When was the last time you relied on an old-fashioned map to figure out the route to an unfamiliar place? For many, the GPS has revolutionized navigation, making a paper map almost obsolete? So how has this piece of technology developed over its 26 years of existence? On February 14,1989,the first satellite in the US Global Positioning System was sent into space from Cape Canaveral, beginning the start of one of the wonders of the modern world.

    GPS stands for Global Positioning System, which is made of a network of around 30 satellites that move around the earth. The system uses a process called trilateration to find out one's position. By measuring the time it takes for the signal to reach one satellite, the GPS can determine your distance from the satellite, creating a sphere(范围) of possible locations. Measuring your distance from at least three satellites will narrow your location to the place where the three spheres cross one another, to the accuracy(精确) of about less than 1 meter!

    The GPS was first invented during the Cold War by the United States Department of Defense. In 1960, the first system, which was made of just five satellites, was put into place. It was initially created for strictly military(军事的) use; however, in 1983, as a result of faulty navigation technology, a Korean passenger plane mistakenly flew into USSR territory(苏联领土) and was shot down. In order to prevent such bad events, American President Ronald Reagan allowed civilian(民用的) use of the GPS.

    Over the next ten years, the system's accuracy improved as the network was increased to 24 satellites. And during the first Persian Gulf War, the new GPS was finally used by the military. Now scientists use the technology to track animals to better understand their movement and behavior. Parents who may be worried about their children can also use GPS technology to track them.

Hong Kong Science Museum

    You might really like the Science Museum if you are interested in science. The Museum wants to teach kids science. It gives them a place to have fun with the equipment there. However, adults can learn some science too.

    The Museum has 6,500 square metres. There are over 500 exhibits, and nearly 70 percent of them are suitable for visitors of all ages. Since its opening in April 1991, the Hong Kong Science Museum has proven itself to be a good place for learning science. Through having better exhibits and fun science programs in an enjoyable environment, the Museum wants to popularize science to the public and the support science education in schools. Visitors at the Science Museum can visit the exhibition in their own way and enjoy the fun of discovery learning.

    If you want to have a visit, you'd better read the information carefully.

    In Africa, Christmas Day begins with groups of carolers (欢唱颂歌的人) walking to and from through the village, along the roadway, by the houses of the missionaries (传教士), singing the lovely carols known to the world around. Often people may be awakened by a group of carolers beginning to gather at the house of worship(敬神活动). They return home to make final preparations as to the clothes one must wear and also as to their offering for the Christmas service.

    The most important part of their Christmas worship service is the love offering. This is the gift in honor of Jesus. At about 8 or 9 o'clock everyone goes to the celebration of the birthday of Jesus. Everyone who attends the service goes forward to lay down their gift upon the raised platform near the Communion table. No one will attend the service without giving a gift.

    Christmas in South Africa is a summer holiday. There is no snow, but it has many flowers, many beautiful varieties of wild flowers being in their full pride.

    In Ghana, most churches show the coming of Christmas by decorating the church and homes beginning with the first week in Advent, four weeks before Christmas. This season happens to be the time of cocoa harvest, so it is a time of wealth. Everyone returns home from wherever they might be such as farms or mines.

    In Africa, it is the traditional dinner of turkey, roast beef, mince pies, or suckling pig, yellow rice with raisins, vegetables, and plum pudding, crackers. In the afternoon, families go out into the country and usually there are games or bathing in the warm sunshine, and then home in the cool of the evening. Boxing Day is also a proclaimed (正式宣布的) public holiday usually spent in the open air. It falls on December 26 and is a day of real relaxation.

    Hobbies in general are becoming something of the past. Our lives are already filled with classes, homework, working, relationships and sleeping. When we do have a spare moment, it is all too easy to spend it on the endless entertainment and media that are right at our fingertips.

    I do not doubt that there are some people who could become a great writer or musician. I only fear that so many people are busy pursuing their education and their careers, but they never even see the potential (潜能) they have. The next great photographer or singer could be going to college right now. But they might not even know they have a gift for photographing or singing if they've never picked up a camera or a guitar.

    Of course, the final goal of pursuing a new hobby shouldn't be to become rich and famous. For most people, a hobby is just something they enjoy doing for the purpose of the thing itself. Such hobbies are still very useful. Studies have shown that people who have a hobby are less likely to have stress and more likely to have more meaningful lives.

    Most importantly, a hobby is just something you do to make you happy. I hate to break it to you, but we all have a long lifetime of work and stress ahead of us. It will make things much easier if we can practice the piano or make some collections after work.

    Sure, it's not easy to start a new hobby while going to school, but it will likely never get easier than it is right now. So think about the thing that you have always wanted to try but were too embarrassed or busy or whatever. You never know, you might become the world's next great people. If not, you'll at least be a little more well-rounded, more interesting and less stressed.

    Time zone:

    Eastern Standard Time(EST): GMT+10 hours.

    There is no daylight saving time in Queensland.

    Legal drinking age:

    18 years and older. Always keep your ID with you to prove your age.

    Alcohol(酒) shops & hotels are the only places where alcohol can be bought.

    Dangers:

    Dial 000 from a fixed line or 112 from a mobile phone. Police, ambulance, fire.

    Electricity:

    240/250 volts AC 50Hz Universal outlets for 110 volts (shavers only) standard in hotels, apartments, motels.

    Telephones:

    Australian international code is 61.

    Road rules:

    Left hand side driving. There is a 50kmh speed limit in most living areas and on open highways100-110kmh. Seat belts must be worn all the time. If you want to hire a car, take along your driver's license.

    No smoking:

    Indoors: Indoor areas are no smoking.

    Poker Machines: Poker machine areas are no smoking.

    Outdoors: Non-enclosed eating and drinking areas are no smoking.

Swimming Safety:

    ALWAYS SWIM BETWEEN THE RED AND YELLOW FLAGS and pay attention to the life guards' advice. Gold Coast beaches are guarded by skilled life guards and volunteers at weekends.

Few people enjoyed getting shots at the doctor's office. But many of these shots are important vaccines (疫苗) that help prevent us from getting certain diseases or types of infection.

Vaccines got their start in Europe in the 1720s, when a British woman named Lady Mary Wortley Montagu was visiting Turkey. She saw Turkish doctors purposefully inoculating (接种) people with small amounts of smallpox. Smallpox is a painful, deadly disease that had no cure at the time. But Lady Montagu was amazed that the patients not only recovered, but then proved to be immune (免疫的) to the disease!

Lady Montagu quickly returned to England, excited to share this new procedure. But inoculation took many years to catch on. One problem was that no one had a correct way of inoculating people safely. Occasionally, patients would become fully infected and then begin spreading the disease. However, inoculation eventually saved enough people for it to become the common practice for preventing smallpox.

Some years later, a scientist named Edward Jenner discovered that people who had been infected with a disease called cowpox became resistant to smallpox. Cowpox was less much harmful than smallpox. Jenner convinced doctors to inoculate people with cowpox, which led to a very safe vaccine and far fewer outbreaks of smallpox. Finally, a French scientist named Louis Pasteur realized that Jenner's idea could be used to treat other diseases. Since then, vaccines have been made for many other diseases, such as polio, tetanus, and rabies.

Today, scientists and doctors continue to create new vaccines that could potentially save millions of lives worldwide.