Grown-ups are often surprised by how well they remember something they learned as children but have never practiced ever since. A man who has not had a chance to go swimming for years can still swim as well as ever when he gets back in the water. He can get on a bicycle after many years and still ride away. He can play catch and hit a ball as well as his son. A mother who has not thought about the words for years can teach her daughter the poem that begins "Twinkle, twinkle, little star" or remember the story of Cinderella or Goldilocks and the Three Bears.

    One explanation is the law of overlearning, which can be stated as follows: Once we have learned something, additional learning trials increase the length of time we will remember it.

    In childhood we usually continue to practice such skills as swimming, bicycle riding, and playing baseball long after we have learned them. We continue to listen to and remind ourselves of words such as "Twinkle, twinkle, little star" and childhood tales such as Cinderella and Goldilocks. We not only learn but overlearn.

    The multiplication tables(乘法口诀表) are an exception to the general rule that we forget rather quickly the things that we learn in school, because they are another of the things we overlearn in childhood. The law of overlearning explains why cramming (突击学习) for an examination, though it may result in a passing grade, is not a satisfactory way to learn a college course. By cramming, a student may learn the subject well enough to get by on the examination, but he is likely soon to forget almost everything he learned. A little overlearning, on the other hand, is really necessary for one's future development.

    The vast majority of green sea turtles in the northern Great Barrier Reef are female because of warmer temperatures due to climate change, which influences their sex, researchers said. Scientists are concerned populations of these animals could turn almost completely female.

    A recent study by the National Oceanic and Atmospheric Administration, California State University and Worldwide Fund for Nature Australia examined two genetically distinct populations of green sea turtles living in the Great Barrier Reef. The study found that a group of about 200,000 turtles living in the northern part of the reef was almost entirely female. While the southern population was 65 to 69 percent female, females in the northern group accounted for 99.1 percent of young turtles and 86.8 percent of adults.

    After combining their results with temperature data, the scientists found that most sea turtle populations are living above the most suitable temperature. The northern green turtles have been producing mainly females for more than two decades and that the complete feminization of this population is possible in the near future, making it clear that climate change is threatening the survival of these populations.

    Dermot O'Gorman, the chief executive of World Wildlife Fund Australia, said, “That's a very visible sign of the impact of climate change. But this is a quiet change.”

    O'Gorman said more urgent action on climate change is clearly needed, adding that some conservationists have already taken practical measures, such as using shade cloth on turtle nesting beaches to lower the sand temperature, and reducing by catch in the fishing industry.

    “Shade cloth can be used in certain places, but there's a limit to the scale you can do that,” he said, “Now every large male who can reproduce is going to be even more important.”

    There's a word of wellness I've loved for years. It's HALT: the idea that if you want to be calm and content, never let yourself get too hungry, angry, lonely or tired. Researchers are increasingly looking more closely at the "L" in "HALT", with one report presented to the American Psychological Association finding that long-term loneliness might be a greater public health risk than obesity.

    Loneliness is a problem with many faces. Some people are alone most of the time—data collected by the United Kingdom found that 200, 000 people over the age of 75 had not had a conversation with a friend or a relative in more than a month. But some people feel lonely even in a crowded room, disconnected from meaningful relationships even though their days are filled with people.

    To me, walking a positive path means walking alongside others—people who lift our spirits, share our values, challenge us to grow and learn and bring us joy. But social satisfaction doesn't come automatically or even easily to too many people. And in our age of individualized electronic devices, social media and text-based communication, it can be harder than ever to feel truly connected to others.

    I was so heartened to read that recently the British Parliament (议会) has created a "Minister for Loneliness" position to promote research, education and principles so as to cure what some researchers call "the loneliness disease". More and more doctors in America are also screening adult patients for loneliness at annual physical examinations, which is another promising sign.

    With proper social support and community participation, loneliness can be prevented from happening. If you are feeling lonely, make a list of your daily routines and ask yourself how you could add more social interactions to each day. Try reaching out for volunteer opportunities, clubs and organizations to join and old friendships to renew. If you are struggling, ask a consultant to help you identify your social obstacles and overcome them.

    Ever walked to the shops only to find, once there, you've completely forgotten what you went for? Or struggled to remember the name of an old friend? For years we've accepted that a forgetful brain is as much a part of aging as wrinkles and gray hair. But now a new book suggests that we've got it all wrong.

    According to The Secret Life of the Grown-up Brain, by science writer Barbara Strauch, when it comes to the important things, our brains actually get better with age. In fact, she argues that some studies have found that our brain hits its peak between our 40s and 60s — much later than previously thought.

    Furthermore, rather than losing many brain cells as we age, we keep them, and even produce new ones well into middle age. For years it's been assumed that brain, much like the body, declines with age. But the longest, largest study into what happens to people as they age suggests otherwise.

    This continuing research has followed 6,000 people since 1956, testing them every seven years. It has found that on average, participants performed better on cognitive (认知的) tests in their 40s and 50s than they had done in their 20s. Specifically, older people did better on tests of vocabulary, verbal memory (how many words you can remember) and problem solving. Where they performed less well was number ability and perceptual speed — how fast you can push a button when ordered. However, with more complex tasks such as problem-solving and language, we are at our best at middle age and beyond. In short, researchers are now coming up with scientific proof that we do get wiser with age.

    Neuroscientists are also finding that we are happier with aging. A recent US study found older people were much better at controlling and balancing their emotions. It is thought that when we're younger we need to focus more on the negative aspects of life in order to learn about the possible dangers in the world, but as we get older we've learned our lessons and are aware that we have less time left in life: therefore, it becomes more important for us to be happy.

When Juni Stefanus Santoso from Indonesia rode a camel in a desert in Dunhuang, Gansu Province — an important cultural center on the Silk Road {#blank#}1{#/blank#} cultures from the East and the West met and mixed hundreds of years ago — he felt like he was "stepping into another world" that was foreign, and very different from his previous {#blank#}2{#/blank#} (impress) of China. 

On a four-day trip to Dunhuang in late April, Santoso, together with other foreign students, mostly from nations along the Silk Road, {#blank#}3{#/blank#} (be ) on a cultural journey to explore the desert landscape, to visit the local museum, the Mogao Caves and craftsmen, {#blank#}4{#/blank#} to communicate with students from the Dunhuang College of Northwest Normal University. All of these activities offered the 23-year-old Indonesian an impressive experience, {#blank#}5{#/blank#} which he could learn the culture of ancient China. 

"It was so {#blank#}6{#/blank#} (amaze). It's like another side of the country," says Santoso. Before he came to China, he thought it was a country full of technology-related companies — an impression that was supported by the fast and convenient technology- {#blank#}7{#/blank#} (drive) services that came to be a part of his daily life when he moved to Tianjin. 

"I was impressed by China's science and technologies before coming to China. You can do everything on your phone," says Santoso, {#blank#}8{#/blank#} (refer) to services like electronic payment and online shopping. 

The cultural trip, however, showed Santoso a view of China {#blank#}9{#/blank#} art and goods were transported along the Silk Road more than a thousand years ago. The young man said he {#blank#}10{#/blank#} (teach) a little bit about the Silk Road in his middle school history class.