Traffic problems are an everyday concern in many cities, including Washington, D. C. A growing number of Washingtonians are turning to bicycles to get to and from work. In fact, the number of commuters who use bicycles has doubled in the city since 2007.

    Ralph Buehler teaches urban planning at the Virginia Polytechnic Institute and State University，popularly known as Virginia Tech. He has written a book about urban biking, called City Cycling. He says there is a reason why urban bike tiding is now becoming more popular.

    “Over the last 60 to 70 years, cities in America have been adapted to the automobile.”

    “Most cities took advantage of the money coming for the interstate (洲际)highway system, from the federal government, starting in 1956. There was a 90 percent federal match(补贴)so the cities only had to put up 10%. It was very tempting.(临时的).”

    In the years after World War Two, many Americans moved to suburban communities, just outside major cities, They decided to travel great distances to and from work in exchange for a home in the suburbs. Their cars became a symbol of freedom.

    But today, many people believe they can save money by living in the city.

    Greg Billing is with the Washington Area Bicyclist Association. “When a person makes a change from using a car to using a bike, he/she is saving anywhere between 8 or$9,000 a year.”

    Ralph Buehler says governments save money when people use bicycles. “Building bicycling facilities(设施) is much cheaper than building and maintaining road facilities or public transport.”

    Washington, D.C has also taken steps to protect bike riders. It approved a safe passing law and created areas on the road between cars and bikes.

    The United States Census Bureau says 4% of the city's workers ride to work by bike. The only city on the East Coast with more bike commuters is New York.

    The gray-haired lady can't wait to leave the building to search for her dad. Unless watched, she will walk in the streets in an effort to find her father, who died 30 years ago.

    Not all cases of Alzheimer's disease look like this, but Alzheimer's is a serious disease that is said to be the fourth or fifth leading cause of death for people over age 75. It is said that about three percent of the U.S. population over age 65 have Alzheimer's. In the early stages; people may exhibit short-term memory loss. Some may experience changes in personality, easy to be angry. As the disease progresses, patients might lose the ability to move and may be unable to speak or move at all. This progressive disease generally lasts 8 to 10 years before death occurs.

    While no one is certain what causes these changes in the brain's nerve fibers, their effect is certain. Alzheimer's destroys not only the patients, but also spouses（配偶）, friends and families.

    What should you do if you notice progressive memory loss in yourself or a loved one? Have the person examined by a doctor who is a specialist in the treatment of Alzheimer's disease. Though many reasons other than Alzheimer's disease may cause memory loss, its early diagnosis（诊断）and treatment may delay some of the most serious effects.

    What feeling will you likely experience if a loved one suffers from Alzheimer's disease? A person will often go through the various stages of sadness, shock, anger, and so on. If the spouse develops the disease, you may experience hurt and disappointment when he or she doesn't remember you are married.

    Life for the Alzheimer's patients and their loved ones will never be the same as the disease progresses, bringing a deep sorrow, loss and even anger towards God. No matter what feelings are present, facing them honestly will serve one better than burying them.

    Like most July days, it was hot. I stepped into a tiny ice-cream shop to cool off with a chocolate ice-cream. It was an old-time store with little round tables and chairs.

    As I entered, I found a very old woman bent over a table near the door. Her back was so badly twisted by some sadness that her face nearly touched the table top. I sat down facing her several tables away.

    “Poor woman,” I thought. “What does she get out of life? Why God let people live so long past their prime?”

As I thought, another aged lady entered the shop and sat down with her. Soon the two of them were talking about childhood days. They talked of how little the shop had changed in 70 years… In minutes, the two of them were trembling with laughter.

    I looked again at the first woman, then in the mirror on a nearby wall, catching a picture of myself.

I was wearing a dirty shirt. She was well dressed in white, her hands shining with gold rings.

    I was gloomy(愁闷的). She was laughing, smiling.

    I was putting the pieces of my life together. She had millions of wonderful memories to recall.

    I sat alone. She was sharing the day with a good friend.

I was secretly worried about getting old. She was old, but it wasn't hurting her.

    As I left the shop, I thought of my foolish question about God letting people live past their prime. Why, that woman was more alive, more sensitive to life than I was. Age has not bent her spirit.

    A mechanical bicycle lock, like a U-lock, should be attached to a solid and immobile object like a rack (架子) to ensure safety. However, these racks are quite rare and popular, thus often occupied and although a bicycle lock prevents the bike from being carried away, as it fixes single parts like the frame or the wheels, other parts can be dismounted. Therefore an electronic system, consisting of several sensors, can extend the range of protection with only few components and less effort.

    The ‘FID Bikealarm' is a motion sensitive electronic alarm system that is attached to the rails of a bike saddle (座椅). Featuring omnidirectional (全方位) movement sensing to detect tiny movements or speeding-up and a small whistle emitting >120dB alarm sound to scare off potential thieves by arousing attention.

    The internal microcontroller uses a complex computer program to distinguish between a serious theft and harmless shaking movement as it senses and adapts to the environment. The usage is quite simple: identify yourself by holding the RFID tag close to the case to lock or unlock the alarm system signaled by feedback sounds. The RFID-technology is predestined for achieving this simple and secure interaction because it doesn't require any complex system, interaction or other devices—just a small tag.

    The ‘RFID Bikcalarm' is meant to be a useful add-on to mechanical bicycle locks as it massively extends the range of protection with few components. It is low-cost, durable and easy to use. The internal battery can be charged by USB.

    Animals, including insects, do not have a language like ours. They do not talk to each other in words and sentences. But if we watch them, we can see that they do have ways of communicating with each other.

    Can you see the rabbits' tail? When rabbits see this white tail moving up and down, they run too. The rabbit has reminded them of potential dangers without making a sound. It has given them a signal.

    Many other animals use this kind of language. When a cobra (眼镜蛇) is angry, it raises its hood (兜帽) and makes itself look fierce. This warns other animals. When a bee has found some food, it goes back to its home. It cannot tell the other bees where the food is by speaking to them, but it does a little dance in the air. This tells the bees where the food is.

    Some animals say things by making sound. A dog barks, for example, when a stranger comes near. A cat purrs (猫的呜呜声) when pleased. Some birds make several different sounds, each with its own meaning. Sometimes we human beings speak in the same way. We make sounds like “Oh” or “Ah!” when we are frightened or pleased or when we drop something on our toes.

    But we have something that no animals have — a large number of words which have the meanings of things, actions, feeling or ideas. We are able to give each other all kinds of different information in words and sentences, which no other animals can do. No other animals have so wonderful a language as we have.

    Sure, it's good to get along with your teacher because it makes the time you spend in the classroom more pleasant.

    And yes, it's good to get along with your teacher because, in general, it's smart to learn how to understand the different types of people you'll meet throughout your life

    "But really, there's one super-important reason why you should get along with your teacher. When you do, learning bursts right open," says Evelyn Vuko, a longtime teacher who writes an education column (专栏) called "Teacher Says" for the Washington Post newspaper.

    In fact, kids who get along with their teachers not only learn more, but they're more comfortable asking questions and getting extra help. This makes it easier to understand new material and do your best on tests. When you have this kind of relationship with a teacher, he or she can be someone to turn to with problems, such as problems with learning or school life like bullying.

    As a kid in a primary or middle school, you're at a wonderful stage in your life. You're like a sponge(海绵), able to absorb lots of new and exciting information. On top of that, you're able to think about all this information in new ways. Your teacher knows that, and, in most cases, is very excited to be the person who's giving you all that material and helping you make it. Remember, teachers are people, too, and they feel great if you're open to what they're teaching you. That's why they wanted to be teachers in the first place—to teach!

    Some kids may be able to learn in any situation, whether they like the teacher or not. But most kids are sensitive to the way they get along with the teacher, and if things aren't going well, they won't learn as well and won't enjoy being in class.