Biologists believe that love is fundamentally a biological rather than a cultural construct, because the capacity for love is found in all human cultures and similar behavior is found in some other animals. In humans the purpose of all the desire is to focus attention on the raising of offspring. Children demand an unusual amount of parenting, and two parents are better than one. Love is a signal that both partners are committed, and makes it more likely that this commitment will continue as long as necessary for children to reach independence. But what does science have to say about the notion of love at first sight?

    In recent years the ability to watch the brain in action has offered a wealth of insight into the mechanics of love. Researchers have shown that when a person falls in love, a dozen different part of brain work together to release chemicals that trigger feelings of euphoria, bonding and excitement. It has also been shown that the unconditional love between a mother and a child is associated with activity in different regions of the brain from those associated with pair-bonding love.

    Passionate love is rooted in the reward circuitry of the brain—the same area that is active when humans feel a rush from cocaine. In fact, the desire, motivations and withdrawals involved in love have a great deal in common with addiction. Its most intense forms tend to be associated with the early stages of a relationship, which then give way to a calmer attachment form of love one feels with a long term partner.

    What all this means is that one special person can become chemically rewarding to the brain of another. Love at first sight, then, is only possible if the mechanism for generating long-term attachment can be triggered quickly. There are signs that it can be. One line of evidence is that people are able to decide within a second how attractive they find another person. This decision appears to be related to facial attractiveness, although men may favor women with waist-to-hip ratio of 0.7, no matter what their overall weight is. (This ratio may indicate a woman's reproductive health.)

    Another piece of evidence comes from work by a psychologist at Ben-Gurion University, who found in a survey that a small percentage (11%) of people in long-term relationships said that they began with love at first sight. In other words, in some couples the initial favorable impressions of attractiveness triggered love which sustained a lengthy bond. It is also clear that some couples need to form their bonds over a longer period, and popular culture tells many tales of friends who become lovers.

    One might also assume that if a person is looking for a partner with traits that cannot be quantified instantly, such as compassion, intellect or a good sense of humor, then it would be hard to form a relationship on the basis of love at first sight. Those more concerned with visual appearances, though, might find this easier. So it appears that love at first sight exists, but is not a very common basis for long-term relationships.

    A story of a man who made the brave journey of love, cycling from India to Sweden to see his sweetheart, has gained the hearts of thousands online. A Facebook post, that has been linked more than 113,000 times, shares the tale of how Dr. Pradyumna Kumar Mahanandia crossed eight countries to be reunited with his wife Charlotte Von Schedvin in her native country.

    The story began in 1975 when wealthy 19-year-old Charlotte Von Schedvin, who was a student in London at the time, travelled to India in 1975 to meet the poor but famous artist Mahanandia. The Indian was born in 1949 into a poor family in Odisha, Dhenkanal and was considered an untouchable in the society.

Although his family couldn't afford his education, he managed to gain a place at the College of Art in New Delhi where word of his talent quickly spread.

    In events that wouldn't be out of place in a romantic movie, when the young Charlotte Von Sledvin met with the painter, the two fell in love with one another. He was greatly impressed by her beauty and she, with his pure simplicity. Despite their contrasting backgrounds, the pair shortly married.

    In 1978, the time came for Charlotte to return to her native country, and she requested her husband join her back in Europe. However, Mahanandia was in the middle of his studies and said he would join her after these were completed. The couple stayed in touch through letters and despite Charlotte's offers to send flight tickets, Mahanandia was determined to meet her in his own way.

    Selling his belongings, he managed to get enough money to buy a second-hand bike and set out on the intrepid journey to be reunited. From New Delhi, the brave love-struck adventurer entered Afghanistan, Iran, Turkey, Bulgaria, Yugoslavia, Germany, Austria and Denmark. It wasn't all easy sailing. His bike broke down a lot of times along the way and he had to go on without food for days.

    In total the trip took four months and three weeks before he finally reached Gothenburg, Sweden. Upon arrival, he was questioned by immigration officers, who were said to be amazed at his story of devotion after he shared photographs of his marriage.

    Her parents welcomed him with open arms and 40 years later, the pair are still happily married. Dr PK Mahanandia serves as the Odiya Cultural Ambassador of India to Sweden and lives with his wife and two children in Sweden. He has become well-known in Sweden as an artist and as an adviser of Art and Culture, under the Swedish Government too.

    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 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 weekdays, only 21% of Americans actually get a full eight hours of sleep, and another 21% get less than six hours.

    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.”

    Bill Bowerman was a track coach. He wanted to help athletes run faster. So he had learned how to make running shoes. He had also started a shoe company with a friend. It was 1971. Running shoes at the time were heavy. They had spikes (鞋钉) on the sole (鞋底). The spikes tore up the track and slowed down runners.

    To make a lighter shoe, Bill tried the skins of fish. To make a better sole, he wanted to replace the spikes. Bill dug through his wife Barbara's jewelry box. He hoped to find a piece of jewelry with an interesting pattern. He would then copy the pattern onto the new soles. Nothing worked. Bill was defeated.

    Then, one Sunday morning, Barbara made Bill waffles (华夫饼) for breakfast. Bill watched her cook.

    He studied the criss-cross pattern on a waffle iron.

    Inspiration struck. The pattern on the waffle iron was just what Bill was looking for. The squares were flatter and wider than sharp spikes. The pattern would help the shoes hold any surface without tearing into it.

When Barbara left the house, Bill ran to his lab. He took the liquid chemicals that, when mixed, would harden into the sole of a shoe. He poured the mixture into the waffle iron—and the Waffle Trainer was born.

Bill's company put the Waffle Trainer on market in 1974. It was a huge hit. Maybe you've heard of that company—it's called Nike. And today it's worth around $100 billion.

It was the waffle iron that had changed the course of Bill's life—and helped turn Nike into a well-known name. Today, the waffle iron is kept at Nike headquarters. It serves as a reminder that if we keep trying, we can find a solution to even the most difficult problems. And those solutions can come from unlikely places, even the breakfast table.

    Americans think much about time .From children they learn to value( 珍惜) time .As children, they are taught to be on time to go to school, to work and to do everything .When they are having a good time , they say that time flies .When a person is dying, they say he is living on borrowed time.

    Time is money. Time is knowledge. Time is everything in America. A working American has to work hard for 8 hours a day or 40 hours a week. This is the working time. In his spare time, he also works hard for money .Even on Saturday and Sunday he also works hard as usual. In the street you can hardly see that a man walks slowly. They walk very fast. In fact, they are running.

    They love time because time can bring money and a lot of things .But sometimes they also hate time, because they feel they have become servants of the clock.

    It was May 23, 2016. Arnot, the 32-year-old mountain guide, reached the top of Everest without the use of oxygen (O2) equipment. It was achieved after seven years, three previous attempts, and fourteen straight hours of climbing.

After 15 minutes at the top, Arnot began her descent (下坡). Eight hours later, she reached the camp at 7, 600 meters and became the first American woman-and only the seventh woman ever—to successfully reach Mount Everest without oxygen equipment.

    "There are so many reasons for her impressive achievement, especially the physical and emotional efforts that she has put forth over the years to make this happen," says the professional climber and photographer Richards, "The mental courage that it requires is something very few people have."

    Arnot didn't start climbing until she was 19 years old. Money was tight in her family, and climbing mountains never occurred in her mind. After graduating from college, Arnot was invited by her friend to climb a mountain. "It totally changed my life," says Arnot. I always know that if you want something, you can achieve it, but knowing what you want is a whole different thing," she says. "I am athletic but not competitive. After my first climbing, I knew immediately that mountains are what I want—as that is where I felt home for the first time in my life."

    After that first climb, she devoted herself to learning how to climb and move through mountain. It was during her second trip to Everest in 2009 that she first set her sights on a no-oxygen attempt. However, while hiking into Everest Base Camp that year, she hurt her leg and wasn't able to climb without oxygen. In 2013 she nearly made it to the top, but was forced to take oxygen at 8,504 meters while helping another climber.

    When Arnot finally stood at the top Everest, she called her best friend, "I reached the top and I'm not using any oxygen." Then, tears began to stream down from her eyes. So much of Arnot's life has been about pushing the limits of her abilities, and in this case, she's also pushed up against the outer limits of the human spirit.