On a Saturday morning earlier this September, the world got its first look at the Strati. This electric vehicle is unlike any other currently on the road. It rolls on four wheels, but its body and chassis(底盘) weren't built in a factory. Instead, Strati's designers used a technology called 3-D printing. It created those parts of the car in one piece, from the ground up.

    “Compared to a typical vehicle on the road, the Strati definitely looks different,” says Greg Schroeder, a senior research engineer at the Center for Automotive Research in Ann Arbor, Mich. He did not work on the new car. His organization studies trends and changes in th e auto industry.

    It took 44 hours to print the new car at the International Manufacturing Technology Show in Chicago. Over the next few days, the car's designers installed additional parts. These included the car's engine, brakes and tires. Then, early on September 13, Jay Rogers climbed into the car, started its engine and drove the vehicle onto the street. Rogers helped found Local Motors. It's the Arizona-based company behind the Strati. Two weeks later, his team printed a second Strati, and just as fast, at a fair in New York City.

    Justin Fishkin, a local Motors official, sees the Strati as a window into the future. Today, car buyers are limited in their choice of a vehicle. They can order only what car companies have already designed. But in the future, he says, you may be able to design your own car online and then get it printed to order.

    Manufacturing experts say 3-D printing has begun to revolutionize how they make things. The technology has been around for decades. But these machines used to be so expensive that only large companies could afford them. In the last few years, though, that has changed. Many of the machines are now inexpensive enough for small companies—or even individuals —to own. Some local libraries make them available to the public. High Schools are beginning to use them in classrooms. Wide access to these printers means people can now design and print a wide variety of new things.

    The car's printer is a one-of-a-kind device.

    The technology behind the 3-D printer used in Chicago is an example of additive manufacturing. This proce ss builds solid objects, slice by slice, from the bottom up. (“Strati” means layers, in Italian.) A mechanical arm moves a nozzle from one side to another, back and forth. As it moves, the nozzle deposits a liquid—often melted plastic or metal (but it could be food, concrete or even cells) —that quickly hardens or bonds to become solid or semi-solid. This creates a single, thin layer. Once a layer is complete, the printer starts depositing the next one.

     “There's a lot of interest in 3-D printing in the auto industry,” says Schroeder. Right now, the technology is particularly useful for building models of cars or car parts.

    To compete with current auto manufacturers, the 3-D printer would have to increase in a hurry, Schroeder says. By contrast, he notes, a Ford F-150 pickup truck rolls off an assembly line at a rate of roughly one per minute. To print as many Stratis would require many more printers. Schroeder says he doesn't see 3-D printing soon taking over for such high-volume manufacturing. But, he adds, “Who knows what will h appen in the long term?”

    Scientists at Oak Ridge National Laboratory in Tennessee designed the 3-D printer used in Chicago. Lonnie Love, a research scientist at the lab, led the effort.

    Additive manufacturing often is slow and expensive. It also may produce materials that are unreliable, Love says. So for two years, his team searched for ways to make 3-D printing better. They built new machines and tested them over and over.

    All of that work paid off: their new machine is fast and uses less expensive material than earlier printers. In addition, it prints a plastic embedded with fibers of carbon to produce a stronger material. This helps ensure the material won't crack or break under pressure.

    I still remember my first day at school in London and I was half-excited and half-frightened. On my way to school I wondered what sort of questions the other boys would ask me and practiced all the answers: “I am nine years old. I was born here but I haven't lived here since I was two. I was living in Farley. It's about thirty miles away. I came back to London two months ago.” I also wondered if it was the custom for boys to fight strangers like me, but I was tall for my age. I hoped they would decide not to risk it.

    No one took any notice of me before school. I stood in the center of the playground, expecting someone to say “hello”, but no one spoke to me. When a teacher called my name and told me where my classroom was, one or two boys looked at me but that was all.

    My teacher was called Mr. Jones. There were 42 boys in the class, so I didn't stand out there, either, until the first lesson of the afternoon. Mr. Jones was very fond of Charles Dickens and he had decided to read aloud to us from David Copperfield, but first he asked several boys if they knew Dickens' birthplace, but no one guessed right. A boy called Brian, the biggest in the class, said: “Timbuktu”, and Mr. Jones went red in the face. Then he asked me. I said: “Portsmouth”, and everyone stared at me because Mr. Jones said I was right. This didn't make me very popular, of course.

    “He thinks he's clever,” I heard Brian say.

    After that, we went out to the playground to play football. I was in Brian's team, and he obviously had Dickens in mind because he told me to go in goal. No one ever wanted to be the goalkeeper.

    “He's big enough and useless enough.” Brian said when someone asked him why he had chosen me.

    I suppose Mr. Jones, who served as the judge, remembered Dickens, too, because when the game was nearly over, Brian pushed one of the players on the other team, and he gave them a penalty (惩罚). As the boy kicked the ball to my right, I threw myself down instinctively (本能地) and saved it. All my team crowded round me. My bare knees were injured and bleeding. Brian took out a handkerchief and offered it to me.

    “Do you want to join my gang (帮派)?” he said. At the end of the day, I was no longer a stranger.

    She was walking home from work one evening when she got the idea. Rosa didn't like her job at the factory, but it was better than no job at all. So, while she was trying not to think about work, she saw the pots in an alley. They were cheap plastic pots, but there were dozens of them piled up behind the flower shop. Such a waste, she thought. When the pots were still there three days later, Rosa went in and asked if she could take some. The flower shop lady said she didn't mind, so Rosa carried home a tower of pots, pretending she was a circus performer on the way.

    At home, Rosa set them on the fire escape outside her tiny apartment. And there they sat. Once a gust of wind sent them slipping to the street three floors below, and she had to go to run after and catch them before the gathering storm.

    Every day, Rosa went to work and thought about her pots- She was wailing for something, but she had patience.

    At last, the newspaper brought good news. A hardware store had a sale on potting soil. Rosa carefully counted her money, then walked six blocks to the store. She bought six bags and carried them home. She bought seeds, too. Rosa slept well that night and dreamed of masses of flowers and fat, glowing fruits,

    Sundays were always good days. Rosa didn't have to work on Sundays. But Rosa couldn't remember when she had had such a good Sunday. She got up early and ate her breakfast on the fire escape with her pots. Then, she began to put dirt into the pots. She sang a little song until all six of her bags of soil were empty. Then, she laid her precious seed packets out and planned her garden. Tomatoes for the biggest pots, and peppers for the next-biggest ones. Flowers in all the rest.

    At the end of the day, Rosa sat in her garden and watched the sunset. Soon, she thought, there will be masses of flowers and fat, glowing fruits.

    So many of us hold on to little resentments that may have stemmed from an argument, a misunderstanding, or some other painful event. Stubbornly, we wait for someone else to reach out to us―believing this is the only way we can forgive or rekindle(重新点燃) a friendship or family relationship.

    An acquaintance of mine whose health isn't very good, recently told me that she hasn't spoken to her son in almost three years. "Why not" I asked. She said that she and her son had had a disagreement about his wife and that she wouldn't speak to him again unless he called first. When I suggested that she be the one to reach out, she resisted initially and said, "I can't do that. He's the one who should apologize." She was literally(简直) willing to die before reaching out to her only son. After a little gentle encouragement, however, she did decide to be the first one to reach out. To her amazement, her son was grateful for her willingness to call and sincerely said sorry to her. As is usually the case when someone takes the chance and reaches out, everyone wins.

    Whenever we hold on to our anger we turn "small thing" into "big thing" in our minds. We start to believe that our positions are more important than our happiness. They are not. If you want to be a more peaceful person you must understand that being right is to let go, and reach out. Let other people be right. This doesn't mean that you're wrong. Everything will be fine. You'll experience the peace of letting go as well as the joy of letting others be right. You'll also notice that as you reach out and let others be "right" they will become less defensive and more loving toward you. They might even reach back. But if for some reason they don't that's okay too. You will have the inner satisfaction of knowing that you have done your part to create a more loving world and certainly you'll be more peaceful yourself.

    Plants are helpful to human: they provide us with wood and other products, they give us shade, and they help to prevent drought and floods.

    Sadly, in many parts of the world man has not realized that the third of these services is the most important. In his eagerness to draw quick profit from the trees, he has cut them down in large numbers, only to find that without them he has lost the best friends he had.

    Several thousand years ago a rich and powerful country cut down its trees to build warships, with which to gain itself an empire. It gained the empire but, without its trees, its soil became hard and poor. When the empire fell to pieces, the country found itself faced by floods and starvation.

    Even if a government realizes the importance of a plentiful supply of trees, it is difficult for it to persuade the villager to see this. The villager wants wood to cook his food with, and he can earn money by making charcoal(木炭) or selling wood to the townsman. He is usually too lazy or too careless to plant and look after trees. So unless the government has a good system of control, or can educate the people, the forests will slowly disappear.

    This does not only mean that the villagers? Sons and grandsons have fewer trees. The results are even more serious. For where there are trees their roots break the soil up—allowing the rain to sink in and also hold the soil, thus preventing it being washed away easily, but where there are no trees, the soil becomes hard and poor. The rain falls on hard ground and flows away on the surface, causing floods and carrying away with it the rich topsoil, in which crops grow so well. When all the topsoil is gone, nothing remains but a worthless desert.

    Now people are very concerned about the food problem. Steve Wilson prefers organic fruit, delivered right to the doorstep. He is willing to pay for it. If this is not possible, the 30-year-old computer technician will spend the extra money at the supermarket to buy organic food.

    “Organic product is always better,” Wilson said. “The food is free of pesticides(农药), and you are generally supporting family farms instead of large farms. And more often than not that it is locally grown and seasonal, so it is more tasty.” Wilson is one of the growing number of shoppers buying into the organic trend, and supermarkets across Britain are counting on more like him as they grow their organic food business. But how many shoppers really know what they are getting, and why are they willing to pay a higher price for organic product? Market research shows that Wilson and others who buy organic food can generally give clear reasons for their preferences—but their knowledge of organic food is far from complete. For example, small amounts of pesticides can be used on organic products. And about three quarters of organic food in Britain is not local but imported(进口)to meet growing demand. “The demand for organic food is increasing by about one third every year, so it is a very fast-growing market,” said Sue Flock, a specialist in this line of business.