A team of engineers at Harvard University has been inspired by Nature to create the first robotic fly. The mechanical fly has become a platform for a series of new high-tech integrated systems. Designed to do what a fly does naturally, the tiny machine is the size of a fat housefly. Its mini wings allow it to stay in the air and perform controlled flight tasks.

    “It's extremely important for us to think about this as a whole system and not just the sum of a bunch of individual components (元件),” said Robert Wood, the Harvard engineering professor who has been working on the robotic fly project for over a decade. A few years ago, his team got the go-ahead to start piecing together the components. “The added difficulty with a project like this is that actually none of those components are off the shelf and so we have to develop them all on our own,” he said.

    They engineered a series of systems to start and drive the robotic fly. “The seemingly simple system which just moves the wings has a number of interdependencies on the individual components, each of which individually has to perform well, but then has to be matched well to everything it's connected to,” said Wood. The flight device was built into a set of power, computation, sensing and control systems. Wood says the success of the project proves that the flying robot with these tiny components can be built and manufactured.

    While this first robotic flyer is linked to a small, off-board power source, the goal is eventually to equip it with a built-in power source, so that it might someday perform data-gathering work at rescue sites, in farmers' fields or on the battlefield. “Basically it should be able to take off, land and fly around,” he said.

    Wood says the design offers a new way to study flight mechanics and control at insect-scale. Yet, the power, sensing and computation technologies on board could have much broader applications. “You can start thinking about using them to answer open scientific questions, you know, to study biology in ways that would be difficult with the animals, but using these robots instead,” he said. “So there are a lot of technologies and open interesting scientific questions that are really what drives us on a day to day basis.”

    When the evening is coming, my dear son and I are preparing for the tape time. “Shoes on,” I remind 9-year-old Sam. “Snakes are always waiting for the chance to kiss you. But with our feet stepped into my car, we are safe.” We take blankets and cups of milk and head out to the shelter that serves as our garage. This has become our bedtime habit.

    I press “play.” A motherly voice fills the car. My mother and my aunt send us books on tape obtained from secondhand shops or rescued from the back of drawer. Maybe no one in England lays cassettes anymore, but I still love them.

    Sam rests on his seat. He's sitting in the front seat. I am listening to the cassette. But I am also thinking. In a month's time, my boy will be 10. Next year, he will be 11. And so it will go on, until he leaves me and his father and his sister to live out his own stories— as it is only right and proper he should.

    Will he think back to the times when he sat in the dark in a car in Africa, listening to tales of Wales in World War Ⅱ, the finest lady detective of Botswana, or a country he has visited, and tells me he finds them “very interesting”? Will he think , when he is grown-up, the poor mum always makes the ancient tape player which is out of date work?

    I like to believe that he will recall those wonderful moments. By then, perhaps, my child will realize a deep love of sharing and understanding by listening to the old tape player. I hope Sam will think that these evenings we spend in the car are a story themselves. It is his own first chapter. In time my boy will ease off the hand brake and roll out into the world. Until then, I'll keep pressing “play”.

    Doctors in Britain are worried because British teenagers eat lots of fried potatoes, sweets and fat food. Most teenagers don't have enough fruit or vegetables and more than one million British school children are overweight.

    Some teenagers say that they don't have time to eat good food, but kids who have a poor diet often have health problems when they are older.

    Americans have been with fast food for a long time, and it was born there. American fast food is now a part of life far beyond the stores of the United States. McDonald's, Pizza Hut, and KFC have restaurants all over the world.

    No one can say no to the fact that fast food at a fair price has its place around the world. It is popular now, and it is giving a hand to a country's economy (经济).

    A diet of hamburgers, fries and soda may seem happy, but it won't give your body things you need to stay healthy. Fast food has little of many important things our bodies need.

    Some parents are saying no to the fast food restaurants where people eat junk food and doctors are giving young people books and games about a good diet. Having a healthy and well-balanced diet can help you feel better and live longer.

    It's not easy being a teenager– nor is it easy being the parent of a teenager. You can make your child feel angry, hurt, or misunderstood by what you say without realizing it yourself. It is important to give your child the space he needs to grow while gently letting him know that you'll still be there for him when he needs you.

    Expect a lot from your child, just not everything. Except for health and safety problems, such as drug use or careless driving, consider everything else open to discussion to help them grow up more independently. If your child is unwilling to discuss something, don't insist he tell you what's on his mind. The more you insist, the more likely that he'll clam up. Instead, let him attempt to solve things by himself. At the same time, remind him that you're always there for him should he seek advice or help. Show respect for your teenager's privacy (隐私). Never read his mail or listen in on personal conversations.

    Teach your teenager that the family phone is for the whole family, which can make them more mature. If your child talks on the family's telephone for too long, tell him he can talk for 15 minutes, but then he must stay off the phone for at least an equal period of time. This not only frees up the line so that other family members can make and receive calls, but teaches your teenager moderation (节制). Or if you are open to the idea, allow your teenager his own phone that he pays for with his own pocket money or a part-time job.

    Steven Stein likes to follow garbage trucks. His strange habit makes sense when you consider that he's an environmental scientist who studies how to reduce litter, including things that fall off garbage trucks as they drive down the road. What is even more interesting is that one of Stein's jobs is defending an industry behind the plastic shopping bags.

    Americans use more than 100 billion thin film plastic bags every year. So many end up in tree branches or along highways that a growing number of cities do not allow them at checkouts(收银台). The bags are prohibited in some 90 cities in California, including Los Angeles. Eyeing these headwinds, plastic-bag makers are hiring scientists like Stein to make the case that their products are not as bad for the planet as most people assume.

    Among the bag makers' argument: many cities with bans still allow shoppers to purchase paper bags, which are easily recycled but require more energy to produce and transport. And while plastic bags may be ugly to look at, they represent a small percentage of all garbage on the ground today

    The industry has also taken aim at the product that has appeared as its replacement: reusable shopping bags. The stronger a reusable bag is, the longer its life and the more plastic-bag use it cancels out. However, longer-lasting reusable bags often require more energy to make. One study found that a cotton bag must be used at least 131 times to be better for the planet than plastic.

    Environmentalists don't dispute(质疑) these points. They hope paper bags will be banned someday too and want shoppers to use the same reusable bags for years.

We were on the way from Hutchinson to Chicago for a short spring break. For many years I had wanted to take my family on the train. We all went to Chicago four years ago, and the kids loved it. Chicago is one of my favorite cities, too, so the thought struck me again last fall to ride the train to Chicago. Of course, flying would have been faster. But I don't think flying is easier, especially these days, with all the security and waiting in lines at airports.

Though we were tired in the middle of the night, the kids got on the train with the exhilaration of this adventure. "We're moving," my son William shouted happily with big eyes as the train began to pull away from the Hutchinson station.

I removed my shoes and lay down to try to finish my night's sleep. The sleeper car would have better enabled that, but the ordinary train seats were not too bad. An airline flight is a more miserable experience for me：not enough room, two hours of pain with my knees almost touching my chin, the hard seatback in front cracking my kneecaps (膝盖) with every move of the body planted in front of me. On the train I could almost outstretch all of my 6­foot­2­plus body in the generous legroom.

The journey didn't feel at all as long as it was. We all found the train ride a joy. The car ride would have felt every minute of 13 hours. But on the train you are free to walk around, sit in the observation carriage for a while and enjoy the scenery out the windows, have a nice meal in the dining car, read a book, or play a board game.

In short, the train is all about enjoying the trip, which isn't something I do so much when travelling by airline or by car, when the trip seems more of a mission (任务) to get there than an experience to enjoy along the way.

Chicago offers much to do for a family. This time, getting there was half the fun.