The iPhone, the iPad: each of Apple's products sounds cool and has become a fad(一时的风尚). Apple has cleverly taken advantage of the power of the letter “i” --and many other brands are following suit. The BBC's iPlayer--which allows Web users to watch TV programs on the Internet--used the title in 2008. A lovely bear--popular in the US and UK--that plays music and video is called “iTeddy”. A slimmed-down version(简装本) of London's Independent newspaper was started last week under the name “i”.

    In general, single-letter prefixes(前缀) have been popular since the 1990s, when terms such as e-mail and e-commerce(电子商务) first came into use.

    Most “I” products are targeted at(针对) young people and considering the major readers of Independent's “I”, it's no surprise that they've selected this fashionable name.

    But it's hard to see what's so special about the letter “i”. Why not use “a”, “b”, or “c” instead? According to Tony Thorne, head of the Language Center at King's College, London, “i” works because its meaning has become ambiguous. When Apple uses “i”, no one knows whether it means Internet, information, individual or interactive, Thorne told BBC Magazines. “Even when Apple created the iPod, it seems it didn't have one clear definition(定义),” he says.

    “However, thanks to Apple, the term is now connected with portability (轻便).” adds Thorne.

    Clearly the letter “i” also agrees with the idea that the Western World is centered on the individual. Each person believes they have their own needs, and we love personalized products for this reason.

    Along with “Google” and “blog”, readers of BBC Magazines voted “I” as one of the top 20 words that have come to define the last decade(十年).

    But as history shows, people grow tired of fads. From the 1900s to 1990s, products with “2000” in their names became fashionable as the year was connected with all things advanced and modern. However, as we entered the new century, the fashion disappeared.

    "If you want to see a thing well, reach out and touch it!"

That may seem a strange thing to say. But touching things can help you to see them better.

    Your eyes can tell you that a glass ball is round. But by holding it in your hands, you can feel how smooth and cool the ball is. You can feel how heavy the glass is. When you feel all these about the ball, you really see it. With your skin, you can feel better. For example, your fingers can tell (辨别) the difference between two coins in your pocket. You can feel a little drop of water on the back of your hand, too. You can even feel sounds against your skin. Have you ever wanted to know why some people like very loud music? They must like to feel the sounds of music.

    All children soon learn what "Don't touch!" means. They hear it often. Yet most of us keep on touching things as we grow up. In shops, we touch things we might buy: food, clothes. To see something well, we have to touch it. The bottoms of our feet can feel things, too. You know this when you walk on warm sand, cool grass or a hard floor. All feel different under your feet.

    There are ways of learning to see well by feeling. One way is to close your eyes and try to feel everything that is touching your skin. Feel the shoes on your feet, the clothes on your body, the air on your skin. At first, it is not easy to feel these things. You are too used to them!

    Most museums are just for looking. But today some museums have some things to touch. Their signs say, "Do touch!" There you can feel everything on show.

    If you want to see better, reach out and touch. Then you will really see!

    How much weight a baby gains during its first month could determine its IQ, as a new research suggests. The study found that children who gain more weight, and whose heads grow quickly during the first month of life, tend to have a higher IQ when they start school.

    Researchers at the University of Adelaide, in Australia^ studied 13,800 children who were born at full-term. They found that those who put on 40% of their birth weight in the first four weeks had an IQ 1.5 points higher than those who only put on 15% of their birth weight. Those who experienced the biggest growth in head circumference (头围) also had the highest IQs by the age of six.

“Head circumference is an indicator of brain volume, so a greater increase in head circumference in a newly-born baby suggests more rapid brain growth,” says the led author of the study, Dr. Lisa Smithers.

    She added, “Overall, newly-born children who grew faster in the first four weeks had higher IQ scores later in life. Those children who gained the most weight scored especially high on verbal (言语) IQ at age 6. This may be because the neural (神经的) structures for verbal IQ develop earlier in life, which means the rapid weight gain during the first month could be having a direct cognitive benefit for the children.”

    Previous studies have shown the association between early postnatal (产后的) diet and IQ, but this is the first study of its kind to focus on the IQ benefits of rapid weight gain in the first month of life. Dr. Smithers says the study further highlights the need for successful feeding of newly-born babies. “We know that many mothers have difficulty establishing breastfeeding in the first week of their babies' life,” Dr. Smithers said.

    “The findings of our study suggest that if babies are having feeding problems, there needs to be early intervention (干预) in the management of that feeding.”

    My timing has always been a little off with Elizabeth Strout. I've read and pretty much admired everything she's written, but, for whatever reason, the books of hers I've picked to review have been the good ones, like Amy and Isabelle andThe Burgess Boys, rather than the extraordinary ones, like Olive Kitteridge, which won the 2009 Pulitzer Prize. Anything Is Possible is Strout's latest book and it's gorgeous. Like Olive Kitteridge, Anything Is Possible reads like a novel constructed out of linked stories. In fact, it's hard to know exactly what to call this — a novel or a short story collection. In any case, these stories are animated (栩栩如生) by Strout's signature themes: class humiliation, loneliness, spiritual and, sometimes, reawakening. When Strout is really on her game, as she is here, you feel like you've been carefully lowered into the unquiet depths of quiet lives.

    Strout began working on Anything Is Possible at the same time she was writing her novel My Name Is Lucy Barton, which was published last year. Lucy, a dirt-poor child who grows up to become a celebrated writer, floats in and out of these interlocking stories. Some characters catch a glimpse of her being interviewed on TV; one travels to see her at a bookstore. An older Lucy even appears “in the flesh” in one story when she returns home to the small town in rural Illinois where most of these tales are set to visit her troubled brother; but Anything Is Possible also stands on its own. Indeed, a few of the characters here would be ticked off if they thought their stories depended in any way on that Barton girl. Strout's writerly eye works like a 360 degree camera, so that a character or place that's on the margins of one tale takes center stage in a later one. This technique sounds contrived, but Strout carries it off lightly.

    ①One of the most powerful stories here is called “Dottie's Bed & Breakfast,” which is an establishment we readers glimpse earlier in the book. Dottie desires to be middle-class and she harbors a grudge (怨恨) against life because she's had to rent out rooms to make a living. Dottie also possesses a sensitive nose for sniffing out the lower-class origins of some of her guests.

    ②“Shoes always gave you away,” comments a woman in a story called “Cracked” about a houseguest's too-high cork wedges(坡跟鞋). And, in the final story here, called “Gift,” a once-poor man made good says, “The sense of apology did not go away, it was a tiring thing to carry.”

    ③But, back to Dottie. When an elderly doctor and his wife come to stay at her guesthouse, Dottie bonds over tea with the wife, Shelley, who shares a story about a long-ago social humiliation.

    ④At breakfast the next morning, however, Shelley obviously regrets that confidence and becomes the Doctor's wife again. She freezes Dottie out and puts her back in her place as the inn-keep.

    There's comic satisfaction in seeing Dottie secretly spitting into the breakfast jam, but the more profound rewards of this story have to do with its recognition of the many varieties of human insecurity — or, as Lucy Barton herself more bluntly puts it, the many ways “people are always looking to feel superior to someone else.”

    Other stories have to do with sexual shame, or with the tragic ways close neighbors or family members misread each other; but I'm making Anything Is Possible sound too grim when, in fact, so many of these stories end in an understated (低调的) gesture of forgiveness. Strout is in that special company of writers like Richard Ford, Stewart O'Nan and Richard Russo, who write simply about ordinary lives and, in so doing, make us readers see the beauty of both their worn and rough surfaces and what lies beneath.

    You discover a shampoo that leaves your hair looking beautiful. But gradually, as you use it more, it's magical effects seem to disappear. "It's just your hair getting used to it, "your mom says. And so you put the shampoo away and look for your next wonder product.

    It sort of makes sense -why would something that left you looking nice at first suddenly start losing its effect after some time? Are there some other factors(因素)at play? Can your hair really get used to a certain shampoo?

    Marie Claire spoke to hair experts and it turns out that it's not true. Your hair cannot get so used to a product that it just stops working.

    So what is the deal? Cynthia Alvarez, a famous hair stylist, explained that there are a number of factors leading to your hair puzzle, but basically, it's not the shampoo. "A shampoo does not stop working because your hair get used to it, she said." If your shampoo stops giving you the results you want, the condition and needs of your hair have most likely changed, or the season may have changed -it's more humid(in $), the sun is stronger, or the air is drier. Your state of health may also be different from a recent illness.

    In other words, you need to give up blaming the shampoo. So what can you do to make your hair look beautiful for a little longer? Alvarez suggests changing your ways of hair care when factors, such as the weather, change. Experts also suggest keeping an eye on the amount of shampoo and conditioner(H%i )you're using because over conditioning can be bad for your hair.

    Exercise could not only benefit your body, but also imp rove your memory, researchers found recently. In their paper published on Monday, researchers from the University of California, Irvine in the United States and the University of Tsukuba in Japan introduced their experiment and conclusion.

    Scientists invited 36 volunteers who were in their early 20s to do 10 minutes of light exercise before taking a memory test in which they were shown pictures like broccoli(西兰花)or picnic baskets and asked to recall them later. The same experiment was repeated with the same group of volunteers without exercising. "The memory task was really quite challenging ,said Michael Yassa, co-author of the study and a neuroscientist (神经科学家)at the University of California, Irvine. "We used very tricky similar items to see if they would remember whether it was this exact picnic basket versus (对抗)that picnic basket. "

    Researchers also scanned brains of some of the participants during the experiment. They found strengthened communication between regions involved in the storage and recollection of memories in brains of those who had exercised. This suggested that just 10 minutes of light exercise like walking, yoga or Tai Chi might increase memory power.

    As all the volunteers in the experiment were relatively young, researchers are still working to look at the effects of light exercise on older people. " Our future goal is to try to develop an exercise prescription (处方)that can be used by older adults who might have disabilities or mobility impairments, but can still adopt very simple exercise rules of life and be able to, perhaps, delay cognitive decline temporarily," said Yassa.

Libraries

    Public libraries

    Most towns in Britain have a public library. A library usually has a large selection of books and other resources, which library members can use and borrow for free.

    Britain's First Public Library

    The first public library in Britain opened in Manchester in1852. It's first librarian was a man called Edward Edwards, Edwards attended the library's opening ceremony and two famous writers called Charles Dickens and William Thackeray were there too.

    How to Join a Library

    To join a library, go to your local library and fill in a form. You'll receive a library card which is needed when using library services.

    Mobile Libraries

    Not everyone can get a library. Some people live far away from towns and cities. Other people find it difficult to go out because they have an illness or a disability. Thanks to mobile libraries, these people can still borrow books.

    Unlike most libraries, which store books in buildings, mobile libraries usually keep their books in a mini-bus. The back of the mini-bus has shelves for the books, and it is big enough for borrowers to step inside and look around. A driver takes the mini-bus to a certain place at a certain time, so people know when to expect it. They can then return their books and borrow some more.

    All Aboard the Library!

    A school in London didn't have space for a library inside the building. However, everybody agreed that it was still important to have a school library. So the head of the school, Graham Blake decided to park an old bus on the school car park and changed it into a library. Pupils helped to paint the bus, and after eight months, the new library was ready.

The Greatest show on Earth

    The Olympic Games are the greatest festival of sports in the world. Every four years, many countries send their best sportsmen to compete for the highest honour in sport. As many as 6, 000 people take part in over 20 sports. For the winners, there are gold medals and glory. But there is honour, too, for all who compete, win or lose. That is in the spirit of the Olympics—to take part is what matters.

    The Olympic Games always start in a bright colour and action. The teams of all the nations parade in the opening ceremony and march round the track. The custom is for the Greek team to march in first, for it was in Greece that the Olympics began. The team of the country where the Games are being held—the host country—marches in last.

    The runner with the Olympic torch (火炬) then enters the stadium and lights the flame. A sportsman from the host country takes the Olympic oath (宣誓) on behalf of all the competitors. The judges and officials also take an oath. After the sportsmen march out of the stadium, the host country puts on a wonderful display.

    The competitions begin the next day. There are usually more than twenty sports in the Games. The rule is that there must be at least fifteen. The main events are in track and field, but there are a few days before these sports start. Each day the competitors take part in different sports, like riding, shooting, swimming, and cross-country running. Points are gained for each event. Medals are awarded for the individual winners and for national teams.

    More and more women are taking part in the Games. They first competed in 1900, in tennis and golf. Women's swimming events were introduced in 1912. But it was not until 1928 that there were any track and field events for women. Now they compete in all but half a dozen of the sports. In horse riding, shooting, and boat racing, they may compete in the same events as men.

    Facebook is an American online social media and social networking service. The Facebook website was launched on February 4, 2004, by Mark Zuckerberg, along with fellow Harvard College students and roommates.

    The founders had limited the website's membership to Harvard students at first; however, later they expanded it to various other universities, and eventually to high school students as well. Since 2006, anyone who claims to be at least 13 years old has been allowed to become a registered (注册了的) user of Facebook, though differences exist in the youngest age requirement, depending on local laws. Facebook has more than 2 billion monthly active users as of June 2017. As of April 2016, Facebook was the most popular social networking site in the world, based on the number of active user accounts.

    Facebook may be accessed by a large range of desktops, smartphones over the Internet and mobile networks. After registering to use the site, users can create a user profile (简介) showing their names and so on. Users can add other users as "friends", exchange messages, post photos and so on.

    Facebook makes most of its income from advertisements which appear on screen, marketing access for its customers to its users.

    Sleep, considered a luxury by many, is essential for a person's wellbeing. Researchers have found that insufficient sleep increases a person's risk of developing severe medical conditions, such as obesity, diabetes, and cardiovascular diseases. Now, a new study by Boston's Massachusetts Institute of Technology (MIT) has found that getting sufficient sleep is also the key to improving academic performance.

    Jeffrey Grossman, who led the research, was not trying to find the link between sleep and grades when he handed out Fitbits to the 100 students in his introduction to Solid-State Chemistry class. Instead, the professor of Computational Materials Science hoped the popular wrist-worn device which, tracks a person's activity 24/7, would show a connection between physical exercise and academic achievement.

    However, the study, published in the journal “Science Learning” on October 1, 2019, discovered a surprising insight. Then was a straight-line relationship between the average amount of sleep a student got and his/her grade on the 11 quizzes, three midterms, and the final exam administered during the semester.

    Even more interesting, it was also not sufficient for students to just head to bed early the night before a test. Instead, it's the sleep you get during the days when learning is happening that matters most.

    The time students went to bed each night was similarly important. Those who went to bed in the early hours of the morning performed poorly, even if the total sleep time was the same as a higher - performing student. “When you go to bed matters. Grossman says. If you go to bed after 2, your performance starts to go down even if you get the same seven hours. So, quantity isn't everything.”

    New Jersey Middle School Makes Students Go Phone-Free

    A middle school in Union County, New Jersey, is forcing its students to stay disconnected in class, by prohibiting cellphones. Maxson Middle School Principal Kevin Stansbury put forward the phone ban last week after he noticed some major issues in the school. "Our test scores were down, discipline was up," he says. According to him, students were too focused on their phones to pay attention to their lessons. So, he purchased Yondr pouches for the school.

    Yondr pouch

    When students come into class each morning, they place their phones in the pouch, which is then locked up tight. It can only be opened using a special device at the end of the day. The ban on mobile devices applies not just during class time but during breaks, with the only exceptions being in times of emergency or in cases of students who need such devices to help with disabilities.

    Eighth-graders who spoke with News 12 New Jersey say that they noticed a change in a matter of hours. "It's just better for everyone because you'll understand how it feels to get more work done instead of paying attention to the phone," says student Charlene V. "I'm usually listening to music, but today I got to communicate with all my friends," says student Desiree Duncan.

    The program was originally met with resistance from students and parents, so the process was not that smooth. But teachers and administrators say that the program will have a major impact. "Students were talking and laughing and there were no cellphones other than being carried in the pouches," Stansbury says.

    Teacher Nia Cummings says she even noticed students bouncing ideas off each other in class. She says students used to give up quickly and just look for answers on their phones. She says they now try to figure it out themselves. "Everyone is socializing and eating lunch together. That's what I wasn't seeing enough of when phone usage was at its worst," she adds.

    Maxson Middle School is currently the only one in the district to use these pouches. Kevin Stansbury also called on all the schools in the community that it's worth paying close attention to cellphone issues at secondary schools and taking actions when necessary.

    Amsterdam, capital of the Netherlands, is one of the most popular travel destinations in the world. It is often referred to as the "Venice of the North" due to its huge system of bridges and canals. Here are some key points to remember as you plan your trip to Amsterdam.

    Must-see Attractions

    The Old Centre is full of traditional architecture and coffee shops. You'll also want to check out Amsterdam's Museum Quarter in the South District, which is great for shopping at the Albert Cuyp Market and having a picnic in the Vondelpark.

    Transportation

Amsterdam Airport Schiphol is one of the busiest airports in the world. You can catch a train from Schiphol to Amsterdam Central Station, which has many connecting routes. Cycling is very popular here, and it's easy to find cheap bike rentals around town.

    Recommended Restaurants

    Amsterdam is a top destination for foodies(Ex), so it is difficult to narrow down your dining choices. Here are a couple of our favourites.

    Money-saving Tips

    Unless you really want to see the tulips(郁金香) blooming, avoid booking between mid-March and mid-May. This is when hotel and flight prices rise sharply.

Look for accommodations in Amsterdams South District, where rates are generally cheaper than in the city centre.

    Buy train tickets at the machine instead of the counter to save a bit of money.

Instead of hiring a tour guide, take a canal boat. They're inexpensive and will give you a different view of the city.

    Tiny as they are, bats have the ability to "see" in the dark by using a special skill called echolocation (回声定位法). They make noises and wait for sound waves, or an echo, to bounce back off objects. They can tell the distance of various objects by how quickly the sound waves bounce back off them. If no sound bounces back, they can then fly forward.

    This special ability has been copied in the human world for a long time, such as in submarines and planes. But apart from helping vehicles "see" where they are, what if blind people could use echolocation for themselves? American Daniel Kish, who is blind, is known as "Batman". This isn't because he walks around in a cape (披风) and a mask, but because he has a bat-like ability to locate where he is through sharp clicks he makes by moving his tongue against the roof of his mouth. Kish is so skilled at echolocating that he can ride a bike and hike on his own.

    Recently, a research carried out at the University of Durham in England shed some light on the power of human echolocation. Kish, as well as other volunteers, worked with a group of scientists who studied the way blind people listen to the echoes that they produce from clicks. The team found that people were capable of hearing even very faint echoes, ones far fainter than had been previously thought.

    Lore Thaler, lead scientist of the group, said, "We found that in some conditions, they were really faint-about 95 percent softer than the actual clicks, but the echolocators were still able to sense this."

    Andrew Kolarik, another expert in echolocation, told BBC News that echolocation "can be very useful at providing information at face or chest height" and could help people "avoid objects like low hanging branches that might not get detected by the cane or a guide dog".

    According to BBC News, echolocation is a skill blind people can acquire and develop, just like learning a language. As Kolarik said, "Teaching echolocation skills could provide blind people with the means of exploring new places."

A typical school day in the UK starts around 8:30 am. This is often even earlier elsewhere in the world, with students sitting down to their first lesson at 7:30 am in the US. The average teenager ideally needs eight to nine hours' sleep each night, but in reality a lot of teenagers struggle to get this much. A lot of the problems happen because our sleep patterns are not fixed, and they change as we grow.

So a later school start time could help to solve this problem, by ensuring to get their eight plus hours of sleep and react properly to their body's natural rhythms (规律). There has been a general change over the past 25 years to shorten the school day. This is not at the cost of teaching time (which has remained constant) but at the cost of natural breaks, which has led to reduced lunch time and lesson breaks.

Later start times could help teens' grades and health. This is mainly because it makes the management of children easier. Managing hundreds of children "playing" requires effective staffing. And there is always the fear that behavior worsens during breaks. So the theory goes that having them in class and strictly managed must be better.

But this means that students barely have enough time to absorb what they were doing in maths before suddenly they are forced to study ancient history. And teaching staff also move through from one class to another, with hardly a rest or time to refocus.

Clearly rethinking the school day could benefit everyone included. Anyway, it could also lead to better achievement in teenagers and less of a struggle for parents in the mornings. For teachers, it could also mean a less stressful day all around and what could be better than that?

Why should mankind explore space? Why should money, time and effort be spent exploring and researching something with so few apparent benefits? Why should resources be spent on space rather than on conditions and people on Earth? These are questions that, understandably, are very often asked.

Perhaps the best answer lies in our genetic makeup as human beings. What drove our ancestors to move from the trees into the plains, and on into all possible areas and environments? The wider the spread of a species, the better its chance of survival. Perhaps the best reason for exploring space is this genetic tendency to expand wherever possible.

Nearly every successful civilization has explored, because by doing so, any dangers in surrounding areas can be identified and prepared for. Without knowledge, we may be completely destroyed by the danger. With knowledge, we can lessen its effects.

Exploration also allows minerals and other potential resources to be found. Even if we have no immediate need of them, they will perhaps be useful later. Resources may be more than physical possessions. Knowledge or techniques have been acquired through exploration. The techniques may have medical applications which can improve the length or quality of our lives. We have already benefited from other spin -offs including improvements in earthquake prediction, in satellites for weather forecasting and in communications systems. Even non-stick pans and mirrored sunglasses are by-products(副产品) of technological developments in the space industry!

While many resources are spent on what seems a small return, the exploration of space allows creative, brave and intelligent members of our species to focus on what may serve to save us. While space may hold many wonders and explanations of how the universe was formed or how it works, it also holds dangers. The danger exists, but knowledge can help human beings to survive. Without the ability to reach out across space, the chance to save ourselves might not exist.

While Earth is the only planet known to support life, surely the adaptive ability of humans would allow us to live on other planets. It is true that the lifestyle would be different, but human life and cultures have adapted in the past and surely could in the future.

People from all walks of life tend to become more personal and hide less of themselves when using email. Researchers from Open University in Britain have found in a recent study that there are good reasons for this.

The team of researchers asked 83 pairs of students, all strangers to each other, to solve a problem. They had to discuss this question: If only five people in the world could be saved from a world disaster, who should they be? The pairs of students had to talk over the problem either face to face or by computers. Dr. Johnson said, "They told their partners four times as much about themselves when they talked over the Internet as when they talked face to face. When the computers were fitted with cameras so that students could see each other, this limited the personal side of the conversation."

Generally the information was not extremely personal. It was mainly about things such as where they went to school, or where they used to live. But some students discussed their love stories, and personal childhood experiences.

Dr. Johnson believes that emailing encourages people to focus on themselves. And when they do this, they become more open, especially if there are no cameras. "If you cannot see the other person, it becomes easier to talk about yourself. This is because you are not thinking what the other person is thinking of you. So emailing has become the modern way of talking," said Dr. Johnson. However, this style of talking is not completely new. "In the 19th century people started to use the "telegraph' to communicate. Now the same kind of thing has happened and people ended up speaking more freely."

Dr. Johnson thinks that emailers need to know about these effects of emailing, especially when they start work in a company." If you don't know about it, you could find yourself saying more about yourself than you wanted to."

American country music is also known as country western music. It has a very long history. It comes from the folk songs of immigrants (移民) from Britain.

 Country music uses simple music and words to express everyday feelings such as loneliness, love, and sadness. That is to say, country music describes life. It talks about friends and enemies, trucks and roads, farm and crops. People in many parts of the world like country music, because everyone can understand what the music is about.

Country western music became popular first among cowboys (牛仔) in the American west countryside. Cowboys had to take care of cows day and night. When they were alone with the cows, they often sang beautiful and peaceful songs to calm the animals and to overcome their own fear. They were not well-educated and so they sang about their daily life in very simple words. They played guitars, violins and other instruments. In the south of America, many people added instruments from their homes, like bottles and spoons. When cowboys visited their friends and families on holidays like Thanksgiving, they usually sang and played country western music.

In recent years, many musicians have made country western music a little different from the one in the past. These changes make the songs sound even better. Today singers such as Carth Brooks, Reba McEntire, Emmylou Harris, Lyle Lovett, Eddie Rabbitt, LeAnn Rimes, Randy Travis and a group called Alabama are singing and playing in different styles. They have brought country western music more and more fans from all over the world.

As you know, different countries have different customs. Also there are many gestures showing many meanings in many countries. Here are a few examples of gestures.

A fisherman in Britain will show the size of a fish he has caught by holding his two hands, palms (手掌) facing each other, the right distance apart in front of him. But the one from certain parts of Africa will measure off the size along his left arm with his right hand. In Britain the gesture to show the number "one" is made holding up the index finger (the second finger), but in Switzerland it is the thumb—the first finger which is held up. Some people point at objects with fingers, others by sticking out the lips. The gesture for "come here" is made in Britain with the index finger, which is held, pointing upwards, at eye level and bent towards the body; in Egypt the hand is held at arm's length, palm downwards, and the fingers are then bent.

The difference between the movements is very important, and the meanings of the same gestures may be opposite in different countries. It may bring trouble to those who do not know it well.

Mercury (汞), an unusual element, is poisonous and can be found just about everywhere. It can also exist as an organic compound, the most common of which is methylmercury (甲基汞). While we can take steps to avoid both elemental and inorganic mercury, it is much harder to avoid methylmercury.

Most of the mercury in the environment comes from coal-burning power plants. The concentration of mercury in the air from power plants is very low, so it is not immediately dangerous. However, the mercury is then washed out of the air by rainstorms and eventually ends up in lakes and oceans.

The mercury in the water doesn't immediately get absorbed by fish, as elemental mercury doesn't easily spread into cells. However, methylmercury spreads into cells easily, and certain bacteria in the water change the elemental mercury to methylmercury. Methylmercury in the water spreads into plankton (浮游生物). Small animals eat the plankton and absorb the methylmercury in the plankton and then large animals eat small animals and absorb the methylmercury. Because each animal passes the methylmercury much more slowly than it absorbs it, methylmercury builds up in the animal over time and is passed on to whatever animal eats it.

As people became aware of the concentration of mercury in fish, many reacted by removing seafood from their diet. Scientists have studied the effects of mercury. By determining the levels of mercury consumption that cause any of the known symptoms of mercury poisoning, they were able to identify a safe level of mercury consumption. The current recommendation is for humans to take in less than 0. 1 microgram of mercury for every kilogram of weight per day. This means that a 70-kilogram person (about 155 pounds) could safely consume 7 micrograms of mercury per day.

Nutritionists recommend that, rather than remove fish from our diet, we try to eat more of the low-mercury fish and less of the high-mercury fish. Low-mercury species tend to be smaller fish while high-mercury species tend to be the largest carnivorous (食肉的) fish. Awareness of the particulars of this problem, accompanied by mindful eating habits, will keep us on the best course for healthy eating.

The governing body of emojis（表情符号）released a new group of the graphic images that convey human expressions and add other visual context to text communications.

Among them are a face holding back tears and hands making a heart shape. But big tech companies including Alphabet Inc. 's Google, Microsoft Corp. and Facebook Inc. have also been updating their existing emojis, adding new visual polish, animation（动画制作）, flexibility and sounds.

"We spent a lot of time thinking about how we can make what somebody is saying resonate（共鸣）more, and be emotionally more clear and more present for people, " said Loredana Crisan, vice president of messaging experiences at Facebook's Messenger, which introduced 31 emojis with sounds in July.

Technology companies' efforts to improve emojis come while opportunities for in-person communication remain limited as many people continue to work from home. That has increased the role of not only videoconferencing platforms such as Zoom but of emojis as well, according to observers.

"There's always been a visual component to our communication, "said Paul Hunt, typeface designer and font developer at Adobe Inc. , which is a member of the Unicode Consortium, a non-profit corporation that serves as gatekeeper for the creation of emojis and other characters. "And when we're using only text, then things like tone of voice and gesture and facial expressions get lost. So using emojis as a communication tool can help to reintroduce some of that visual emotional content. "

Emojis still have many potential evolutions to experience, designers who work on them say. "That includes the ways that people find and use them", said Jennifer Daniel, creative director of emoji at Google and chair of the Unicode emoji-development subcommittee. "It is not just about adding new emojis or changing new emojis, "Ms. Daniel said. "It is about the whole experience. "