It is said that if you want to stay young, sit down and have a good think. This is the research finding of a team of Japanese doctors, who say that most of our brains are not getting enough exercise — and as a result, we are growing old unnecessarily soon.

    Professor Taiju Matsuzawa wanted to find out why otherwise healthy farmers in northern Japan appeared to be losing their ability to think and reason at a relatively early age, and how the process of aging could be slowed down. With a team of colleagues at Tokyo National University, he set about measuring brain volumes of a thousand people of different ages and varying occupations. Computer technology enabled the researchers to obtain precise measurements of the volume of the front and side parts of the brain, which controls functions like eating and breathing, does not contract with age, and one can continue living without intellectual on economical faculties. Contraction of front and side parts — as cells die off — was observed in some subjects in their thirties, but it was still not evident in some sixty-and seventy-year-olds. Matsuzawa concluded from his tests that there is a simple way to the contraction normally connected with age — using the head.

    The findings show in general terms that contraction of the brain begins sooner in people in the country than in the town. Those least at risk, says Matsuzawa, are lawyers, followed by university professors and doctors. White collar workers doing routine work in government offices are, however, as likely to have shrinking (萎缩) brains as the farm worker, bus driver and shop assistant.

    Matsuzawa's findings show that thinking can prevent the brain from shrinking. Blood must circulate properly in the head to supply the fresh oxygen the brain cells need. “The best way to maintain, good blood circulation is through using the brain.” he says. “Think hard and engage in conversation. Don't rely on pocket calculators.”

根据短文内容，选择最佳答案，并将选定答案的字母标号填在题前括号内。

    The Indian government may use 3D paintings as virtual (虚拟的) speed-breakers on major highways and roads, in an attempt to check speeding and careless driving, and eventually make its deadly roads a little safer. “We are trying out 3D paintings used as virtual speed breakers to avoid unnecessary requirements of speed breakers (减速带),” India's transport minister Nitin Gadkari tweeted.

    The visual illusions (幻象) are supposed to encourage drivers to slow down automatically. Earlier this month, India bad ordered the removal of all speed breakers from highways, which are considered to be a danger to safety for high-speed vehicles.

    India has the highest number of road accident deaths in the world According to the World Health Organization, over 200,00 people are killed by road accidents due to poor application of road safety laws. This is considerably higher than its official figures of 141,526 for 2014.

    The use of visual illusions as speed breakers was first pioneered in the American city of Philadelphia in 2008, as part of a campaign against speeding motorist. The technique has also been tried out in China to create floating 3D crossings.

    India, cities such as Ahmadabad and Chennai have already experimented with 3D zebra crossings in the last one year. In Ahmadabad for instance, two artists, mother and daughter have painted 3D crosswalks in the first few months of this year. The artists say their motto is “to increase the attention of drivers”, and that the concept has been successfully tested in zones where accidents easily occur on a highway.

    However, critics argue that once divers know that these speed briers are visual illusions, they may ignore them. Others also point out that India's decision does not consider the safety of a large walkers. In the end, the new policy may be just one step towards improving road safety.

    ARNOLD Schwarzenegger is back, once again taking on his iconic killer robot role, the T-800, in August's new movie Terminator Genisys. While the T-800 model—even if it can be evil—has a fond place in moviegoers' hearts, the reality of autonomous machines is no joke, according to scientists.

    Autonomous weapons use artificial intelligence (AI) to choose targets without human help. They were described as “the third revolution in warfare, after gunpowder and nuclear arms” in an open letter signed by over 1,000 important technology figures in July. The list included British scientist Stephen Hawking and Apple co-founder Steve Wozniak. They asked governments around the world to ban autonomous weapons, warning that killer robots could start ethnic cleansings and an arms race.

     “They will look like tanks. They will look like battleships. They will look like jet fighters,” UK robotics professor Noel Sharkey told CNET, a leading technology website.

    But unlike these machines, which require a human hand in their action, so-called “killer robots” would have some decision-making abilities and the ability to act on their own.

     “If any major military power pushes ahead with AI weapon development, a global arms race is almost inevitable,” said the letter released at the 2015 International Joint Conference on Artificial Intelligence in Buenos Aires, Argentina.

    The idea of an automated killing machine was made famous by Schwarzenegger's first Terminator movie in 1984. While no red-eyed robots have been sent after human beings, the idea of AI being used as a weapon has gotten much more likely in the years ever since. The US military is already developing autonomous flying vehicles that can carry out all the steps of a strike mission without a human controlling them, according to a May report in Nature magazine.

    Scientists have even painted a destructive picture of autonomous weapons falling into the hands of terrorists or warlords hoping to carry out ethnic cleansings.

     “The development of full artificial intelligence could lead to the end of the human race,” Hawking said to the BBC in 2016.

Authorities are gradually waking up to the risk of robot wars. Last May, for the first time, the United Nations brought governments together to begin talks on autonomous weapons systems.

    Still, a ban on autonomous weapons is “easier said than done”, commented The Guardian. The dual (双重的) uses of the AI technology—for harm and for good—is difficult to manage. This is because the exact same technology can be used in a wide range of ways, the paper said.

    Frank Woolworth was born in Rodman, New York, in 1852. His family were very poor farmers, and there was never enough to eat. Frank decided he did not want to be a farmer. He took a short business course, and went to work as a salesman in a large city.

    Woolworth realized he had a natural skill for showing goods to attract people's interest, but he soon learned something more important. One day his boss told him to sell some odds and ends (小商品) for as much as he could get. Frank put all these things on one table with a sign which said FIVE CENTS EACH. People fought and pushed to buy the things and the table was soon cleared.

    Soon afterwards, Woolworth opened his own store, selling goods at five and ten cents. But he had another lesson to learn before he became successful. That is, if you want to make money by selling low-price goods, you have to buy them in large quantities directly from the factories. Once, for example, Woolworth went to Germany and placed an order for knives. The order was so large that the factory had to keep running 24 hours a day for a whole year. In this way, the price of the knives was cut down by half.

    By 1919, Woolworth had over 1000 stores in the US and Canada, and opened his first store in London. He made many millions and his name became famous throughout the world. He always run his business according to strict rules, of which the most important was: “ THE CUSTOMER IS ALWAYS RIGHT.”

    Most foodies (吃货) agree that eating healthy food is important. But sometimes making good food choices can be tough. Now, there are apps that can help people learn about the food they eat to improve their diets and their dining out experiences.

Cheese & Wine Pairing app

    Wine and cheese can be a great combination. But which wines go best with which cheeses? Max McCalman's Cheese & Wine Pairing app can help. It provides information about hundreds of different cheeses and advises wines to pair with each. Max McCalman's Cheese & Wine Pairing app is free for iPhones and iPads.

Calorific app

    What does 200 calories look like? It can be hard to picture. Calorific provides images of 200 calories worth of food. The pictures can help people on a diet and those who just want to eat healthier food. The app is free for iPads and iPhones. There is also a version that provides more information for a price.

    HappyCow app

    Vegetarians do not eat animal meat. Vegans do not eat any animal products. The HappyCow app is made for both groups. Users can search for vegetarian-vegan restaurants and stores around the world. A free version of HappyCow is available for Android that has ads and requires an Internet connection.

    LocalEats app

    Restaurant chains, like McDonald's, can be found almost anywhere a person might travel. But sometimes travelers want to eat like locals. LocalEats is designed for that. It lists locally owned restaurants so users can try foods from that area. The app costs about a dollar.

    Sam Allred suffers from a rare and incurable kidney (肾脏)disease. One day, when his sister was playing a song repeatedly, Sam sang along. His sister thought it was funny so she recorded it and posted the video online. The video—and Sam—became a hit. Only 8 years old at that time, he couldn't have expected the response.

    "(The television show) The Doctors called and wanted me on their show so they paid for me to go to California," says Sam, now 13,"and we got to stay in a hotel where all the movie stars stayed."

    During that visit to California, Angle Allred, Sam's mother, had an idea about Sam writing a children's book. Together, she and Sam wrote Opening Hearts, which tells Sam's experience of living with a chronic (慢性的) illness.

    "I wrote the book to teach people to be kinder to people," Sam says.

    Moreover, Sam wanted to send pillows to sick children staying in hospitals around the country to make their stay more comfortable, an idea that came from a time when he was in the hospital.

    "A few kind boys came in with pillows and they gave me one and it meant a lot to me that someone cared about kids in the hospital," says Sam.

    Angie thought of starting a nonprofit organization to provide a way for people to contribute money to realize Sam's ideas. She named the nonprofit organization Kindness for Kids.

    Since then, Sam has taken pillows to children staying at Providence Hospital in Anchorage.

    Sam's father, Scott Allred, owns a small business that contracts (承包) shipping services with FedEx Ground. He asked the company for help.

    "FedEx Ground learned about Sam's pillow project, "says Erin Truxal, manager of public relations for FedEx Ground. "We thought, 'What a perfect way for us to get involved.'"

    The company provided shipping services for Sam to ship about 5,000 pillows to hospitals.

    Sam wants to send more pillows to all of the children's hospitals in every state. His goal is simple: Kids in the hospital as happy as they were before they got sick.