You are sitting on the desk. A teacher is writing on the blackboard. Kids are yelling in the playground outside. A book falls off the desk next to you. Suddenly, the teacher hands you a pop quiz.

Don't panic! {#blank#}1{#/blank#} You're in a “virtual（虚拟的）classroom”. Everything you see and hear is coming to you through a computer-operated display that you're wearing on your head like a pair of very big glasses. Wearing this kind of virtual-reality equipment, you can find yourself sitting in a classroom, touring a famous museum, wandering across a strange landscape, flying into space, or playing with a cartoon character. {#blank#}2{#/blank#} Virtual-reality equipment that delivers images and sounds directly to your eyes and ears makes these fake worlds seem lifelike.

Unlike the classroom, the technology is real. It's a type of technology that uses computer programs to imitate real world situation.{#blank#}3{#/blank#} Movie directors and video game producers have been using computers for years to create ever more realistic special effects. Some companies are now building three-dimensional（三维）fantasy worlds in which players, linked by computer networks, appear to meet and go on explorations together.

    {#blank#}4{#/blank#} They see virtual reality technology as a useful tool for learning more about why people act as they do. It could help psychologists deter identify and come up with solutions for behaviors problems, for example.

“We've spent the last 100 years looking for certain laws in how people interact with the real world,” says psychologist Albert. “ {#blank#}5{#/blank#} This is psychologist's dream.”

    Do you want to go abroad to make money? If you've decided to invest（投资）overseas, you may be wondering which countries are the best, and which countries will give you the biggest returns. In some locations, investment is easier than others. Here are the top 4 best countries to invest in housing:

    Italy

    A charming hillside area, Abruzzo makes for a great investment. This beautiful place has lots of local housing resources, and you can buy a home that needs just $45,000. With proper repair, selling for at least four times that much, you can easily make money.

    Argentina

    Central America's Argentina's tourism is popular, so it has a lot to offer locals and tourists alike. This coastal country is affordable, too, especially in the busy city of Buenos Aires. As the city is rapidly expanding, now it's time to get this hot investing opportunity.

    Mexico

    In the south of the border, you can find unbelievable investment. Playa del Carmen will give you the most for your money. Plus its tourism is popular and it's a nice place to visit and easily accessible from the United States.

    Panama

    Historic and lively, Panama is a safe place for shopping. You'll enjoy great tax（税金）benefits in Panama. Panama does not charge income tax for the first 10 years of your investment.

        No matter where you choose to buy, these four countries will provide you with a great location and return on investment.

    Getting rid of dirt, in the opinion of most people, is a good thing. However, there is nothing fixed about attitudes to dirt.

    In the early 16^th century, people thought that dirt on the skin was a means to block out disease, as medical opinion had it that washing off dirt with hot water could open up the skin and let ills in. A particular danger was thought to lie in public baths. By 1538, the French king had closed the bath houses in his kingdom. So did the king of England in 1546. Thus began a long time when the rich and the poor in Europe lived with dirt in a friendly way. Henry IV, King of France, was famously dirty. Upon learning that a nobleman had taken a bath, the king ordered that, to avoid the attack of disease, the nobleman should not go out.

    Though the belief in the merit of dirt was long-lived, dirt has no longer been regarded as a nice neighbor ever since the 18^th century. Scientifically speaking, cleaning away dirt is good to health. Clean water supply and hand washing are practical means of preventing disease. Yet, it seems that standards of cleanliness have moved beyond science since World War Ⅱ. Advertisements repeatedly sell the idea; clothes need to be whiter than white, cloths ever softer, surfaces to shine. Has the hate for dirt, however, gone too far?

    Attitudes to dirt still differ hugely nowadays. Many first-time parents nervously try to warn their children off touching dirt, which might be responsible for the spread of disease. On the contrary, Mary Ruebush, an American immunologist(免疫学家)，encourages children to play in the dirt to build up a strong immune system. And the latter position is gaining some ground.

    You are a new manager at the American branch of your German firm in Chicago. With a few minutes to spare between meetings, you go to get a quick cup of coffee.

    "Hey, David, how are you?" one of the senior partners at the firm asks you.

    "Good, thank you, Dr. Greer," you reply. You've really been wanting to make a connection with the senior leadership at the firm, and this seems like a great opportunity. But as you start to think of something to say, your American colleague breaks in to steal your spotlight.

    "So Arnold", your colleague says to your boss, in such a casual manner that it makes your German soul cringe(畏缩), "So what's your Super bowl prediction? I mean, you're a Niners fan, right?"

    The conversation moves on, and you walk silently back to your desk with your coffee. You know how important small talk is in the U.S., and you feel jealous of people who can do it well.

    There's nothing small about the role that small talk plays in American professional culture. People from other countries are often surprised at how important small talk is in the U.S. and how naturally and comfortably people seem to do it —— with peers, men, women, and even with superiors. You can be the most technically skilled worker in the world, but your ability to progress in your job in the United States is highly dependent on your ability to build and maintain positive relationships with people at work. And guess what skill is critical for building and maintaining these relationships? Small talk.

    What can you do if you are from another culture and want to learn to use small talk in the U.S. to build relationships and establish trust? Work hard to hone(磨练) your own version of American-style small talk. Watch how others do it. You don't have to imitate what they do; in fact, that would likely backfire because people would see you as inauthentic(假的,不可信的). But if you can develop your own personal version, that can go a long way toward making you feel comfortable and competent.

    If you are travelling in Britain, besides so many world-class things to see and do in London, planning a day trip away from it can also be good.

Stonehenge

    Stonehenge consists of a group of large standing stones. The 5,000-year-old stones are one of the world's biggest mysteries(谜) that no one has understood yet. While travelling Stonehenge, you can imagine wildly and decide for yourself how the stones came to be there and why. Although you can't touch the stones, you can walk among them and feel the changes of seasons.

Windsor

    Most people visit Windsor to see Windsor Castle, where the Queen spends most of her time. The castle(城堡) itself could keep you busy for days. The best way to appreciate Windsor Castle is to approach via the Long Walk, a straight road where there are no cars, but you might see some deer.

Oxford

    Oxford is best known for its world-famous university. The large student population keeps the university young and fresh, though there's no shortage of history if you want it. 30 colleges make up the university itself. A tour of the colleges is a must—Harry Potter fans will find many places used in the movies.

Bath

    Founded by the Romans, who used the area's springs to create a spa retreat（水疗中心）, Bath's now the best tourist attraction of Southwest England. Visitors never miss the Roman Bath Complex, which is divided into four main parts—the Bath House, the Sacred Spring, the Roman Temple and the museum, which displays fascinating finds from the historical ruins of the city.

    Give yourself a test. Which way is the wind blowing? How many kinds of wildflowers can be seen from your front door? If your awareness is as sharp as it could be, you'll have no trouble answering these questions.

    Most of us observed much more as children than we do as adults. A child's day is filled with fascination, newness and wonder. Curiosity gave us all a natural awareness. But distinctions that were sharp to us as children become unclear; we are numb(麻木的）to new stimulation(刺激), new ideas. Relearning the art of seeing the world around us is quite simple, although it takes practice and requires breaking some bad habits.

    The first step in awakening senses is to stop predicting what we are going to see and feel before it occurs. This blocks awareness. One chilly night when I was hiking in the Rocky Mountains with some students, I mentioned that we were going to cross a mountain stream. The students began complaining about how cold it would be. We reached the stream, and they unwillingly walked ahead. They were almost knee-deep when they realized it was a hot spring. Later they all admitted they'd felt cold water at first.

    Another block to awareness is the obsession(痴迷) many of us have with naming things. I saw bird watchers who spotted a bird, immediately looked it up in field guides, and said, a "ruby-crowned kinglet" and checked it off. They no longer paid attention to the bird and never learned what it was doing.

    The pressures of "time" and "destination" are further blocks to awareness. I encountered many hikers who were headed to a distant camp-ground with just enough time to get there before dark. It seldom occurred to them to wander a bit, to take a moment to see what's around them. I asked them what they'd seen. "Oh, a few birds," they said. They seemed bent on their destinations.

    Nature seems to unfold to people who watch and wait. Next time you take a walk, no matter where it is, take in all the sights, sounds and sensations. Wander in this frame of mind and you will open a new dimension to your life.