-time deal. Peter Chane, senior product manager of Google Video, said "C-Span has some very, very unique content", adding that "online is really great distribution outlet". But Julie Supan, senior director for marketing at YouTube, said officials there were stung by C-Span"s behavior, because, she said, the site had helped fuel momentum for the Colbert clip. "This was an exciting moment for them in a viral, random way", she said. "To take it down from one site and uploading on another, it is perplexing".

One of the most important results of research into ageing has been to pinpoint the significance of short-term memory. This faculty is easily (1)_____ as ageing advances. What seems to (2)_____ is that information is received by the brain, (3)_____ scans it for meaning in order to decode it at some future time. It looks as if the actual (4)_____ of the short-term memory itself may not change too much (5)_____ age. A young man and a man in his late fifties may (6)_____ be able to remember and repeat a(n) (7)_____ of eight numbers recited to them. But what (8)_____ change is that when the older man is asked to remember anything (9)_____ between the time he is first given the numbers to memorize and the time he is asked to (10)_____ them, he will be much less likely to remember the (11)_____ numbers than the young man. This is because the scanning stage is more easily (12)_____ by other activities in (13)_____ people. In (14)_____ living one experiences this as a fairly minor (15)_____—a telephone number forgotten while one looks (16)_____ an area code, or the first part of (17)_____ street directions confused with the last because the last "turn lefts" and "turn rights" have interfered (18)_____ remembering the first directions. In more formal learning, however, the (19)_____ of short-term memory is more than just a mild social embarrassment. It can be a serious bar to further (20)_____ or indeed to any progress at all.

Whether you"re a New Jersey mall rat or a farmer in India, being poor can exhaust your smarts. The findings indicate that an【C1】______need— making rent, getting money for food—tugs at the attention so much that it can【C2】______the brainpower of anyone who experiences it, regardless of innate intelligence or【C3】______. As a result, many social【C4】______programs set up to help the poor could backfire(have an undesired effect)by adding more【C5】______to their lives. There"s a widespread tendency to【C6】______that poor people don"t have money because they are lazy,【C7】______or just not that sharp, said study coauthor Sendhil Mullainathan. "Our【C8】______was quite different: It"s not that poor people are any different from rich people, but that being poor【C9】______itself has an effect." Mullainathan wanted to find out how those psychologically【C10】______situations affected their overall mental【C11】______. To do so, the researchers traveled to India and【C12】______464 sugar cane farmers before and after a harvest. Sugar cane farmers get paid only once a year. One month before harvest time, they are【C13】______for cash; one month after harvest, they"re flush with【C14】______. The farmers took tests before and after harvest. When money was running low, they performed【C15】______on the IQ test and took slightly longer to answer questions on the test than they did when【C16】______wasn"t a problem. The drop was【C17】______—about 9 IQ points. The research lends support to the idea that many behaviors【C18】______to being poor—using less preventive healthcare, having higher obesity rates, be ing less【C19】______parents and making poor financial decisions—may be caused by【C20】______rather than the other way around.

Write a composition according to the following outline: 1. 请家教的益处 2. 家教可能带来的负作用； 3. 我是怎样看待家教的。 You should write about 160-200 words neatly.

When Melissa Mahan and her husband visited the Netherlands, they felt imprisoned by their tour bus. It forced them to see the city according to a particular route and specific schedule—but going off on their own meant missing out on the information provided by the guide. On their return home to San Diego, California, they started a new company called Tour Coupes. Now, when tourists in San Diego rent one of their small, brightly coloured three-wheeled vehicles, they are treated to a narration over the stereo system about the places they pass, triggered by Global Positioning System (GPS) satellite technology. This is just one example of how GPS is being used to provide new services to tourists. "What we really have here is a technology that allows people to forget about the technology", says Jim Carrier of IntelliTours, a GPS tourism firm which began offering a similar service over a year ago in Montgomery, Alabama. The city is packed with sites associated with two important chapters in American history, the civil war of the 1860s and the civil-rights movement a century later. Montgomery has a 120-year-old trolley system, called the Lightning Route, which circulates around the downtown area and is mainly used by tourists. On the Lightning Route trolleys, GPS-triggered audio clips point out historical hotspots. Other firms, such as CityShow in New York and GPS Tours Canada in Banff, Canada, offer hand-held GPS receivers that play audio clips for listening to while walking or driving. In South Africa, Europcar, a car-rental firm, offers a device called the Xplorer. As well as providing commentary on 2,000 points of interest, it can also warn drivers if they exceed the local speed limit. If such services prove popular, the use of dedicated audio-guide devices could give way to a different approach. A growing number of mobile phones have built-in GPS or can determine their locations using other technologies. Information for tourists delivered via phones could be updated in real time and could contain advertisements. "Location-based services", such as the ability to call up a list of nearby banks or pizzerias, have been talked about for years but have never taken off. But aiming such services at tourists makes sense—since people are more likely to want information when in an unfamiliar place. It could give mobile roaming a whole new meaning.

Two nuclear missile submarines—one British, one French—armed with a likely total of well more than 100 thermonuclear warheads collided under the Atlantic Ocean earlier this month. It"s a terrifying reminder of how many of these hugely destructive weapons are still routinely deployed and how little thought is given to keeping them as safe and secure as possible. Two decades after the end of the cold war, all of the nuclear powers have been inexcusably negligent about rethinking nuclear strategies, sharply reducing arsenals and eliminating needlessly risky practices, including some that contributed to this month"s collision. Fortunately, the damage to the submarines was minor, and the warheads were not compromised. British and French missiles, like those of the United States, are protected against accidental launch or detonation of their warheads. But a stronger impact could have sent both subs and their crews to the bottom and possibly dispersed plutonium into surrounding waters. The warheads on the two submarines that collided could, if ever launched, kill millions of people. And Britain and France together have far fewer than 1, 000 nuclear warheads in their arsenals. The United States and Russia still have more than 20,000. President Obama must move quickly to revive arms negotiations with the Russians—committing to deep reductions both in deployed weapons and the many thousands more in storage. He must then bring the British, French and Chinese into the talks. The most important missiles to retain in any shrinking arsenal would be those based on submarines. Because they are quiet and constantly moving, they are essentially invulnerable to pre-emptive attack; there is less pressure to use them or lose them. That advantage is also at the root of this month"s accident. The four nuclear navies operating in the Atlantic—American, British, French and Russian—refuse to disclose any information about which parts of the ocean their missile submarines operate in. Such accidents are rare. But they can and should be made rarer. That can be done without compromising security. As long as we depend on nuclear weapons for our security, we will have to live with uncomfortable risks. Governments must keep those risks to an absolute minimum by eliminating thousands of weapons that no longer have any military justification and insisting on the highest possible safety standards.

Billed as the Silicon Valley Robot Block Party and held during National Robotics Week, the party yesterday was a celebration of human-robot interactions.【F1】 Developers, researchers, and makers shared tips and explored the very ideas of what a robot can be and do. The people I met here are interested in robots on many levels.【F2】 There were startups pitching their businesses, home-brew builders looking to have some fun, high-school kids building competition robots, and Ph.D. students just exploring. That high-fiving robot? It"s the creation of Willow Garage, a founding member of the Silicon Valley Robotics group that hosted the block party. In 2010, Willow Garage announced it would be delivering 11 of its $400, 000 PR-2 robots free to research groups.【F3】 The program, however, which began as an opensource platform intended to encouraged roboticists to collaborate on creating a universal robot language, has quickly evolved. After just a few years, following an announcement in February, Willow Garage says it is shifting toward becoming a profitable and self-sustaining company. What"s next in the lives of robots? That"s the question everyone here wants to answer. Even after the PR-2"s 2010 release, within a year the stereoscopic cameras that provided the PR-2"s vision were replaced with commercially available hardware—Microsoft"s Kinect, highlighting the rigorous pace of innovation.【F4】 The commercial, off-the-shelf technology available to each of us today, as NASA has discovered, is fast, smart, and constantly upgraded. And as the evolution of robotics quickens, maybe that"s what events like National Robotics Week and the Robot Block Party, are all about. There"s a sense that though robots are already a great part of our lives, we are still in the early stages of robotics innovation. Things are evolving quickly. For that reason, a marketplace of ideas such as this is incredibly important. People and ideas are being connected.【F5】 Across genres, robotics hobbyists are talking to startups, educators are talking with industry, and students are envisioning a future where automation is smarter, machines are more useful, and everyone has the technical skills to live side by side with our robot friends.

Forests remove carbon dioxide from the air, conserve soil and water, and are home to a variety of species. (46) They are also repositories of potentially valuable new products, such as pharmaceuticals, and as a source of building material and firewood they provide employment for millions worldwide. In 1990 forests took up about a quarter of the planet"s land surface (not including an additional 13 percent of other woody vegetation, such as sparsely covered woodland and brush land). Russia accounts for perhaps a fifth of the globe"s forest. Brazil for about a seventh, and Canada and the U.S. each for 6 to 7 percent. (47) Historically, virtually all countries have experienced deforestation, mostly because of the need for new farmland, pasture, fuelwood and timber. In the U.S., forests now cover 22 percent of the land area, a decline of perhaps 40 percent since European colonization began. (48) Forest acreage, however, has remained about the same since 1920 as rising agricultural productivity moderated the need for new cropland. Among the most pressing concerns today in the U.S. are declining biodiversity of forests and stagnant or declining productivity of commercial timberland. In Europe, west of the former U.S.S.R., forests cover about 30 percent of the land, roughly half its original extent. A major problem there, particularly in Eastern Europe, is defoliation, apparently caused mostly by air pollution. Forests in the former U.S.S.R. once blanketed about half the land but now cover about a third. (49) Forest degradation is most serious there, not only because of air pollution but also because of a lack of effective conservation policies, such as replanting. Among other temperate regions, North Africa and the Middle East in 1990 had less than 2 percent forest cover, a decline since 1980. In contrast, China, through a massive tree-planting program, recently increased forest area, which now takes up 14 percent of its land. (50) The biggest changes have been in the tropics, where the natural forest dropped by a fifth from 1960 to 1990 as a result of population pressure, large-scale government development projects and commercial logging. The greatest decline was in tropical Asia, which lost a third of its forest. Almost all tropical countries lost ground in the 1980s except India, whose forest expanded by 5 percent. Brazil, which accounts for almost a third of the global tropical cover, suffered a 5 percent decline in the 1980s. There was a loss of 137 million hectares (338 million acres) of tropical forest worldwide, equal to the total land area of Spain, France and Germany. Agricultural expansion accounted for somewhat less than half the tropical contraction.

Thefollowingparagraphsaregiveninawrongorder.ForQuestions1-5,youarerequiredtoreorganizetheseparagraphsintoacoherentarticlebychoosingfromthelistA-Gtofillineachnumberedbox.ThefirstandthelastparagraphshavebeenplacedforyouinBoxes.[A]Theproblemsfacedbymissingandrunawaychildrenandtheirfamilieshavereceivednationalattention,resultinginanetworkofprogramsandservices.Policeoffertheprimaryserviceintherecoveryofchildren.Parentsorotherfamilymembersshouldreportallchildrenbelievedmissingorrunawayimmediatelytopolice.Swiftactionisimportanttoachild"ssafetyandrecovery.[B]Runawaysusuallyleavehomevoluntarilyandtendtobeteenagers.Therearemanyreasonswhychildrenrunawayfromhome.Mostrunawaysfeelmisunderstood,unlovedorangrywiththeirparents.Theyfindlifeathomeunbearableandbelievethatlivingelsewherewillbebetter.Somerunawaysactuallyare"thrownout"oftheirhomes.Parentsofthese"throwaway"childrenoftendonotwantthefinancialburdenofchildrearingorcannothandledifficultadolescentbehaviors.[C]Familiesofmissingandrunawaychildrenfacemanyproblems.Parentsofmissingchildrenfeelguiltyorresponsiblefortheirchild"sabduction.Theyalsocansufferfromfearandanxietyaboutwhatmayhappentotheirmissingchild.Parentsofrunawaychildrenalsomayexperiencethesameorsimilarconcerns.Notknowingthewhereaboutsorconditionofachildcancreatestressforallfamilymembers.[D]Preventionisthebeststrategyforkeepingchildrenfromtheranksofthemissingandrunaway.Understandingwhattodotorecovermissingandrunawaychildrenalsoisessential.[E]Otherprogramsandservicesalsoareavailable.Manybusinessesandorganizationsdisplaypicturesofmissingchildren."Hotlines"provideameansforrunawaychildrentocommunicatewiththeirfamilies."Safehouses"andsheltersareavailabletorunaways.Severalprogramsprovidefreeridestorunawayswhowishtoreturnhome.Thegrowingnationalconcernaboutmissingandrunawaychildrenmirrorstheseriousnessoftheproblem.Unfortunately,however,thenumberofmissingandrunawaychildrencontinuestorise.[F]BetweentwoandthreemillionAmericanchildrenaremissingorrunawayeachyear.Aroundthree-quartersofamillionareclassified"missingchildren"andabouttwomillionare"runaways".TheprecisenumberofAmericanchildreninthesetwocategoriesisunknown.Somemissingchildrenturnouttoberunawaysandsomerunawaysaremissingchildren.Parentsdonotalwaysreporttheirrunawaychildren.[G]Missingchildrenarelostorvictimsofabduction.Theytendtobeyoungerthanrunaways,usuallyunder14yearsofage.Strangerskidnaplessthan20%ofthesechildren.Familymembers,mostoftenthenon-custodialparent,abductthemajorityofmissingchildren.Separatedordivorcedparentswhodonothavelegalcustodymay"steal"theirownchildren.Childrenwhoarethevictimsofabduction,eitherbystrangersorbyfamilymembers,arelikelytosufferemotionaldamagebecauseoftheexperience.Order:

BSection II Reading Comprehension/B

Evidence of the benefits that volunteering can bring older people continues to roll in. "Volunteers have improved physical and social functioning," said Fengyan Tang, an assistant professor at the University of Pittsburgh School of Social Work, who has【C1】______older volunteers. "They report better well-being and greater life【C2】______. There's a reduced risk of death compared to non-volunteers." I reported a few weeks back on a public school program【C3】______volunteers, in a small-scale initial study, appeared to【C4】______their risk of cognitive decline. 【C5】______we're also learning that not all volunteering is created equal. In Dr. Tang's most recent study,【C6】______in The Gerontologist, she【C7】______207 volunteers(average age: 72)who spent【C8】______six hours a week on programs providing【C9】______services as preparing meals or teaching computer skills. The results【C10】______how important the programs' organization and administration can be. Volunteers reported greater "socioemotional benefits"—a sense of having made important【C11】______, feelings of enhanced well-being—when the programs【C12】______greater "organizational support." What's organizational support? Thoughtfully【C13】______volunteers with jobs that interest them. Offering training so that volunteers feel【C14】______with the work environment, the【C15】______, the task, the possible challenges【C16】______Making volunteering more convenient for older people by providing parking or transportation,【C17】______small salaries. 【C18】______their efforts with events or awards. "Organizational support is more important than the individual characteristics of the volunteer,【C19】______longer participation and greater benefit," Dr. Tang said. Seniors and families looking for engaging volunteer opportunities, and programs hoping to【C20】______and retain older volunteers, take note.

Could the bad old days of economic decline be about to return? Since OPEC agreed to supply-cuts in March, the price of crude oil has jumped to almost $26 a barrel, up from less than $10 last December. This near tripling of oil prices calls up scary memories of the 1973 oil shock, when prices quadrupled, and 1979-1980, when they also almost tripled. Both previous shocks resulted in double-digit inflation and global economic decline. So where are the headlines warning of gloom and doom this time? The oil price was given another push up this week when Iraq suspended oil exports. Strengthening economic growth, at the same time as winter grips the northern hemisphere, could push the price higher still in the short tern. Yet there are good reasons to expect the economic consequences now to be less severe than in the 1970s. In most countries the cost of crude oil now accounts for a smaller share of the price of petrol than it did in the 1970s. In Europe, taxes account for up to four-fifths of the retail price, so even quite big changes in the price of crude have a more muted effect on pump prices than in the past. Rich economies are also less dependent on oil than they were, and so less sensitive to swings in the oil price. Energy conservation, a shift to other fuels and a decline in the importance of heavy, energy intensive industries have reduced oil consumption. Software, consultancy and mobile telephones use far less oil than steel or car production. For each dollar of GDP (in constant prices), rich economies now use nearly 50% less oil than in 1973.The OECD estimates in its latest Economic Outlook that, if oil prices averaged $22 a barrel for a full year, compared with $13 in 1998, this would increase the oil import bill in rich economies by Only 0.25～0.5 % of GDP. That is less than one-quarter of the income loss in 1974 or 1980. On the other hand, oil-importing emerging economies—to which heavy industry has shifted—have become more energy-intensive, and so could be more seriously squeezed. One more reason, not to lose sleepover. The rise in oil prices is that, unlike the rises in the 1970s, it has not occurred against the background of general commodity price inflation and global excess demand. A sizable portion of the world is only just emerging from economic decline. The Economist"s commodity price index is broadly unchanging from a year ago. In 1973 commodity prices jumped by 70%, and in 1979 by almost 30%.

What does the hamburger say about our modern food economy? A lot, actually. Over the past several years Waldo Jaquith intended to make a hamburger from scratch, to no avail. "Further【C1】______revealed that it's quite impractical—【C2】______impossible—to make a hamburger from scratch," he writes. "Tomatoes are in season in the late summer. Lettuce is in season in spring and fall. Large mammals are【C3】______in early winter. The【C4】______of making such a burger would take nearly a year and would inherently involve omitting some core hamburger【C5】______." That the hamburger—our delicious and comforting everyman food—didn't【C6】______100 years ago is a greasy, shiny example of all that is both right【C7】______wrong with our modern food economy.【C8】______fertilizers, genetically modified crops, concentrated farming operations and global overnight shipping, much of the world was lifted out of starvation【C9】______it could finally grow【C10】______quantities of food with decreasing labor【C11】______. But these same【C12】______that allow food to be grown out of【C13】______and in all corners of the globe contribute to a whole host of environmental【C14】______. The "industrialization of food," as author Paul Roberts puts it, is an endless cycle driven by very small price【C15】______that force food processors to【C16】______more advanced techniques to produce even more food【C17】______lower prices. This system will only be aggravated as food demand【C18】______. Recently David Tilman and Jason Hill of the University of Minnesota released a study【C19】______that global food demand could double by 2050. It's【C20】______that our current, impractical food economy can sustain that demand.

"WHAT"S the difference between God and Larry Ellison?" asks an old software industry joke. Answer: God doesn"t think he"s Larry Ellison. The boss of Oracle is hardly alone among corporate chiefs in having a reputation for being rather keen on himself. Indeed, until the bubble burst and the public turned nasty at the start of the decade, the cult of the celebrity chief executive seemed to demand bossy narcissism, as evidence that a firm was being led by an all-conquering hero. Narcissus met a nasty end, of course. And in recent years, boss-worship has come to be seen as bad for business. In his management bestseller, "Good to Great", Jim Collins argued that the truly successful bosses were not the serf-proclaimed stars who adorn the covers of Forbes and Fortune, but instead self-effacing, thoughtful, monkish sorts who lead by inspiring example. A statistical answer may be at hand. For the first time, a new study, "It"s All About Me", to be presented next week at the annual gathering of the American Academy of Management, offers a systematic, empirical analysis of what effect narcissistic bosses have on the firms they run. The authors, Arijit Chatterjee and Donald Hambrick, of Pennsylvania State University, examined narcissism in the upper levels of 105 firms in the computer and software industries. To do this, they bad to solve a practical problem: studies of narcissism have hitherto relied on surveying individuals personally, something for which few chief executives are likely to have time or inclination. So the authors devised an index of narcissism using six publicly available indicators obtainable without the co-operation of the boss. These are: the prominence of the boss"s photo in the annual report; his prominence in company press releases; the length of his "Who"s Who" entry; the frequency of his use of the first person singular in interviews; and the ratios of his cash and non-cash compensation to those of the firm"s second-highest paid executive. Narcissism naturally drives people to seek positions of power and influence, and because great self-esteem helps your professional advance, say the authors, chief executives will tend on average to be more narcissistic than the general population. How does that affect a firm? Messrs Chatterjee and Hambrick found that highly narcissistic bosses tended to make bigger changes in the use of important resources, such as research and development, or in spending and leverage; they carried out more and bigger mergers and acquisitions; and their results were both more extreme (more big wins or big losses) and more transient than those of firms run by their humbler peers. For shareholders, that could be good or bad. Although (oddly) the authors are keeping their narcissism ranking secret, they have revealed that Mr. Ellison did not come top. Alas for him, that may be because the study limited itself to people who became the boss after 1991—well after he took the helm. In every respect Mr. Ellison seems to be the classic narcissistic boss, claims Mr. Chatterjee. There is life in the old joke yet.

Writeanessayof160-200wordsbasedonthefollowingdrawing.Inyouressay,youshould1)describethedrawingbriefly,2)explainitsintendedmeaning,and3)giveyourcomments.YoushouldwriteneatlyontheANSWERSHEET.(20points)

The first two stages in the development of civilized man were probably the invention of primitive weapons and the discovery of fire, although nobody knows exactly when people acquired the use of (1)_____. The (2)_____ of language is also obscure. No doubt it began very gradually. Animals have a few cries that serve (3)_____ signals, (4)_____ even the highest apes have not been found able to pronounce words (5)_____ with the most intensive professional instruction. The superior brain of man is apparently (6)_____ for the mastering of speech. When man became sufficiently intelligent, we must suppose that he (7)_____ the number of cries for different purposes. It was a great clay (8)_____ he discovered that speed could be used for narrative. There are those who think that (9)_____ picture language preceded oral language. A man (10)_____ a picture on the wall of his cave to show (11)_____ direction he had gone, or (12)_____ prey he hoped to catch. Probably picture language and oral language developed side by side. I am inclined to think that language (13)_____ the most important single factor in the development of man. Two important stages came not (14)_____ before the dawn of written history. The first was the domestication of animals; the second was agriculture. Agriculture was (15)_____ in human progress to which subsequently there was nothing comparable (16)_____ our own machine age. Agriculture made possible (17)_____ immense increase in the number of the human species in the regions where it could be successfully practised. (18)_____ were, at first, only those in which nature fertilized the soil (19)_____ each harvest. Agriculture met with violent resistance from the pastoral nomads, but the agricultural way of life prevailed in the end (20)_____ the physical comforts it provided.

The output of coal has doubled.

Researchers have established that when people are mentally engaged, biochemical changes occur in the brain that allow it to act more effectively in cognitive areas such as attention and memory.