Lisa: My best teacher is my geography teacher in 10th grade. Why? Because we did school projects! Back then I wrote about India and never forgot what I had learned. He brought the culture to life by letting me become part of it. He also listened to us and was always ready with a kind word.

David: My best teacher is my high school social studies and history teacher, Thomas Ladenburg. He respected us, though we were just teenagers. His class was never boring because he often asked us to discuss in class. He used his own materials which made the class very interesting.

Henry: My best ever teacher is my biology teacher in high school. I really liked her class. She explained everything very clearly. She also checked our notebooks to make sure we had written down what she said. Now, many years later, I can still remember a large part of the things she taught!

Susan: The best teacher I have ever had is my 10th grade social studies teacher. She was always in a good mood and kept us laughing. She was really young, so she acted like us teenagers, which made learning fun. If we needed to talk to an adult about a problem, we would always come to her because we knew she could help us.

Tom: My favourite teacher is Mr. Yelle. He taught us math, science and music. He spoke to us “at eye level”, and was very patient and kind. We did great projects for the science fairs. Forty years later, I still remember his lessons very well. By the way, though he was called Mr Yelle, he didn't yell(喊叫).

    When asked about happiness, we usually think of something extraordinary, an absolute delight, which seems to get rarer the older we get.

For kids, happiness has a magical quality. Their delight at winning a race or getting a new bike is unreserved (毫无掩饰的).

    In the teenage years the concept of happiness changes. Suddenly it's conditional on such things as excitement, love and popularity. I can still recall the excitement of being invited to dance with the most attractive boy at the school party.

    In adulthood the things that bring deep joy—love, marriage, birth—also bring responsibility and the risk of loss. For adults, happiness is complicated (复杂的).

    My definition of happiness is “the capacity for enjoyment”. The more we can enjoy what we have, the happier we are. It's easy to overlook the pleasure we get from the company of friends, the freedom to live where we please, and even good health.

    I experienced my little moments of pleasure yesterday. First I was overjoyed when I shut the last lunch-box and had the house to myself. Then I spent an uninterrupted morning writing, which I love. When the kids and my husband come home, I enjoyed their noise after the quiet of the day.

    Psychologists tell us that to be happy we need a mix of enjoyable leisure time and satisfying work. I don't think that my grandmother, who raised 14 children, had much of either. She did have a network of close friends and family, and maybe this what satisfied her.

    We, however, with so many choices and such pressure to succeed in every area, have turned happiness into one more thing we've got to have. We're so self-conscious about our “right” to it that it's making us miserable. So we chase it and equal it with wealth and success, without noticing that the people who have those things aren't necessarily happier.

    Happiness isn't about what happens to—it's about how we see what happens to us. It's the skillful way of finding a positive for every negative. It's not wishing for what we don't have , but enjoying what we do possess.

    The advice offered from any other 82-year-olds might have made young people yawn and roll their eyes. But when former South African president Nelson Mandela advised two dozen local youth leaders in Los Angeles to take education seriously, his audience was listening.

    The famed old man said to the young people that if they expected to improve the lives of others in the future, they must work at improving their own lives now. "Education is one of the most important weapons you have,” Mandela advised. “It will place you in a far better position to serve yourself and your community.”

“The point is, he was young once and rebellious(叛逆的)once and he kept his dream alive, just as you each have dreams,” explained South Africa's ambassador to the United States, Sheila Sisulu, as she introduced Mandela to the young crowd.

    Asked for specific advice about changing society by 21-year-old Ahmed Younis, Mandela suggested that somehow helping arouse more American interest in foreign affairs might be a start.

There is an impression that Americans, in general, have not followed international developments properly, Mandela said. “I'm not making that statement myself, but there are serious political analysts who say Americans are not well informed as to what has happened in the world.”

22-year-old Omari Trice said Mandela left him full of enthusiasm. “ He's a person who set the tone for an entire nation, said Trice. “You come away feeling you need to be a superman in order to get things done.”

    Some places in the world have strange laws. It's important for you to know about them before going there.

    Whoever likes to chew gum(口香糖) may have to leave Singapore. The government really wants to keep the city clean and will fine you for chewing gum.

     Before you leave for the United Arab Emirates you'd better make sure you aren't visiting during Ramadan(斋月). During that time you aren't allowed to eat or drink in public. Tourists have been fined up to $275 for drinking in public.

    Lovers spend so much time kissing each other goodbye at train stations that trains often start late. This law— no kissing your lover goodbye at train stations – is rather old, and isn't in use today in France.

In Thailand it's against the law to drive a car or motorcycle without a shirt on, no matter how hot it is. Punishments are different in different areas and can include warnings and tickets costing about $10. No joke — the local police will stop you.

     Studies in Denmark have shown that cars with their headlights on are more noticeable by other drivers than those with their headlights off. Drivers there are required to leave their headlights on even during the day, or they may face a fine up to $100.

    Do you often buy things using coins? Don't do it in Canada. The Currency Law of 1985 doesn't allow using only coins to buy things. Even the use of the dollar-coin is limited (受限制的). The shop owner has the right to choose whether to take your coins or not.

    Make sure you know about these laws before your next trip. Better safe than sorry.

    Next time you make yourself a hot cup of tea or coffee, you might want to let it cool down a bit before drinking.

    Researchers say letting your hot drinks cool off could help you avoid some kinds of cancer. Researchers at the International Agency for Research on Cancer (IARC) found evidence that drinks at temperatures above 65℃, when swallowed, can cause cancer of the esophagus (食道). The researchers examined findings from other studies where tea and coffee were often served at 70℃ or above. Those studies were completed in Iran, China and South America.

    In developed countries, health experts have linked esophageal cancer to smoking and alcoholic（酒精）drinks. However, this form of cancer is more common in areas where people drink beverages（饮料；酒水）at very high temperatures.

    In Europe and the United States, many people drink coffee and tea at temperatures around 60℃.And they often add milk which lowers the temperature greatly. However, tea-drinkers in Iran and mate-drinkers in South America often enjoy their beverages at closer to 70℃.

    The researchers find that South Americans not only drink their mate very hot, they also drink it through a metal straw(吸管). This sends the scalding liquid directly into the throat.

    The findings, however, are good news for coffee drinkers. In 1991, the World Health Organization listed coffee as possibly carcinogenic (致癌的).” The WHO officials have since changed their position on that listing. They now suggest that the temperature of your hot drink is a greater risk factor than the actual drink itself.

    The results suggest that drinking very hot beverages is one probable cause of esophageal cancer and that it is the temperature, rather than the drinks themselves, that appears to be responsible.

    Most people feel lonely sometimes, but it usually lasts only between a few minutes and a few hours. This kind of loneliness is not serious. In fact, it is quite normal. For some people, though, loneliness can last for years. Now researchers say there are three different types of loneliness.

    The first kind of loneliness is temporary. This is the most common type. It usually disappears quickly and does not require any special attention. The second kind, situational loneliness, is a natural result of a particular situation－for example, the death of a loved one, or moving to a new place. Although this kind of loneliness can cause physical problems, such as headaches and sleeplessness, it usually does not last for more than a year.

    The third kind of loneliness is the most severe. Unlike the second type, chronic(长期的) loneliness usually lasts more than two years and has no specific cause. People who experience habitual loneliness have problem socializing and becoming close to others unfortunately, many chronically lonely people think there is little or nothing they can do to improve their condition.

    Many researchers agree that the loneliest people are between the ages 18 and 25, so a group of psychologists decided to study a group of college students. They found that more than 50% of the students were situationally lonely at the beginning of the term as a result of their new circumstances, but had adjusted after a few months, 13% were still lonely after seven months due to shyness and fear. They felt very uncomfortable meeting strangers, even though they understood that their fear was not reasonable. The situationally lonely students overcame their loneliness by making new friends, but the chronically lonely remained unhappy because they were afraid to do so.

    Psychologists are trying to find ways to help habitually lonely people for two reasons: they are unhappy and unable to socialize and there is a connection between chronic loneliness and serious illness such as heart disease. While temporary and situational loneliness can be a normal, healthy part of life, chronic loneliness can be a very sad, and sometimes dangerous condition.