People always think men are more skilled than women in driving. Nowadays women appear to have a positive image of themselves as safer drivers than men.

    In a survey done for insurer MetLife, 51% of women said they drive more safely. The evidence is on their side: Men are 3.4 times more likely than women to get a ticket for careless driving and 3.1 times as likely to be punished for drunk driving. “Women are on average less aggressive and more law abiding (守法的) drivers, which leads to fewer accidents.” the report says. However, not all male drivers share the same opinion. Of the men surveyed by MetLife, 39% claimed male drivers were safer. The findings did back them up on one point: automotive knowledge. The report showed that more men are familiar with current safety equipment such as electronic stability control, which helps prevent rollover accidents.

    Auto safety unavoidably matters to money. Insurance companies focus on what classes of drivers have the lowest dollar amounts of claims, and for now, that mainly includes women. In general, women pay about 9% less for auto insurance than men. A study by the website Insweb also showed that auto insurance rates are lower for women in most states. Among individual states, women get the greatest advantage in Wyoming (where they pay 20% less), South Dakota and Washington, D. C., where their insurance costs are 16% lower.

    “More than 11,900 male drivers died in U.S. traffic accidents in 2009, compared with just under 4,900 women drivers,” according to the study. “Based on miles traveled, men died at a rate of 2.5 deaths per 100 million miles traveled, v.s. 1.7 deaths for women.”

    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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    Our warming planet is expected to face serious water crisis（危机）in the coming decades — which means each nation's natural resource will be more important than ever.

    In the fall of 1985, I was a bright-eyed girl heading off to Howard University, 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 adopted 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 fully occupied I became, raising four boys under the age of 8! Our home was a complete zoo — a joyous zoo. Not surprising, I never did make it back to college fulltime. 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.

    Getting stitched(缝合)up by Dr. Robot may one day be reality. Scientists have created a robotic system which did just that in living animals without a real doctor pulling the strings. Much like engineers are designing self-driving cars, the medical research is part of a move toward autonomous surgical robots, removing the surgeon's hands from certain tasks that a machine might perform all by itself.

    Doctors wouldn't leave the bedside they're supposed to watch, plus they'd handle the rest of the surgery. In small tests using pigs, the robotic arm performed at least as well, and in some cases a bit better, as some competing surgeons in stitching together intestinal(肠的)tissue. “The purpose wasn't to replace surgeons,” said Dr. Kim who led the project. “If you have all intelligent tool that works with a surgeon, can it improve the outcome? That's what we have done.”

    If you've heard about machines like the popular Da Vinci system, you might think robots already are operating. Not really. Today many hospitals offer robot-assisted surgery, where surgeons use the machinery as tools that they control by hand, typically,to operate through tiny openings in the body. But robot-assisted surgery has been controversial, as some studies have shown it can bring higher costs without better outcomes.

    Kim's team at Children's Sheikh Zayed Institute invented the new STAR system—it stands for Smart Tissue Autonomous Robot—works sort of like a programmable sewing machine. They added sensors to help guide each stitch and tell how tightly to pull. But the approach wasn't perfect. In the living animals, the robot took much longer and made a few stitching mistakes while the surgeon sewing by hand made none. Kim said the robot can be sped up. Fie hopes to begin human studies in two or three years.

    If you follow these insider tips, your photos will look like you had the place to yourself at the popular tourist attractions.

    Vatican Museums: Vatican City

    The Vatican draws more than five million people each year, and queues can reach four hours during peak season. Christie Hudson, senior communications manager at Expedia, recommends, choosing a skip-the-1ine tour. "This not only lets you avoid the ticket counter, but also includes the use of a private partner entrance." Extra time to visit the Sistine Chapel? Yes!

    Bamboo Forest: Kyoto, Japan

    Bamboo Forest is the most worthy sight in Kyoto. If you're longing to enjoy the pathways and take pictures in total quietness, Kyoto Arashiyama Travel Guide recommends hitting the famous Bamboo Grove Path as early in the morning as possible—think 7 a.m. if you're up for it. Don't miss these hidden treasures you can only witness in Japan.

    Chichen Itza: Yucatán, Mexico

    Home to E1 Castillo and the Temple of the Warriors, Chichen Itza is a must-see. Want to beat the rush? Schedule an early tour that takes place before a site opens to the public. Led by an archaeologist guide, it's full of fascinating insights and facts—without tons of pack-wearing tourists.

    Louvre Museum: Paris, France

    The Louvre is one of the most popular museums on the planet. If waiting around in line to get in isn't the way you prefer to spend your time in Paris, consider purchasing a reserved ticket. This will give you entry to the pyramid within a half-hour window. The Louvre is also open until 9:45 p. m. on Wednesdays and Fridays, if you're up for some late-night art visits.