Reflecting(回忆) on the past about those decisions or actions that can't be reversed(推翻) and being occupied with thoughts of “What if?” is no way to live. But there are a few things in life I'd probably do differently if I had the chance.

    I once majored in architecture — something I had been crazy about for as long as I could remember — and then I suddenly had a change of heart. I made an appointment with my adviser, and told him I was no longer certain I wanted to pursue a career in architecture.

    “Don't give up on your childhood dream!” “He's right,” I thought. “I should just stick it out and I shouldn't disappoint the little girl who once loved architecture.”

    It was awful. I was agonized, holding on to a childhood dream that had long since faded. When I talked with a friend about it a year later, he asked: “Right now, what do you want to do with your life?” That's when I came to the realization that dreams change over time and that you should give up the childhood dream if it's not what you want as an adult. Luckily, it wasn't too late. After some serious thought, I changed my major to journalism. It wasn't something I had always imagined myself pursuing — but at that moment,  it was what I wanted.

    We grow up, and sometimes our dreams change — and that's perfectly OK. You just need to ask yourself every once in a while, “Is this still what I want?” If the answer is no, move on and start chasing a new one.

    Gesture is the use of such movements to express thought, emotion, etc. A gesture can be many things. Slamming a book shut shows anger and frustration. Opening a door lor someone shows kindness. Gestures go much beyond small actions.

    My friend once told me a story in high school. One day he met a girl who was on the girls' basketball team. He said hello, gave her a hard handshake and wished her good luck as she had a game later. He came to find out he saved that girl's life. She had planned on committing suicide and by shaking her hand and saying good luck, he made her realize someone really cared about her. I'm not saying all actions are going to change someone else's life that much, but it may make their day better.

    Gestures can be negative too. In my senior year of high school, a guy on my football team was late and was walking down the field to practice. Everyone on the team knows our coach hates it when people are late and walk on the field. He was walking in as if he owned the place and had no care of what his teammates were thinking. His body language had never been good. The other players on the team had never liked him because of his body language.

    Gestures can often say more than a person wants. One day I was mad at my parents for some pointless reason. All day I stayed downstairs. When one of them walked by, I would just stare at the TV or my phone and hope they wouldn't try to start a conversation. When they tried to talk to me, I would give one-word answers. Sitting on the couch and watching TV by myself all day was not my intent but that was what my gestures told my parents.

    One simple gesture can change a person's thoughts, day or maybe even save their lives. If everyone made a nice gesture to someone else every day, our school, town, and world would become a better place. One single act of random kindness at a time or a kind gesture can change the world.

    When you're on the go, your best friend and resource can be your phone. In the age of smart phones, apps are like guiding stars: They can point you in the right direction for a hotel, list expenses, send postcards, and much more. When used together, these apps can be the basic travel tool, placing a wealth of information at your fingertips no matter where you are on the planet. U.S. NewsTravel has picked the essential travel apps, known for their utility and reliability. Best of all, they cost absolutely nothing.

Trip It

    Your Personal Travel Agent

    Be your own travel agent and plan every detail of your trip—from car rental to accommodating restaurants—with Trip It. You can make travel schedule by hand, or simply forward the email confirmations of your flight, rental car, train tickets, and hotels to plans.

Weather Free

    Your Go-To Meteorologist(气象学者)

    Stop trying to explain the weather forecast on the evening news (particularly when it's in a foreign language). The Weather Free app informs you (in English) of the climate in various locations. It features the local weather, and other key factors that will inform your decision about what to wear before stepping outside.

Goby

    Your Event Guru

    When you're in a foreign city, you sometimes look around and ask: Where are all the people? Goby has the answer. This app pinpoints the neighborhood hot spots (including museums, hotels, eateries, and more) in your neighborhood. But its true value comes in finding nearby events. You'll discover concerts, plays, and more right around the corner.

    Dogs were living as companions to the early settlers of North America over 10,000 years ago. The oldest domestic dogs in the Americas were thought to be around 9500 years old. Angela Perri of Durham University, UK, and her colleagues have carried out fresh radiocarbon dating on the two dog skeletons that gave this date, discovered in the prehistoric Koster site in Illinois, and found they were even older: around 10,100 years old.

    A third dog from another Illinois site called Stilwell II was older still, at 10,190 years old. That makes it the oldest known domesticated dog in the Americas. The team concluded that all three dogs were domesticated as they skeletons were complete and unskinned, and so hadn't been butchered for food. They had also been carefully buried, evidence they were valued by their owners. The Stilwell II dog, which probably resembled a small English settler, was under what seemed to be the floor of a living area. It is unclear why it took so long for tame dogs to arrive in the Americas, given that they were domesticated at least 14,000 years ago in Eurasia. By this time, people were already moving into North America from Siberia; there is evidence some reached Chile 18,500 years ago. Geneticists have found signs of at least three waves of migration over the following millennia. There is no evidence that domestic dogs accompanied them. “We don't know if dogs were part of the first waves of immigration to the Americas" says Luc Janssens of Ghent University in Belgium. "It could be so, but no archaeological bones have yet been found." It is "overwhelmingly probable" that some of the early settlers did bring dogs to the Americas, but they may not have had "the time or the spiritual compulsion to bury them", says Pat Shipman of Pennsylvania State University.

    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.

    Mark Elliot Zuckerberg was born on May the 14th, 1984. He is the creator of the social media site Facebook. He was a star student at school, winning prizes in astronomy, maths and physics. He was also good at Classical studies. He studied Psychology and Computer Science at Harvard University, which is where he created Facebook. His invention led to his becoming Time magazine's Person Of the Year for 2010.

    Zuckerberg excelled in everything he did in his youth. He was captain of the school fencing team, spoke many languages and was a highly skilled computer programmer. While other kids played computer games, he designed them. He created his first network while in high school to connect all of the computers - in his father's dental surgery. He also built a media player which attracted the interest of Microsoft and AOL.

    Zuckerberg started at Harvard in September 2002. In his first year, he created Facemash, a Facebook predecessor (前身), which let students select the college's best looking people from a selection of photos.

    He launched Facebook from his Harvard room in February 2004. It was the start of a rollercoaster ride that would connect half a billion people worldwide and make him the world's youngest billionaire.

    Mark Zuckerberg is now one of the most influential people on the planet. He has dined with the president of the USA and regularly attends global economic summits and technology conferences. He stated: "The thing I really care about is the mission, making the world open." In 2010, Zuckerberg signed a promise, in which he promised to donate at least half of his life wealth to charity.