There's a new frontier in 3D printing that's beginning to come into focus: food. Recent development has made possible machines that print, cook, and serve foods on a mass scale. And the industry isn't stopping there.

    Food production

With a 3D printer, a cook can print complicated chocolate sculptures and beautiful pieces for decoration on a wedding cake. Not everybody can do that—it takes years of experience, but a printer makes it easy. A restaurant in Spain uses a Foodini to" re-create forms and pieces" of food that are" exactly the same,” freeing cooks to complete other tasks. In another restaurant, all of the dishes and desserts it serves are 3D-printed, rather than farm to table.

    Sustainability(可持续性)

    The global population is expected to grow to 9.6 billion by 2050, and some analysts estimate that food production will need to be raised by 50 percent to maintain current levels. Sustainability is becoming a necessity. 3D food printing could probably contribute to the solution. Some experts believe printers could use hydrocolloids( 水解胶体)from plentiful renewables like algae(藻类) and grass to replace the familiar ingredients(烹饪原 料). 3D printing can reduce fuel use and emissions. Grocery stores of the future might stock "food" that lasts years on end, freeing up shelf space and reducing transportation and storage requirements.

    Nutrition

    Future 3D food printers could make processed food healthier. Hod Lipson, a professor at Columbia University, said, "Food printing could allow consumers to print food with customized nutritional content, like vitamins. So instead of eating a piece of yesterday's bread from the supermarket, you'd eat something baked just for you on demand."

    Challenges

    Despite recent advancements in 3D food printing，the industry has many challenges to overcome. Currently, most ingredients must be changed to a paste( 糊状物)before a printer can use them, and the printing process is quite time-consuming, because ingredients interact with each other in very complex ways. On top of that, most of the 3D food printers now are restricted to dry ingredients, because meat and milk products may easily go bad. Some experts are doubtful about food printers, believing they are better suited for fast food restaurants than homes and high-end restaurants.

    Africa is a very diverse land with many different tribes. One tradition that many of these groups share is painting or marking their bodies and faces in color. They do this for many reasons. Some marks are used to identify people as part of the group. Other marks are used for ceremonies such as wedding and during times of war. Let's look at some different examples of body painting.

    Red is a common color in body painting because it often represents health and long life. Among the Masai of East Africa, when men are old enough to marry and make decisions for their people, they participate in a special ceremony in which they paint their heads and faces red. This ceremony takes place every seven to fourteen years, so there is not an exact age for participating in it.

    The Samburu, also from East Africa, like to paint their faces and hair red because they think it looks pretty.

    The Masai men also have a unique way of showing that they are brave. To show that he has killed a lion, a man will paint his body with a natural white material, making special marks to represent this accomplishment. The Masai men also use this white to show that they are no longer boys and are considered adults.

    One quite unusual example of face painting is done by the Wodaabe people of West Africa. Once a year, they have a beauty contest for men. The men paint their faces yellow and red. Then they add white and black circles and lines. Black paint is used near the eyes and on the lips to draw attention to the whiteness of their eyes and teeth, which the Wodaabe consider most beautiful. The women then decide which man they like best.

    As you travel, enjoy the beautiful and bright colors of Africa.

    John, a very thin boy, loved football with all his heart when he was very young. Practice after practice, he eagerly gave everything he had. But being half the size of the other boys, he could only sit on the bench and hardly ever played in games. Even though the son was always on the bench, his father was always standing with cheers and encouraging him.

    When John went to college, he decided to try out for the football team as a “walk-on”. Everyone was sure he could never make the cut, but he did. The coach thought he could provide the other members with the spirit they needed.

    The news that he had survived the cut excited him so much that he rushed to the nearest phone and called his father. His father shared his excitement and was sent season tickets for all the college games.

    It was the end of this last football season. One day John received a telegram and asked one week off. Nobody knew what happened except the coach. The coach said, “Don't plan to come back to the game on Saturday.”

    Saturday arrived, and the game was not going well：When the team was ten points behind, John came back. “Coach, please let me play. I've just got to play today,” said John. The coach pretended not to hear him. But John persisted, and finally feeling sorry for the kid, the coach gave in.

    Before long everyone could not believe their eyes. John was doing everything to fight. The opposing team could not stop him. He ran, he passed and blocked like a star. And at last his team won the game.

    After the game, John looked at the coach, with tears in his eyes, and said, “Well, you knew my dad died, but did you know that my dad was blind?'' John swallowed hard and forced a smile, “Dad came to all my games, but today was the first time he could see me play, and I wanted to show him that I could do it.”

    At times my mom has been uncomfortable seeing some quality in me. For example, when I was 12, I went to Puerto Rico all by myself to stay with my grandmother for the summer. My mom was extremely nervous about it. She kept telling me how things were different in Puerto Rico, to always put on sunscreen, not to wander away from my grandmother, and other warnings. She helped me pack and did not leave the airport until she saw my plane take off.

    But despite her worries, she let me go on my own. As I moved into my teens, she continued to give me space to grow and learn, even when it might have been difficult for her. When I reached my senior year, I decided to move away for college. Once again I found that I differed from my peers: while many of them wanted to stay close to home, I couldn't wait to be out in the world on my own. While my mom may not have been happy at the thought of my going away, she was supportive and excited for me.

    One big thing I realized during my senior year, as my mom granted me more freedom, was that she actually believes in me and trusts me. That means a lot. Most of my life, and especially when I was little, the main person I tried to impress in my schoolwork or other things was my mother. I knew she expected nothing but the best from me. Sometimes it was hard to live up to her standards: getting a single B on my report card would make me feel bad because I knew she wanted me to have all A's.

    I know that her high standards have helped me stay focused on what's important, like education, and made me who I am. I am thankful for her support and involvement in my life. Most of all I respect her. She is the strongest woman I know and that's why I have turned out so strong and independent.

    Michelle Kwan was born on July 7, 1980, in Torrance, California. The daughter of Hong Kong immigrants (移民), Kwan watched her older brother play ice hockey as a kid. She began skating when she was five, and entered and won her first figure skating competition at seven. She won the world title in the 1994 World Championships at the age of 13, and earned a spot as an alternate (候补者) for the 1994 Olympic Games. Kwan went on to capture the world title in 1996, 1998, 2000, 2001 and 2003.

    At the Nagano Winter Olympics in 1998, Kwan was believed to win gold, but ended up with a disappointing silver medal when fellow US skater Tara Lipinski surprisingly took first place. Shortly before the Salt Lake City Winter Olympics in 2002, Kwan, who was then the reigning world champ, surprisingly fired both her choreographer (编舞者), Lori Nichol, and longtime coach, Frank Carroll. Once again, she failed to get the gold medal when she finished third behind Irina Slutskaya of Russia and US skater Sarah Hughes, who took first.

    As a student at the University of California at Los Angeles, Kwan has continued to compete since her defeat (战败) in Salt Lake City. In February 2006, she was unable to take part in the Olympic Games in Torino, Italy because of a serious injury. Though Michelle Kwan did not compete during the 2006－2007 figure skating season, she has turned down an offer to work for NBC Sports and says she is not retiring.

    Working or learning in a foreign country can be a difficult experience. The hardest part of working abroad isn't finding a place to stay or learning the language. It's learning to overcome the culture shock.

    These things are part of everyday life, and include many signs, gestures, facial expressions, and customs. When we enter a new culture, these cues (提示)are usually not present or so different that they're no longer understandable to us.

    "When a person enters a foreign culture," wrote Oberg, "all or most of these familiar cues are eliminated. He or she is like a fish out of water. No matter how broad-minded he or she may be, lots of props(支柱) have been knocked out from the environment."

    This is what happened to Lara, a young IT consultant (顾问) from America moved last year to their company in southern Europe. Three weeks after she arrived in Europe. Lara sent a desperate e-mail begging to return home. "The people are so unfriendly, "Lara wrote ,"They eat at strange hours and I'm starting to get allergic (过敏的)to the local food. I can't get anything done because their way of doing business is so disorganized and so inefficient and I have a terrible skin itch because of the water. I want to come home! "

    What Lara and other IT consultants meet on their first assignment abroad is a culture shock. While you can't prevent the culture shock from happening, you can take some measures to cut down its effects.