About this time every year, I get very nostalgic(怀旧的)．Walking through my neighborhood on a fall afternoon reminds me of a time not too long ago when sounds of children filled the air，children playing games on a hill, and throwing leaves around in the street below. I was one of those children, carefree and happy. I live on a street that is only one block long. I have lived on the same street for sixteen years. I love my street. One side has six houses on it, and the other has only two houses, with a small hill in the middle and a huge cottonwood tree on one end.When I think of home, I think of my street. Only I see it as it was before. Unfortunately things change. One day, not long ago, I looked around and saw how different everything has become.Life on my street will never be the same because neighbors are quickly grown old, friends are growing up and leaving, and the city is planning to destroy my precious hill and sell the property to contractors.

    It is hard for me to accept that many of my wonderful neighbors are growing old and won't be around much longer. I have fond memories of the couple across the street, who sat together on their porch swing almost every evening, the widow next door who yelled at my brother and me for being too loud, and the crazy old man in a black suit who drove an old car. In contrast to these people, the people I see today are very old neighbors who have seen better days. The man in the black suit says he wants to die, and another neighbor just sold his house and moved into a nursing home. The lady who used to yell at us is too tired to bother any more, and the couple across the street rarely go out to their front porch these days. It is difficult to watch these precious people as they near the end of their lives because at once I thought they would live forever.

    The “comings and goings” of the younger generation of my street are now mostly “goings”as friends and peers move on. Once upon a time, my life and the lives of my peers revolved around home. The boundary of our world was the gutter at the end of the street. We got pleasure from playing night games or from a breathtaking ride on a tricycle. Things are different now, as my friends become adults and move on. Children who rode tricycles now drive cars. The kids who once played with me now have new interests and values as they go their separate ways. Some have gone away to college like me, a few got married, two went into the army, and one went to prison. Watching all these people grow up and go away makes me long for the good old days.

    Perhaps the biggest change on my street is the fact that the city is going to turn my precious hill into several lots for now homes. For sixteen years, the view out of my kitchen window has been a view of that hill. The hill was a fundamental part of my childhood life; it was the hub of social activity for the children of my street. We spent hours there building forts, sledding, and playing tag. The view out of my kitchen window now is very different; it is one of tractors and  dump trucks tearing up the hill. When the hill goes, the neighborhood will not be the same. It is  a piece of my childhood. It is a visual reminder of being a kid. Without the hill, my street will be just another pea in the pod.

    There was a time when my street was my world, and I thought my world would never change. But something happened. People grow up, and people grow old. Places changes, and with the change comes the heartache of knowing I can never go back to the times I loved. In a year or so, I will be gone just like many of my neighbors. I will always look back to my years as a child, but the place I remember will not be the silent street whose peace is interrupted by the  sounds of construction. It will be the happy, noisy, somewhat strange, but wonderful street I knew as a child.

    Soaping up your hands may do more than just get rid of germs. It may wash away the inner confusion you feel right after being forced to make a choice between two appealing choices, according to a new study. The study builds on the past research into a phenomenon known as “the Macbeth effect” (麦克白效应）.

    It turns out that Shakespeare was really onto something when he imagined Lady Macbeth trying to clean her conscience by rubbing invisible bloodstains from her hands.

    A few years ago, scientists asked people to describe a past wrong act. If people were then given a chance to clean their hands, they later expressed less guilt than people who hadn't cleaned.

    This finding interested W. S. Lee, a researcher. “Anything from the past, any kind of negative emotional experiences, might be washed away,” says Lee.

    He decided to test hand washing's effect on one kind of bad feeling：the tension we feel after being forced to choose between two attractive choices, because picking one choice makes us feel that we've lost the other. People usually try to calm this inner conflict by later exaggerating (夸大）the positive aspects of their choice.

    He had students rank 10 different music CDs. Then he offered students two of the CDs and told them to select one as a gift. Some students then used liquid soap. Others only looked at the soap or sniffed (闻)it. “Actually, you do not need water and soap,” says Lee.

    Later, the students again had to rank all the music CDs. People who didn't wash their hands had the normal response — they scored their take-home CD higher, suggesting that they now saw it as an even more attractive one than before. But this wasn't true for the hand washers. They ranked the music about the same. “They feel no need at all to justify (证明…正确）the choice,” says Lee.

    But the effects of it just aren't clear. Schwarz says it's too soon to know whether people should head for a sink after making a tough choice. He says washing may help decision-makers by cleaning away mental disorder. But perhaps if they don't go through the usual post-decision process of justifying their choice, they might feel more sorrow in the long run.

    For many foreigners who have visited or worked in China, one of their strong impressions is that the country is very safe. Here , you can go out alone late at night to eat at a food stand without feeling nervous. You can also let your younger children ride public transport all by themselves without worrying about their safety.

    This year, 2018 , marks 8 special anniversary of the launching of the reform and opening up policy, which took place two score years ago in China. Over the past few decades, the country has achieved fast economic growth, while social peace and stability have been maintained(维护) to the fullest extent at the lowest cost. Of course, there are still unsolved problems. However, from the overall aspect, Chinese society remains harmonious and safe. In my eyes , this should be attributed(归于) largely to the cultural ;economic and political environment of the country.

    A society can be stable and orderly only when its people can lead a prosperous(繁荣的) life. After the introduction of the reform and opening up policy, China achieved fast economic growth and significant scientific and technological progress. In the meantime, the Chinese government has taken various measures such 2s those to fight corruption, reduce poverty and promote the rule of law, in order to uphold social equity. Thanks to these efforts, the potential factors that might cause social problems have been greatly reduced.

    Apart from government departments including the police and judicial(司法的) departments , the general public also contributes much to social governance. The development of information technology has created new ways of linking the police and the public. By jointly fighting crimes in such ways, the public and the police have developed an ever-increasing level of mutual trust and positive interaction.

    The safety and stability in China did not come easily. Rather; it should be attributed to the efforts made by 1.3 'billion people. For both Chinese and foreigners living in the country, the sense of safety and security is very precious.

    There is some unwelcome news for students preparing for exams and officers putting in long hours—you don't need that "refreshment（提神） break" as much as you may think.

    Scientists believed it was not easy for people to continue their work if they felt the need to have a snack or a rest to make them feel better. They argued that the only way to regain willpower is by supplying more energy to our bodies with rest, food or entertainment.

    But psychologists have challenged this theory, saying weak willpower is in your head. They found that a person's mindset(理念) and belief about willpower determine how long and how well they'll be able to work on a tough mental exercise. "If you think of willpower as something that's limited, you're more likely to be tired when you perform a difficult task," said Professor Veronika Job. "But if you think of willpower as something that is not easily depleted, you can go on and on."

    The researchers led by Mr. Job designed an experiment to test the students' beliefs about willpower. After a tiring task those who believed or were led to believe that willpower was a limited resource performed worse on standard concentration tests than those who thought of willpower as something they had more control over.

    Mr. Job said, "Students who may already have trouble studying are being told that their powers of concentration are limited, and they need to take frequent breaks. But a belief in willpower as a non-limited resource makes people stronger in their ability to work through challenges."

    The findings could help people who are battling with temptation(诱惑): people following strict diets and doing exercise regularly to lose weight, people trying to overcome addictions, employees facing a tight deadline. Willpower isn't driven by a biologically based process as much as we used to think.

    I was asked by a reader recently why so many animals seem to have pink ears, when their bodies are all different colours? The truth is that most animals actually don't have pink ears. Let us explain.

    Near the equator (赤道), where the climate is hot, animals are likely to have darker skin, including on their ears. Think of the African elephant, which has quite dark ears. In colder climates, skin colour is usually lighter and often pink.

    Why is skin colour different in different climates？Skin pigmentation, which is what gives skin its colour, can protect against sunburn and skin cancer (癌症). When animals live in colder parts of the world, they don't need it as much to survive. Light-coloured skin also helps animals stay warmer because it reduces heat loss, which is useful if you're in a colder climate.

    For most animals, the colour of their fur or other body covering has generally developed as camouflage. That allows animals to mix into the background and avoid being eaten, or for predators (捕食者) to remain hidden during hunting. One example is the sandy-coloured coat of the desert fennec fox, which uses camouflage for both hunting and hiding.

    By the way, in many animals, ears come in many different shapes and sizes. For example, in bats, the serval (a type of African wildcat) and the fennec fox, the ears are large compared to their body size—this helps them hear better because it allows them to sense more sound waves. Naked mole-rats have tiny ears because they need to dig a lot. Big ears would get in the way. The other downside of big ears is that you can lose a lot of body heat. That's why animals that live in really cold places, like the Arctic fox, have quite small ears.

    There is a cry of anger, and a tennis racket crashes to the ground. Jake, age 7, has just lost another match and is now in tears beside the court. His sister Sally, just one year older, looks at her mother and rolls her eyes: it is hard to enjoy winning when this keeps happening. It is not an unusual situation, and it is one reason why many people argue that competition is bad for children. However, the truth is that competitive games are a valuable preparation for adult life.

    Games with winners and losers give children the chance to experience life's ups and downs. Take Jake, for example. Even though he is unhappy now, he will probably be smiling and laughing with his sister in a few minutes, just like the last time this happened. Gradually, he will learn that the world does not end when you lose a game. Eventually, he may even be able to lose with a smile on his face. This is an important lesson. Not everything in life goes the way you would like, and it is important to know how to handle disappointment when it occurs.

    Children who participate in competitive games develop qualities that allow them to succeed in the complex world of adult life. For example, one of the missions of the Youth Olympic Games is to inspire young people to adopt the Olympic values, which include striving, determination and optimism. Competition creates a desire to do better. Children have to learn to succeed in a competitive atmosphere in order to take advantage of opportunities in the future. Although it is possible to win by chance occasionally, people who win and keep winning work very hard to achieve their success.

    On the negative side, there are those who will say that competition actually encourages some values, which does happen. It is common to see sports competition in which the desire to win has replaced the desire to have fun. You may even see very young children playing violently—like the superstars they see on TV. While the bad behavior of young athletes is troubling, the problem is not the competition itself. In reality, the blame lies with the professional players who are bad role models for these children. In fact, a recent study of young athletes by the school of Physical Health Education at the University of Wyoming showed an improvement in mood after exercise, athletes were less depressed or tense.

    Of course, there are parents who argue that children of Jake's age are too young to handle the pain of losing. But whether we like it or not, adult life is very competitive, and keeping children away from competition does them more harm than good. If children do not learn how to compete, they will be defeated by people who can. It is an unfortunate fact of life: whether ten or a hundred people want the same job, there can be only one winner. Wouldn't you want your child to be that person?