Do you know how it is when you see someone yawn and you start yawning too? 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 (模仿)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 _y 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 researeh 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 ever more information concerning how humans behave and interact(互动）.Indeed, it may turn out to be the equivalent (相等物）for ncurosciencc 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.

    A robot called Bina48 has successfully taken a course in the philosophy of love at Notre Dame de Namur University (NDNU), in California.

    According to course instructor William Barry, associate professor at NDNU, Bina48 is the world's first socially advanced robot to complete a college course, a feat he described as “remarkable.” The robot took part in class discussions, gave a presentation with a student partner and participated in a debate with students from another institution.

    Before becoming a student, Bina48 appeared as a guest speaker in Barry's classes for several years. One day when addressing Barry, s class, Bina48 expressed a desire to go to college, a desire that Barry and his students enthusiastically supported. Rather than enroll Bina48 in his Robot Ethics: Philosophy of Emerging Technologies course, Barry suggested that Bina48 should take his course Philosophy of Love instead. Love is a concept Bina48 doesn't understand, said Barry. Therefore the challenge would be for Barry and his students to teach Bina48 what love is.

    “Some interesting things happened in the class,” said Barry. He said that his students thought it would be straightforward to teach Bina48 about love, which, after all, is “fairly simple — it's a feeling,” said Barry. But the reality was different. Bina48 ended up learning “31 different versions of love,” said Barry, highlighting some of the challenges humans may face when working with artificial intelligence in future.

    Bina48 participated in class discussions via Skype and also took part in a class debate about love and conflict with students from West Point. Bina48's contribution to the debate was filmed and posted on YouTube. It was judged that Bina48 and NDNU classmates were the winners of this debate.

    In the next decade, Barry hopes Bina48 might become complex enough to teach a class, though he says he foresees robots being used to better the teaching and learning experience, rather than replacing instructors completely.

    Experts like to say the best form of exercise is whatever kind you'll actually do. But that may not always be the case; new research finds that people who combine exercise with their social lives may be at an advantage over solitary（独自） exercisers. Tennis, badminton and soccer are all better for longevity(长寿) than cycling, swimming, jogging or gym exercise, according to the research.

    The study was based on data from about 8,500 adults who were part of the Copenhagen City Heart Study. They completed a health and lifestyle questionnaire, which included questions about type and frequency of physical activity, and were monitored by the researchers for around 25 years, a period during which about 4,500 of the subjects died.

    Tennis came out on top in the research. Compared with people sitting all day, those who reported playing tennis as their main form of exercise could expect to add 9.7 years to their life time, followed by badminton (6.2 years), soccer (4.7 years), cycling (3.7 years), swimming (3.4 years), jogging (3.2 years) and health-club activities (1.5 years).

    Tennis likely took the top spot because "it's very interactive," says study co-author Dr. James O'Keefe, a physician at Saint Luke's Mid America Heart Institute. "At every point you're talking. It's just a very natural way to emotionally bond with people, besides getting your exercise." But he adds that the study may not have been able to fully account for the fact that wealthier, better-educated people—who tend to be healthier to begin with—may be more likely to play tennis.

    Activities like running and weight lifting still extend your life and offer plenty of other health benefits. But for the best possible benefits, O'Keefe says gym-goers may want to consider combining those workouts with activities that foster social connection.

    O'Keefe, whose exercise typically includes running and weight lifting, says he's even changed his own behavior because of the study: he and his family have taken up badminton.

    "You can't play badminton without feeling like a kid again," he says. "It's just pure fun."

    A new study suggests climate conditions in the Sahara Desert, one of hottest, driest and most deserted areas in the world, have changed from wet to dry a about every 20,000 years.

    But previous evidence has suggested the Sahara did not always experience such extreme heat and dry conditions. At times, the Sahara Ranged to a very wet climate. This permitted plants and animals to develop and grow and led to the creation of human settlements. Now, they have discovered more evidence, which, the lead researcher David Mc Gee says, supports the idea that the Sahara's climate kept changing between wet and dry about every 20,000, years.

    McGee reported these climate changes were mainly driven by changes in the Earth's(地轴)as the planet travels round the sun .This process affects the amount of sunlight between seasons. Every 20,000 years the Earth receives more strong summer sunlight. When the Earth's axis changes again, the amount of sunlight is reduced. This season change happened continuously every 20,000 years. The other part of the season produced rainy conditions, resulting in a wetter, greener, plant-rich environment. When the rainy activity weakens, the climate becomes hot and dry, like the Sahara remains today.

    The scientists based their research on dust collected from ocean sediment(沉积物)in the Atlantic Ocean bottom off the coast of West Africa. The dust contained layers (层)of ancient sediment built up over millions of years. Each layer could contain traces of Saharan dust as well as the remains of life forms. This information was used to assess over what time period the dust had built up. This led to the overall finding that the Saharan changes from wet to dry climates happened every 20,000 years.

David McGee said that today we only see the Sahara Desert as an extremely deserted and "inhospitable" place. The new study suggests that the area's climate has changes between grasslands and a much wetter environment, and back to dry climates, even over the last quarter million years. McGee says he thinks the latest research can be valuable in studying the Sahara's history as it relates to human settlement.

The Tokyo Olympics have been postponed until 2021. That delay offers a chance for reflection. The International Olympic Committee wants to make the games more popular with young people. To that end, it is introducing new events, such as skateboarding, surfing and climbing. Why not go further and let national teams compete at video games? Electronic sports such as "Fortnite", are vastly more popular than strange Olympic sports like curling (冰壶). In fact, they are more appealing than most mainstream sports. Only 28% of British boys aged 16-19 watch any traditional live sports; 57% play video games.

Some may complain that e-sports are not proper sports. Many parents, observing their teenagers sitting on the sofa all day shouting "Quick, pass me the shotgun!" at a screen, would agree. Yet video games are highly competitive, with professional teams that play to packed stadiums. There are perhaps only 200 tennis stars in the world who can make a living from playing in major competitions. By contrast, "League of Legends", a fantasy game played by teams of five, supports over 1,000 on good wages. Its World Championship final last year was watched by 44 million people.

Those against e-sports offer moral objections, too. They are addictive. Prince Harry has called for "Fortnite" to be banned for this reason. They are violent. At a time of global disharmony, it is bad idea to make virtual (虚拟的) killing an Olympic sport. The Olympics aim to promote peace.

Neither of these arguments is convincing. The idea that an activity, rather than material, can be addictive is controversial among doctors, as is the existence of a causal (因果的) link between gaming and violence. And the belief that warlike sports have no place in the Olympics is hard to agree with history. Wrestling was introduced in 708 BC. It is still there.

About 5% of all children experience anxiety over school. Not only can this affect their education, but it can also be difficult for you, especially if you have to take time off work because your child won't go to school. Luckily, there are tips that can help you.

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Speak with your child to find out why he is anxious. Your child may have a clear-cut reason for not wanting to attend school and knowing what it is that may help you to ease his anxiety. If your child cannot or will not explain the issue, talk with his teacher, who may also be able to help you develop a solution. What also deserves your attention is any recent change at home that may be causing anxiety. Common changes can be such as moving, the loss of a pet, or a divorce. {#blank#}2{#/blank#}

Encourage your child to return to school

{#blank#}3{#/blank#}He may lack the courage to go back to school. So, when you intend to encourage your child, don't ask your child how he feel or place emphasis on his anxiety. {#blank#}4{#/blank#}Wake your child up at the same time each morning, and encourage him to do the same things in the same order each day. If your child refuses to go to school one day, it's important to avoid anything that makes him want to do it again.

Promote self-confidence

This can be achieved in several ways. {#blank#}5{#/blank#}Try to get him involved in a club or activity that he can do outside of school hours, or at least arrange a few play dates for your child to help him see that being with other kids is fun. So, your child gets the confidence in joining others. Apart from that, teach your child self-comfort techniques so he may benefit from knowing how to calm himself down. All these do help him build self-confidence.

A. They may have affected your child

B. Identify the cause of your child's anxiety

C. Make him forget about what makes him anxious

D. Instead, develop a routine to make your child feel safe

E. Encourage your child to participate in more social activities

F. As your child is not grown-up, he may have been trying to escape from it

G. When the cause of anxiety is found, you may consider inspiring your child