One of the most important things in the world is friendship. In order to have friends, you have to be a friend. But how can you be a good friend at school?

    Listen — Listen when they are talking. Don't say anything unless they ask you a question. Sometimes it's not necessary for you to have anything to say; they just need someone to talk to about their feelings.

    Help them — If your friend is ever in need of something, be there to help them. You should try to put them first, but make sure you don't do everything they want you to do. Try to take an extra (额外的) pencil or pen with you to classes in case (以防) they forget one. Have a little extra money in your pocket in case they forget something they need.

    Be there for them — Try to make something for your friend to help make them feel better in hard times. Making cards and encouraging them are among the nicest things you can do for a friend. Marilyn Monroe, a famous U.S. actor, once said, “I often make mistakes. Sometimes I am out of control. But if you can't stay with me at my worst, you are sure not to deserve (值得) to be with me at my best.” Always remember this! If you don't want to stay with your friends when they're in hard times, then you don't deserve to be with them when they're having a good time!

    Try to make plans with your friends. Go shopping, go for ice cream, have a party, go to a movie and so on. Take time to know each other even better by doing something you both enjoy. By planning things together, you both can have a good time. And you'll remember these things when you're all old!

    Are you looking for some new and exciting places to take your kids to? Try some of these  places:

    Head to a natural history museum. This is where kids can discover the past from Dinosaur (恐龙) models to rock collections and pictures of stars in the sky. Also, ask what kind of workshops and educational programs are prepared for kids and any special events that are coming up.

    Go to a Youtheater. Look for one in your area offering plays for child and family visitors. Pre-show play shops are conducted by area artists and educators where kids can discover the secret about performing arts. Puppet (木偶) making and stage make-up are just a couple of the special offerings you might find.

    Visit art museums. They offer all kinds of activities to excite your kids' interest. Many offer workshops for making hand-made pieces, traveling exhibits, book signings( 签名) by children's favorite writers, and even musical performances and other arts.

    Try hands-on science. Visit one of the many hands-on science museums around the country. These science play-lands are great fun for kids and grown-ups alike. They'll keep your child mentally and physically active the whole day through while pushing buttons, experimenting, and building. When everyone is tired, enjoy a fun family science show, commonly found in these museums.

    You're sitting on the sofa, and there's your dog, right at your feet. You stand up? He stands up. But then you head to the bathroom, and guess who comes with? Why, your dog, of course. But why? Why does your dog follow you like a shadow, no matter where you go?

    Ever get the feeling you're being followed? As for why your companion follows you everywhere you go, read on!

    "When dogs follow their owners, there can be several scientific explanations, depending on the dog and the individual situation," according to Mary Burch, Ph.D., an animal behaviorist(行为学家).

    These explanations include:

    Positive reinforcement(正面强化): When your dog follows you, good things happen. Think dog food, a hot bath and taking a walk around the neighborhood. Your dog's no dummy. And one of his many talents is learning from experience, that is "reinforcement."

    Natural instinct(本能) to be part of a pack: In fact, a study out of Princeton University that was published in the journal, Science Advances, shows that your dog's drive (驱动力)to follow you around (as well as watch you attentively and seek physical contact (身体接触) from you) lies in his genes(基因).

    Feel good chemicals(化学物质): Your presence causes your dog's brain to release "feel good" chemicals, Dr. Primm explains, citing this study. Considering how much we as humans enjoy those feel-good chemicals, it's no surprise your dog likes them too—and will follow you around to get some!

    Sense of responsibility : As you move about your home, your dog might feel that you are patrolling your territory (巡视领地) and take on the duty to assist you.

    Travelling can be a way to gain life experiences, especially during Spring Break — a week long school vacation in the United States. But what if you're a student and don't have enough money for a trip? Don't worry. Here are some useful suggestions.

    Save: This probably is the most important preparation for travelling. Cut expenses to fatten your wallet so you'll have more choices about where to go and how to get there.

    Plan ahead: Don't wait until the last minute to plan your trip. Tickets may cost more when bought on short notice. Giving yourself several months to get ready can mean security(安全) and savings.

    Do your homework: No matter where you go, research the places you will visit. Decide what to see. Travel books will provide information on the cheapest hotels and restaurants.

    Plan sensibly: Write down what you expect to spend for food and hotels. Stick to your plan or you may not have enough money to cover everything.

    Travel in groups: Find someone who is interested in visiting the same places. By travelling with others you can share costs and experiences.

    Work as you go: Need more money to support your trip? Look for work in the places you visit.

    Go off the beaten path: Tourist cities may be expensive. You may want to rethink your trip and go to a lesser－known area. Smaller towns can have many interesting activities and sights.

    Pack necessary things: The most important things to take are not always clothes: Remember medicine in case you get sick and snacks in case you cannot find a cheap restaurant.

    Use the Internet: The Net can help to save money. Some useful websites include www. Travelocity.com, www. bargains－lowest－fare.com and www. Economic－travel.com.

    By planning sensibly, even students can enjoy the travel.  Your travel experiences will be remembered for a lifetime.

    As an oceanographer（海洋学家）, I've spent many years developing robots to explore the ocean, and now we're putting that technology to use in our JASON Project, a program that's designed to inspire students and get them interested in science, technology, engineering and mathematics. In theaters throughout the country, we bring kids together and send back to them on large screens our live explorations of large areas of the globe. Not only are the kids observers, but they can operate robots moving across the area while broadcasting images back to them. The kids have the sensation（感受） of really being at the site with us.

    I believe advances in robot technology will one day be the key to a new kind of travel. In the next 10 or 15 years, people will have rooms in their houses that will be able to simulate (模拟) other environment. I like to call this rooms “home domes” -- small theaters with screens and advanced equipment that can reproduce the sights, sounds, smells, and feel of a desert, or a forest. Hand in hand with these rooms, I can see a market for travel robots located in countries around the world. You could rent (租)a robot working in a rain forest, then go into your home dome, where you yourself operate the robot's movements. The equipment in the room will receive the sensations in the robot's environment and simulate them for you.

    Today, much of the world's population never travels more than 50 or 60 miles from home. And even a person with enough time can see only a part of the earth's sights. But this new way of travel will cost so much less in both time and money and allow people to see a lot more of the globe. And simulated travel will also help protect our planet. You can't take large groups of tourists to look at Dian Fossey's gorillas（大猩猩）. But a small robot, with no animal smell, can get very close to a gorilla and send the sights, sounds, and smells back to a million people.

    We can video chat with astronauts aboard the International Space Station and watch live footage from the frozen heights of Everest. But communicating with a submarine (潜艇）or a diver is not so easy. The lack of practical methods for sharing data between underwater and airborne devices has long been a frustration for scientists. The difficulty stems from the fact that radio signals work perfectly in air travel but poorly in water. Sonar (声呐）signals used by underwater sensors reflect off the surface of the water rather than reaching the air.

    Now, researchers at MIT have developed a method with the potential to revolutionize underwater communication. "What we've shown is that it's actually feasible to communicate from underwater to the air," says Fadel Adib, a professor at MJT's Media Lab, who led the research.

    The MIT researchers designed a system that uses an underwater machine to send sonar signals to the surface, making vibrations (震动)corresponding to the ls and Os of the data. A surface receiver then reads and decodes these tiny vibrations. The researchers call the system TARF. It has any number of potential real-world uses, Adib says. It could be used to find downed planes underwater by reading signals from sonar devices in a plane's black box and it could allow submarines to communicate with the surface.

    Right now the technology is low-resolution. The initial study was conducted in the MIT swimming pool at maximum depths of around 11 or 12 feet. The next steps for the researchers are to see if TARF is workable at much greater depths and under varying conditions—high waves, storms, schools of fish. They also want to see if they can make the technology work in the other direction— air to water.

    If the technology proves successful in real-world conditions, expect "texting while diving" to be the latest underwater fashion.