Food serves as a form of communication in two basic ways. Sharing bread or other foods is a common human tradition that can promote unity and trust. Food can also have a special meaning, and play an important role in a family or culture's celebrations or traditions. The foods we eat—and when and how we eat them—are often unique to a particular culture or may even differ between rural(郊区的) and urban(市区的) areas within one country.

    Sharing bread, whether during a special occasion(时刻) or at the family dinner table, is a common symbol of togetherness. Many cultures also celebrate birthdays and marriages with cakes that are cut and shared among the guests. Early forms of cake were simply a kind of bread, so this tradition has its roots in the custom of sharing bread.

    Food also plays an important role in many New Year celebrations. In the southern United States, pieces of corn bread stand for blocks of gold for prosperity(兴旺) in the New Year. In Greece, people share a special cake called vasilopita. A coin is put into the cake, which signifies(预示) success in the New Year for the person who receives it.

    Many cultures have ceremonies to celebrate the birth of a child, and food can play a significant role. In China, when a baby is one month old, families name and welcome their child in a celebration that includes giving red-colored eggs to guests. In many cultures, round foods such as grapes, bread, and moon cakes are eaten at welcome celebrations to represent family unity.

    Nutrition(营养) is necessary for life, so it is not surprising that food is such an important part of different cultures around the world.

    Watching a 3D movie can more than double the concentration powers and cognitive(认知) processing of children, a new research claims.

    A study made by visual technology firm RealD and led by child psychologist Dr. Richard Woolfson suggests that children aged between 7 and 14 experienced twice the cognitive processing speed and performed better in testing after watching 20 minutes of a 3D film. This is despite suggestions that attention spans(时期) in children have shortened in the last decade due to unlimited to access to entertainment, including on-demand TV, gaming and social media. A 2015 study claimed that watching 3D content had a similar effect to brain-training exercises.

    Consumer psychologist Mr. Fagan said that the increased stimulation(刺激) found in watching something in 3D "exercised" the brain and improved performance in the short term. "3D films can play the role of ‘brain-training' games and help to make children ‘smarter' in the short term," he said. "The shortening of response times after watching 3D was almost three times as big as that gained from watching 2D; in other words, 3D helps children process aspects of their environment more quickly. This is likely to be because 3D is a mentally stimulating experience which ‘gets the brain's juices flowing'."

    The experiment saw children given a range of cognitive tests before watching 20 minutes of a movie in either 2D or 3D and being tested again. The results showed those who saw the 3D content reacted faster and performed bettering the second round of testing. Mental engagement also rose by 13% among 3D watchers. Child psychologist Dr. Woolfson added that “supportive parenting” and regularly listening to classical music can also aid a child's memory.

    There's a whole lot of things that people fill their stomachs with. Some of them keep people alive. Some of them taste good to people. Some of them help people win pie-eating contests. Alcohol does none of these things. Why do people keep drinking it? And what does it do once it gets to their stomachs?

    There are all kinds of alcohol molecules (分子), but the one that people most often pour down their throat is ethanol (乙醇). Ethanol is very tiny and it dissolves in water, so it gets into all sorts of places that it's not supposed to. Alcohol heads for the digestive system. Because it dissolves in water, it can get into the water in the bloodstream. Because ethanol, to a certain extent, can pass through cell membranes(膜). It can go almost anywhere. It spreads through the muscles, and is sweated（出汗） — unmetabolized(未经新陈代谢的) and whole — through the skin. It gets into the heart. It even takes a walk through the brain, and this is the secret of its powers.

    Alcohol depresses the nerves, and the nerves affect almost every area of the body. Enough alcohol makes people sleep, so people who become unconscious choke on their own vomit (呕吐物). Most worryingly, enough alcohol can shut down those parts of the brain just like any other parts. People become unconscious and their brains simply forget to breathe.

    Alcohol is broken down in the liver. Alcohol doesn't destroy the liver, but products that the liver breaks the alcohol into do cause damage. A glass of wine per day can not do any harm. Instead, it can prevent heart attacks or can make someone functionally young. And it is kind of nice to know that sometimes, relaxation and cheer can be bottled. All that's needed is to take care how much alcohol is let into a person's brain.

    China will build a comprehensive (综合性的) network to detect (检测) pollution of the land, sea and air by 2020, employing satellites, drones(无人机)and remote sensors to monitor the environment.

    The national leadership agreed to the network plan in July, saying the government will lead the monitoring, share information among departments and regions, and be held accountable (追究责任) if violations (违规行为) are found, the Ministry of Environmental Protection said on Tuesday.

    Satellites, a major tool for monitoring air pollution, will receive a boost (大力发展)  this year. The ministry said it will accelerate research on two atmospheric environmental monitoring satellites.

    The ministry will improve a remote sensor network, guided by the goals of the 13th Five-Year Plan (2016-2020), which is scheduled to be released at the end of this year, according to the ministry's Environmental Supervision Department.

    Remote monitoring has played a bigger role in locating pollution sources. Drones helped authorities locate polluted areas in the Tengger Desert in northern China and identify scattered summer straw burnings.

    Hebei province, which has a serious air pollution problem, has cooperated with the ministry's Satellite Environment Center to conduct monitoring from satellites and monitoring stations since January last year.

    "We used the data from the center's satellites to forecast the movement of smog during the Asia-Pacific Economic Cooperation meetings in November, "Zhang Feng, an engineer in the Environmental Supervision Department of the provincial environmental watchdog, said on Tuesday.

    Data collected from monitoring stations helped authorities provide accurate forecasts on hazy days during that period, he said.

    A nation's humor is linked to the historical development of the country. How funny somebody finds a certain thing depends on many things including ages, personal experiences, levels of education and locations. Therefore, humor is something that is not always transferable (可转移的) in another country.

    What about when both countries speak the same mother tongue? Does that mean they will then share the same sense of humor, or can differences still take place? Let's take the example of Britain and America. Time and time again, people say that Brits and Americans don't "get" each other's sense of humor. It is often argued that one of the most common differences between the British and American sense of humor is that Americans don't understand irony (反话). Simon Pegg explores this topic in depth in his article What Are You Laughing At? He concludes that this statement isn't true and I agree with him.

    In fact, Brits use irony on a daily basis while Americans don't. I think Americans understand British irony (most of the time anyway); what they don't understand is the need to use it so frequently. When Americans use irony, they tend to say that they are "only kidding". They feel the need to make a joke more obvious than Brits do. Maybe this comes from a fear of offending (冒犯) people.

    The American sense of humor is generally more slapstick (闹剧的) than that in Britain. I think this arises from a cultural difference between the two. Their jokes are more obvious and forward, a bit like Americans themselves. British jokes, on the other hand, tend to be more subtle. This may stem from the fact that British culture is more reserved (矜持的) than American culture.

    The world's first hydrogen-powered trains have begun running in Germany. They began carrying passengers Monday in Germany's northern Lower Saxony state. The new train will run 100-kilometer trips and can travel up to 140 kilometers an hour.

    A French railroad company called Alstom built the two trains. Team in Germany and France cooperated on the project, which was supported by the German government. The new train model ,called the Coradia ilint, signals the beginning of efforts in Germany and other nations to move away from pollution-producing diesel(柴油) trains.

    The Coradia iLint is designed to run on non-electrified train lines with low levels of noise.

    It uses a process that combines hydrogen and oxygen to produce electrical power. If the system produces more energy than the train needs at that time, it can store the extra energy in batteries. The only emissions (排放物) are water and steam.

    A single tank of hydrogen can run a Coradia iLint train for about 1,000 kilometers. This is very similar to the distance a diesel-powered train can run on with a single tank.

    Hydrogen-powered trains cost more than diesel trains to build. But Alstom officials say the operating costs are much lower. The company plans to provide another 14 Coradia iLint trains to Lower Saxony by 2021.

    The head of railroad operations in the area, Carmen Schwab, praised replacing diesel trains with hydrogen. She said the move was an important first step in using clean-burning technologies to reach climate protection goals.

    Officials say the area's many wind turbines (涡轮机)will produce part of the energy to create the hydrogen to power the trains.

    Alstom says several other European countries have also expressed interest in developing hydrogen train systems. France has already said it wants its first hydrogen train to be operating by 2022.