Hummingbirds(蜂鸟) are one of nature's most energetic fliers and the only birds to hover(盘旋) in the air by relying on their strength alone.

    Now scientists have found that it is the ratio(比值) of the bird's wing length to its width that makes them so efficient. The discovery is helping experts compete with 42 million years of natural selection to build helicopters that are increasingly efficient.

    David Lentink, an assistant professor at Stanford University in California, tested wings from 12 different species of hummingbirds, which he sourced from museums. He placed them on a machine used to test the aerodynamics(气力学) of the helicopter blades(桨叶). Professor Lentink's team used the same machine to test the blades from an advanced micro-helicopter used by the UK's army. They found that the micro-helicopter's blades are as efficient at hovering as the average hummingbirds.

    But while the micro-helicopter's blades kept pace with the average hummingbird wings, they could not keep up with the most efficient hummingbird's wing. The wings of Anna's hummingbird were found to be about 27 percent more efficient than the man-made micro- helicopter's blades.

    While Professor Lentink wasn't surprised at nature's superiority, he said that helicopter blades have come a long way. “The technology is at the level of an average hummingbird,” he said. “A helicopter is really the most efficient hovering device that we can build. The best hummingbirds are still better, but I think it's amazing that we're getting closer. It's not easy to match their performance, but if we build better wings with better shapes, we might match hummingbirds.”

    Professor Lentink said that we don't know how hummingbirds maintain their flight in a strong wind, how they navigate(确定方向) through branches, or how they change direction so quickly. He thinks that great steps could be made by studying wing aspect ratios-the ratio of wing length to wing width. Understanding these abilities and characteristics could be a benefit for robotics and will be the focus of future experiments.

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    In the early morning, I head for the back door and find 10 inches of snow covering our home. Oh no, Bryan will have to clear the roof again, I think. But Rio rolls onto his back, playing in the white snow and kicking his back legs, delighted. His days in an animal shelter in New Mexico are long forgotten—he's wholeheartedly enjoyed life as a Colorado dog.

    Rio needs a walk. I've planned to attend an emergent webinar, but my husband is busy clearing. Rio pushes my leg with his snout(口鼻部), wondering why we are still inside. We're late for our morning hike. I pull on my boots reluctantly. I don't have time for this!

    Rio and I walk a block through our neighborhood to the beginning of a road. Rio jumps happily into the snow, which is up to his neck. But I walk slowly with heavy steps, worrying about my to-do list, and I don't notice the world around me until Rio starts barking.

    A squirrel (松鼠) chitters at him from a high branch of a pine tree. We haven't seen a squirrel in at least a week because of all the snow storms, so this is a treat for us.

    Once again, my animal teacher is reminding me to enjoy the present moment, and I'm grateful. I take a deep breath and look around. Suddenly there is an explosion(爆炸) of snow. a nearby tree has released its heavy burden, snapping(迅速恢复) back upright. Silver snowflakes(雪花) dust the air around me as a group of birds flees the area, talking to one another as they fly overhead.

I watch and listen in wonder for what seems like a full minute. There will be 1440 munites on this day, but this is the one I'll remember most. Then I look back to the earth and there is my sweet dog, waiting patiently for a treat. He knows I'll want to celebrate this moment we've just shared. “I love you, Rio!” I say as I give him a cookie. He has trained me well!

    When we walk home, I smile broadly, spirit washed clean, ready for whatever the day may bring.

    During his first week as a new Atlanta police officer, Officer Che Milton answered a call for shoplift at the nearby Family Dollar store. When he arrived, Milton found a 12-year-old girl in tears over trying to steal a $2 pair of shoes. Crying, she told Milton that the shoes were supposed to surprise her 5-year-old sister.

    Milton, instead of arresting the girl, asked her to take him to her home instead. When he arrived, Milton's heart sank. He found a house nearly empty, with only a sofa and sheets on the floor instead of beds. There was no food in the kitchen and the kids were there. The girl's mother told the officer that her husband worked but didn't make much money and that she couldn't afford to do the same with several children to take care of and no daycare money to spare.

    Moved, the officer drove to a restaurant and bought four pizzas for them and he called the Division of Family and Children Services and asked if there was a social worker who could help.

    When the police department found out about Milton's trips, instead of punishing him, the department decided to share his story on Facebook and added that “not only is he here to enforce(实施) the law but also to go the extra mile and be a bigger part of the community he is policing.”

    Hundreds of citizens liked the post, asking how they could help. The department followed with posts including the six children's sizes and mother's clothing sizes. It also called for blanket and furniture donations. Visit the posts to learn how you can help and find more useful ways to donate your old things.

    A Canadian man is asking forgiveness for a birdbrained thing he did 17 years ago: inadvertently（无心地） encouraging seagulls to trash his hotel room.

    Back in 2001, Burchill checked into the Fairmont Empress Hotel in Victoria, B.C, for a business meeting. He brought a small suitcase full of Brothers Pepperoni from his hometown to share with former Navy buddies in the area. But his room had no fridge so he opened a window to keep it cool. And then he went for a long walk. That was when things got messy. Really messy. The result was such a housekeeping nightmare that the hotel permanently banned him.

    “I remember walking down the long hall and opening the door to my room to find an entire flock of seagulls in my room. There must have been 40 of them and they had been eating pepperoni for a long time.” Burchill said.

    When he walked into the room, Burchill recalled he frightened the birds. They “immediately started flying around and crashing into things as they desperately tried to leave the room.” The result was a tornado of seagull feathers, pepperoni chunks and fairly large birds whipping around the room. The lamps were     falling. The curtains were trashed. The coffee tray was just disgusting.

    Eventually, Burchill called the front desk and requested help cleaning up the room. “I can still remember the look on the lady's face when she opened the door. ”said Burchill. A short time later, he received a note from the hotel saying he'd been banned for life.

    Recently, Burchill visited the hotel to apologize in person, in hope of making amends with the woman who had to clean the seagull-and-pepperoni-trashed room, but was told she was no longer there.

    “When I was talking to the people at the desk and the manager, they did say that they had heard this story from a long-term employee that works there,” said Burchill, “I was just kind of in and out. I didn't     want to overstay my welcome.” So he apologized and was forgiven. Burchill left them a present of about a pound of Brothers Pepperoni as a peace offering. It seemed to have worked.

    The world's first luxury space hotel, Aurora Station, was announced Thursday at the Space 2.0 Summit in San Jose, California. Developed by US-based space technology start-up Orion Span, the space station will host six people at a time, including two crew members, for 12-day trips of space travel. It plans to welcome its first guests in 2022.

    "Our goal is to make space accessible to all," Frank Bunger, CEO and founder of Orion Span, said in a statement." Upon launch, Aurora Station goes into service immediately, bringing travelers into space quickly and at a lower price point than ever seen before."

    While a$10 million trip is outside the budget of most people's two-week vacations, Orion Span claims to offer an authentic astronaut experience. "It has taken what was historically a 24-month training to prepare travelers to visit a space station and streamlined(精简)it to three months, at a fraction(小部分)of the cost," says Bunger. During their 12-day adventure, the super-rich travelers will fly at a height of 200 miles above the Earth's surface in Low Earth Orbit, where they will witness incredible views of the blue planet. The hotel will orbit Earth every 90 minutes, which means guests will see around 16 sunrises and sunsets every 24 hours.

    Activities on board include taking part in research experiments such as growing food while in orbit, which guests can take home for a super-smug souvenir, and soaring over their hometown. Guests can have-live-video chats with their less-fortunate loved ones back home via high-speed wireless Internet access and, upon(return to Earth will be greeted with a specially arranged hero's welcome. While enjoying the thrills of zero gravity, the travelers will be able to float freely through the hotel, taking in views of the northern and southern aurora from the station's windows.   Deposits are already being accepted for future stays on the space hotel.

Are Happy Meals Really Happy?

    Don't we all know a “Happy Meal” when we see one--the famous boxed meal that includes a hamburger, kid-sized French fries, fruits and milk, served with a toy that's extremely popular with children who love to collect them?

    A Happy Meal is a form of kids' meal sold at a certain fast-food chain since 1979. A toy is included in the meal, both of which are usually contained in a box or paper bag. However, collectors of these little toys will not get them any longer, since the company will replace toys with books and each of these books will mainly pass on nutritional messages.

    Happy Meals are extremely popular with kids, especially for their collectable toys, when you consider that over 1.3 billion of these packages are sold each year. These packages have been very controversial. Health supporters believe that drawing kids to these meals with toys is a clever way of promoting unhealthy food choices. They see it as an advertising a strategy of “catching its customers young”--a move that has paid off very well for the fast-food company.

    Child development experts say that food habits get formed in children by age six and continue through to their adult life. Fatty and sugary foods such as those served in Happy Meals are believed to play a big role in growing health problems such as obesity and diabetes. Public health care costs have gone up and untold amounts of money have been spent on coping with these health problems. On November 2, 2010, the San Francisco Board of Supervisors passed a law requiring that children's meals sold in restaurants must meet certain nutritional standards before they could be sold with toys, to overcome the problem of childhood obesity--in other words, the State of California tried to ban the toys in Happy Meals. However, it was strongly opposed by some as being heavy-handed, and the ban was thrown out by the government.

    While some people believe that the fast-food company, with its large following of children, can create a powerful message through the books, others believe its actions are contradictory. Anyway, the company is trying to spread the message of nutrition while it is serving food that is anything but healthy.