Argentina in the late nineteenth century was an exciting place. Around 1870, it was experiencing an economic boom（繁荣）, and the capital, Buenos Aires, attracted many people. Farmers, as well as a flood of foreigners from Spain and Italy, came to Buenos Aires seeking jobs. These jobs didn't pay well, and the people felt lonely and disappointed with their new life in the city. As the unhappy newcomers mixed together in the poor parts of the city, the dance known as the tango(探戈舞) came into being.

    At the beginning the tango was a dance of the lower classes. It was danced in the bars and streets. At that time there were many fewer women than men, so if a man didn't want to be left out, his only choice was to dance with another man so that he could attract the attention of the few available women. Gradually, the dance spread into the upper classes of Argentinean society and became more respectable.

    In Europe at this time, strong interest in dance from around the world was beginning. This interest in international dance was especially evident in Paris. Every kind of dance from ballet(芭蕾舞) to belly dancing could be found on the stages of the Paris theaters. After tango dancers from Argentina arrived in Europe, they began to draw the interest of the public as they performed their exciting dance in cafes. Though not everyone approved of the new dance, saying it was a little too shocking, the dance did find enough supporters to make it popular.

    The popularity of the tango continued to grow in many other parts of the world. Soldiers who returned to the United States from World War I brought the tango to North America. It reached Japan in 1926, and in 2003 the Argentinean embassy(大使馆) in Seoul hired a local tango dancer to act as a kind of dance ambassador, and promote tango dancing throughout South Korea.

    Why do so many tourists come to Easter Island? Because it has world-famous stone statues (雕像) . These statues, whose likenesses look like humans with huge stone cylinders（柱状物）balancing on their heads like hats, have tourists coming from all over the world. The tourists come to see these works of ancient art carved by the early inhabitants of the island. They come to see the mystery that has puzzled historians for decades.

    Easter Island is located in a remote part Of the South Pacific Ocean about 2,300 miles west of Chile. Easter Island covers just 45 square miles and its Polynesian name is Rapa Nui.

    On Easter Sunday 1722, a Dutch explorer named Jacob Roggeveen was the first European to see Easter Island. The early Polynesians carved the statues within the holes of the volcano (火山) using only stone tools. Then they moved these huge statues to various destinations throughout the island. These 600 statues range in height from 10 to 40 feet. Some of them weigh as much as 50 tons. How could the early Polynesians lift hundreds of heavy statues out of the volcano? How did they move them across the island to their various locations? All of these questions, as well as many others, remain unanswered.

    The early islanders probably worshiped (崇拜) these eyeless giants until sometime around 1670. In 1680, a war broke out between two groups of islanders. The victors（胜利者）of the war and ancestors of the present inhabitants, broke down many of the statues. In most cases, they broke the necks of the statues.

    Now 15 of the statues on Easter Island have been repaired to their original positions on their stone platforms. Even today, using modern tools and machinery, putting up such large statues and balancing cylinders on top of their heads presents a challenging task.

    How much television do you watch? Did you really give an honest answer? A recent study shows that people aren't totally truthful about their television-watching habits.

    The study in question was conducted at Ball State University in the US. Researchers there wanted to find out how much television people view according to their age. The study was paid for by a council associated with the Nielsen Company, which determines television ratings. The conclusions were that people spend more than 8 hours a day looking at a screen. This included cell phones and computers，but the majority were television screens.

    There are three interesting things about this study. The first is that people are exposed to more than one hour of advertisements per day. The second is that even with access to DVDs and internet videos, television is still the most popular media source. The third is that the amount of screen-watching people do is relatively the same from the ages of 18-65.

    So, if everyone is watching television, why lie about it? Well, if someone admits they watch television for five or six hours, they could be considered a couch potato. Michael Phillips, one of the study's main researchers, says, “There's a social stigma for people who watch too much television. Sometimes, however, watching the latest reality show or the funniest sitcom gives co-workers and friends fun things to talk about.”

    Even if you do watch a lot of television, perhaps we can use this study as a reason to be honest with ourselves about how much time we spend in front of the television. I mean, after all, everyone else is doing it...

    Grown-ups are often surprised by how well they remember something they learned as children but have never practiced ever since. A man who has not had a chance to go swimming for years can still swim as well as even when he gets back in the water. He can get on a bicycle after many years and still ride away. He can play catch and hit a ball as well as his son. A mother who has not thought about the words for years can teach her daughter the poem that begins "Twinkle, twinkle, little star" or remember the story of Cinderella or Goldilocks and the Three Bears.

    One explanation is the law of overlearning, which can be stated as follows: Once we have learned something, additional learning trials(尝试) increase the length of time we will remember it.

    In childhood we usually continue to practice such skills as swimming, bicycle riding, and playing baseball long after we have learned them. We continue to listen to and remind ourselves of words such as "Twinkle, twinkle, little star" and childhood tales such as Cinderella and Goldilocks. We not only learn but overlearn.

    The multiplication tables(乘法口诀表) are an exception(例外) to the general rule that we forget rather quickly the things that we learn in school, because they are another of the things we overlearn in childhood.

    The law of overlearning explains why cramming(突击学习)for an examination, though it may result in a passing grade, is not a satisfactory way to learn a college course. By cramming, a student may learn the subject well enough to get by on the examination, but he is likely soon to forget almost everything he learned. A little overlearning, on the other hand, is really necessary for one's future development.

    When John was growing up, other kids felt sorry for him. His parents always had him weeding the garden, carrying out the garbage and delivering newspapers. But when John reached adulthood, he was better off than his childhood playmates. He had more job satisfaction, a better marriage and was healthier. Most of all, he was happier. Far happier.

    These are the findings of a 40-year study that followed the lives of 456 teenage boys from Boston. The study showed that those who had worked as boys enjoyed happier and more productive lives than those who had not. "Boys who worked in the home or community gained competence（能力）and came to feel they were worthwhile members of society, " said George Vaillant, the psychologist（心理学家）who made the discovery. "And because they felt good about themselves, others felt good about them."

    Vaillant's study followed these males in great detail. Interviews were repeated at ages 25, 31and 47. Under Vaillant, the researchers compared the men's mental-health scores with their boyhood-activity scores. Points were awarded for part-time jobs, housework, effort in school, and ability to deal with problems.

    The link between what the men had done as boys and how they turned out as adults was surprisingly sharp. Those who had done the most boyhood activities were twice as likely to have warm relations with a wide variety of people, five times as likely to be well paid and 16 times less likely to have been unemployed. The researchers also found that IQ and family social and economic class made no real difference in how the boys turned out.

    Working—at any age—is important. Childhood activities help a child develop responsibility, independence, confidence and competence—the underpinnings（基础）of emotional health. They also help him understand that people must cooperate and work toward common goals. The most competent adults are those who know how to do this. Yet work isn't everything. As Tolstoy once said, "One can live magnificently in this world if one knows how to work and how to love, to work for the person one loves and to love one's work."

    The next time your brain refuses to recall a simple fact or name, be thankful. That could be a sign that your brain is getting rid of unnecessary information so that it can operate more efficiently, and help you make better decisions.

The researchers say there are numerous neurobiological(神经生物学的)studies conducted on how the brain stores information, a process called persistence (暂留). However, scientists also assumed that our occasional inability to recall facts was due to a are an the brain. In 2013, scientists discovered that as new neurons combine with the hippocampus(海马区)—a region of the brain that plays a significant role in learning and remembering—they overwrite old memories, making them harder to access. There is also evidence that the brain weakens or removes connections between neurons, in which memories are encoded.

    The scientists have a theory on why the brain spends so much energy erasing memories. They say what the brain decides to forget is determined by our daily life. An example is that our brains remember phone numbers according to the need. Instead of storing this irrelevant information that our phones can store for us, our brains are freed up to store the memories that actually do matter for us. They also believe that memorizing too much detail could prevent us from making good decisions.

    So the next time you are unable to recall a seemingly important fact, don't be hard on yourself. Just throw it to your brain's “rubbish can” to make room for information that can contribute to making you smarter! Remember, even Albert Einstein was absent-minded!