March 21 has been declared World Sleep Day, a time to recognize and celebrate the value of sleep. Many sleep experts hope it will be a wake-up call.

    According to a 2016 poll（民意调查）by the National Sleep Foundation, nearly 4 in 5 Americans don't get as much sleep as they should during the workweek. On average, adults are thought to need at least eight hours of sleep a night, although some can manage with less and some won't do well without more. But the survey found that, on workdays, only 21% of Americans actually get a full eight hours of sleep, and another 21% get less than six.

    To many of us, the thought of spending more time sleeping is, well, a big yawn. On the other hand, the thought of being smarter, thinner, healthier and more cheerful has a certain appeal. And those are just a few of the advantages that can be ours if we consistently get enough sleep,  researchers say. Also on the plus side： We're likely to have better skin, better memories, better judgment, and, oh, yes, longer lives.

    "When you lose even one hour of sleep for any reason, it influences your performance the next day, " says Dr. Alon Avidan, director of the UCLA Sleep Disorders Center.

    A study published last year found the same to be true even of children.  When kids aged 8 to 12 slept for just one hour less for four nights, they didn't function as well during the day.

    But sleeping has an image problem. "We see napping or sleeping as lazy, " says Jennifer Vriend, a clinical psychologist in Ottawa, Canada, and the leading author of the study with children. "We put so much emphasis on diet, nutrition and exercise. Sleep is in the back seat. " In fact, she adds, no matter how much we work out, no matter how well we eat, we can't be in top physical shape unless we also get plenty of sleep.

    While visiting the North pole in winter may not be at the top of your bucket list, the ever-changing ICEHOTEL, which opened its doors to visitors on December 14 this year, may change your mind.200 km north of the Arctic Circle in the Swedish village of Jukkasjārvi, the hotel, which is carved entirely from ice, is rebuilt annually.

    The 35 rooms, built to accommodate visitors on all kinds of budgets, vary from expensive suites to basic rooms that are furnished with just an icy bed and a reindeer skin. Among the highlights this year is the “Spruce Woods” suite. Sculpted by Christopher Pascoe and Jennie O'Keefe of Canada, it describes a camping scene complete with a classic microbus, a forest, and even an artificial campfire.

    There is also the artfully-carved “Living Ocean” suite to remind visitors of the importance of saving our oceans. The room is full of carved sea life that includes coral and a shark “swimming” right over the ice bed. “The suite is inspired by global warming and the overfishing that affects our oceans.” says artist Jonathan Paul Green. “I also think the idea of using frozen water from a river in northern Sweden to create an ocean with shells, fish, and corals is exciting.”

    The nearby “Haven” suite is a “magical gate of ice” guarded by two large animals. “We are inspired by the meeting between people and want to create an experience that invites curiosity and creativity, "says artist Jonas Johansson." It feels like a dream to get to work with ice that allows our love for light, shine, and reflection to wander freely from thought to creation.”

    Regardless of whether visitors select the carved suites or the basic ice rooms, the temperature is always set to a bone-chilling －5℃! That is why guests are advised to snuggle(蜷缩)up inside sleeping bags and wear gloves and winter hats all night. Not surprisingly, most end up spending just a single night at this unique hotel before moving on to the conventional and warmer hotels nearby.

    Ten years ago, I set out to examine luck. I wanted to know why some people were always in the right place at the right time, while others consistently experienced ill fortune. I placed advertisements in national newspapers asking for people who felt consistently lucky or unlucky. Hundreds of extraordinary men and women volunteered for my research. Over the years I have interviewed them, monitored their lives and had them take part in various experiments.

    In one of the experiments, I gave both lucky and unlucky people a newspaper, asking them to look through it and tell me how many photographs were inside. I had secretly placed a large message halfway through the newspaper, saying, "Tell the experimenter you have seen this and you will win $50." This message took up half of the page and was written in type that was more than two inches high. It was staring everyone in the face, but the unlucky people tended to miss it and the lucky people tended to spot it.

    Unlucky people are generally more nervous than lucky people, and this anxiety affects their ability to notice the unexpected. As a result, they miss opportunities because they are too focused on looking for something else. They go to gatherings concentrating on finding their perfect partners and miss opportunities to make good friends. They look through newspapers determined to find certain types of job advertisements and miss other types of jobs.

    Lucky people are more relaxed and open, and therefore see what is there rather than just what they are looking for. My research eventually showed that lucky people are skilled at noticing opportunities, make lucky decisions by listening to their intuition (直觉), are open to new experiences, and adopt a never-say-die attitude that transforms bad luck into good luck.

    Any foreigner who has tried to learn Chinese can tell how hard it is to master the tones required to speak and understand. And anyone who has tried to learn to play the violin or other instruments can report similar challenges.

    Now researchers have found that people with musical training have an easier time learning Chinese. Writing in the online edition of Nature Neuroscience, researchers from Northwestern University say that both skills draw on the same parts of the brain that help people discover changes in pitch(音调).

    One of the study's authors, Nina Kraus, said the findings suggested that studying music "actually tunes our sensory system". This means that schools that want children to do well in languages should hesitate before cutting music programs, Dr. Kraus said. She said music training might also help children with language problems.

    Mandarin(普通话)speakers have been shown to have a more complex encoding(编码) of pitch patterns in their brains than English speakers do. This is because in Mandarin and other Asian languages, pitch plays a central role. A single­syllable word can have several meanings depending on how it is intoned.

    For this study, the researchers looked at 20 non­Chinese speaking volunteers, half with no musical background and half who have studied an instrument for at least six years.

    As they were shown a movie, the volunteers also heard an audio tape of the Mandarin word "mi" in three of its meanings: squint, bewilder and rice. The researchers recorded activities in their brain stems to see how well they were processing the sounds. Those with a music background showed much more brain activities in response to the Chinese sounds.

    The lead author of the study, Patrick C.M. Wong, said it might work both ways. It appears that native speakers of tonal languages may do better at learning instruments.

    Imagine someone who has spent the majority of their life sitting with a sign on the side of the road and that very person giving someone their last 20 dollars. That's exactly what Marine Corps veteran (退伍军人) Johnny Bobbitt, 34, did in October in Philadelphia.

    Bobbitt served in the U.S. Marine Corps and worked as a paramedic (医务辅助人员) in Vance County, N. C. before he became homeless. Nobody knew how he got to where he was because he was discreet about that.

    One night in October, Bobbitt was sitting roadside with a sign in Philadelphia as usual, when Kate McClure of Florence Township, N. J. was driving home down Interstate 95 and ran out of gas. Scared and nervous, she got out of the car to head to the nearest gas station. As McClure was heading to the nearest gas station, she ran into Bobbitt and he told her to get back in the vehicle and lock the door. Minutes later, he appeared with a red gas can. He'd used his last $20 to buy her gas.

    After that unexpected meeting, McClure and her boyfriend, Mark D'Amico, who both live in New Jersey, visited Bobbitt several times to deliver gift cards, cash, snacks and toiletries. They then decided to create a fund raising page so he wouldn't have to spend the holidays sleeping on the street.

    McClure started the GoFundMe page on November 10. With the page, the couple hoped to raise $10,000, enough money for his rent, a reliable vehicle and up to six months' expenses. Bobbitt's story ran in a local paper. By November 15，more than 10,000 local people had made donations through the GoFundMe page and more than $300,000 had been raised.

    On Thanksgiving, Bobbitt was resting in a hotel, his feet up on the bed, drawing up a grand plan for his new life, thanks to several thousand dollars raised to repay him for a good deed.

Jean was a teacher who taught first grade. She drove an old Jetta with dull blue paint and worn seats. It wasn't the speediest tool, but Jean was never late to work. In fact, each school day she was the first teacher to arrive and the last teacher to leave.

She took great care to plan instruction, create assessments, and decorate her classroom. Parents in the neighborhood would beat down the principal's door to have their children arranged to her class. Jean could teach a mouse to read, and all her students passed into second grade with advanced vocabularies and language skills.

One August, two sisters in high school did not want to enter foster care (家庭寄养). They contacted their first grade teacher, Jean. Jean lived in quite an ordinary home with her son. Yet, she took the sisters in. Packed with children, the little blue Jetta sputtered (劈啪作响), but they had a good laugh.

One day, Jean spoke about her car, which she had driven for many years and had been old enough to retire. It was kind of dangerous for students to ride in such a car. She wanted a van. However, a new van was not within her ability. As a good friend, I listened to her concerns. Then, an idea came to me. I wrote a letter to The Oprah Winfrey Show, sharing Jean's story and her wish.

A month passed. Jean was invited to attend The Oprah Winfrey Show. Oprah hugged the teacher and told the details of Jean's story. Oprah announced that Jean deserved a new van.

The year was 1999. Six hundred miles away, I watched the joy of it all from the television. Jean's big heart taught me many lessons that year. One of them is that the simplest acts (like writing a letter) can require a strong faith. And nothing impossible.