One of the main challenges facing many countries is how to maintain their identity in the face of globalization and the growing multi-language trend. "One of the main reasons for economic failure in many African countries is the fact that, with a few important exceptions, mother-tongue education is not practiced in any of the independent African states." said Neville Alexander, Director of the Project for the Study of Alternative Education in South Africa at the University of Cape Town.

    In response to the spread of English and the increased multi-language trends arising from immigration, many countries have introduced language laws in the last decade. In some, the use of languages other than the national language is banned in public spaces such as advertising posters. One of the first such legal provisions(规定) was the 1994 "Toubon law" in France, and the idea has been copied in many countries since then. Such efforts to govern language use are often considered as futile by language experts, who are well aware of the difficulty in controlling fashions in speech and know from research that language switching among bilinguals is a natural process.

    It is especially difficult for native speakers of English to understand the desire to maintain the "purity" of a language by law. Since the time of Shakespeare, English has continually absorbed foreign words into its own language. English is one of the most mixed and rapidly changing languages in the world, but that has not been a barrier to acquiring superiority and power. Another reason for the failure of many native English speakers to understand the role of the state regulation is that it has never been the Anglo-Saxon way of doing things. English has never had a state-controlled authority for the language, similar, for example, to the Academic Francaise in France.

    The need to protect national languages is, for most western Europeans, a recent phenomenon—especially the need to ensure that English does not unnecessarily take over too many fields. Public communication, education and new ways of communication promoted by technology, may be key fields to defend.

    I had worried myself sick over Simon's mother coming to see me.I was a new teacher,and I gave an honest account of the students' work.In Simon's case,the grades were awfully low.He couldn't read his own handwriting.But he was a bright student.He discussed adult subjects with nearly adult comprehension.His work in no way reflected his abilities.

    So when Simon's mother entered the room.my palms（手掌心）were sweating.I was completely unprepared for her kisses on both my cheeks."I came to thank you,"she said,surprising me beyond speech.Because of me,Simon had become a different person.He talked of how he loved me,he had begun to make friends,and for the first time in his twelve years,he had recently spent an afternoon at a friend's house.She wanted to tell me how grateful she was for the self-respect I had developed in her son.She kissed me again and left.

    I sat,stunned,for about half an hour,wondering what had just happened.How did I make such a life-changing difference to that boy without even knowing it?What I finally came to remember was one day,several months before, when some students were giving reports in the front of the class,Jeanne spoke quietly,and to encourage her to raise her voice,I had said,"Speak up.Simon is the expert on this.He is the only one you have to convince,and he can't hear you in the back of the room."That was it.From that day on,Simon had sat up straighter,paid more attention,smiled more,and became happy.And it was all because he happened to be the last kid in the last row.The boy who most needed praise was the one who took the last seat that day.

    It taught me the most valuable lesson over the years of my teaching career,and I'm thankful that it came early and positively.A small kindness can indeed make a difference.

    Both humans and animals have enemies. It is easy for us to know the difference between our friends and our enemies. But can other animals do the same? Elephants can! They can use their sense of vision and smell to tell the difference between people who pose a threat(威胁) and those who do not. In Kenya, researchers find that elephants react differently to clothing worn by men of the Maasai and Kamba ethnic groups. Young Maasai men spear(刺)animals and thus pose a threat to elephants; Kamba men are mainly farmers and are not a danger to elephants.

    In an experiment conducted by animal scientists, elephants were first presented with clean clothing or clothing that had been worn for five days by either a Maasai or a Kamba man. When the elephants noticed the smell of clothing worn by a Maasai man, they moved away from the smell faster and took longer to relax than when they noticed the smells of either clothing worn by Kamba men or clothing that had not been worn at all.

    Clothing color also plays a role. In the same study, when the elephants saw red clothing not worn before, they reacted angrily, as red is typically worn by Maasai men. Rather than running away as they did with the smell, the elephants acted aggressively(攻击地) toward the red clothing.

    The researchers believe that the elephants' emotional(情绪的) reactions are due to their different senses of the smells and the sights. Smelling a potential danger means that a threat is nearby and the best thing to do is run away and hide. Seeing a potential threat without its smell means that risk is low. Therefore, instead of showing fear and running away, the elephants express their anger and become aggressive.

    Let us all raise a glass to AlphaGo and the advance of artificial intelligence. AlphaGo, DeepMind's Go-playing AI, just defeated the best Go-playing human, Lee Sedol. But as we drink to its success, we should also begin trying to understand what it means for the future.

    The number of possible moves in a game of Go is so huge that in order to win against a player like Lee. AlphaGo was designed to adopt a human—like style of gameplay by using a relatively recent development--deep learning. Deep learning uses large data sets," machine learning" algorithms （计算程序） and deep neural networks to teach the AI how to perform a particular set of tasks. Rather than programming complex Go rules and strategies into AlphaGo DeepMind designers taught AlphaGo to play the game by feeding it data based on typical Go moves. Then, AlphaGo played against itself, tirelessly learning from its own mistakes and improving its gameplay over time. The results speak for themselves.

    Deep learning represents a shift in the relationship humans have with their technological creations. It results in AI that displays surprising and unpredictable behaviour. Commenting after his first loss, Lee described being shocked by an unconventional move he claimed no human would ever have made. Demis Hassabis, one of DeepMind's founders, echoed this comment:"We're very pleased that AlphaGo played some quite surprising and beautiful moves."

    Unpredictability and surprises are—or can be—a good thing. They can indicate that a system is working well, perhaps better than the humans that came before it. Such is the case with AlphaGo. However, unpredictability also indicates a loss of human control. That Hassabis is surprised at his creation's behaviour suggests a lack of control in the design. And though some loss of control might be fine in the context of a game such as Go, it raises urgent questions elsewhere.

    How much and what kind of control should we give up to AI machines? How should we design appropriate human control into AI that requires us to give up some of that very control? Is there some AI that we should just not develop if it means any loss of human control? How much of a say should corporations, governments, experts or citizens have in these matters? These important questions, and many others like them, have emerged in response, but remain unanswered. They require human, not human - like, solutions.

    So as we drink to the milestone in AI, let's also drink to the understanding that the time to answer deeply human questions about deep learning and AI is now.

    Public Health England (PHE) is targeting pizzas, ready meals, ready meat and takeaways. The government has also required the food industry to start using healthier food and encourage the public to opt for lower calorie foods.

    It is all part of an effort to cut calorie (卡路里) intake by 20% by 2024. The target will point to 13 different food groups, which are equal to about a fifth of the calorie taken by children. If action is not taken, PHE said, it would be prepared to ask the government to pass laws.

    PHE would be strictly monitoring progress by looking at which products people were buying and would be prepared to punish companies which do not take their duties. The government is also organizing a program encouraging adults to consume (消耗) 400 calories at breakfast and 600 each at lunch and dinner.

    At present, adults consume between 200 and 300 calories more than they should each day. PHE chief nutritionist Dr Alison Redstone said the 400-600-600 tip would make it easier for "people to make healthier choices" by being able to judge what they should be eating in each sitting.

    How many calories should we eat? It is suggested that women eat no more than 2,000 calories a day, while men should limit their intake to 2,500. For children, it depends on age. A four-year-old should consume no more than 1,300, while for teens aged 17 and 18, it is about 3,000, but overweight children are eating up to 500 calories more than that.

    Prof Russell Viner, of the Royal College of Pediatrics and Child Health, said it was a necessary move. He said, "Over the past 40 years, there had been a slow growth in food sizes, with pizzas and hamburgers simply much bigger than they were in our parents' time." The convenience of fast food at pocket money prices and the advertisement of unhealthy food and drinks to children add to the problem.

    The doctor made it sound easy. Just walk. It was easy for him to say. I couldn't walk to the end of the road to pick up my mail. I tried to stand up, but soon got breathless and just stopped. My mailbox seemed to be so far away. It was hard for me, though I am only 39 years old!

    A month ago, my wife Stephanie and I were in Colorado Springs with our friends when I woke up at 12 o'clock at night and didn't feel very well. Stephanie and I drove to the hospital, and my 10­day vacation turned into a 10­day hospital stay. I got a scar (伤疤) on my body. It was really tough to walk around then and I needed practice.

    Stephanie had to go to work so she encouraged me to try to take a few walks. Minutes later, she came back with a puppy. "Where did you get that?" I asked. "In our mailbox," she replied. What a wonder! The puppy was dirty, with big pleading (恳求的) eyes. Stephanie was late for work. I was not very happy. I couldn't take care of myself. How could I look after this puppy? "He's going to the pound (动物收容所)," I thought. However, wherever I went, the puppy would closely follow me. I tried walking. The puppy ran ahead, looked back and repeated it again and again. He seemed to say "come on". I took a deep breath, and then tried stepping; the puppy was right at my side. I succeeded at last. I didn't take the puppy to the pound. Instead, we walked toward the mailbox.

    We named him Cheyenne. Before long, I was walking with Cheyenne every day. Pretty soon, I was strong enough to work on the farm again. Now I wonder who put a puppy in a mailbox. Nobody is so crazy after all, Cheyenne was maybe what the doctor ordered.