The term “to extend an olive（橄榄） branch” means to make an offer of peace or reconciliation(和好). This term has Biblical（圣经的）origins, coming from the section of the Old Testament that deals with the flood; the sign that the flood is over is an olive branch brought back to the ark(方舟) by a dove. Olive branches were also symbols of peace in Ancient Greece and Rome, and they continue to be used in various works of art that are meant to suggest peace.

    Some people have suggested that the olive was a very deliberate and well-considered choice as a metaphor(比喻）for peace, because olive trees famously take years to mature. War is typically very hard on the trees because people cannot take the time to nurture them and plant new ones. Therefore, the offer of an olive branch would suggest that someone is tired of war, whether it is an actual war or a falling out between friends.

    In Ancient Greek and Roman times, people would offer actual olive branches. In Rome, for example, defeated armies traditionally carried olive branches to indicate that they were giving in, and the Greeks used them into weddings and other ceremonies. In the modern era, the branch is usually metaphorical, rather than actual, not least because the plants can be a bit difficult to obtain.

    Many people agree that peace negotiations at all levels of society are a good idea. Between nations, obviously, it is important to extend an olive branch to ensure mutual safety and to help the world run more smoothly. This act can also be important on a personal level, as resolving conflict and learning to get along with others is viewed as an important life skill in many cultures.

    At some point in their lives, many people will be advised to extend an olive branch to settle a dispute or resolve an issue. Some people believe that it takes an immense amount of courage to take this action, as it often comes with an admission of wrongdoing and regret.

    It is a cold and dry winter morning. When you wake up, you feel that your throat hurts. You begin to sneeze and later you may cough. You must have a cold! Wait a moment. Could it just be a common cold or the flu that's been going around?

    A cold gives you a runny nose and cough. But it's usually easy to deal with. Some take medicine while others drink herbal tea or chicken soup. Usually you feel better after a week.

    On the other hand, the flu can be much more dangerous. It usually gives you fever.

    Sometimes it can cause death. According to an American magazine, the worst flu killed about 50 million people from 1918 to 1919.

    Don't worry. If you get a flu vaccine（疫苗）, it can stop you from getting the virus. Flu vaccines work by giving the body a small amount of flu viruses. This causes your body to develop antibodies. So next time you get the flu, the antibodies should help you.

    The flu virus changes every few years. Therefore, there are so many types of flu, such as H1N1 and H5N1. The antibodies for one type of flu can't help us against all types of flu. That's why we need to get vaccine every year.

    However, good health habits may also help stop you developing a cold or flu. Washing your hands often helps stop you from getting viruses. It is also important to get regular exercise and eat healthy food. All these can help you strengthen your immune system.

A HALF - EMPTY BASKET

    Once there was a poor farmer and his farm belonged to a rich man. One day he brought a basket of apples to the rich man's house. On the doorsteps, he met two monkeys dressed like children. They jumped onto the basket to eat the apples and threw some on the ground. The farmer politely took off his hat and asked the monkeys to get off. They obeyed(服从) and the farmer went into the house. He asked to see the rich man. A servant took him to the room where the rich man was sitting.

    "I have brought you the basket of apples you asked for," he said.

    "But why have you brought a half-empty basket?" the rich man asked.

    "I met your children outside, and they stole some of the apples."

    A recent study surveyed 5,000 British families about their experiences with volunteering and their mental health. Participants completed the same survey every two years from 1996 to 2008.

    About 20 percent of the survey participants reported doing regular unpaid work Researchers found that these volunteers also scored highest on their mental health scores. The two were linked so directly that the more a person volunteered, the happier they were.

    One could argue a chicken-and-egg theory: happier people are more likely to have the time, money, energy and resources to give back to others. But even when researchers adjusted for education, social class and total health, the link was there, suggesting that the mental increase came from volunteering and not the other way around.

    According to Dr. Stephen G. Post, author of The Hidden Gifts of Helping, when you help others, your brain releases feel-good chemicals, which can help cells repair themselves and grow. And this translates to better health.

    So volunteering can help improve both your physical and mental health—on one condition. You have to mean it. People who volunteered for "self-oriental" reasons, either because they were forced to do so for work or school or because they were trying to get away from problems in their lives, had a mortality（死亡率）risk that was similar to those who didn't volunteer at all. It was only when people were volunteering out of a true sense of sympathy that they saw any health benefits.

    So whether it's arranging books at the library or walking dogs at the animal shelter, find a cause that's important to you and give it a try. Volunteering is a good way to develop a sense of connection that not only helps your community, but may also be good for you.

    Houses have been getting progressively "smarter" for decades, but the next generation of smart homes may offer what two Case Western Reserve University scientists are calling an "Internet of Ears."

    Today's smart home features appliances, entertainment systems, security cameras and lighting, heating and cooling systems that are connected to each other and the Internet. They can be accessed and controlled remotely by computer or smartphone apps.

    But a group of electrical engineering and computer science professors in the Case School of Engineering have been experimenting with a new suite of sensors (传感器). This system would read not only the vibrations (震动), sounds and even other movements associated with people and animals in a building, but also any slight changes in the existing electrical field.

    While there still maybe a decade or so away, the home of the future could be a building that adjusts to your activity with only a few small, hidden sensors in the walls and floor with-out the need for monitoring cameras.

    "We are trying to make a building that is able t0 61isten' to the humans inside," said Ming-Chun Huang, an assistant professor in electrical engineering and computer science. "We are using principles similar to those of the human ear, where vibrations are picked up and our algorithms (计算程序) recognize them to determine your specific movements. That's why we call it the 61nternet of Ears'. "

    “There is actually a constant 60 Hz electrical field all around us, and because people are somewhat conductive, they short out the field just a little," Huang said. "So, by measuring the disturbance in that field, we are able to determine their presence, or even their breathing, even when there are no vibrations associated with sound.”

    Huang said they have used as few as four small sensors in the walls and floor of a room.

    As for privacy concerns, the system would not be able to identify individuals, although it could recognize people's different ways of walking.

    The Largest World Fairs of All Time

    New York World Fair — New York, 1939

    The 1939 New York World Fair was the largest exposition (博览会) in US history with visitors over 14 million. The Fair was planned during the Great Depression and was aimed at relieving the city from economic depression by attracting foreign investment. Major inventions to emerge (出现) at the New York World Fair included nylon fabric, a streamlined pencil sharpener, and a futuristic car city imagined by General Moiors.

    Exposition liniverselle — Paris, 1900

    The Exposition Universelle was one of the earliest expositions to feature multiple countries with France inviting various countries to display their technological advancements and cultural heritage. Exposition Universelle was the birthplace of many inventions that we enjoy today including escalators (自动扶梯) and talking films.

    Expo' 70 — Osaka, Japan

    Expo' 70 was the biggest exposition of the 20th century and the second largest in history. Expo 70 had a record attendance of over 64 million visitors, a 40-year record that would not be broken until Expo 2010 in Shanghai. Notable exhibitions included a large piece of moon rock that was brought back from the Apollo 12 mission.

    Expo 2010 — Shanghai. China

    Expo 2010 goes down as the largest fair in history, having attracted 73 million people. It also had the highest international participation of any exposition in the world with 246 countries participating. The opening ceremony featured the biggest LED screen in the world as well as one of the biggest fireworks displays in history.