Ideas about polite behavior are different from one culture to another. Some societies, such as America and Australia, for example, are mobile and very open. People here change jobs and move houses quite often. As a result, they have a lot of relationships that often last only a short time, and they need to get to know people quickly. So it's normal to have friendly conversations with people that they have just met, and you can talk about things that other cultures would regard as personal.

    On the other hand, there are more crowded and less mobile societies where long–term relationships are more important. A Malaysian or Mexican business person, for example, will want to get to know you very well before he or she feels happy to start business. But when you do get to know each other, the relationship becomes much deeper than it would in a mobile society.

    To Americans, both Europeans and Asians seem cool and formal at first. On the other hand, as a passenger from a less mobile society puts it, it's no fun spending several hours next to a stranger who wants to tell you all about his or her life and asks you all sorts of questions that you don't want to answer.

    Cross-cultural differences aren't just a problem for travelers, but also for the flights that carry them. All flights want to provide the best service, but ideas about good service are different from place to place. This can be seen most clearly in the way that problems are dealt with.

    Some societies have “universalist” cultures. These societies strongly respect rules, and they treat every person and situation in basically the same way.

     “Particularist” societies, on the other hand, also have rules, but they are less important than the society's unwritten ideas about what is right or wrong for a particular situation or a particular person. So the normal rules are changed to fit the needs of the situation or the importance of the person.

    This difference can cause problems. A traveler from a particularist society, India, is checking in for a flight in Germany, a country which has a universalist culture. The Indian traveler has too much luggage, but he explains that he has been away from home for a long time and the suitcases are full of presents for his family. He expects that the check–in official will understand his problem and will change the rules for him. The check–in official explains that if he was allowed to have too much luggage, it wouldn't be fair to the other passengers. But the traveler thinks this is unfair, because the other passengers don't have his problem.

    A British friend told me he couldn't understand why Chinese people love eating sunflower seeds as a snack so much. “I've met a lot of older Chinese and many have a crack in their front teeth; I believe that's from cracking the seeds, ” he said.

    I had never noticed the habit, but once he mentioned it, I suddenly became more aware. I realized that whenever I'm watching TV or typing a report, I always start mindlessly cracking sunflower seeds. My friend doesn't like sunflower seeds, and, to him, it seems unnecessary to work so much just to get one small seed.

    When we were young, the whole family would usually get together for Chinese New Year. Then, we all lived close to one another, usually in a small city, and sometimes even neighbors would go door-to-door on Chinese New Year's Eve to check out what every household was making.

    I remember my parents would be in the kitchen cooking. Out in the living room , a large table would already be laid out, complete with fancy tablecloth, ready-made dumpling fillings, and dishes full of candy, fruits and sunflower seeds. Some of the dishes were to be offered to our ancestors later, while others were for neighbors and children to eat before the evening feast. I must have learned how to crack sunflower seeds back then.

    I don't think it's right to criticize one's choice in food or eating habits, no matter how strange they may seem.

    It's not only in China. When I went abroad, I found people had all sorts of strange habits when it came to food. In Denmark, they put salted red fish on bread and eat it for dinner, no matter how much it ruins your breath. They think it's a delicacy, and it's connected to their culture. I think it's a wonderful tradition.

    Millions of people all over the world use the word okay. In fact，some people say the word is used more often than any other word in the world.

    It may be common，but no one can seem to agree on how the “OK” came to be.

    Okay means “all right” or “acceptable”. It expresses agreement or approval. You might ask your brother，“Is it okay if I borrow your car?” Or if someone asks you to do something，you might say，“Okay ， I will.” Still，language experts do not agree about where the word came from.

    Some people say it came from the Native American Indian tribe known as the Choctaw. The Choctaw word “okeh” means the same as the American word okay. Experts say early explorers in the American West spoke the Choctaw language in the nineteenth century. The language spread across the country.

    But many people dispute(不同意)this.

    Language expert Allen Walker Read wrote about the word okay in reports published in the 1960s.He said the word began being used in the 1830s.It was a short way of writing a different spelling of the words “all correct.” Some foreign-born people wrote “all correct” as“o-l-l k-o-r-r-e-c-t.” and used the letters O.K.

    Other people say a railroad worker named Obadiah Kelly invented the word long ago. They said he put the first letters of his names—O and K—on each object people gave him to send on the train.

    Still others say a political organization invented the word. The organization supported Martin Van Buren for president in 1840.They called their group，the O.K. Club. The letters were taken from the name of the town where Martin Van Buren was born—Old Kinderhook，New York.

    Not everyone agrees with this explanation，either. But experts do agree that the word is purely American. And it has spread to almost every country on Earth.

    Peter Skyllberg, a Swedish man, was trapped in his car for two months, with temperatures reaching -30^oC, with no food or water, and yet he survived. The best explanation was that his vehicle created an “igloo (snow house) effect” and protected him from the extremely low temperatures and that his body would hibernate(冬眠) during this time.

    Can humans get into a low-energy consumption state like a bear by reserving energy, and reducing body temperature? Chinese scientists are looking for the key to regulating body temperature.

    Scientists have found the hypothalamus (下丘脑), an area in the central lower part of the brain, is responsible for regulating body temperature. Wang Hong, a brain scientist at the Shenzhen Institutes of Advanced Technology of the Chinese Academy of Sciences, led her team to mark the neurons (神经元) responsible for regulating body temperature in mice by means of a cutting-edge genetic biology technique. In the experiments, they injected (注射) drug into mice to make the body temperatures of the mice drop rom 37℃ to 27 in two hours. The team found the change in body temperature caused no harm to the health of the mice. “We don't know if we can develop a drug that can control human body temperature. We still need a lot of study.” Wang said.

    Chinese scientists are not alone in such research. Body-cooling techniques are being used in pioneering hospitals around the world. Dutch doctors are now using low temperatures for patients who have suffered brain injuries in accidents, According to doctors working in Florence, it may even help to save the brains of babies who are born suffering from severe epileptic fits (癫痫病发作).

    If you're a cycling lover, you will have to pay a lot of attention to your bicycle and maintain it well, for bicycle parts are exposed to wear and tear (磨损) over time and you have to examine the bicycle to see if there are any signs of wearing such as scratches, dents (凹陷) etc. Sometimes, a part may not work because it has exceeded its life expectancy. Sometimes, you will need to find replacement parts for it to keep up the performance of the bicycle.

    Different parts of a bicycle will wear at different rates so it is very important that you have a basic understanding about the role played by each part. One of the most important parts of the bicycle is the frame. You will need to choose a frame that lasts for a very long time. Of course, you will see some paint scratches after some time. When you're selecting a frame, you have to think about the material. Aluminium (铝) frames will not rust easily, but they have a higher chance to dent. Steel frames will be hard to dent, but you will need to make sure they get a good paint job so that they won't rust.

    Wheels also experience a lot of wear and tear and you should go for a professional seller when you want to buy wheels. There are different types of wheels that you can buy, like Zipp wheels that provide more aerodynamic efficiency (空气动力学效能). Investing in new tyres instead of going for used is a good idea because you will be able to get more use out of it. The same goes for chain as there's a higher chance of a used chain breaking. You may also experience shifting problems. However, some parts of bicycles such as pedals can be used for a long time and you can find different styles.

    Other parts that you can buy used are seats, handlebars and the stem. When you are buying handlebars, you have to see if there are any dents or if they have been bent out of shape. There shouldn't be any cracks in the seat post or the handlebars. There are many shops where you can buy parts, so you will have to check the references to see how customers respond to them before you buy anything.

    When a group of children politely stop a conversation with you, saying, "We have to go to work now." you're left feeling surprised and certainly uneasy. After all, this is the 21st century and the idea of children working is just unthinkable. This is, until you are told that they are all pupils of stage schools, and that the "work" they go off to is to go on the stage in a theatre.

    Stage schools often act as agencies to supply children for stage and television work. More worthy of the name "stage school" are those few places where children attend full time, with a training for the theatre and a general education.

    A visit to such schools will leave you in no doubt that the children enjoy themselves. After all, what lively children wouldn't settle for spending only half the day doing ordinary school work, and acting, singing or dancing their way through the other half of the day?

    Then of course there are times for the children to make a name and make a little money in some big shows. Some stage schools give their children too much professional work at such a young age. But the law is very tight on the amount they can do. Those under 13 are limited to 40 days in the year; those over 13 to 80 days.

    The schools themselves admit that not all children will be successful in the profession for which they are being trained. So what happens to those who don't make it? While all the leading schools say they place great importance on children getting good study results, the facts seem to suggest this is not always the case.