A report says older adults who test their minds with increasingly difficult projects have better mental ability than those who do less demanding activities.

    To keep our brains sharp as we age, we are often told to keep our minds active. As the old saying goes, “Use it or lose it.” But, there is very little scientific evidence to support than.

Denise Park is head of the university's Center for ? Vital Longevity. She designed a study in which she and her tern placed 221 healthy aging and older adults into one of three groups.

    “We asked people to learn new things, like quilting or photography. We asked other people to just do fun things like being in a social group function but were not likely to have a very large effect.”

    The subjects took part in their assigned activities for 15 hours a week over three months. At the end of that time, the researchers found that the adults who learned new skills, such as digital photography, showed the greatest improvements on memory tests.

    No improvements were seen in the results of those in the social group that did activities together like going on field trips. There were also no improvements among the third group that listened to classical music or did crossword puzzles.

    Denise Park believes one reason for improved memory in the active learning group is that its members were being pushed to learn new skills. The other groups took part in what she call receptive activities. Learning new skills may not cure age-related mental decline. But, Ms. Park thinks being mentally active slows down the process.

Denise Park says the latest information shows that the improvements lasted for at least a year. She and her team plan to do longer follow-up studies with all three groups. She also is interested in learning whether taking part in demanding mental activities delays the development of conditions like Alzheimer's disease.

    The Nazca Lines are a series of large ancient geoglyphs (地画) in the Nazca Desert, in southern Peru. It is ranging from geometric patterns to drawings of different animals and stylized human-like forms. The ancient lines can only be truly taken in from high in the air, leaving generations puzzled as to how these precise works could have been completed long before the documented invention of human flight.

    The Lines were first spotted when commercial airlines began flying across the Peruvian desert in the 1920,s. Who built them and what was their purpose? Are they roads, star pointers，maybe even a gigantic map? If the people who lived here 2,000 years ago had only a simple technology, how did they manage to construct such precise figures? Did they have a plan? These markings are like a vast puzzle.

    The Nazca Lines are the most outstanding group of geoglyphs in the world. There are also huge geoglyphs in Egypt, Malta，United States (Mississippi and California), Chile，Holivia and in other countries. But the Nazca geoglyphs, because of their numbers， characteristics, dimensions and cultural continuity as they were made and remade throughout a certain history period, form the most impressive archeological (考古学的) group.

    The Nazca plain is unique for its ability to preserve the markings upon it, due to the combination of the climate (one of the driest on Earth, with only twenty minutes of rainfall per year) and the flat, stony ground which minimizes the effect of the wind at ground level. With no dust or sand to cover the plain and little rain or wind to erode (腐蚀) it, lines drawn here tend to stay drawn. These factors, combined with the existence of lighter-colored subsoil beneath the desert surface, provide a vast writing pad that is suited to the artist who wants to leave his mark eternal.

    For most of my 20 years as a teacher, summer vacation was my time to relax. So why was I standing in the schoolyard of an unfamiliar school, wearing myself out for a summer teaching job? The extra paychecks were nice, but I lacked the energy of my younger colleagues. Like Stella. She was in her early twenties, and made keeping up with the kids look effortless. She reminded me of myself, back when I was a bright-eyed student teacher at Ramona Elementary…

    I'd never forget my first day. I was too full of energy. Nervous energy. My supervising teacher was watching, and I wanted to make a good impression. I asked my third graders to take out their crayons for the day's lesson. All of them obeyed. Except one. A girl with two long, dark braids(辫子). Everyone called her Estrellita, or “little star.” Why was she unprepared for class? I demanded to know.

    “My sister has my crayons,” she said.

    “You should each have your own crayons,” I told her. “That's no excuse.”

    “There are 10 children in my family,” Estrellita said quietly, her big brown eyes never leaving my face. “We have to take turns.”

    I was taken aback. I'd completely misjudged the situation. All day Estrellita's words played on my mind. The next morning I bought a pack of crayons to leave on Estrellita's desk. She was so happy! That experience taught me an important lesson. Every student had a unique set of challenges—it was my mission to help my students overcome them. That mission used to energize(激励 )me.

    Rest was almost over. Stella turned to me and we started chatting. “How long have you been teaching?” she asked. I told her I'd started twenty years before, at Ramona Elementary.

    “I went to school there twenty years ago!” Stella said. I looked at her again, this time really seeing her. Those big brown eyes. That long, dark hair...

    “Did you use to have two long braids?” I said. “We called you Estrellita… ”

    Stella shouted. “ You ! You gave me the crayons!”

She'd become a teacher. To help students like I did. Even doing something that small mattered.

    That summer, I threw myself into teaching with a renewed sense of purpose. Estrellita had taught me a lesson once again.

    We know that St. Patrick's Day festivities may include a little bit of drinking. But there are plenty of kid-safe St. Patrick's Day events around metro Phoenix, too. Here are the lucky St. Patrick's Day celebrations for kids.

    3/17: Lucky St. Patrick's Day Cupcakes

    Kids can make their own treats at the Children's Museum of Phoenix this St. Patrick's Day. Children can make and decorate their cupcakes with rainbow candies and chocolate. To-go containers will also be provided.

    Details: 1-3 p.m. Friday, March 1. Children's Museum of Phoenix, 215 N.7^th Street, Phoenix. $ 3 for members. $ 4 for non-members. 602-253-0501.

    3/17-19: Fountain O' Green Artisan Market

    This community festival will include sculptures, paintings, handcrafted jewelry and clothes from selected local and regional artists, live music and dance performances throughout the weekend. There will also be a food court.

    On Friday, emerald-colored water will shoot from the town's fountain at noon. Take the kids to see the annual tradition and picnic in the park.

    Details: 10 a.m.-5 p.m, Friday-Sunday, March 17-19.Avenue of the Fountains and Saguaro Boulevard, Fountain Hills. Free. 480-488-2014.

    3-17: St. Patrick's Day Party at AZ Air Time

    Kids above 12 years old can collect their free, green glow necklaces and jump for three hours, scale the rock climbing wall or dive into the giant pit of foam（泡沫橡胶）. Jump socks required.

Details: 8-11p.m. Friday, March 17. AZ Air Time, 13802 N. Scottsdale Road, Suite 145, Scottsdale. $15, which is a $14 savings. 480-427-2000.

    Tom arrived at the bus station quite early for the London bus. The bus for London would not leave until five to twelve. He saw a lot of people waiting in the station. Some were standing in lines, others were walking about. There was a group of school-girls. Their teacher was trying to keep them in order. Tom looked around but there was nowhere for him to sit.

    He walked into the station cafe. He looked up at the clock there. It was only twenty to twelve. He found a seat and sat down, facing a large mirror(镜子) on the wall. Just then, John, one of Tom's friends, came in and sat with Tom.

    "What time is your bus?" asked John.

    "Oh, there is plenty of time yet," answered Tom.

    "Oh, I'll get you some more tea then," said John.

    They talked while drinking. Then Tom looked at the clock again.

    "Good heavens! It's going backward!" he cried. "A few minutes ago it was twenty to twelve and now it's half past eleven."

    "You are looking at the clock in the mirror," said John.

    Tom wanted to kick himself for being so foolish. The next bus was not to leave for another hour. He has never liked mirror since then.

    A dog spent the last four years of his life waiting a crossroad in the Thai city of Khon Kaen as if waiting for someone. People originally thought the dog had been abandoned, but then realized that he looked healthy, so people asked around about him. It turned out that the dog had indeed been spending most of his time around that crossroad, but a woman had been coming round regularly to bring him food and water.

    One day, while photographing the dog everyone called Leo, a reporter met the woman who had been taking care of him. She had come to drop off some food. After learning the story about the dog and the woman, the reporter decided to share the story on social media. The post soon went viral and the photos of Leo got shared hundreds of times. And the photos reached the eyes of Leo's former old owner.

    Nang Noi Sittisarn, a 64-year-old woman from Thailand's Roi Et Province, almost had a heart attack when her daughter showed her a photo of the beloved dog named BonBon she had lost during a car trip. When she learned that he had been waiting for her in the same spot for the last four years, her heart melted(融化).

    Auntie Noi told her daughter to drive her to where the dog was waiting. When she got there and called his name. BonBon, the poor dog started wiggling(扭动)his tail and came to her, but when she tried to take him home with her, he was unwilling to follow. She didn't want to force the dog to come with her so she agreed to leave him with his new master. However, she and her daughter will come to visit him regularly.