What would it be like to walk on Mars? If you could build the highest building in the world，what would it look like? Do you dream of being the next J. K. Rowling? This summer, you can experience all of these things, and more. All you need is an Internet connection and your imagination.

    A recent study by the Kaiser Family Foundation found that kids spend an average of 1 hour and 29 minutes online each day. Many kids like to use that time to chat with friends, play games or check e­mails. But the next time you get on the Web, try exploring the world instead. “With the Internet，you can go back 11,000 years in time，or go 11,000 kilometers across the planet.” said Russell, Web search expert of Google. “The whole scope of history and the world is open to you.”

    There is a wealth of information to be found online. For example, if your family is going on vacation somewhere, do a quick online search on the area before you even get in the car. “What's the background of the place; what's the history？” says Russell. “I like to tell my kids, ‘Whenever you have a question, whenever you have a doubt, search it out.'”

    Ready to launch a virtual journey of your own? Here are a few starting points to get you thinking and to help you on your way. You can invite your parents along for the ride, too. Always ask for permission before downloading programs and software onto your computer. And check with a parent or an adult before visiting any new Web site.

    Navigate the world in 3­D with Google Earth. Begin in outer space and zoom (快速移动) into the streets of any city, from Hong Kong to San Francisco. Or visit ancient monuments, watch the changing rainforests over time, and dive underwater to explore tropical reef.

    With the Moon in Google Earth tool, you can walk in Neil Armstrong's famous footsteps. Take a guided tour of the moon's surface with Armstrong's fellow shuttle mate astronaut Buzz Aldrin.

    When you're exploring that part of the solar system, hop on over to the Red Planet with Google Mars. There, you can move very quickly around the surface and see images from the Mars Rovers.

    A good teacher is many things to many people. In my own experience, the people I respect the most and think about the most are the teachers who demanded the most discipline (纪律) from their students.

    I miss one teacher in particular that I had in high school. I think she was a good teacher because she was a very strict person. I remember very clearly a sign on her classroom door. It was a simple sign that said,    "Laboratory: in this room the first five letters of the word was stressed not the last seven." In other words, labor for her was more important than oratory, which means making speeches.

    She prepared her work very carefully and told us to do the same. We got lots of homework from her. Once she had broken her arm, and everybody in the class thought that maybe the homework load would be reduced, but it continued just the same. She checked our work by stamping her name at the bottom of the papers to show that she had read them.

    I think sometimes teachers who demand the most are liked the least. But as time goes by, this discipline really seems to benefit the students.

    Hundreds of years ago, a Roman army came north from England to make war on Scotland. The Scots, a brave people, love their country. They fought hard to drive the enemy out of Scotland. But there were too many of the Romans. It looked as if the Romans would win.

    One night, the leader of the Scots marched his soldiers to the top of a hill. “We will rest here tonight, my men,” he said, “Tomorrow we will fight one more battle. We must win, or we will die.”

    They were all very tired. So they ate their supper quickly and fell asleep. There were four guards on duty, but they were very tired, too, and one by one, they fell asleep.

    The Romans were not asleep. Quickly they gathered at the foot of the hill. Slowly they went up the hill. Closer they came to the sleeping Scots. They were almost at the top. A few minutes more the war would be over. Suddenly, one of them put his foot on a thistle (蓟). He cried out and his sudden cry woke the Scots. In a minute they were on their feet and ready for a battle. The fighting was hard, but it did not last long. The Scots wiped out the Romans and saved Scotland.

    The thistle is not a beautiful plant. It has sharp needles all over it. Few people liked it. But the people of Scotland liked it so much that they made it their national flower.

    As kids, my friends and I spent a lot of time out in the woods. "The woods" was our part-time address, destination, purpose, and excuse. If I went to a friend's house and found him not at home, his mother might say, "Oh, he's out in the woods," with a tone (语气) of airy acceptance. It's similar to the tone people sometimes use now a days to tell me that someone I'm looking for is on the golf course or at the gym, or even "away from his desk". For us ten-year-olds, "being out in the woods" was just an excuse to do whatever we feel like for a while.

    We sometimes told ourselves that what we were doing in the woods was exploring (探索). Exploring was a more popular idea back then than it is today. History seemed to be mostly about explorers. Our explorations, though seemed to have less system than the historic kind something usually came up along the way. Say we stayed in the woods, throwing rocks, shooting frogs, picking blackberries, digging in what we were briefly persuaded was an Indian burial mound.

    Often we got "lost" and had to climb a tree to find out where we were. If you read a story in which someone does that successfully, be skeptical; the topmost branches are usually too skinny to hold weight, and we could never climb high enough to see anything except other trees. There were four or five trees that we visited regularly-tall beeches easy to climb and comfortable to sit in.

    It was in a tree, too, that our days of fooling around in the woods came to an end. By then some of us has reached seventh grade and had begun the rough ride of adolescence (青春期). In March, the month when we usually took to the woods again after winter, two friends and I set out to go exploring. We climbed a tree, and all of a sudden it occurred to all three of us at the same time that we really were rather big to be up in a tree. Soon there would be the spring dances on Friday evenings in the high school cafeteria.

    My wife and I went to this vegan(严格的素食主义的)restaurant to give it a try.As we were eating our pepper and salt tofu, a young lady named Debra walked in. She wasn't aware that the place is vegan and was looking for some meat. My wife and I talked up the place and invited her over to try some of our tofu. Debra tried it, nodded and went out.

    After a few minutes, she and her mother both walked back in. We were having the rest of our meal at that time, so we told her what we had ordered. Debra then asked the waitress to just repeat our order for them. Next, Debra said, "And we want to pay for their meal", pointing to my wife and me. We tried to say no, but Debra wouldn't listen.

    That was not the end of it. Hugs were in order. Debra came over to our table and my wife got up to hug her. Debra hugged my wife and put $100 into her hand. My wife firmly said NO, but Debra insisted. Debra kept talking about our kindness, and we did the same about hers and her mother's. With tears in the eyes, the workers were blown away by this whole exchange between four strangers. I left the waiters a tip that would cover all of our meals and we were on our way.

    I've been witnessing so much kindness, especially over the last few years, as I began to pay more attention. We now have a new favorite restaurant and every time we go there my plan is to pay for someone else's meal.

    Dogs are our best friends. That's especially true after a disaster, such as an earthquake. When buildings fall down, search and rescue dogs help find trapped people. Dogs' amazing noses can pick up the smell of survivors. Now scientists have developed an electronic tool that does the same thing. It's taking smell detection(探测) to a whole new level.

    The new invention is a sort of electronic nose, which can detect extremely low levels of many compounds(化合物) from people's skin. This isn't the first time engineers have developed such an object. Earlier models, however, have been bulky and expensive. They could not detect low levels of target compounds either. The new one is inexpensive and small enough to fit inside hand-held equipment.

    The electronic nose can detect extremely slight smell of more than one compound at the same time. "Being able to do this, in such a small object, is the significant discovery," says Sotiris E. Pratsinis, Professor of Process Engineering&Materials Science at the Swiss Federal Institute of Technology in Zurich. His team tested it in special spaces. They were like the small spaces where people might be trapped. Chemicals given off by the volunteers built up inside. The electronic equipment detected those compounds at unbelievably low levels.

The results were good news for the research team. But they may be not for our four-legged friends, who could soon be out of a job. "Ideally, this technology could replace search and rescue dogs," Pratsinis says.

    Stephen Taylor, an electrical engineer, agrees that the new technology has some benefits over dogs. Still, he thinks it may be too soon to have our trusty friends retire. He suspects, "I foresee that such an object could add to the fine work done by the dogs." Taylor also pointed out some potential limitations of the new invention. "E-noses are useful, but can be very likely to be affected by unstable readings and interruption," he says.