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.

    Your school asked parents about the social development in children in the last Parents' Meeting. Here are some opinions. Read following information and answer the questions.

Two good friends, Simon and Jason, met with a car accident on their way home one snowy night. The next morning, Simon woke up blind. His legs were broken. The doctor, Mr. Smith, was standing by his bed, looking at him worriedly. When he saw Simon awake, he asked, " How are you feeling, Simon?” Simon smiled and said, “Not bad, doctor. Thank you very much for doing the special operation. Mr. Smith was moved by Simon. When he was leaving, Simon said, "Please don't tell Jason about it. “Well…Well…OK,” Mr. Smith replied.

Months later when Jason's wounds healed, Simon was still very sick. He couldn't see or walk. He could do nothing but stay in his wheelchair all day long. At first, Jason stayed with him for a few days. But days later, Jason thought it boring to spend time with a disabled man like Simon. So he went to see Simon less and less. He made new friends. From then on, he didn't go to visit Simon any more. Simon didn't have any family or friends except Jason. He felt very sad.

    Things went from bad to worse. Simon died a year later. When Jason came, Mr. Smith gave him a letter from Simon. In the letter Simon said, “Dear Jason, I am disabled. But I want you to be a healthy man. So I gave my eyes to you so that you can enjoy life as a healthy man. Now you have new friends.

I'm glad to see that you are as healthy and happy as usual. I'm glad you live a happy life. You are always my best friend". Simon”. When he finished reading the letter, Mr. Smith said, “I have promised that I will keep this a secret until Simon is gone. Now you know it.

    Jason stood there like a stone. Tears ran down his face.

    When I was in the fifth grade and Mr. Gardner asked a question, my hand would often shoot up in enthusiasm. After giving me a few opportunities, he would try to give other students a chance. My hand, though, would remain in the air, and after some time, I'd start waving it around. Then, there was the time I entered drumming classes. But all we were allowed to do in the first class was practice one beat over and over again. I never went back.

    I would have done terribly in the Stanford Marshmallow(果浆软糖) Experiment. In this classic study, researchers gave children a choice between one marshmallow right away and two later. The results showed that those who could wait 15 minutes ended up scoring 210 points higher on the SAT, an examination that American high school students take before they go to college.

    So clearly, delaying(延迟的) gratification or bearing up under pain have their benefits. It needs patience, which keeps us from being stuck to ideas formed previously, and helps us let go of our strong desire for consequences. We come to accept that we don't always or immediately know what is best, and learn to recognize that our reality is in constant changes. Patience improves our understanding of deeper truths and helps us expand our views.

    The journey of patience is rooted in knowing that our present reality will finally give way to changes. But changes won't always happen when we think they should, and patience with ourselves comes from accepting that there are things we can control and things we can't. And though we must make great efforts to keep pushing the boundaries of our awareness and to improve our ability to rest in comfort in the present moment, how fast we develop isn't up to us.

    That same fifth grader who couldn't wait to speak out answers now sees the value of meeting questions with a heart of patience.

    Garden parties are one of the traditions that began in the United Kingdom and France a number of centuries ago. Both the British and French versions have roots in the weekend getaways that were enjoyed by the upper classes. In the afternoons and evenings, the grounds of the estates (房产) would be softly lit with candles and lanterns, food prepared and set in long buffet tables for the guests, and comfortable seating always within reach.

    People tended to dress up for these types of outdoor events, which made them quite a festive occasion. String bands often provided a graceful melody that served as one of the ways that the elegant tone of the occasion was set and maintained.

    Today, the concept lives on around the world. No longer just an event for the well to do, the garden party is a weekend gathering in many neighborhoods. Neighbors are invited to come enjoy the outdoors by attending a cookout, complete with plenty of grilled food, lots of seating, and usually plenty to drink. It is not unusual for a few simple games to be available as well, depending on the size of the space. Music does not necessarily have to be provided by a live band anymore, although some people prefer the chatter and laughter of people enjoying themselves to any type of musical accompaniment.

    The modern version can be very free form, or use a special occasion or theme as the basis for the event. For example, a birthday is a great reason to throw this type of party. Major patriotic holidays often provide the theme, with the decorations revolving around the national colors and other symbols. Fun times, such as Valentine's Day or and Easter egg hunt, can also be the reason for putting together a party. As long as the event takes place outdoors, has people to interact, and includes food and drink, the event is complete.

    I often dreamed about Pisa when I was a boy. I read about the famous building called the Leaning Towers of Pisa(比萨斜塔）. But when I read the word Pisa, I was thinking of pizza. I thought this tower must be the best place to buy pizza in the world.

    Many years later, I finally saw the Leaning Tower. I knew then that it was Pisa and no pizza and that the tower got its name because it really did lean to one side. Some people want to try to fix it. They are afraid that it may fall over and they don't want it to lean over the city.

    I don't think it a good idea to try to fix it. The tower probably will not fall down. It's 600 years old. Why should anything happen to it now? And, if you ask me, I like what it looks like. It seems to say nothing is perfect. Imperfect things may be more interesting. Why is it so famous? There are many other older, more beautiful towers in Italy but Pisa tower is the most famous.