One of the traditions which is now a necessary part of Christmas is that of Father Christmas, or Santa Claus. According to the modern legend, he is a magical figure who visits all the children of the world during the night before Christmas Day, leaving presents, which they find the next morning. He flies through the night sky in a sledge pulled by reindeer, and enters houses by climbing down chimneys. This strange legend is based on the life of a man called Nicholas, but in fact we know very little about him. Historians think he was a Christian bishop（主教）in Turkey in about 285-350 A.D. One of the stories about him is that he helped three poor girls. No one would marry them because they were so poor.

    To provide them with money for their weddings, Nicholas secretly dropped some gold coins down the chimney of their house. After Nicholas died, he was made a saint（圣人）by the church. (The name Santa Claus thus comes from St Nicholas.) His feast day was celebrated in December, and parents started giving their children secret presents from St Nicholas. Over the years, this custom became part of our Christmas traditions.

    Recently, a psychologist has claimed that Father Christmas is “the perfect fantasy” for children. According to Professor Anthony Clare, children love the character of Father Christmas because he is like an ideal father: he loves children and gives them presents, but he never criticizes them, is never angry and children do not even need to thank him for presents. Other writers, however, point out that Father Christmas can be a frightening character to some children. Jane Bidder says that some children are terrified of this fat, bearded old man. It can certainly confuse many children. As presents, we warn our children to be careful of strangers and never to let them into the house, and yet we tell children that a strange man will come into their bedroom at night! Some children can become very worried about this idea and fear that he is a kind of burglar.

    Most children, however, understand from their parents and from the media that Father Christmas is basically a benign character, and look forward to his annual visit with joy and excitement.

    Good health is the most valuable thing a person can have but one cannot take good health for granted. It is important to remember that the body needs proper care in order to be healthy. There are three things that a person can do to help stay in good shape, eat right food, get enough sleep, and exercise regularly.

    Proper nutrition is important for good health. Your body cannot work well unless it receives the proper kind "fuel". Don't eat too much food with lots of sugar and fat, eat plenty of foods high in protein, like meat, fish, eggs and nuts. Vegetables and fruits are very important because they provide necessary vitamins and minerals. However, don't overeat It is not helpful to be overweight

    Getting the proper amount of sleep is also important. If you don't get enough sleep, you feel tired and easily get angry. You have no energy. Over a long period of time a little amount of sleep may even result in a change of personality(人的个性).Be sure to allow yourself from seven to nine hours of sleep each. If you do, your body will feel strong and refreshed, and your mind will be sharp.

    Finally, get plenty of exercise. Exercise firms the body, strengthens the muscles, and prevents you from gaining weight. It also improves your heart and lungs. If you follow a regular exercise program, you will probably increase your life-span(寿命). Any kind of exercise is good. Most sports are excellent for keeping the body in good shapes: basketball, swimming, bicycling, running and so on. Sports are not only good for your body, but they are enjoyable and interesting, too.

    If everybody were to eat the right foods, get plenty of sleep and exercise regularly, the world would be a happier and healthier place. We would all live to be much older and wiser.

    If you have a chance to go to Finland, you will probably be surprised to find how "foolish" the Finnish people are.

    Take the taxi drivers for example. Taxis in Finland are mostly high­class Benz with a fare of two US dollars a kilometer. You can go anywhere in one，tell the driver to drop you at any place，say that you have some business to attend to，and then walk off without paying your fare. The driver would not show the least signs of anxiety.

    The dining rooms in all big hotels not only serve their guests，but also serve outside diners. Hotel guests have their meals free, so they naturally go to the free dining rooms to have their meals. The most they would do to show their good faith is to wave their registration cards to the waiter. With such a loose check，you can easily use any old registration card to take a couple of friends to dine free of charge.

The Finnish workers are paid by the hour. They are very much on their own as soon as they have agreed with the boss at the rate. From then on they just say how many hours they have worked and they will be paid accordingly.

    With so many loopholes(漏洞) in everyday life, surely Finland must be a heaven to those who love to take "petty advantages". But the strange thing is that all the taxi passengers would always come back to pay their fares after they have attended to their business and that not a single outsider has ever been found in the free hotel dining rooms. And workers always give an honest account of the exact hours they put in. As the Finns always act on good faith in everything they do, living in such a society has turned everyone into a real “gentleman”.

    Food sometimes gets poisoned with harmful things. A person who eats such food can get an illness called food poisoning. Food poisoning is usually not serious, but some types are deadly. The symptoms of food poisoning usually begin within hours of eating the poisoned food. Fever is one of the most common symptoms.

    Certain microorganisms(微生物)cause most types of food poisoning. Bacteria and other microorganisms can poison eggs, meat, vegetables, and many other foods. After entering the body, these tiny living things release(释放)poisons that make people sick.

    Some chemicals can also cause food poisoning. They are often added to food while it is being grown, processed, or prepared. For example, many farmers spray chemicals on crops to kill weeds and insects. Some people may have a bad reaction to those chemicals when they eat the crops.

    Some plants and animals contain natural poisons that are harmful to people. These include certain kinds of seafood, grains, nuts, seeds, beans, and mushrooms.

    When people handle food properly, the risk of food poisoning is very small. Microorganisms multiply rapidly in dirty places and in warm temperatures. This means that people should never touch food with dirty hands or put food on unwashed surfaces. Food should be kept in a refrigerator to stop microorganisms from growing. Meat needs to be cooked thoroughly to kill any dangerous microorganisms. People should also wash food covered with chemicals before eating it. Finally, people should not eat wild mushrooms or other foods that grow in the wild. Some of these foods may contain natural materials that are poisonous to humans. In addition, some types of fish can be poisonous.

    Most people recover from food poisoning after a few days of resting and drinking extra water. If people eat natural poisons, they must go to the hospital right away to have their stomachs emptied.

    Since we've headed into the snowy part of the year, it seems like a good time to solve a language puzzle that Eskimos have a huge number of words for snow. The idea was popularized by the now well-known expert Benjamin Lee Whorf in the 1940s. His number was approximately five Eskimo words for snow, but somehow the story was so wide spread and romantic that it got out of control and grew bigger and bigger.

    There are two problems with the concept of Eskimos having tons of words for snow.

    First, Eskimos speak at least two different languages—Inuit and Yupik. Just as we have talked about how English and many other languages developed from a common language called Proto-Indo-European, Inuit and Yupik come from a different common language called Eskimo-Aleut. So saying Eskimos have 100 words for snow is like saying Europeans have 100 words for kings or queens. It might be telling you something broad about culture, but it isn't really telling you much about language.

    The second problem is "What is a word?” The Inuit and Yupik languages make words in different ways from how we make words in English. For example, the West Greenlandic word 'siku,' (sea ice), is used as the root for 'sikursuit (pack ice), 'Sikuliaq (new ice), and 'sikurluk (melting ice). But it's not that West Greenlandic has so many more words for describing snow than English, it's just that West Greenlandic expresses ideas by combining meaningful units of language together into one word while English uses more phrases and compounds. We express all the same ideas; we just do it a little differently because of the way our language is built.

    So you're probably still wondering, "If it's not 50 or 100 or 400 words, how many is it?" Well, Woodbury lists 15 that are present in a Yupik dictionary published in 1984, but he says that depending on how you look at it this is not an exact number. It could be 12; it could be 24. But it's certainly not 100.

    Sometimes, the "hundred words for snow" puzzle is used to argue that because Eskimos have so many words for snow, they think about snow in ways that we can't even begin to imagine—that your language decides or limits your thoughts. Languages are just different. They don't decide what we are able to think about or are not able to think about. I can think about snow floating on water even if we don't have a word for that in English.

    So when you're out skiing or snowboarding or just shoveling your driveway this winter, don't believe the people who try to tell you that Eskimos have 100 words for snow.

With the summer heat becoming increasingly unbearable over the years due to climate change,the cooling load in the summertime has also been on the rise.Insulation(隔热) is currently the main solution for blocking heat from entering a building,but by applying an additional material that can delay heat penetration(渗透),it can prevent the indoor temperature from rising and in turn lower the cooling load of the building.

A research team in Korea has developed a new material for building walls that can help reduce the penetration of heat from the outside.The team directed by Dr.Sarng Woo Karng from KIST revealed that they have successfully done it through building walls by applying a phase change material(PCM).One of the most common types is paraffin oil,which is used to make candles.

A solid PCM absorbs heat as it transforms into a liquid phase,so by using a case to hold it when it is in a liquid phase without causing any leakage(渗漏),it is possible to apply them to a building wall to block heat from entering inside.

The problem,however,is that the PCM turns into liquid starting from the outermost layer,and the parts that are hot move upward,while the parts that are still relatively cool move downward.Thus,while the upper part may have completely melted,the lower part will have not,and as a result,heat will penetrate into the building through the area where the PCM is in a liquid phase.In the end,the PCM becomes ineffective in controlling the indoor temperature and is rendered useless.

Dr.Karng's team addressed the non-uniform phase change with bubble injections.Injecting bubbles into the bottom part of the PCM enabled uniform circulation(流动)of the PCM in a liquid phase.Dr.Karng said,"We expect that the insulating wall using the PCM bubble generator used in this study will contribute to reducing the amount of energy used to heat or cool a building.Insulation techniques using the PCM help reduce heat penetration,in combination with the building insulating material,and it can also be used as the outer walls of zero-energy buildings."