单选题 Six Secrets of High-Energy People A. There's an energy crisis in America, and it has nothing to do with fossil fuels. Millions of us get up each morning already weary over the day holds. 'I just can't get started,' people say. But it's not physical energy that most of us lack. Sure, we could all use extra sleep and a better diet. But in truth, people are healthier today than at any time in history. I can almost guarantee that if you long for more energy, the problem is not with your body. B. What you're seeking is not physical energy. It's emotional energy. Yet, sad to say, life sometimes seems designed to exhaust our supply. We work too hard. We have family obligations. We encounter emergencies and personal crises. No wonder so many of us suffer from emotional fatigue, a kind of utter exhaustion of the spirit. C. And yet we all know people who are filled with joy, despite the unpleasant circumstances of their lives. Even as a child, I observed people who were poor, or disabled, or ill, but who nonetheless faced life with optimism and vigor. Consider Laura Hillenbrand, who despite an extremely weak body, wrote the best-seller Seabiscuit. Hillenbrand barely had enough physical energy to drag herself out of bed to write. But she was fueled by having a story she wanted to share. It was emotional energy that helped her succeed. D. Unlike physical energy, which is finite and diminishes with age, emotional energy is unlimited and has nothing to do with genes or upbringing. So how do you get it? You can't simply tell yourself to be positive. You must take action. Here are six practical strategies that work. 1. Do something new. E. Very little that's new occurs in our lives. The impact of this sameness on our emotional energy is gradual, but huge: It's like a tire with a slow leak. You don't notice it at first, but eventually you'll get a flat. It's up to you to plug the leak—even though there are always a dozen reasons to stay stuck in your dull routines of life. That's where Maura, 36, a waitress, found herself a year ago. F. Fortunately, Maura had a lifeline—a group of women friends who meet regularly to discuss their lives. Their lively discussions spurred Maura to make small but nevertheless life altering changes. She joined a gym in the next town. She changed her look with a short haircut and new black T-shirts. Eventually, Maura gathered the courage to quit her job and start her own business. G. Here's a challenge: If it's something you wouldn't ordinarily do, do it. Try a dish you've never eaten. Listen to music you'd ordinarily tune out. You'll discover these small things add to your emotional energy. 2. Reclaim life's meaning. H. So many of my patients tell me that their lives used to have meaning, but that somewhere along the line things went stale. I. The first step in solving this meaning shortage is to figure out what you really care about, and then do something about it. A case in point is Ivy, 57, a pioneer in investment banking. 'I mistakenly believed that all the money I made would mean something,' she says. 'But I feel lost, like a 22-year-old wondering what to do with her life.' Ivy's solution? She started a program that shows Wall Streeters how to donate time and money to poor children. In the process, Ivy filled her life with meaning. 3. Put yourself in the fun zone. J. Most of us grown-ups are seriously fun-deprived. High-energy people have the same day-to-day work as the rest of us, but they manage to find something enjoyable in every situation. A real estate broker I know keeps herself amused on the job by mentally redecorating the houses she shows to clients. 'I love imagining what even the most run-down house could look like with a little tender loving care,' she says. 'It's a challenge—and the least desirable properties are usually the most fun.' K. We all define fun differently, of course, but I can guarantee this: If you put just a bit of it into your day, you energy will increase quickly. 4. Bid farewell to guilt and regret. L. Everyone's past is filled with regrets that still cause pain. But from an emotional energy point of view, they are dead weights that keep us from moving forward. While they can't merely be willed away, I do recommend you remind yourself that whatever happened is in the past, and nothing can change that. Holding on to the memory only allows the damage to continue into the present. 5. Make up your mind. M. Say you've been thinking about cutting your hair short. Will it look stylish—or too extreme? You endlessly think it over. Having the decision hanging over your head is a huge energy drain. Every time you can't decide, you burden yourself with alternatives. Quit thinking that you have to make the right decision; instead, make a choice and don't look back. 6. Give to get. N. Emotional energy has a kind of magical quality: the more you give, the more you get back. This is the difference between emotional and physical energy. With the latter, you have to get it to be able to give it. With the former, however, you get it by giving it. O. Start by asking everyone you meet, 'How are you?' as if you really want to know, then listen to the reply. Be the one who hears. Most of us also need to smile more often. If you don't smile at the person you love first thing in the morning, you're sucking energy out of your relationship. Finally, help another person—and make the help real, concrete. Give a massage (按摩) to someone you love, or cook her dinner. Then, expand the circle to work. Try asking yourself what you'd do if your goal were to be helpful rather than efficient. P. After all, if it's true that what goes around comes around, why not make sure that what's circulating around you is the good stuff?

单选题 Bathing Suits and Swimming Habits Have Changed a Lot Over the Years A. Have you picked out your swimsuit for summer yet? Some kids spend hours shopping for the right look. Others go with whatever Morn or Dad chooses for them. Whatever you wear to the pool or the beach this summer, enjoy the sun and water. And be glad you weren't around 100 or 200 years ago, when swimsuits were made of itchy wool and looked like Hogwarts robes. (Or maybe you'd like to wear a Hogwarts robe to the beach!) Turn the page to take a peek at the history of the bathing suit. B. In ancient Greece and Rome, men swam for exercise and to train as warriors. They also went to the public baths. Usually, they wore nothing at all. But sometimes they would put on loose-fitting gowns called togas. Women had their own public baths. Some early Roman art shows girls playing sports in what we would call bikinis. But there is no hint that these outfits were used for swimming, which was not something women and girls did back then. C. Over time, bathing and swimming became less popular. Before the 1500s, in fact, people in Europe thought that public bathing helped spread the diseases that killed millions and wiped out entire towns during the Middle Ages. It wasn't until the 17th century that swimming and public bathing spas became popular again. In addition to men, women were able to enjoy these activities, though they had to do so in nightgown like dresses. D. A British fashion report from 1687 described ladies' 'bathing costumes'. The dresses were made of stiff canvas and had big sleeves. The sleeves filled with water and kept the gowns from clinging and revealing too much. Men wore canvas pants called drawers and vests called waistcoats. A big cover-up E. Back then, showing off one's body was considered improper. So people covered themselves as much as possible. Men's one-piece wool swimsuits, the style that replaced drawers and waistcoats, looked like long underwear, with full-length sleeves and legs. Women's bathing dresses often had high collars and went all the way down to their toes. They also wore bathing caps and long black stockings. F. Women were expected to be modest in other ways as well. Some, like Martha Washington, had lead weights sewn into the hems of their bathing gowns so the clothing would not float up. Others took to the water inside covered wooden frames called 'bathing machines'. G. This term also was used for small wooden cabins at Atlantic Ocean beaches in the early to mid-1800s. The cabins were set on tall wheels. While the bather was inside changing, a horse pulled the machine into the ocean. When the water was high enough, the horse was taken ashore. The bather could then step down from the cabin and into the sea. Few people ashore saw anything but a head bobbing in the surf. H. Many beaches had separate swim times for men and women. Colored flags were posted to let them know when it was their turn to be in the water. When bloomers bloomed I. Until 1850, men and boys in England often swam naked in lakes, rivers and seas. When the practice was banned, swimming in one's underwear became popular. Striped shirts and shorts were the rage for men in the 1870s. Flannel replaced wool and linen as the most popular material for bathing suits. It was thought to be warmer when swimming in the cold sea. J. Women, meanwhile, were shifting to bloomers—a long skirt worn over loose pants. The skirt's hem was about three inches above the ankle, which was pretty shocking back then. Gloves, a belt, a cap and rubber shoes completed the outfit. K. As swimming grew more popular among European women, they traded in their skirts for a less bulky trousers-and-blouse swim garment. American women found that look too manly and kept their skirts for decades more. They also wore toe-length cloaks over their wet suits when crossing the beach. Today: sleeker, baggier L. When they began sharing the beach with men at the turn of the 20th century, American women wanted more stylish swim attire. And with swimming now an acceptable activity, they wanted their suits to be more functional. So sleeves were shortened, then done away with. Necklines were lowered. Colored braid, ribbons and bows were added. A one-piece 'princess' suit, with a separate skirt, was a big hit, as were matching mother-daughter suits. M. Men's suits were changing, too, but not always for the better. The first modern swim trunks actually made swimming more difficult because they weighed nine pounds when wet and could slip off! Form-fitting suits came along in the 1930s. Swimsuits got smaller. Men removed their tops in 1937. Bikinis followed nine years later. With the arrival of new fabrics such as spandex and lycra, women's and girls' suits got sleeker. Men's and boys' trunks, meanwhile, got baggier. Suits made for speed N. Timing is everything in competitive swimming. One one-hundredth of a second can decide who wins a medal at a meet. So swimmers are always looking for ways to cut a sliver off their racing times. O. In the 1990s, swimsuit makers had a bold new idea: high-tech bodysuits. U. S. space engineers even helped with the design and testing of some of these suits. They were made of lighter materials such as plastic and rubber, which soaked up less water than woven materials. Some bodysuits had no stitching, which also reduced the water's 'drag'. And their skintight fit kept muscles from tiring as quickly. P. As a result, swimmers went faster. At the 2008 Summer Olympics, more than 90 percent of all swim medals were won by athletes wearing Speedo's new LZR Racer bodysuit. Baltimore's Michael Phelps, who won eight gold medals at those Games, said his LZR suit made him 'feel like a rocket' in the pool. Q. Not everyone was happy with the performance-enhancing suits. Many people felt they favored scientific advances over a swimmer's natural abilities. In 2010, the sport's top officials banned full-length suits from major swim events. They put limits on the thickness and type of materials used in suits, as well as their length. But that hasn't stopped researchers. They are now working on new types of goggles and swim caps.

单选题 故宫(Imperial Palace)又名紫禁城，为明清共二十四位皇帝统治中国近500年的皇宫。它位于北京市中心，在天安门广场的北侧，形状为长方形。南北长约960米，东西宽约750米，占地72公顷，总建筑面积达15万平方米。故宫是世界上现存规模最大、最完整的古代木构宫殿。它分为外朝和内廷两部分，外朝是皇帝上朝处理国家大事的地方，内廷是皇帝和皇室的居住地。1987年，故宫被联合国教科文组织列入世界文化遗产。

单选题It is estimated that about 10 million people go into coastal waters every year to get a closer look at whales. When the eco-tourists (生态旅游者) try to have a look at the 28 mammals rising above the water line, killer whales' lives are greatly 29 , though they are the top of the food chain in the sea. 'We now have more whale-watch boats than there are whales,' said Kelley Balcomb-Bartok of an 30 in Washington State that works with scientists to protect whales. All this activity is causing people to show more 31 . about the whales' health and survival. Some scientists say noise from all the boat traffic may 32 a whale's sonar (声纳，声波) ability as much as 95 percent The whales need sonar to find food. Three new studies 33 this month suggest the interference caused by the tourists is damaging the whales, whose population in the Puget Sound region has fallen from 98 to 80 in less than a 34 . Scientists say all the traffic also forces the whales to move around more, wasting energy needed for 35 food. 'I would say that at times when there are a lot of boats and there is a lot of noise, they are 36 ,' said Tom McMillen, captain of the whale-watching boat Stellar Sea, which takes out three groups a day. Scientists say there are less food in the sea for the whales to eat, besides, the pollution in the sea is more serious, 37 , the noise from the boats makes the life of the whales even worse. A. threatened B. decade C. delicate D. initially E. concerns F. cautious G. irritated H. hunting I. huge J. decrease K. monument L. cease M. released N. thus O. organization

单选题As food is to the body, so is learning to the mind. Our bodies grow and muscles develop with the 24 of adequate nutritious food. Likewise, we should keep learning day by day to maintain our keen mental power and expand our 25 capacity. Constant learning 26 us with inexhaustible fuel for driving us to sharpen our power of reasoning, analysis, and judgment. Learning incessantly is the surest way to keep 27 with the times in the information age, and an infallible 28 of success in times of uncertainty. Once learning stops, vegetation sets in. It is a common fallacy to regard school as the only workshop for the 29 of knowledge. On the contrary, learning should be a never-ending process, from the cradle to the 30 . With the world ever changing so fast, the cease from learning for just a few days will make a person lag behind. What's worse, the animalistic instinct dormant deep in our subconsciousness will come to life, weakening our will to 31 our noble ideal, sapping our determi nation to sweep away 32 to our success and strangling our desire for the refinement of our character. Lack of learning will inevitably lead to the stagnation of the mind, or even worse, its fossilization. Therefore, to stay mentally young, we have to take learning as a 33 career. A. grave B. supplies C. pursue D. pace E. acquisition F. difficult G. intake H. warrant I. decoration J. intellectual K. learn L. determination M. mental N. lifelong O. obstacles

单选题 When young women were found to make only 82 percent of what their male peers do just one year out of college, many were at a loss to explain it. All the traditional reasons put forward to interpret the pay gap—that women fall behind when they leave the workforce to raise kids, for example, or that they don't seek as many management roles—failed to justify this one. These young women didn't have kids yet. And because they were just one year removed from their undergraduate degrees, few of these women yet had ,the chance to go after (much less decline) leadership roles. But there are other reasons why the pay gap remains so persistent. The first is that no matter how many women may be getting college degrees, the university experience is still an unequal one. The second is that our higher education system is not designed to focus on the economic consequences of our students' years on campus. Now that women are the majority of college students and surpass men in both the number of undergraduate and advanced degrees awarded, one might think the college campus is a pretty equal place. It is not. Studies show that while girls do better than boys in high school, they start to trail off during their college years. They enroll in different kinds of classes, tend to major in less rigorous (非常严格的) subjects, and generally head off with less ambitious plans. As a result, it's not surprising that even the best educated young women enter the workplace with a slight disadvantage. Their college experience leaves them somewhat confused, still stumbling (栽倒) over the dilemmas their grandmothers' generation sought to destroy. Are they supposed to be pretty or smart? Strong or sexy (性感的)? All their lives, today's young women have been pushed to embrace both perfection and passion—to pursue science and sports, math and theater—and do it all as well as they possibly can. No wonder they are not negotiating for higher salaries as soon as they get out of school. They are too exhausted, and too scared of failing'.

单选题 On average, American kids ages 3 to 12 spent 29 hours a week in school, eight hours more than they did in 1981. They also did more household work and participated in more of such organized activities as soccer and ballet (芭蕾舞). Involvement in sports, in particular, rose almost 50% from 1981 to 1997: boys now spend an average of four hours a week playing sports; girls log half that time. All in all, however, children's leisure time dropped from 40% of the day in 1981 to 25%. 'Children are affected by the same time crunch (危机) that affects their parents,' says Sandra Hofferth, who headed the recent study of children's timetable. A chief reason, she says, is that more mothers are working outside the home. (Nevertheless, children in both double-income and 'male breadwinner' households spent comparable mounts of time interacting with their parents, 19 hours and 22 hours respectively. In contrast, children spent only 9 hours with their single mothers.) All work and no play could make for some very messed-up kids. 'Play is the most powerful way a child explores the world and learns about himself,' says T. Berry Brazelton, professor at Harvard Medical School. Unstructured play encourages independent thinking and allows the young to negotiate their relationships with their peers, but kids ages 3 to 12 spent only 12 hours a week engaged in it. The children sampled spent a quarter of their rapidly decreasing 'free time' watching television. But that, believe it or not, was one of the findings parents might regard as good news. If they're spending less time in front of the TV set, however, kids aren't replacing it with reading. Despite efforts to get kids more interested in books, the children spent just over an hour a week reading. Let's face it, who's got the time?

单选题 The simple act of surrendering a telephone number to a store clerk may not seem harmful—so much so that many consumers do it with no questions asked. Yet that one action can set in motion a series of silent events, as that data point is acquired, analyzed, categorized, stored and sold over and over again. Future attacks on your privacy may come from anywhere, from anyone with money to purchase that phone number you surrendered. If you doubt the multiplier effect, consider your e-mail inbox. If it's loaded with spam, it's undoubtedly because at some point in time you unknowingly surrendered your e-mail to the wrong website. Do you think your telephone number or address is handled differently? A cottage industry of small companies with names you've probably never heard of—like Acxiom or Merlin—buy and sell your personal information the way other commodities like corn or cattle futures are bartered. You may think your cell phone is unlisted, but if you've ever ordered a pizza, it might not be. Merlin is one of many commercial data brokers that advertises sale of unlisted phone numbers compiled from various sources—including pizza delivery companies. These unintended, unpredictable consequences that flow from simple actions make privacy issues difficult to grasp, and grapple with. In a larger sense, privacy also is often cast as a tale of 'Big Brother'—the government is watching you or a big corporation is watching you. But privacy issues don't necessarily involve large faceless institutions: A spouse takes a casual glance at her husband's Blackberry, a co-worker looks at e-mail over your shoulder or a friend glances at a cell phone text message from the next seat on the bus. While very little of this is news to anyone—people are now well aware there are video cameras and Internet cookies everywhere—there is abundant evidence that people live their lives ignorant of the monitoring, assuming a mythical level of privacy. People write e-mails and type instant messages they never expect anyone to see. Just ask Mark Foley or even Bill Gates, whose e-mails were a cornerstone of the Justice Department's antitrust case against Microsoft.

单选题 In the past, falling oil prices have given a boost to the world economy, but recent forecasts for global growth have been toned down, even as oil prices sink lower and lower. Does that mean the link between lower oil prices and growth has weakened? Some experts say there are still good reasons to believe cheap oil should heat up the world economy. Consumers have more money in their pockets when they're paying less at the pump. They spend that money on other things, which stimulates the economy. The biggest gains go to countries that import most of their oil like China, Japan and India. But doesn't the extra money in the pockets of those countries' consumers mean an equal loss in oil-producing countries, cancelling out the gains? Not necessarily, says economic researcher Sara Johnson. 'Many oil producers built up huge reserve funds when prices were high, so when prices fall they will draw on their reserves to support government spending and subsidies (补贴) for their consumers.' But not all oil producers have big reserves. In Venezuela, collapsing oil prices have sent its economy into free-fall. Economist Carl Weinberg believes the negative effects of plunging oil prices are overwhelming the positive effects of cheaper oil. The implication is a sharp decline in global trade, which has plunged partly because oil-producing nations can't afford to import as much as they used to. Sara Johnson acknowledges that the global economic benefit from a fall in oil prices today is likely lower than it was in the past. One reason is that more countries are big oil producers now, so the nations suffering from the price drop account for a larger share of the global economy. Consumers, in the U.S. at least, are acting cautiously with the savings they're getting at the gas pump, as the memory of the recent great recession is still fresh in their mind. And a number of oil-producing countries are trimming their gasoline subsidies and raising taxes, so the net savings for global consumers is not as big as the oil price plunge might suggest.

单选题 One in six. Believe it or not, that's the number of Americans who struggle with hunger. To make tomorrow a little better, Feeding America, the nation's largest 24 hunger-relief organization has chosen September as Hunger Action Month. As part of its 30 Ways in 30 Days program, it's asking 25 across the country to help the more than 200 food banks and 63,000 agencies in its network provide low-income individuals and families with the fuel they need to 26 . It's the kind of work that's done every day at St. Andrew's Episcopal Church in San Antonio. People who 27 at its front door on the first and third Thursdays of each month aren't looking for God—they're there for something to eat. St. Andrew's runs a food pantry (食品室)that 28 the city and several of the 29 towns. Janet Drane is its manager. In the wake of the 30 , the number of families in need of food assistance began to grow. It is 31 that 49 million Americans are unsure of where they will find their next meal. What's most surprising is that 36% of them live in 32 where at least one adult is working. 'It used to be that one job was all you needed,' says St. Andrew's Drane. 'The people we see now have three or four part-time jobs and they're still right on the edge 33 .' A. survive B. surrounding C. serves D. reviewed E. reported F. recession G. households H. gather I. formally J. financially K. domestic L. competition M. communities N. circling O. accumulate

单选题 Public or Private? A. When jobseekers encounter an opening, they typically ask themselves a few basics—Am I qualified? Is it interesting work? What does it pay? Whether the job is in the public or private sector is a secondary matter. First and foremost is to find rewarding work that offers a good salary and comprehensive benefits. Yet there are significant differences between the public and private sector that could make similar sounding positions two very different experiences. Some workers seem quite capable of working in either environment, while others learn the hard way that they are ill-suited for one or the other. How do you know which is right for you? Here are some key differences to consider in making your career decision. B. Private organizations are funded by individuals or shareholders with a goal of making money. Public organizations are typically taxpayer supported and exist to serve some public need not adequately addressed by private companies. Rather than being profit-driven, they strive to deliver maximum services within the constraints of a fixed budget. In the private sector, job counselors advise clients to contact hiring managers directly whenever possible, via phone calls or through networking. Usually, you can talk your way into an interview. The public sector operates differently. Directly contacting hiring managers in the public sector will do little good because, typically, they must first post job openings (often to a website or telephone hotline), then consider only those who pass the initial job application screening. In the public sector, you must familiarize yourself with an agency's procedures, then follow them to the letter lest you be disqualified. In some cases, you will be required to take an exam. Books that help you prepare for civil service exams are readily available at book stores and many career centers. C. The sea of red ink that has swamped several public agencies has forced many to do the unthinkable—let people go, just like in the private sector. In fact, government has been losing jobs in California throughout 2004. In addition, a recent report by the governor advocates converting many government positions into private-sector contracting jobs. Still, if you can land a job at the city, county or state level and acquire some seniority, you have a good chance of weathering such cutbacks. So if job security is vital to you, a civil service position is your best bet. If you plan on changing jobs and moving out of the area, you will want the flexibility of the private sector. D. Some might argue that you will have more job satisfaction in the private sector. But I am not so sure. I know a teacher, social worker, administrator, and health educator, and they all enjoy their work. As with anything, much of their job satisfaction depends upon the meaningfulness of the work and the quality of their supervisor. A teacher, for example, may experience more job satisfaction than a secretary. The key is landing a job you want to do, whether it's public or private. If you are eager to be a manager, private employment may be for you. It's easier to win a promotion and you have more flexibility with employees since there are fewer rules to follow. In public employment, you will have to compete with any and all who want to apply for the job. E. In the public sector, pay is determined by your job title and years of service. In private industry, pay levels are usually based on your skills, qualifications, productivity, and contributions to the bottom line. Salary schedules with private employers may be more susceptible to downturns in the economy. However, the pay scale in a public agency is etched in stone, while in the private world you are only limited by what you can convince an employer you are worth. Certainly the public sector in general has better healthcare coverage, although many agencies are trying to pass on greater costs to workers(just as in the private sector). There is one area of benefits in which the private sector cannot compete—holidays. In addition, many public agencies pay retirees for a portion of their unused sick leave, a rarity in the private world. As for retirement, see below. F. Having lived through corporate politics, I understand how onerous they can be. But you are not free of this in public agencies. At the state level, everyone has to keep the governor happy. County-level staffers answer to a board of supervisors. At the local level, it's the city council or the school board. The military, police and fire departments have very. rigid chains of command. Perhaps the only place you can escape corporate or public politics is working for a small, privately held company. With less distance between you and the owner, you are more readily able to have a positive influence on what happens in your firm. If you hate sitting through meetings that drone on, well, there is no escape. The private and public sectors both have their share of monotonous(枯燥无味的) get-togethers in the conference room. G. You won't find a job selling widgets(小产品) with a government agency, and you won't find work as a tax collector in the private sector. Still, you can find a variety of challenging jobs in both the private and public world. If, for example, you are into marketing, you could find a private company interested in enhancing its image—or a public agency that needs to market a new public health campaign. The possibilities are only limited by your ability to think of ways to apply your skills. H. Retirement benefits provide one of the most glaring differences between working for a public or private entity. In the public sector, it's unlikely that your retirement benefits would ever be in danger, particularly if your agency is part of the California Public Employees Retirement System (CALPERS), the largest such investment entity in the world. It's quite a different matter in the private sector. While Enron was perhaps the most dramatic and tragic case of a company pension plan collapsing, more and more, firms are trying to ease the pension burden by reducing benefits to workers. For example, United Airlines earlier this year attempted to renege on its retirement plan in order to avoid bankruptcy. The courts, however, rejected the bid. Still, countless other companies have indeed pulled back on promises of retirement benefits to current workers as well as reducing actual benefits to those already retired. I. Of course, there are wide variances within the sectors—working for Chevron for example, is not the same as working for Morn Pop's Pet Shop. Nor is working for the Post Office the same as laboring at the city hall. As always, wise jobseekers do their homework on target employers before applying—whether public or private.

单选题 What Is Your Dog Thinking? A. Your cute companion rests by your side, but is she dreaming of you? Does she feel guilty about stealing your steak off the kitchen counter and eating it for dinner? What is she trying to say with that annoying bark? Does she smile to you today? After decades of research, neuroscientists (神经系统学家)have begun to answer such questions, giving us access to the once-secret inner lives of our cute companions and even translating their barks and wags so mere humans can understand them. At the forefront of this effort is Stanley Coren, a behaviorist from the University of British Columbia, who draws on decades of research to explore the psychological motivations behind dogs' everyday behaviors. B. Dogs have the same brain structures that produce emotions in humans. They have the same hormones (荷尔蒙)and undergo the same chemical changes that humans do during emotional states. Dogs even have what in humans is involved with love and affection.However, it is important not to go overboard: The mind of a dog is roughly equivalent to that of a human who is 2 to 2 1/2 years old. A child that age clearly has emotions, but not all possible emotions, since many emerge later in the path to adulthood. C. Dogs go through their developmental stages much more quickly than humans do, attaining their full emotional range by the time they are 4 to 6 months old. A dog has the basic emotions: joy, fear, anger, disgust, excitement, contentment, distress, and even love. A dog does not have, and will not develop, more complex emotions, like guilt, pride, contempt, and shame, however. You might argue that your dog has shown evidence of feeling guilty. In the usual case, you come home and your dog starts avoiding you and showing discomfort and you then find his smelly brown deposit on your kitchen floor. It is natural to conclude that the dog's actions show a sense of guilt about its ill behavior. However, this is simply the more basic emotion of fear. The dog has learned that when you appear and his droppings are visible on the floor, bad things happen to him. He will also never feel shame, so feel free to dress him in that ridiculous party costume. D. Many people believe that dogs have dreams. Most dog owners have noticed that at various times during sleep, some dogs may quiver, suddenly move a leg, even utter angry sounds or snap at a sleep-created evil image, giving the impression that they are dreaming about something. At the structural level, the brains of dogs are similar to those of humans. In addition, during sleep the brain-wave patterns of dogs are similar to people's, and they exhibit the same stages of electrical activity that are observed in humans—all of which is consistent with the idea that dogs are dreaming. E. Actually, it would be surprising if dogs didn't dream, since recent evidence suggests that animals simpler and less intelligent than dogs seem to do so. Neuroscientists Matthew Wilson and Kenway Louie of Massachusetts Institute of Technology have evidence that the brains of sleeping rats function in a way that definitely suggests dreaming. Much of the dreaming you do at night is associated with the activities you engaged in that day. The same seems to be the case in rats. F. From studies of electrical recordings of the rats made while the rats were awake and learning a maze, Wilson and Louie found that some electrical patterns were quite specific and could be identified, depending on what the rat was doing. Later, when the rats were asleep and their brain waves indicated that they had entered the stage in which humans normally dream, these same electrical patterns appeared. The patterns were so clear and specific that the researchers were able to tell where in the maze the rat would be if it were awake, and whether it would be moving or standing still. Since a dog's brain is more complex than a rat's and shows the same electrical sequences, it is reasonable to assume that dogs dream as well. G. There is also evidence that they dream about common dog activities. The human brain stem contains a special structure that keeps us from acting out our dreams. When scientists removed or inactivated this same part of the brain in dogs, they observed that the dogs began to move around, even though electrical recordings of the dogs' brains indicated that they were still fast asleep. The animals started to move only when the brain entered that stage of sleep associated with dreaming. During the course of a dream episode, the dogs actually began to execute the actions they were performing in their dreams. There is also an odd fact that small dogs have more dreams than big dogs do. H. In the minds of most people, the equivalent of a dog's smiling is when he is wagging his tail. But there is actually one facial expression that comes close to what we mean by smiling in humans. In this expression, slightly opened jaws reveal the dog's tongue hanging over his front teeth. Frequently the eyes take on a teardrop shape at the same time, as if being pulled upward slightly at the outer comers. It is a casual expression that is usually seen when the dog is relaxed, playing, or interacting socially, especially with people. I. Dogs are also capable of laughing, and they typically do so when they are playing. The laughter begins with the doggy equivalent of smiling but also includes a sound that is much like heavy breathing. Several years ago, animal behaviorist Patricia Simonet at Sierra Nevada College recorded those sounds while dogs played. In one experiment, Simonetnoticed that puppies ran around for joy when they heard recordings of these sounds; in another, she was able to show that these same sounds helped to calm dogs in an animal shelter.