Kids seem to spend endless hours on smartphones, computers and tablets these days. The best thing parents can do to prevent it is to encourage youngsters to spend more time outdoors in the sunlight.

    There has been a massive rise around the globe in short-sightedness—or myopia as it's officially known—over recent decades. Myopia or short-sightedness is becoming more common. Lack of natural light seems to be the key issue. “The main factor seems to be a lack of exposure to direct sunlight, because children who study a lot and who use computers or smartphones or tablet computers a lot have less opportunity to run around outside and are less exposed to sunshine and because of that children seem to be at more risk of developing shortsightedness.”

    Professor Hammond says, “It may be there's no coincidence that in East Asian countries, the most myopic ones all relate may to be the that maths league tables(排名表). These kids are being pushed with very intensive education from a very young age and spend a lot of time indoors studying close up. Therefore the concern is that all close work—like playing with the iPhone—carries the potential that it could make them more shortsighted.”

    The best thing to do, say the experts, is to get children playing outside as much as possible. “In a perfect world, probably on average across the week and the weekend, two hours a day outdoors is protective of becoming short-sighted in children. Healthy diet is really also important—in terms of getting oily fish, green vegetables, green leafy vegetables as much as possible.

    “What we need to look at is ways of modifying the impact that these activities have on their visual development.” Professor Hammond said, “There are eye drops and other treatments to slow myopia progression. But in terms of preventing myopia itself, there isn't any data out there at the moment in terms of the question, 'Could the drops we use slow progression or stop myopia developing at all? ' ”

    When you go to the doctor, you like to come away with a prescription．It makes you feel better to know you will get some medicine. But the doctor knows that medicine is not always needed. Sometimes all a sick person needs is some reassurance that all will be well. In such cases the doctor may prescribe a placebo.

    A placebo is a sugar pill, a harmless shot, or ail empty capsule. Even though they have no medicine in them, these things seem to make people well. The patient thinks it is medicine and begins to get better. How does this happen?

    The study of the placebo opens up new knowledge about the way the human body can heal itself. It is as if there was a doctor in each of us. The doctor will heal the body for us if we let it. But it is not yet known just how the placebo works to heal the body. Some people say it works because the human mind fools itself. These people say that if the mind is fooled into thinking it got medicine, then it will act as if it did, and the body will feel better.

    Placebos do not always work. The success of this treatment seems to rest a lot with the relationship between the patient and the doctor. If the patient has a lot of trust in the doctor and if the doctor really wants to help the patient, then the placebo is more likely to work. So in a way, the doctor is the most powerful placebo of all.

    A placebo can also have bad effects. If patients expect a bad reaction to medicine, then they will also show a bad reaction to the placebo. This would seem to show that a lot of how you react to medicine is in your mind rather than in your body. Some doctors still think that if the placebo can have bad effects it should never be used. They think there is still not enough known about it.

    The strange power of the placebo does seem to suggest that the human mind is stronger than we think it is. There are people who say you can heal your body by using your mind. And the interesting thing is that even people who swear this is not possible have been healed by a placebo．

    It sounds almost too good to be true, but a new study on sleeping brains suggests that listening to languages while you sleep can actually help you to learn them.

    For the study, researchers played recordings of foreign words and their translations to subjects enjoying slow-wave sleep, a stage when a person has little consciousness of their environment. To ensure that the results were not compromised by foreign language words that subjects may have had some contact with at some point in their waking lives, researchers made up totally nonexistent foreign words.

    When the subjects woke up, they were presented with the made-up words again without their translations. The subjects were then asked to imagine whether this made-up word indicated an object that was either smaller or larger. This vague(模糊的)way of testing their understanding of the words is an approach that is supposed to tap into the unconscious memory.

    Unbelievably, the subjects were able to correctly classify the words in this way at an accuracy rate that was 10 percent higher than random chance. That's not a rate high enough to have them suddenly communicating in a foreign tongue, but it is enough to suggest that the brain is still absorbing information on some level, even during sleep.

    Researchers have long known that sleep is important for memory, but previously its role in memory was thought to relate only to the preservation and organization of memories acquired during wakefulness. This is the first time that memory formation has been shown to be active during sleep.

    In other words, our brains are listening to the world, and learning about it, even when our conscious selves are not present.

    The next step for researchers will be to see if new information can be 1earned quicker during wakefulness if it was already presented during sleep. If so, it could forever change how we train our brains to learn new things. Sleep learning might become a widespread practice.

    When you were at school, the last thing you probably wanted to do was spend your weekends going to work. There was homework to do, sport to play and fun to have. But our parents probably persuaded us to find a job to earn some money and get some life experience. When I was a teenager I had a paper round: delivering newspapers to people's homes. I then progressed to a Saturday job in a supermarket: stacking shelves and working at the checkout.

    Today in the UK you are allowed to work from the age of 13, and many children do take up part-time jobs. It's one of those things that are seen almost as a rite of passage(成人仪式).It's a taste of independence and sometimes a useful thing to put on your CV(简历).Teenagers agree that it teaches valuable lessons about working with adults and also about managing their money.

    Some research has shown that not taking up a Saturday or holiday job could be deleterious to a person later on. A 2015 study by the UK Commission on Employment and Skills found that not participating in part-time work at school age had been blamed by employer's organizations for young adults being ill-prepared for full-time employment, but despite this, recent statistics have shown that the number of schoolchildren in the UK with a part-time job has fallen by a fifth in the past five years.

    So, does this mean that British teenagers are now afraid of hard work? Probably not. Some experts feel that young people feel going out to work will affect their performance at school, and they are under more pressure now to study hard and get good exam results-and a good job in the long term. However, Geoff Barton, general secretary of the Association of School and College Leaders, told BBC News that "Properly regulated(控制的)part-time work is a good way of helping young people learn skills that they will need in their working lives." In reality, it's all about getting the right balance between doing part-time work and having enough time to study and rest.

Growing up in a suburban neighborhood in the Northeastern United States, the advent of springtime didn't hold much significance for me. While it did bring a week-long respite from school, the focus was more on the vacation aspect than the season itself.

For the children in my community, spring was largely an overlooked period. The year was divided into two primary seasons: winter, which offered the thrill of ice skating, sledding, and constructing snow forts; and summer, which allowed us to fully enjoy the beach located a short distance from my home. Spring and autumn were merely transitional periods, marking the countdown to the more exciting seasons.

It's true that as I matured, spring began to hold a certain charm for me, as suggested by the poetic line, "In the spring a young man's fancy lightly turns to thoughts of love," penned by Alfred Lord Tennyson. However, my fascination was more with the romantic notions associated with the season rather than the season itself.

In essence, spring was not a season I paid much heed to... until my journey to China. After spending roughly three months in Beijing, my first Spring Festival made its presence known in an undeniable way. The sporadic fireworks throughout the day and night were a clear indication, but what truly struck me was the apparent absence of the usual hustle and bustle in the city.

The usual throngs of people, streams of vehicles, and the general city noise seemed to have vanished. This mystery was resolved upon my return to work. My colleagues enlightened me that it is customary for Chinese people to travel, if necessary, to reunite with their families during the Spring Festival. Many residents of Beijing are not originally from the capital.

Furthermore, I was introduced to a fascinating aspect of the Spring Festival that continues to astonish me. Regardless of when the holiday commences, there is an almost instantaneous and perceptible improvement in the weather. Spring truly makes its entrance.

The ancient Chinese ability to devise a system that could consistently and accurately herald the change of seasons, year after year, is beyond my comprehension. Yet, they managed to achieve this remarkable feat.