There is an old saying about volunteer work that goes like this: “ No one can do everything, but everyone can do something.”

    Today, many people volunteer their time and energy to help others. There are a lot of ways to meet other people's needs. For example, some volunteers provide help after a disaster. Others are happy to get dirty while repairing homes or planting trees or flowers in poor neighborhoods. Young people see suffering and loneliness around them and find ways to help. And history lovers help archeologists(考古学家) search for ancient objects to help deepen our knowledge of the past.

    Volunteers work in many areas around the world, including Haiti. More than four years have passed since a 7.0 earthquake shook the nation. The exact number of people who died may never be known. Thousands of survivors of the Haitian earthquakes still live in temporary shelters. Last year, former American President Jimmy Carter and his wife Rosalynn joined five hundred volunteers in the town of Leogane to build houses.

    Organizations do not have to be large to get volunteers. An activist group in Dharamsala, India is a good example, Jodie Underhill from England arrived in northern India several years ago. She planned to volunteer for an environmental project. She could almost not believe how much rubbish was ruining some of the area's most beautiful sights. Jodie Underhill learned about how to deal with the rubbish while taking part in other volunteer projects. But soon enough she formed her own group, Mountain Cleaners. Jodie Underhill says the work is very hard. But she praises the group's efforts as a wonderful experience. The young Englishwoman says the Indian media started calling her “Garbage Girl”. And she says she was pleased with the name.

    American teenagers also volunteer in many ways .

    Travel is fun and exciting, but it's not if you get sick. You may think, “Not me, I won't get sick on my vacation. ”But for many people, that is what happens.

    A vacation is supposed to be a time for relaxing. But very often it is not.  “What can I do when I am a tourist?” This is what we should often think about.  Usually there are so many places to visit： museums, shops, parks and churches. You may spend most days walking around these places. This can be very tiring. Your feet may hurt.  And you may have a terrible headache after a few hours. If this is what you feel, you should take a rest. Don't ask your body to do too much. A tired body means a weak body. And a weak body can make you get sick easily. Just sit down for a few hours in a nice spot. In good weather, look for a quiet park bench. Or you can rest at a café. You can learn a lot by watching people when you have a rest.

    Sleep is also important. If you want to stay healthy you need enough sleep.  You may have trouble sleeping at night when you travel. Your hotel room may be noisy, or the bed may be uncomfortable.  If that is true, don't be afraid to change rooms or hotels. You may not get enough sleep for another reason. You may want to stay out late at night. In many cities the night life can be very exciting. Then you should plan to sleep for an hour during the day. That extra hour can make a big difference.

    Finally, if you want to stay healthy, you must eat well. That means eating the right kinds of foods. Your body needs fresh fruit and vegetables, and some meat, milk or cheese. When you are in a new country you may want to try new foods but you need to be careful about how much you eat. Lots of rich food is not very good for you.

    The Spanish sculptor Isaac Cordal sees the city as his playground. He specializes in miniature, a street art often representing a social commentary as a critical observation on capitalism, power and so on.

    Cordal first models the sculptures in clay then reproduces them in cement(水泥)about 15cm in height.

    “As a material, cement seems very symbolic because it is one of our most recognizable footprints against nature.” he says. “Today we have been too used to cement city habitat.”

    For several years he's been working on the project, Cement Eclipses, referring to the state when a building covers the sun: “It's a critical reflection on the idea of progress.”

    These tiny cement figures have appeared in cities across Europe, found sitting on top of bus shelters or drowning in the grass land of the big city. “The street became a perfect setting in which I could find enough landscapes for them. Due to their small size and color, they go really well into the urban environment. They even normally go unseen by passersby. I'm very interested in that moment of surprise when someone accidentally discovers them.” he says.

    “Nowadays there is a fear of not being seen in the public area, so everything is always big and bold. We become a product of this and do not focus in as much. I think it is good to pay attention to small details. My work is a reward for those who do and it allows us to understand and change the world we have created in a different angle.”Cordal says.

    Whenever we see a button (按钮), we are eager to press it because we know something will happen. This is true in most cases, for example on a doorbell and on the “on/off” button on the TV. But some buttons are actually fake, like the “close” button on a lift.

    Many people are in the habit of pressing the “close” button because they don't have the patience to wait for the lift doors to shut. But lifts'" close" buttons are a complete scam, at least in the US—the doors will not close any faster no matter how hard you press.

    It started in the 1990s when the Americans with Disabilities Act was passed in the US, making sure that all lifts stayed open long enough so that people with disabilities could enter. Only US firefighters and repairmen can use the buttons to speed up the door-closing process if they have a code or special keys.

    But to normal lift riders, the buttons aren't completely useless. According to psychologists, fake buttons can actually make you feel better by offering you a sense of control.

    “Perceived (能够感知的) control is very important. It reduces stress and increases well-being," Ellen J. Langer, a psychology professor, said, “Having a lack of control is associated with depression.”

    Experts have revealed that a lot of buttons that don't do anything exist in our lives for this same purpose. For example  many offices in the US have fake thermostats (温度调节器) because people tend to feel better when they think they can control the temperature in their workspace.

    But psychologists found it interesting that even when people are aware of these little "white lies", they still continue to push fake buttons because as long as the doors eventually close, it is considered to be worth the effort.

    "That habit is here to stay," John Kounios, a psychology professor, said, ''Even though I have real doubts about the traffic light buttons, I always press them. After all, I've got nothing else to do while waiting. So why not press the button in the hope that this one will work?”

    Have you ever fallen for a novel and been amazed not to find it on lists of great books? Or walked around a sculpture known as a classic, struggling to see why it is famous? If so, you've probably thought about the question a psychologist, James Cutting, asked himself: How does a work of art come to be considered great?

    The direct answer is that some works of art are just great: of inner superior quality. The paintings that win prime spots in galleries, get taught in classes are the ones that have proved their artistic value over time. If you can't see they're superior, that's your problem. But some social scientists have been asking questions of it, raising the possibility that artistic canons(名作目录)are little more than old historical accidents.

    Cutting, a professor at Cornell University, wondered if a psychological pattern known as the "mere­exposure effect" played a role in deciding which paintings rise to the top of the cultural league. Cutting designed an experiment to test his hunch(直觉). Over a lecture course he regularly showed undergraduates works of impressionism for two seconds at a time. Some of the paintings canonical, included in art­history books. Others were lesser known but of comparable quality were exposed four times as often. Afterwards, the students preferred them to the canonical works, while a control group liked the canonical ones best. Cuttings students had grown to like those paintings more simply because they had seen them more.

    Cutting believes his experiment casts light on how canons are formed. He reproduced works of impressionism today bought by five or six wealthy and influential collectors in the late 19th century. Their preferences given to certain works made them more likely to be hung in galleries and printed in collections. And the fame passed down the years. The more people were exposed to, the more they liked it, and the more they liked it, the more it appeared in books, on posters and in big exhibitions. Meanwhile, academics and critics added to their popularity. After all, it's not just the masses who tend to rate what they see more often more highly. Critics' praise is deeply mixed with publicity. "Scholars", Cutting argues, "are no different from the public in the effects of mere exposure."

    The process described by Cutting show a principle that the sociologist Duncan Watts calls "cumulative advantage": once a thing becomes popular, it will tend to become more popular still. A few years ago, Watts had a similar experience to Cutting's in another Paris museum. After queuing to see the "Mona Lisa" at the Louvre, he came away puzzled: why was it considered so superior to the three other Leonardos, to which nobody seemed to be paying the slightest attention?

    When Watts looked into the history of "the greatest painting of all time", he discovered that, for most of its life, the "Mona Lisa" remained in relative obscurity. In the 1850s, Leonardo da Vinci was considered no match for giants of Renaissance art like Titian and Raphael, whose works were worth almost ten times as much as the "Mona Lisa" It was only in the 20th century that "Mona Lisa rocketed to the number­one spot. What brought it there wasn't a scholarly re­evaluation, but a theft. In 1911 a worker at the Louvre walked out of the museum with the "Mona Lisa" hidden under his coat. Parisians were shocked at the theft of a painting to which, until then, they had paid little attention. When the museum reopened, people queued to see it. From then on, the "Mona Lisa "came to represent Western culture itself.

    The intrinsic (本质的) quality of a work of art is starting to seem like its least important attribute. But perhaps it's more significant than our social scientists admit. Firstly, a work needs a certain quality to reach the top of the pile. The "Mona Lisa" may not be a worthy world champion but it was in the Louvre in the first place, and not by accident. Secondly, some objects are simply better than others. Read "Hamlet" after reading even the greatest of Shakespeare's contemporaries, and the difference may strike you as unarguable.

    A study suggests that the exposure effect doesn't work the same way on everything, and points to a different conclusion about how canons are formed. Great art and mediocrity (平庸)can get confused, even by experts. But that's why we need to see, and read, as much as we can. The more were exposed to the good and the bad, the better we are at telling the difference.

In life, once on a path, we tend to follow it, for better or worse. What's sad is that even if it's the latter, we often accept it anyway because we are so used to the way things are that we don't even recognize that they could be different. This is a phenomenon psychologist call functional fixedness.

This classic experiment will give you an idea of how it works and a sense of whether you may have fallen into the same trap: People are given a box of tacks (大头钉) and some matches and asked to find a way to attach a candle to a wall so that it burns properly.

Typically, the subjects try tacking the candle to the wall or lighting it to fix it with melted wax. The psychologists had, of course, arranged it so that neither of these obvious approaches would work. The tacks are too short, and the paraffin (石蜡) doesn't stick to the wall. So how can you complete the task? The successful technique is to use the tack box as a candle-holder. You empty it, tack it to the wall. and stand the candle inside it. To think of that, you have to look beyond the box's usual role as a receptacle just for tacks and re-imagine it serving an entirely new purpose. That is difficult because we all suffer to one degree or another from functional fixedness.

The inability to think in new ways affects people in every corner of society. The political theorist Hannah Arendt coined the phrase" frozen thoughts" to describe deeply held ideas that we no longer question but should. In Arendt's eyes, the self- content reliance on such accepted "truths" also made people blind to ideas that didn't fit their worldview, even when there was plenty of evidence for them.

Frozen thinking has nothing to do with intelligence. She said," It can be found in highly intelligent people."