In France, a man walks on what can only be described as a human-sized hamster wheel. The wheel moves around and around, as the man keeps walking. What is he doing? He is lifting a heavy object to the top of a tower the same way workers moved such objects 800 years ago.

    In the 13th century, workers did not have the 100-meter tall cranes they now use to build tall buildings. So they had to be creative and come up with simple machines to get their work done.

    The man on the large wheel is walking at a reasonable speed. The wheel turns and pulls a rope connected to a pulley(滑轮)at the top of the tower. Another rope tied to the pulley lifts supplies from the ground.

    This is just one way skilled craftsmen arc building a 13th-century castle without using modern tools. Crew have been working on the castle since 1997. It is being built in the Burgundy area of central France. Organizers expect the work to last another 10 to 15 years. That means it will take close to 30 years to finish the project.

    The crew are making progress at about half the speed of the workers from 800 years ago. That is because many of them are accustomed to using modern tools. When the crew use heavy chisels(凿子）and hammers to break rock, as they did hundreds of years ago, they are learning as they go. The goal of the project is to learn more about old building techniques in case they might be of use today.

    Clement Guerard, 44,is a stonemason; he cuts and builds with stone. He has been working on the tower for 17 years. He said one way he is able to work on something like this for so long is by forgetting “some of the pace of modern life", he is able to adapt to working by hand.

    If we are observant(善于观察的), we can find that most of the flowers in nature are red, orange and yellow. If we have seen a black flower, it is a chance in a million. People have made census (统计) to colors of more than four thousand kinds of flowers and discovered that only eight of them are black. Why are black flowers so rare?

    As we know, sunlight is formed by seven different kinds of colored light. The wave length of each light changes, so the quantity of heat in each light changes, too. Flowers, especially their petals (花瓣) , are very weak and easy to the harm caused by high temperature. Black flowers can take in all the light waves, which cause the flowers to dry up in a high temperature. So the black flowers can hardly continue their lives. While red flowers, orange flowers and yellow ones can protect themselves from sunlight by reflecting（反射） the red light, orange light and yellow light, each of which has a large quantity of heat.

    That is why red, orange and yellow flowers are very common in nature while black flowers are so unusual.

Dear World:

    My son starts school today. It's going to be strange and new to him for a while. And I wish you would sort of treat him gently.

    You see, up to now, he's been king of the house. He's been boss of the backyard. I have always been around to repair his wounds, and to ease his feelings.

    But now things are going to be different.

    This morning, he's going to walk down the front steps, wave his hand and start on his great adventure that will probably include wars and tragedy and sorrow.

    So, World, I wish you would sort of take him by his young hand and teach him the things he will have to know. Teach him but gently, if you can. Teach him the wonders of books. Give him quiet time to ponder(思考) the eternal mystery of birds in the sky, bees in the sun, and flowers on the green hill. Teach him it is far more honorable to fail than to cheat. Teach him to have faith in his own ideas, even if everyone else tells him they are wrong. Teach him to sell his physical strength and brains to the person who offers the most money, but never to put a price on his heart and soul. Teach him to close his ears to a criminal gang (团伙) ...and to stand and fight if he thinks he's right. Teach him gently, World, but don't coddle him, because only the test of fire makes fine steel.

A Mother

Seeds on Ice

    Close to the North Pole, remote and rocky Plateau Mountain in the Norwegian archipelago of Svalbard seems an unlikely spot for any global effort to safeguard agriculture. In this cold and deserted environment, no grains, no gardens, no trees can grow. Yet at the end of a 130-meter-long tunnel cut out of solid stone is a room filled with humanity's most precious treasure, the largest and most diverse seed collection—more than a half-billion seeds.

    A quiet rescue mission is under way. With growing evidence that unchecked climate change-will seriously affect food production and threaten the diversity （多样性） of crops around the world, the Svalbard Global Seed Vault （地窖） represents a major step towards ensuring the preservation （贮藏） of hundreds of thousands of crop varieties. This is a seed collection, but more importantly, it is a collection of the traits found within the seeds: the genes that give one variety resistance to a particular pest and another variety tolerance for hot, dry weather.

    Few people will ever see or come into contact with the contents of this vault. In sealed boxes, behind multiple locked doors, monitored by electronic security systems, enveloped in below—zero temperatures, and surrounded by tons of rock, hundreds of millions of seeds are protected in their mountain fortress. Frozen in such conditions inside the mountain, seeds of most major crops will remain viable for hundreds of years, or longer. Seeds of some are capable of retaining （保留） their ability to grow for thousands of years.

    Everyone can look back now and say that the Seed Vault was a good and obvious idea, and that of course the Norwegian government should have approved and funded it. But back in 2004, when the Seed Vault was proposed, it was viewed as a crazy, impractical, and expensive idea.

    We knew that nothing would provide a definite guarantee. But we were tired, fed up, and frankly scared of the steady, greater losses of crop diversity. The Seed Vault was built by optimists who wanted to do something to preserve options so that humanity and its crops might be better prepared for change. If it simply resupplied seed gene banks with samples those gene banks had lost, this would repay our efforts.

    The Seed Vault is about hope and commitment-about what can be done if countries come together and work cooperatively to accomplish something significant, long-lasting, and worthy of who we are and wish to be.

    As long as people have been telling stories, crones(丑陋的老太婆)have been scaring the wits out of children. "Nags(怨妇),witches, evil stepmothers, cannibals(食人妇). It's quite dreadful," says Maria Tatar, who teaches a course on folklore and mythology at Harvard. "But old women are also powerful—they're often the ones who can work magic." In the Disney film Snow White, there's a scene in which the beautiful, charming, wicked queen turns into an old hag and poisons Snow White so she'll sleep forever. The old lady in Hansel and Gretel wants to roast children in her oven and the witch in The Little Mermaid cuts out Ariel's tongue.

    Tatar says old women villains (恶人)are especially scary because，historically, the most powerful person in a child's life was the mother. "Children do have a way of splitting the mother figure into...the evil mother—who's always making rules and regulations, policing your behavior, getting angry at you—and then the kind mother—the one who is giving and protects you, makes sure that you survive."

    Veronique Tadjo, a writer who grew up in the Ivory Coast, thinks there's a fear of female power in general. She says a common figure in African folk tales is the old witch who destroys people's souls. Still, they're not all bitter and evil hags. Elderly women in folk tales often use their knowledge and experience of the world to guide the troubled protagonist(主人公). Tadjo points to the Kenyan story Marwe In The Underworld about a girl who commits suicide by drowning herself and enters the Land of the Dead where she meets an old woman. "That old woman teaches her quite a lot of things," Tadjo says. "And also, when Marwe starts longing for the world of the living, she helps her go back to the surface with a lot of riches. And we understand that Marwe has been rewarded for her goodness." In other words: Do your chores and you'll be rewarded. The point of these ancient tales, no matter what continent they come from, may have been to scare children into behaving.

    Perhaps the scariest old woman character—the ugly Baba Yaga—comes from Russia. She's bony with a hooked nose and long, iron teeth. Her hut(小屋)stands on chicken legs and she kidnaps children and eats them. Safe to say Baba Yaga has been making Eastern European children sleepless for centuries. In one interpretation, a mean stepmother sends the young girl Vasilisa to Baba Yaga's hut in the woods to get a candle. The girl is sure she's being sent to her death. Baba Yaga forces her to cook and clean, and Vasilisa does everything she's told. In the end, the old crone gives her what she needs and sends her home. "You see this kind of double face of the hag,"Maria Tatar says. "On the one hand: aggressive, threatening. And on the other hand: sometimes to make sure that there is a happily ever after."

    There's that power again. In Japanese folklore, the Yama Uba(山姥)is an equally ambiguous old woman. She's a mountain witch who, like Baba Yaga, lures people into her hut and eats them. But she'll also help a lost traveler. Noriko Reider is a professor at Miami University of Ohio who's done extensive research on Yama Uba stories. "She brings fortune and happiness," Reider says. "She can also bring death and destruction for those who are not very good."

    According to Cuban-American writer Alma Flor Ada, in Hispanic(拉美地区的)culture old women are multi-talented. Ada is co-author of Tales Our Grandmas Told, which includes a story about Caliph's son who becomes seriously ill. After "all of the best physicians in the land" fail to cure him, Caliph sends his messengers searching for help. Then one morning, an old woman arrives with this advice: To get well, the prince must wear the overcoat of a man who is truly happy. And of course it works.

    On the night of December 8, 1992, when he was standing in a parking lot talking to friends, Tracy March jumped to the top of a car, as he had done a hundred times before. This time, though, Tracy lost his balance. His head struck the ground, hard.

    All night, Cory, Tracy's mother, stood next to her son, who was lying in a hospital bed, his brown eyes fixed in a lifeless stare. She remembered that Tracy had once mentioned organ donation. Maybe I can spare another family this pain, she thought. When the time came, she and her husband Bill signed the forms permitting his organs to be donated.

    Tracy was declared dead the next day. Twenty-four hours later, in a Boston hospital, Tracy's liver was made part of my husband, David, who was suffering from a hopeless liver disease.

    Months later, we learned from the local organ bank that the donor's parents wished desperately to meet someone who had gained life through the gift from their son. A meeting was arranged by the organ bank to bring together two families linked by the most bittersweet ties imaginable.

    The meeting was risky, but worth it. We talked for 3 hours. They showed us a picture of Tracy. We learned how he had lived and died. We learned something about Bill and Cory too.

    For the Marches, seeing David and knowing he was well seemed to ease their suffering. I'll never forget seeing David's tall figure stopped over Cory, her arms around his waist, as a mother would hug a son. For a long time they held each other tight. It was hard to know if she was saying hello or good-bye. Maybe she was saying both.