Teenagers around the world can be happy with the news that the brain will ignore parents' order when they tap on their smartphones. A new scientific study from the University College London has shown that humans may temporarily go deaf when they're focusing on something visual at the same time.

    The researchers played the normal-volume sounds in the background. And 13 volunteers experienced inattentional deafness as their visual tasks became increasingly difficult. “We found that when volunteers were performing the demanding visual task, they were unable to hear sounds that they would normally hear,” Maria Chait said in a statement. “The brain scans showed that people didn't filter out the sounds on purpose. They were not actually hearing them in the first place.”

    The findings, published in the Journal of Neuroscience, suggest that the centre of sights and the center of sounds share limited resources. Inattentional deafness is a common everyday experience and the study explains why, according to UCL Institute of Cognitive Neuroscience Professor Nili Lavie.

    If you try to talk to someone focusing on a book, game, or television program and don't receive a response, they aren't necessarily ignoring you. They simply might not hear you at all. This could also explain why you might not hear your bus or train stop being announced if you're absorbed in your phone, book or newspaper. However, some loud sounds will still be able to break through.

    Some situations could become potentially dangerous when the quieter ones go unheard. As you can imagine, in the operating room, when a doctor concentrates on his work, he might not hear the equipment beeping. It also applies to drivers who concentrate on complex directions. Fortunately, experts have given us some useful tips on preventing such situations.

    After many considerations and years of heated argument, gray wolves were brought back to Yellowstone National Park. Fourteen wolves were caught in Canada and transported to the park. By last year, the Yellowstone wolf population had grown to more than 170 wolves.

    Gray wolves once were seen here and there in the Yellowstone area and much of the continental United States, but they were gradually displaced by human development. By the 1920s, wolves had practically disappeared from the Yellowstone area. They went farther north into the deep forests of Canada, where there were fewer humans around.

    The disappearance of the wolves had many unexpected results. Deer and elk populations — major food sources for the wolf — grew rapidly. These animals consumed large amounts of vegetation (植被), which reduced plant diversity in the park. In the absence of wolves, coyote populations also grew quickly. The coyotes killed a large percentage of the park's red foxes, and completely drove away the park's beavers.

    As early as 1966, biologists asked the government to consider reintroducing wolves to Yellowstone Park. They hoped that wolves would be able to control the elk and coyote problems. Many farmers opposed the plan because they feared that wolves would kill their farm animals or pets.

    The government spent nearly 30 years coming up with a plan to reintroduce the wolves. The U.S. Fish and Wildlife Service carefully monitors and manages the wolf packs in Yellowstone. Today, the debate continues over how well the gray wolf is fitting in at Yellowstone. Elk, deer, and coyote populations are down, while beavers and red foxes have made a comeback. The Yellowstone wolf project has been a valuable experiment to help biologists decide whether to reintroduce wolves to other parts of the country as well.

    The first day my new teacher walked into our school in Spanish Harlem, I burst out laughing. Ron Clark was this young white guy from North Carolina who talked with a funny Southern accent(口音). He said he used to be a singing waiter. I thought, who is this guy? He's a complete joke.

    It was 1999 and I was in the fifth grade at New York City's P.S. 83. I guessed I'd spend most of the year in the headmaster's office. I'd always been a troublemaker. I'd get shouted at, and then the teachers would give up on me. I thought that's what would happen with Ron Clark.

    I was wrong. That first week, I kept laughing at him. He pulled me out to the hallway and said I'd better shape up(表现好). "Tamara," he said, "you're a smart kid. You can do better."

    He told me I was a natural leader and that I'd go far in life if I started studying hard. I was mad at first, but then something happened: I began to respect him. There were 29 students in our class, and it didn't take long for us to realize that Ron Clark was no ordinary teacher.

    Like most teachers, he had lots of rules: Treat each other like family. Don't cut in line. But the real difference was how concerned he was. Mr. Clark ate with us in the lunchroom instead of going to the teachers' day-room. At first, my friends and I were thinking. What is he doing?

    He asked us what was going on in our lives. Between classes, he came outside with us, and we taught him how to jump rope. When it snowed, Mr. Clark, who'd never seen snow before, threw us with snowballs, and we threw him back.

    Before coming to P.S. 83, he taught at Snowden Elementary in his hometown, Belhaven, North Carolina. His parents were DJs(流行音乐节目主持人)at dance clubs, so he grew up with music and energy. He wanted a life of adventure, he told me, but his mom encouraged him to ask for a position at Snowden when one of the teachers passed away. Mr. Clark ended up loving it. He came to Harlem because he'd seen a TV show about our troubled schools and the lack of qualified teachers. He wanted a challenge. Boy, did he get one.

    It is commonly believed that in medieval France, New Year was celebrated on 1 April. Then in 1562, Pope Gregory introduced a new calendar for the Christian world, changing New Year to 1 January. With no modern communications, news travelled slowly and new ideas were often questioned. Many people did not hear of the change, some merely forgot, and others chose to ignore it. These people were called fools. Invitations to non-existent "New Year" parties were sent and other practical jokes were played. Over time playing tricks on 1 April became a tradition. The custom eventually spread to England and Scotland, and it was later transported across the Atlantic to the American colonies (殖民地) of the English and the French. April Fools' Day has now developed into an international festival of fun, with different nationalities celebrating the day in special ways.

    France and Italy

    In France and Italy, if someone plays a trick on you, you are the "fish of April". By the month of April fish have only just hatched and are therefore easy to catch. Children stick paper fish to their Friends' backs and chocolate fish are found in the shops.

    America and Britain

    Today, Americans and the British play small tricks on friends and strangers alike on 1 April. A common trick is to point to a friend's shoe and say "Your shoelace (鞋带) is untied." When they look down, they are laughed at. Schoolchildren might tell a friend that school has been cancelled. Sometimes the media get involved. Once, a British short film was shown on April Fools' Day about spaghetti farmers and how they harvest their crop from spaghetti trees!

    Scotland

    In Scotland, April Fools' Day lasts for two days! The second day is called "Taily Day" and tricks on this day involve the bottom (or the "tail", in informal speech). Often a sign saying ‘kick me' is stuck onto someone's back without them knowing.

    Lima, the capital of Peru (秘鲁), has countless museums that tourists can't afford to miss. Now start packing up and prepare for your perfect Peruvian history exploration at these wonderful museums.

    ◆Larco Museum

    Stepping inside, visitors get to learn the 5,000-year history of Peru through an unbelievable collection of objects. The best thing about the museum is that it keeps the door to the storeroom open to visitors so that they can admire its collection closely.

    ◆Gold Museum of Peru

    If you like shiny objects or precious metals, then plan a trip to the Gold Museum of Peru. In ancient times, the Peruvian people were celebrated for their skills in metals. And the museum is aimed at preserving this heritage.

    ◆Lima Art Museum

    Art experts are much pleased as the city is also home to the Lima Art Museum. Its permanent exhibit of over 1, 200 pieces is merely a small part of its amazing collection of more than 17, 000 artifacts. The highlight of the museum is its collection of Carlos Baca-Flor's masterpieces, which is considered to be the most complete set in the world.

    ◆Museum of Italian Art

    The only museum dedicated to European art in Peru, the Museum of Italian Art is a storehouse of classical and contemporary paintings and sculptures belonging to the 20th century. The property is easily accessible by a short walk from the Lima Art Museum.

    ◆Museum of Natural History

    Last but certainly not least is the Museum of Natural History. Giving a glimpse into the rich biodiversity in Peru, the museum has on display the skeletons of a sperm whale and fossils of several mammals.

About 50 feet from shore, two brothers were fighting for their lives, their mouths barely able to stay above the water. Thick fog made it difficult for beach goers to see the guys, but the screams were unmistakable and every second counted. The brothers, aged 15 and 20, were wearing shorts and T-shirts, unsuitable for a November day, let alone the 50-degree water. Keven Harder, a supervising ranger, told the North Coast Journal that swimming in such a temperature "will take the fight right out of you."

Luckily, four surfers in wet suits were nearby. Narayan Weibel, Spenser Stratton, and Adrian York, all 16, along with Taj Ortiz-beck, 15, were on their surf boards riding on waves when they heard the cries. They turned and saw two bobbing heads and four flailing arms. "We looked at each other and knew they were about to drown, " Weibel said.

Weibel, Stratton, and Ortiz-beck paddled toward the distressed swimmers while York headed to shore to call 911. As the surfers drew close, the brothers were struggling. "It was pretty stressful, but there wasn't any time to think about it," Ortiz-beck said. He pulled up alongside the younger brother. Grabbing him under his arms, he raised him up onto the board. Stratton and Weibel, meanwhile, were straining(竭力)to help the elder brother. He was large, about 250 pounds, and panicked. Fortunately, York arrived in time to help get the elder brother atop the second board. The surfers then paddled several minutes through rough water to the medical help waiting onshore. The brothers were scared but fine.

"When we get a call like this one, it's usually too late by the time we get there, " said Dillon Ceavenger, the first responder. "I can't say enough about what these boys did. They were willing and prepared to risk their lives."