Have you ever considered why you begin yawning too when you see someone yawn? Or how hard it is to be among people laughing and not laugh yourself? Well, apparently it's because we have mirror neurons (神经元）in our brains.

    Put simply, the existence of mirror neurons suggests that every time we see someone else do something, our brains imitate it whether or not we actually perform the same action. This explains a great deal about how, we learn to smile, talk, walk, dance or play sports. But the idea goes further: mirror neurons not only appear to explain physical actions, they also tell us that there is a biological basis for the way we understand other people.

    Mirror neurons can undoubtedly be found all over our brains, but especially in the areas which relate to our ability to use languages, and to understand how other people feel. Researchers have found that mirror neurons relate strongly to language. A group of researchers discovered that if they gave people sentences to listen to ( for example: “The hand took hold of the ball” ) , the same mirror neurons were triggered as when the action was actually performed (in this example, actually taking hold of a ball).

    Any problems with mirror neurons may well result in problems with behavior. Much research suggests that people with social and behavioral problems have mirror neurons which are not fully functioning. However, it is not yet known exactly how these discoveries might help find treatments for social disorders.

    Research into mirror neurons seems to provide us with even more information regarding how humans behave and interact. Indeed, it may turn out to be the equivalent (相等物）for neuroscience of what Einstein's theory of relativity was for physics. And the next time you feel the urge to cough in the cinema when someone else does — well, perhaps you'll understand why.

    Your school asked parents about the social development in children in the last Parents' Meeting. Here are some opinions. Read the following information and answer the questions.

    To save as much language diversity as possible in the face of its rapidly dying out, researchers suggest using “evolutionary trees”, a tool from conservation biology.

    One of the world's 7,000 languages disappears every other week, and half might not survive the 21st century, experts say.

    When setting conservation goals, ecologists use evolutionary trees—diagrams that show how biological species are related to one another—to identify species that have few close relatives. Such species are said to be evolutionarily distinct. Similarly, recent advances in the construction of language trees make it possible to measure how unique a language is.

    “Evolutionary trees have transformed our understanding of how life has evolved and helped us to decide which species most need conserving,” says Jonathan Davies, senior author of the new study.

    “The rapid rate of language loss, as well as limited resources for preservation（保护）, means that we must choose carefully where to focus our efforts,” adds Max Farrell, a PhD student in Davies' lab. “The more isolated (孤立的) a language in its family tree, the more unique information it contains and eventually contributes to language diversity.”

    As a case study, they used this approach to rank 350 Austronesian languages, spoken in islands spread across Southeast Asia and the Pacific Ocean.

    For each of these languages, the researchers combined measures of evolutionary distinctiveness (ED) and global endangerment (GE) to produce an “EDGE” score. The language with the highest score, which means it is extremely distinct（不同的） yet nearly dying out, was Kavalan, a language native to Tai Wan. The next-highest scores went to Tanibili, an endangered language in the Solomon Islands.

    By building trees for other language groups, language specialists could target preservation efforts and help reduce the loss of language diversity in the future, the researchers say.

    Doctors in hospital emergency rooms often see accidental poisonings. A frightened parent arrives with a child who swallowed a cleaning liquid. Or perhaps the harmful substance is a medicine. Or it might be a product meant to kill insects. These are common causes of accidental poisoning.

    In cases like this, seek medical help as soon as possible. Save the container of whatever caused the poisoning. And look on the container for information about anything that stops the effects of the poison. Save anything expelled from the mouth of the victim. That way, doctors can examine it.

    Millions of people know how to give abdominal thrusts(腹部按压)to save a person choking on something trapped in the throat. The American Red Cross says a rescuer should first hit the person on the back five times between the shoulder bones. If the airway is still blocked, the Red Cross suggests pushing hard five times along the victim's abdomen. You can do these abdominal thrusts by getting directly behind a sitting or standing person.

    The Mayo Clinic health centers suggest several steps if bleeding is severe. First, if possible, remove dirt from the wound and press on it with a clean cloth or piece of clothing. In the past, people were advised to stop severe bleeding with a tourniquet(止血带). But experts now say tourniquets are dangerous because they can crush(挤压) major arteries and nerves. If a wound seems infected, let the victim rest. Physical activity can spread the infection. Treat the wound with a mixture of salt and water until medical help arrives.

    To learn more about first aid, ask a hospital or an organization like the Red Cross or the Red Crescent Society for information. Training may be offered in your area.

    If you know first aid methods, you can be calmer and more helpful in case of emergency. 

    People say money doesn't buy happiness, but how much money you make can affect the way you experience it?

    While it's true that money can't buy happiness, having money has certain benefits. For example, money can buy you time to do things that make you happier, and giving away some of your money can make you happier as well. Now scientists from the University of California at Irvine have found that how much money you make may impact (影响) how you experience happiness; higher earners are more likely to experience positive emotions focused on themselves, while lower earners are more likely to experience positive emotions focused on connecting with other people.

    Scientists used data from an existing survey of 1,519 U.S. adults between the ages of 24 to 93, to be representative of the entire U.S. population. From the survey, scientist collected the household income of each person and analyzed how each person experienced the seven emotions that are believed to cause happiness: amusement, admiration, compassion, satisfaction, enthusiasm, love, and pride.

    What they found was that higher earners were associated with the happiness-related emotions of satisfaction, pride, and amusement, all of which are self-focused in nature. Lower earners were associated with more other-oriented (他人指向) happiness-related emotions: compassion, love, and admiration. There were no differences observed with enthusiasm.

    As to reasons for the difference, the researchers suppose that while pride and satisfaction may reflect upper class individuals' (个人) desire for independence, increased love and compassion may help lower class individuals form more harmonious (和谐的), interdependent bonds to help deal with their more threatening environments. In other words, the researchers are not saying that one way of getting happiness is better than another, but rather that the way one obtains happiness may be a product of existing and coping within one's particular circumstances.

    It is hard to say the first day of school in the United States because when the first day of school is and what happens on the first day of school usually are different by districts(地区).

    The first day of school for many school districts in different states is on the day after the first Monday in September. In some other school districts, school begins in mid-to-late August. For example, the Denver, Colorado schools go back in mid-August and schools in Cleveland, Ohio start back usually one week before the first Monday in September. The Boston, Chicago, New York City and San Diego schools start back on the Tuesday or Wednesday after the first Monday in September.

    Schools in Cleveland, Ohio used to start the school year on the day after the first Monday in September, but in the 1976-1977 and 1977-1978 academic years, the school year was affected by several bad snowstorms, extreme cold. In the 1978-1979 school year, the Ohio Department of Education moved the start of the year to late August, one week before the first Monday in September. This went into effect in the 1980-1981 school year.

    In most school districts in Utah, the school year starts between August 25 and August 30, and goes until the last week of May or the first week in June next year.

    In American high schools, the freshmen class usually goes back one or two days before the rest of the school body for an orientation(迎新)period. An orientation period helps the freshmen get familiar with their new school, its rules, and surroundings.

    In some schools, the freshmen classes have their photographs taken for identification purposes. Some high schools have tried to make the first week of school fun for incoming freshmen.