Have you ever considered why you begin yawning too when you see someone yawn? Or how hard it is to be among people laughing and not laugh yourself? Well, apparently it's because we have mirror neurons (神经元）in our brains.

    Put simply, the existence of mirror neurons suggests that every time we see someone else do something, our brains imitate it whether or not we actually perform the same action. This explains a great deal about how, we learn to smile, talk, walk, dance or play sports. But the idea goes further: mirror neurons not only appear to explain physical actions, they also tell us that there is a biological basis for the way we understand other people.

    Mirror neurons can undoubtedly be found all over our brains, but especially in the areas which relate to our ability to use languages, and to understand how other people feel. Researchers have found that mirror neurons relate strongly to language. A group of researchers discovered that if they gave people sentences to listen to ( for example: “The hand took hold of the ball” ) , the same mirror neurons were triggered as when the action was actually performed (in this example, actually taking hold of a ball).

    Any problems with mirror neurons may well result in problems with behavior. Much research suggests that people with social and behavioral problems have mirror neurons which are not fully functioning. However, it is not yet known exactly how these discoveries might help find treatments for social disorders.

    Research into mirror neurons seems to provide us with even more information regarding how humans behave and interact. Indeed, it may turn out to be the equivalent (相等物）for neuroscience of what Einstein's theory of relativity was for physics. And the next time you feel the urge to cough in the cinema when someone else does — well, perhaps you'll understand why.

    To us, it seems so natural to put up an umbrella to keep the water off when it rains. But in fact the umbrella was not invented as protection against the rain. Its first use was as a shade against the sun.

    Nobody knows who first invented it, but the umbrella was used in very ancient times. Probably the first to use it were the Chinese, way back in the eleventh century B.C..

    We know that the umbrella was also used in ancient Egypt and Babylon as a sunshade. And there was a strange thing connected with its use: it became a symbol of honor and power. In the Far East in ancient times, the umbrella was allowed to be used only by those in high office or by royal people such as the kings or queens.

    In Europe, the Greeks were the first to use the umbrella as a sunshade. And the umbrella was in common use in ancient Greece. But it is believed that the first persons in Europe to use the umbrellas as protection against the rain were the ancient Romans. During the middle ages in Europe, the use of the umbrella most disappeared. Then it appeared again in Italy in the late sixteenth century. And again it became a symbol of power.

    Umbrellas have not changed much in style during all this time, though they have become much lighter in weight. It wasn't until the twentieth century that the umbrellas for women began to be made in all kinds of colors.

    The pillage (掠夺) and destruction of ancient shipwrecks and sunken archaeological sites by treasure hunters seeking gold and other valuables may be illegal under the terms of an international treaty under discussion by UNESCO's 188 Member States.

    "Protecting our underwater heritage is extremely important and increasingly urgent as no site or shipwreck is now out of bounds for treasure hunters. New technologies have made deep-water wrecks easily accessible and these technologies are getting cheaper," warns Lyndel Prott.

    According to estimates by commercial salvors (寻宝者), there are some three million undiscovered shipwrecks scattered across the world's oceans. Even the figures for the known wrecks are impressive. The Northern Shipwrecks Database for example contains 65,000 ship loss records for North America alone from 1500 AD to the present. The Dictionary of Disasters at Sea by Charles Hocking (1969) lists 12,542 sailing ships and war vessels lost between 1824 and 1962.

    Then there are sunken cities such as the trading town and pirate stronghold(海盗堡垒) of Port Royal in Jamaica, which disappeared beneath the waves after an earthquake in 1692. Or the remnants of ancient civilisations, such as the Lighthouse of Alexandria in Egypt, and the Neolithic villages being discovered under the Black Sea, which some believe could help explain Noah's great flood.

    These treasures of cultural heritage are under serious threat. Technology now allows extraordinary access to the ocean depths for determined and well-financed treasure hunters. And the potential rewards are huge. In 1985, American salvor Mel Fisher discovered the wreck of the Señora de Atocha, a Spanish ship that sank off the Florida Keys in 1622 with her cargo of gold, silver and jewellery worth an estimated US $400 million.

    An archaeologist can spend ten years or more studying a ship, conserving its objects and publishing its findings. We gain an enormous amount of information and knowledge from this work. With treasure hunters, all of this is lost. This is tragic, for humanity as a whole.

    Reading can be a social activity. Think of the people who belong to book groups. They choose books to read and then meet to discuss them. Now, the website BookCrossing.com turns the page on the traditional idea of a book group.

    Members go on the site and register the books they own and would like to share. BookCrossing provides an identification number to stick inside the book. Then the person leaves it in a public place, hoping that the book will have an adventure, traveling far and wide with each new reader who finds it.

    Bruce Pederson, the managing director of BookCrossing, says, “The two things that change your life are the people you meet and books you read. BookCrossing combines both.”

    Members leave books on park benches and buses, in train stations and coffee shops. Whoever finds their book will go to the site and record where they found it.

    People who find a book can also leave a journal entry describing what they thought of it. E-mails are then sent to the BookCrossing to keep them updated about where their books have been found. Bruce Pederson says the idea is for people not to be selfish by keeping a book to gather dust on a shelf at home.

    BookCrossing is part of a trend among people who want to get back to the “real” and not the virtual（虚拟）. The site now has more than one million members in more than one hundred thirty-five countries.

    Polish President Andrzej Duda has signed a bill into law that largely limits trade on Sundays, saying it will benefit family life.

    The legislation（立法）, worked out by the government and the Polish trade union, is expected to draw protests from large western supermarket chains that are the main target of the law. A large part of their profit is earned on weekends.

    As of March 1, shops and markets are closed on two Sundays per month; in 2019 only one Sunday a month will be open for shopping; and starting in 2020, there will be no Sunday shopping with a few exceptions.

    Duda praised the law as giving children a chance to be with parents and giving shop workers some needed time off. He also said big traders will need to adjust their practices to the new system and asked them for "understanding". But critics say some of them make employees work long hours for modest pay.

    "A family should be together on Sundays," Olszewska said after buying some food at a local Biedronka, a large discount supermarket chain. She said that before she retired she served cold cuts in a grocery store, and was grateful she never had to work on Sundays.

    There are some exceptions to the ban. For instance, gas stations, cafes, pharmacies and some other businesses are allowed to keep operating on Sundays.

    Anyone breaking the new rules faces a fine of up to 100,000 zlotys （$ 29,500）, while repeat offenders may face a prison sentence. Polish trade union appealed to people to report any violators to the National Labor Inspectorate, a state body.

    Big Ben is not the name of a man. It is the name of a huge(庞大的)clock in London. London is the capital of England. This clock has four faces. So，no matter where you stand, you can read the time on the face of Big Ben. Each face is the size of a double decker(层)bus. The hands are about four metres long. It is about the size of two people standing on top of each other. If you go to London, you may want to visit the Houses of Parliament(国会大厦). There you will find Big Ben sits at the top of the clock tower(塔)in the Houses of Parliament. Maybe you will hear it as well as see it. The huge clock makes such a loud noise. "Ding dong, ding dong, "it goes every quarter of an hour.

    The clock was named after a big man. He was Sir Benjamin Hall. This man did much building work in London many years ago.