What brings a nation together? Of the four choices — shared values, language, history, and religion, it's shared values. In our latest poll (民意调査), seven out of 16 countries chose values as the greatest factor (因素）bringing a nation together, and six preferred language. Both choices scored high in the poll, suggesting that our values and how we express them are closely linked Still, history was not forgotten in some countries, particularly in Mexico and Russia. Even Canada and the United States chose national histories as the second-most important factor uniting their people. The biggest surprise? Not one country picked religion as its top choice.

    No one is sure how the ancient Egyptians built the pyramids near Cairo. But a new study suggests they used a little rock‘n'roll. Long-ago builders could have attached wooden pole s to the stones and rolled then across the sand, the scientists say.

     “Technically, I think what they're proposing is possible,” physicist Daniel Bonn said.

    People have long puzzled over how the Egyptians moved such huge rocks. And there's no obvious answer. On average, each of the two million big stones weighed about as much as a large pickup truck. The Egyptians somehow moved the stone blocks to the pyramid site from about one kilometer away.

    The most popular view is that Egyptian workers slid the blocks along smooth paths. Many scientists suspect workers first would have put the blocks on sleds(滑板). Then they would have dragged them along paths. To make the work easier, workers may have lubricated the paths either with wet clay or with the fat from cattle. Bonn has now tested this idea by building small sleds and dragging heavy objects over sand.

    Evidence from the sand supports this idea. Researchers found small amounts of fat, as well as a large amount of stone and the remains of paths.

    However, physicist Joseph West thinks there might have been a simpler way , who led the new study . West said , “I was inspired while watching a television program showing how sleds might have helped with pyramid construction . I thought , ‘Why don't they just try rolling the things?'“A square could be turned into a rough sort of wheel by attaching wooden poles to its sides , he realized . That , he notes , should make a block of stone” a lot easier to roll than a square”.

    So he tried it.

    He and his students tied some poles to each of four sides of a 30-kilogram stone block. That action turned the block into somewhat a wheel. Then they placed the block on the ground.

    They wrapped one end of a rope around the block and pulled. The researchers found they could easily roll the block along different kinds of paths. They calculated that rolling the block required about as much force as moving it along a slippery(滑的)path.

    West hasn't tested his idea on larger blocks, but he thinks rolling has clear advantages over sliding. At least, workers wouldn't have needed to carry cattle fat or water to smooth the paths.

    Recently I and other Red Cross volunteers met a group of victims from Hurricane Katrina. We were there, as mental health professionals, to offer “psychological first aid” and I was struck by the simple healing power of presence. As we walked in the gate to the shelter, we were greeted with a burst of gratitude from the first person we met. I felt appreciated, but also guilty, because I hadn't really done anything yet.

    I first realized the power of presence many years ago when a friend's mother passed away unexpectedly. I received a call saying she had just passed away. I wanted to rush down there immediately, but didn't want to intrude(打扰) on this very personal period of sadness. I was torn about what to do. Another friend with me then said, “Just go. Just be there.” I did, and I will never regret it.

    Since then, I have not hesitated to be in the presence of others. Once I sat at the bedside of a young man suffering from the pain of his AIDS-ralated dying. He was not awake, and obviously unaware of others' presence. However, the atmosphere was by no means solenm. His family, playing guitars and singing, allowed him to be present with them as though he were still fully alive.

    In my life, I am repeatedly struck by the healing power of presence. In it, none of us are truly alone. It not only is something we give to others but also changes me for the better.

    It's nearly exam time, so check out some of the best free apps around to help you manage the stress of exams and ensure you are studying effectively over the coming weeks.

    Exam Countdown

    This app can help to remind you how many days, hours, and minutes you have until your exam. This can help to motivate you to hit the books before it's too late.

    Block The Internet

    Are you constantly checking Facebook when you should be writing an essay? Or perhaps are you distracted by a battle in League of Legends? Download this app to get rid of online distractions by temporarily blocking Internet sites on your mobile. Simply add the websites you want to block and the period of time to block them for. Guarantee to get yourself focused on that assignment.

    CBT-i Coach

    The US Department of Veterans (老兵) Affairs developed the app, CBT-i Coach, to assist with insomnia (失眠) and help people who would like to improve their sleeping habits. It provides several key parts: information about sleep and insomnia, strategies for improving sleep, relaxation skills and a helpful sleep diary.

    Yoga

    Yoga has great health benefits both for the mind and body, and will help you to perform at your best while at university. Download a yoga app and have your own personal yoga instructor in your living room. You can choose from short or long workouts and have a qualified instructor teaching you how to do each pose. Choose from a variety of yoga routines and watch the instructional videos. Go on, stretch out those sore muscles.

    My friend, Jack, was a taxi driver. We became friends quite by accident. Five years ago, I made a trip to Chicago. The moment I stepped into a cab, I realized it was different. The floor was covered with a rug (小地毯). There were small reproductions of paintings by Van Gogh inside the cab. And the windows were spotless. I told the driver I had never ridden in a more attractive taxi.

    "I like to hear my passengers say that," he replied. "How long have you been decorating your cab?" I asked. "It's not mine," he said. "It's a company cab. I hit upon the idea years ago when I worked as a clean-up man for the taxi company. Each car that came in at the end of the day was like a garbage pit. Cigarette butts and matches covered the floor. Sticky stuff like peanut butter was on the seats or door handles. I thought that if the company and the drivers would give people a car worth keeping clean, they might be more considerate."

    "As soon as I got my taxi license, I tried out my ideas. I put a lot of extra decorations into the cab they gave me to drive. I got a nice rug and some flowers. When each passenger got out, I checked to make sure that everything was in order for the next fare. After about a month of my bringing in a spotless cab, the boss reserved the same car for me each day. That was when I put up the reproductions of great paintings."

    "I've never been disappointed by people in the past ten years—no garbage. Like I say, people appreciate beautiful things. If we planted more flowers and trees in the city and made the buildings more attractive, more people would tend to keep the city clean."

    Later, we became good friends. I was impressed by the taxi-driver, who had hit on a great truth—a sense of beauty comes with the gift of life. Most people don't have to be instructed about the rarity of beauty. They respond when they find it. And, if they are made to feel a part of it, they will try to add to it.

    Alice Moore is a teenager entrepreneur(创业者), who in May 2015 set up her business AilieCandy. By the time she was 13,her company was worth millions of dollars with the invention of a super­sweet treat that could save kids'teeth, instead of destroying them.

    It all began when Moore visited a bank with her dad. On the outing, she was offered a candy bar. However, her dad reminded her that sugary treats were bad for her teeth. But Moore was sick of missing out on candies. So she desired to get round the warning, "Why can't I make a healthy candy that's good for my teeth so that my parents can't say no to it?" With that in mind, Moore asked her dad if she could start her own candy company. He recommended that she do some research and talk to dentists about what a healthier candy would contain.

    With her dad's permission, she spent the next two years researching online and conducting trials to get a recipe that was both tasty and tooth­friendly. She also approached dentists to learn more about teeth cleaning. Consequently, she succeeded in making a kind of candy only using natural sweeteners, which can reduce oral bacteria.

    Moore then used her savings to get her business of the ground. Afterwards, she and her father secured their first business meeting with a supermarket owner, who finally agreed to sell Moore's product­Cancandy.

    As CanCandy's success grows, so does Moore's credibility as a young entrepreneur. Moore is enthusiastic about the candy she created, and she's also positive about what the future might bring. She hopes that every kid can have a clean mouth and a broad smile.

    Meanwhile, with her parents' help, Moore is generally able to live a normal teenage life. Although she founded her company early on in life, she wasn't driven primarily by profit. Moore wants to use her unique talent to help others find their smiles. She donates 10% of AilicCandy's profits to Big Smiles. With her talent and determination, it appears that the sky could be the limit for Alice Moore.