In England, people often talk about the weather because they can experience (经历) four seasons in one day. In the morning the weather is warm just like in spring. An hour later black clouds come and then it rains hard. The weather gets a little cold. In the late afternoon the sky will be sunny, the sun will begin to shine, and it will be summer at this time of a day.       

    In England, people can also have summer in winter, or have winter in summer. So in winter they can swim sometimes, and in summer sometimes they should take warm clothes.     

    When you go to England, you will see that some English people usually take an umbrella (伞)or a raincoat with them in the sunny morning, but you should not laugh at them.     

    If you don't take an umbrella or a raincoat, you will regret (后悔) later in the day.     

    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 fall of 1985, I was a bright-eyed girl heading off to Howard University to study law, aiming at a legal career and dreaming of sitting on a Supreme Court bench somewhere. Twenty-one years later I am still a bright-eyed dreamer and one with quite a different tale to tell.

    My grandma, an amazing woman, graduated from college at the age of 65. She was the first in our family to reach that goal. But one year after I started college, she developed cancer. I made the choice to withdraw from college to care for her. It meant that school and my personal dream would have to wait.

    Then I got married with another dream: building my family with a combination of adopt and biological children. In 1999, we adopted our first son. To lay eyes on him was fantastic and very emotional. A year later came our second adopted boy. Then followed son No.3. In 2003, I gave birth to another boy.

    You can imagine how busy I became, raising four boys under the age of 8. Our home was a complete zoo--a joyous zoo. Not surprisingly, I never did make it back to college full-time. But I never gave up on the dream either. I had only one choice: to find a way. That meant taking as few as one class each semester.

    The hardest part was feeling guilty about the time I spent away from the boys. They often wanted me to stay home with them. There certainly were times I wanted to quit, but I knew I should set an example for them to follow through the rest of their lives.

    In 2007, I graduated from the University of North Carolina. It took me over 21 years to get my college degree!

    I am not special, just single-minded. It always struck me that when you're looking at a big challenge from the outside it looks huge, but when you're in the midst of it, it just seems normal. Everything you want won't arrive in your life on one day. It's a process. Remember: little steps add up to big dreams.

    One night, the first floor of the house suddenly caught fire. The fire was big, and soon became a sea of fire. On the second floor lived a little girl and her grandmother; the little girl's parents had died, and she lived together with her grandma. In order to rescue the little girl, the grandmother was burned to death, leaving the little girl crying for help loudly.

    How could people enter the house? At the very moment, a man carrying a ladder rushed to the flames and got into the window. When he appeared again in the eyes of the people, the little girl was in his arms. He gave the child to the crowd, and then disappeared into the night.

    This little girl had no family. Two months later a meeting was held to find a person to adopt (收养) the girl. A teacher was willing to adopt this child, and said she could give her the best education; a farmer wanted to adopt this child, saying that village life would let the child grow up healthily and happily; a rich man said, “I can give the child everything that others can do.”

    A lot of people who wanted to adopt this child said about many benefits of their adopting the child. But the little girl's face had no expression. At this time, a man, through the crowd, walked straight in front of the little girl, and opened his arms for the little girl. People were puzzled, and they found that the man had terrible scars on his arms. The little girl let out a cry, “This is the man who saved me!” She suddenly jumped up, and buried her face in his arms and sobbed. Naturally the man adopted the girl.

New App Helps People Remember Faces

    Large gatherings such as weddings and conferences can be socially overwhelming. Pressure to learn people's names only adds to the stress. A new facial-recognition app could come to the rescue, but privacy experts recommend proceeding with caution.

    The app, called SocialRecall, connects names with faces via smartphone cameras and facial recognition, potentially avoiding the need for formal introductions. "It breaks down these social barriers we all have when meeting somebody," says Barry Sandrew, who created the app and tested it at an event attended by about 1,000 people.

    After receiving an invitation to download SocialRecall from an event organizer, the user is asked to take two selfies and sign in via social media. At the event, the app is active within a previously defined geographical area. When a user points his or her phone camera at an attendee's face, the app identifies the individual, displays the person's name, and links to his or her social media profile. To protect privacy, it recognizes only those who have agreed to participate. And the app's creators say it automatically deletes users' data after an event.

    Ann Cavoukian, a privacy expert who runs the Privacy by Design Center of Excellence praises the app's creators for these protective measures. She cautions, however, that when people choose to share their personal information with the app, they should know that "there may be unintended consequences down the road with that information being used in another context that might come back to bite you."

    The start-up has also developed a version of the app for individuals who suffer from prosopagnosia, or "face blindness," a condition that prevents people from recognizing individuals they have met. To use this app, a person first acquires an image of someone's face, from either the smartphone's camera or a photograph, and then tags it with a name. When the camera spots that same face in real life, the previously entered information is displayed. The collected data are stored only on a user's phone, according to the team behind the app.

    Scientists have connected the "fat gene" with the "happy gene". They believed there could be genetic evidence which explains why fat people are often happier than their skinny friends. The breakthrough could be an explanation for why fat characters, such as The Laughing Policeman and Father Christmas are often described as joyful and kind.

    FTO is the major genetic contributor to being fat. But it is also connected with an eight percent reduction in the risk of depression. Researchers at McMaster University in Canada had been studying whether there was a connection between being fat and being depressed. They found the opposite was true.

    They studied 17, 200 DNA from participants in 21 countries. Results showed people with FTO gene—the fat gene—showed less signs of depression. This finding was supported by three additional international studies.

    Professor David Meyre said, "We set out from the belief that being depressed and being fat both deal with brain activity. We thought that fat genes may be related to depression. However, we have discovered a molecule (分子) contributing to depression. It is the first evidence that an FTO fat gene is connected with protection against depression.

    In a recent interview, actress Lisa Riley said she was more than comfortable with her size. She said she is a "big, really happy" girl who is lucky enough to be confident in her own skin, and added, "Many people want to be thinner. Not me. I love being different and it drives me mad that people don't believe I'm happy with what I am."