Miss Parker taught physics in a New York school. Last month she explained to one of her classes about sound ,and she decided to test them to see how successful she had been in her explanation. She said to them, “Now I have a brother in Los Angeles. If I was calling him on the phone and at the same time you were 75 feet away, listening to me from across the street, which of you would hear what I said earlier, my brother or you and for what reason?”

    Tom at once answered, “Your brother. Because electricity travels faster than sound waves.”“That's every good,” Miss Parker answered; but then one of the girls raised her hand, and Miss Parker said.“Yes, Kate.”

    “I disagree,” Kate said.“Your brother would hear you earlier because when it's 11 o'clock here it's only 8 o'clock in Los Angeles.”

    There's a warm and wonderful tradition that the British observe on December 26. It's called Boxing Day.

    For many people, Christmas can be a magical day filled with delight. But for those down on their luck or the disadvantaged, it can be a time of sorrow and disappointment. That's why the British have set aside the day after Christmas as Boxing day, and its purpose is to bring a bit of magic to those who could use it

    Every December 26, going at least as far back as the 1830s, the United Kingdom and other countries that are part of the British Commonwealth(英联邦) such as Canada, Australia, New Zealand and India, have observed Boxing Day as an opportunity to provide some holiday joy for those who most need it.

    There are competing stories behind the name boxing Day. One is that it refers to the giving of "Christmas boxes", a term that started in the 17th century to describe gifts, money and the leftovers from Christmas that lords of the manor(庄园)would give to their servants and employees for having worked on Christmas Day. Basically, "Christmas boxes" were holiday bonuses(奖金) for the working class.

    The other is that it refers to the "contribution boxes" that would traditionally appear in charities in the weeks leading up to Christmas for the purpose of collecting money from donators that charity staff would distribute to those in need after Christmas Day.

    The day is still a national holiday in many parts of the British Commonwealth, and while people still give something back to people who have bad luck or give tips to service people on Boxing Day, it has also become a major shopping day like Black Friday in the U.S.

    From: terri wombat. Com. Au

    To: (happylizijun) yaboo. com. cn

    Subject: My school

    Hi, Li Zijun,

    Thanks very much for your email. I really enjoyed reading it. I think we have a lot in common. I wonder if our school life is similar too.

    I go to a big high school in Sydney called Maylands High School. There are about 1000 students and 80 or so teachers. My class has 25 students in it, which is normal for a Year 11 class. In the junior school there are about 30 students in a class.

    In the senior high school we have lots of subjects to choose from, like maths, physics, chemistry, biology, history, German, law, geography, software design, graphic arts and media studies. (Different schools sometime have different optional subjects.) English is a must for everyone and we have to do least three other subjects in Year 11 and 12. At the end of Year 12 we sit for a public exam called the High School Certificate.

    As well as school subjects, most of us do other activities at school such as playing a sport, singing in the choir or playing in the school band. We can also belong to clubs, such as the drama club, the chess club and the debating society.

    We have a lot of homework to do in senior school to prepare for our exam, so unless I have basketball practice, I usually go straight home and start studying. I arrive home about 4 pm, make myself a snack and work till 6. Then I help the family to make dinner and we all eat together. I'm usually back in my room studying by 8 pm. I stop at about 10 o'clock and watch TV or read a book for half an hour to relax. On Saturdays, I usually go out with my family or with friends and I sleep in till late on Sunday morning. Then it's back to the books on Sunday afternoon.

    How about you? What's your school life like? Do you have a lot of homework? What do you do to relax when you're not studying? I'm looking forward to finding out.

Your Australian friend

Terrie

    Almost every second of every day an older adult falls in the United States. That's approximately 29 million falls per year and nearly 27, 000 deaths, according to the Centers for Disease Control and Prevention.

    Still in the stating stage, the Active Pelvis Orthosis (APO) system in Switzerland wants to make a lightweight, wearable exoskeleton (外骨骼) that could detect signs of balance loss and assist with balance recovery to keep the elderly wearer from falling, only when needed.

    Other exoskeletons, either in development or on the market today, assist with movement and make heavy objects feel lighter. Mobility-impaired people can walk again. But none of these devices predict what the wearer is going to do next and take measures to correct an unsteady move.

    The 3 kilogram (6.7 pound) exoskeleton was built entirely from scratch by the research team and is designed to be worn on the lower half of the body. A waistband connects to two movable carbon fiber braces (支架), each one positioned on the outer side of a leg. Tiny motors and so-called "adaptive oscillators" (适配振荡器) in the computer circuits use a special process to detect the, wearer's unique paces. That part takes just a few minutes.

    While wearing the exoskeleton, a person may feel the braces and the motors pushing slightly on their legs. If their paces go against normal, the motors create a force in the braces that cause them to stiffen up and push a little more strongly against the legs, which provides stability.

    In the next three years, the APO hopes to develop something that is commercially available.

    Although not as much as in the past, grandparents are the teachers of the Navajo (纳瓦霍人) youth. They make young people aware of life at an early age. The parents grant them the privilege of teaching the children, and the grandparents take great pride in raising the children or at least having a big part in raising them.

    Young children often stay with their grandparents for years at a time developing a close and trusting relationship. The grandparents teach the children Navajo legends and the principle of life, emphasizing both new culture trends and the preservation of traditions.

    The grandparents are also often the leading figures in teaching the youth the arts of weaving, caring for the livestock, using herbal medicine, and other arts and crafts.

    The children are taught to respect their elders, to care for them, to help them whenever they are in need, and to learn from them. Young people are urged to listen with care to the words of their elders and to keep as much wisdom as possible. Grandparents often go to social gatherings and traditional events, and the young have opportunities to learn more about their culture and traditions.

    I live with my grandmother for thirteen years, and she raised me in the old ways of our people. Although I was going to school, she taught me as much as she could about our traditions. She was a beautiful woman. If I had a chance, I would listen again to her wise teachings, expressed with kindness in a soft voice that touched my heart.

    We used to plant corn and pumpkin every summer. They never grew big enough to feed us, but we planted them anyway. I asked my grandmother why. She said, "Grandson, our plants will be far more beautiful than the flowers outside the fence." I did not understand until one day I saw their beauty as I was coming over the hill with her. She said, "Anything that is a part of you is always far more beautiful than the things which you pass by." We had some beautiful years together. I am glad she is a part of me and I am a part of her.

    Children used to be well disciplined, possessing more respect for culture, tradition, and beliefs than they do now. The world of the Navajo has been influenced by the western world, and the grandparents have less control and influence than they used to. But the young people who have been touched by their teachings have glimpsed a way of life beyond what most people know today.

    It was the last day of the final examination in a college. On the steps of building, a group of engineering students were waiting for the last exam. On their faces was confidence.

    They knew the exam would be easy. The professor (教授) had said they could bring any books or notes during the test.

    Right after they came into the classroom, the professor handed out the papers. There were only five questions on it.

    Three hours passed. Then the professor began to collect the papers. The students no longer looked confident. On their faces was nervous expression. The professor watched the worried faces before him, and then asked, "How many of you have completed all five questions?" No hand was raised. "How many of you have answered four?" Still no hands. "Three? Two?" The students moved restlessly in their seats. "One, then? Certainly somebody has finished one." But the class kept silent. The professor said, "That is exactly what I expected. I just want to make you know clearly that even though you have completed four years of engineering, there are still many things about the subject you don't know. These questions you could not answer are common in everyday practice." Then, smiling, he added, "You will all pass this course, but remember, your education has just begun."

    The years have obscured the name of this professor, but not the lesson he taught.