The brain of an insect isn't very big. But insects are somehow still able to make lots of important decisions. Bees, ants and roaches(蟑螂) build hives(巢穴)with thousands of workers doing specialized work. The jobs are done without a head or even a plan. How do insects manage this?

    To solve the mystery, scientists in Belgium spent months building robotic roaches and then putting them among real roaches. The final goal of the research is to find out how the simple behavior of individuals gives rise to a collective decision. The roach is a good starting point for trying to answer the big question because its social system is simple enough for scientists to study.

    The first step was to build robots that real roaches would accept as their own. Although the robotic roaches don't look much like the real thing, they have similarities with them in three key ways: they naturally head toward dark areas, they are influenced by the behavior of other roaches, and even more importantly, they smell like roaches.

    The next step was getting the robotic and real roaches to work together on common tasks. In experiments, the robots would collectively head towards a dark place, copying the behavior of natural roaches. That got the researchers wondering: if you program the robotic roaches to go woward the lighted place, would the real roaches follow, going against their natural instincts.(本能) ?

    They will – it turned out. Many of the real roaches followed the robots to a lighter shelter. But influence turned out to be a two- way street. On occasion, the real roaches were able to override the programming of the robot roaches and get them to turn into dark hiding places. Being social creatures, both the robotic and natural roaches were paying attention to and following the example set by others.

    In theory, it would be possible to create a robot that could influence collective decision-making in humans. To do this, researchers would have to invent a robot that people would accept. Fortunately, the technology isn't there yet.

    People aren't walking any more—if they can figure out a way to avoid it.

    I felt superior about this matter until the other day I took my car to mail a small parcel. The journey is a matter of 281 steps. But I used the car. And I wasn't in any hurry, either, I had merely become one more victim of a national sickness: motorosis.

    It is an illness to which I had thought myself immune（免疫的）, for I was bred in the tradition of going to places on my own two legs. At that time, we regarded 25 miles as good day's walk and the ability to cover such a distance in ten hours as sign of strength and skill. It did not occur to us that walking was a hardship. And the effect was lasting. When I was 45 years old I raced—and beat—a teenage football player the 168 steps up the Stature of Liberty.

    Such enterprises today are regarded by many middle-aged persons as bad for the heart. But a well-known British physician, Sir Adolphe Abrhams, pointed out recently that hearts and bodies need proper exercises. A person who avoids exercise is more likely to have illnesses than one who exercises regularly. And walking is an ideal form of exercise—the most familiar and natural of all.

    It was Henry Thoreau who showed mankind the richness of going on foot. The man walking can learn the trees, flower, insects, birds and animals, the significance of seasons, the very feel of himself as a living creature in a living world, He cannot learn in a car.

    The car is a convenient means of transport, but we have made it our way of life. Many people don't dare to approach Nature any more; to them the world they were born to enjoy is all threat.To them security is a steel river thundering on a concrete road. And much of their thinking takes place while waiting for the traffic light to turn green.

    I say that the green of forests is the mind's best light. And none but the man on foot can evaluate what is basic and everlasting.

    I grew up with a fat dad 450 pounds at his heaviest. Every week he would try a new diet, and my family ended up eating whatever strange food he was trying at that moment.

    After my third-grade year, my dad landed a life-changing job in Manhattan. My mom, my little sister and I had to move away from our hometown, Chicago, and leave my grandmother and her beautiful food behind.

    Leaving my grandmother was far more frightening than the move to New York City.  There would be no more special weekends at my grandmother's house, the only place I can remember feeling happy, safe and nourished (有营养的). It was what I desired. In this new city, I felt extremely alone and lost, and I missed my grandmother terribly.

    My grandmother knew just how I felt. And she knew the cure. Every week, she would send me a card with a$ 20 bill, a recipe and a list of what to buy at the market. It kept us bonded, and her recipes filled my body and soul.

    Over the years, I have grown to better understand my father's struggles with weight and the toll (代价) it took on him and those who love him. I have come to realize he was driven not by vanity (自负) or selfishness as much as by a deep pain, I  And in spite of growing up in such an unhealthy eating environment ( or perhaps be-cause of it), as an adult I found a passion and a career as a nutrition consultant.

    Today, my father weighs 220 pounds and is a vegan(素食者). How he got there is a story I hope to share in the coming weeks. More importantly, food is no longer a barrier that keeps us apart, but a bridge that keeps us connected. There is nothing my dad enjoys more than talking with me about dietary theories and his weightloss victories. And now I am the one regularly sending recipe cards to my father s house, just as my grandmother did for me.

    Summer holidays are coming. Here are two posters for members of English Club in the  schoolyard：

    Standing in line for the latest iPhone at the Apple store  queuing for tickets to the match or even just waiting at the post office might just have got a lot easier.

Japanese car-maker Nissan announces that it has just the thing to relieve the painful legs of tired queuers.

    The new system of self-driving chairs is designed to detect when someone at the front of the queue is called, and automatically move everyone else one step forward in line.

    The new invention is shown in a company video, which shows a busy restaurant with customers waiting outside. In the video, diners are sitting in a row of chairs, but will not have to stand when the next hungry diner is called to a table. Instead, the chairs, equipped with autonomous technology that detects the seat ahead, move along a path toward the front of the line. When the person at the front of the queue is called, the empty chair at the front can sense it is empty and so moves out of line. Cameras on the remaining chairs then sense the movement and follow automatically.

    “The system, which is similar to the kind used in Nissan's autonomous vehicle technology, will be tested at select restaurants in Japan this year," Nissan said. "It appeals to anyone who has queued for hours outside a crowded restaurant: it rids the boredom and physical pain of standing in line,” Nissan added.

    Although Tokyo has some 160,000 restaurants, long queues are not uncommon. Chosen restaurants that meet the criteria will be able to show the chairs outside their restaurants next year. Nissan also released a short video showing the chairs being used in an art gallery, moving slowly in front of the various paintings to let viewers appreciate the art without the need to stand up.

    Garbage sorting has become a hot issue around China, especially after Shanghai began carrying out a regulation on July 1.

    Beijing, as a forerunner in environmental protection, has thus been expected to follow suit. The capital of the country has long been campaigning for sorting and recycling household waste, as part of its environmental drive for sustainable growth, local media reported.

    The current regulation gives garbage sorting responsibilities to government departments, property management groups and other organizations. It also gives rules for companies, outlining how they're responsible for waste collection, transportation and treatment. Only individuals are not subject to responsibilities.

    The long-awaited revision will soon change the situation, "Taking out the trash without sorting it properly will be illegal," said Sun Xinjun, director of the Beijing Commission of Urban Management. In Shanghai, violators are now fined up to 200 yuan ($30)for trash-sorting violations. The maximum fine in Beijing will not be less than that, he said.

    The Beijing city government first set out to promote garbage sorting in 2009. Authorities have since called on citizens to sort their household waste into four types-recyclable waste, kitchen trash, dangerous waste and others-and leave it in a corresponding dustbin or trash can. Blue-colored dustbins signify items within are recyclable, green represents kitchen trash, red corresponds to dangerous materials and grey to other waste.

    To promote the awareness of garbage sorting and expand the base of participants, authorities have employed workers to help residents on the spot. With intelligent devices, those who throw in recyclable waste at given sites will be rewarded with bonus points, which can be used to buy daily goods. At some communities, there are no color-coded dustbins. Instead, a scheduled garbage collection service is offered to help improve the environment. In other communities, workers offer a door-to-door service to collect recyclables or kitchen waste.

    Beijing Environmental Sanitation Engineering Group has been promoting new garbage sorting facilities such as recycling cabinets and smart kitchen waste trash cans since 2016, Xinhua News Agency reported. Nearly 26,000 metric tons of household waste is generated across Beijing on a daily basis and 29 terminal garbage disposal facilities are working at full capacity. Nearly 9.3 million tons of household waste was processed in the city last year.