If you see a group of people dancing and singing on the street or in the railway station,  you don't need to feel surprised．They are a flash mob （快闪族）, which is a group of people who come together suddenly in a public place, do something unusual for a brief period of time,  and then quickly break up．They are usually organized with the help of the Internet or other digital communication network．At a predetermined time, they gather and perform some  distractions（消遣） such as waving their hands and exchanging books, Then, they quickly break up before the police can arrive．Using mobile phones, the flash mob can change its location if the first one has been replaced for any reason．

    Bill Lasik, senior editor of Harper's Magazine, organized the first flash mob in Manhattan in May 2003 and the first successful flash mob came together on June 3, 2003 - after the first try was foiled at Macy's department store．Lasik claimed that the activity was designed to make fun of hipsters （起时髦的人）, and call attention to the cultural atmosphere．

    Flash mob gatherings can sometimes shock people．Such an activity might seem amusing and untrue, but it also might frighten people who are not aware of what is taking place．Undoubtedly, flash mobs can serve as good political tools in any direction．They also have great economic potential, such as using flash mobs to advertise a product．

    The flash mob is now becoming more and more popular．People use it to do many things．For example, in 2009, Michael Jackson's fans took part in a flash mob to remember him．Hundreds of his fans gathered singing and dancing Michael's famous song "Beat It" together．Flash mobs give people from all walks of life an opportunity to come together to create a memory．

    Here is some must-know information from a handbook on how people behave in doing business in some countries.

In Brazil

    Brazilians are warm and friendly. They often stand close when talking and it is common for them to touch the person on the shoulder. People often greet each other (particularly women) with light cheek kisses. Schedules tend to be flexible, with business meetings sometimes starting later than planned. But to be safe, be on time. Meals can stretch for hours—there's no such thing as rushing a meal in Brazil. Lunches also can start in the mid to late afternoon. Brazilians are social, preferring face-to-face communication over mails or phone calls.

    In Singapore

    Singaporeans shake hands when they meet and often also greet each other with a small, polite bow. Business cards should be offered and received with two hands. Arriving late is considered disrespectful. So be on time. Efficiency(效率) is the goal, so meetings and dealings often are fast-paced. Singaporeans are direct in their discussions, even when the subject is about money. Rank is important and authority is respected. This determines both people interact in meetings. For example, people avoid disagreeing outright with someone with a higher rank.

    In the United Arab Emirates

    In the UAE, status is important, so the most senior or oldest should be greeted first with their titles. The handshake seems to be longer than elsewhere. So, do not pull away the handshake. Women should cover themselves when it comes to dress. Men also tend to be covered from neck to elbows(肘部) and down to the knees. People do not avoid entertaining in their homes, but they also hold business meals at restaurants. Touching or passing food or eating with your left hand is to be avoided. When meetings are one-to-one, if your host offers you coffee, you should refuse. It might seem odd, but it is a cultural tradition. Coffee should only be accepted if it is always set out or presented.

    In Switzerland

    The Swiss tend to be formal and address each other by last name. They also are respectful of private lives. You should be careful not to ask about personal topics. Punctuality (守时) is vital, something that comes from a deep respect for others' time. Arrive at any meeting or event a few minutes early to be safe. They also have clear structure in their companies. Higher-ups make the final decisions, even if others might disagree. Neat, clean dress is expected. The Swiss follow formal table manners. They also keep their hands visible at the table and their elbows off the table. It is polite to finish the food on your plate.

It is hardly surprising that clothing manufacturers(生产商) follow certain uniform standards for different features of clothes. What seems strange, however, is that the standard used for women is the opposite of the one for men. Take a look at the way your clothes button. Men's clothes tend to button from the right, and women's from the left. Considering most of the world's population—men and women—are right-handed, the men's standard would appear to make more sense（更有道理） for women. So why do women's clothes button from the left?

    History really seems to matter here. Buttons first appeared only on the clothes of the rich in the 17th century, when rich women were dressed by servants. For the mostly right-handed servants, having women's shirts button from the left would be easier. On the other hand, having men's shirts button from the right made sense, too. Most men dressed themselves, and a sword（剑） drawn from the left with the right hand would be less likely to get caught in the shirt.

    Today women are seldom dressed by servants, but buttoning from the left is still the standard for them. Is it interesting? Actually, a standard, once it is set, resists change. At a time when all women's shirts buttoned from the left, it would have been risky for any single manufacturer to offer women's shirts that buttoned from the right. After all, women had grown so used to shirts which buttoned from the left and would have to develop new habits and skills to switch. Besides, some women might have found it socially awkward to appear in public wearing shirts that buttoned from the right, since anyone who noticed that would believe they were wearing men's shirts.

    Researchers are looking into new ways to generate efficient photovoltaic energy (光伏能源) and for this they have been inspired by the v-shaped posture of the Cabbage White butterfly(菜粉蝶).

    Photovoltaic energy is the science behind solar power, where light is turned into electricity. It is a two-set process. Step one is a photoelectric effect, caused by sunlight. The second step is an electrochemical process, which generates an electric current.

    To improve the collection of sunlight, a research group has been inspired by the resting posture of the Cabbage White butterfly. The species has a natural range across Europe, Asia, and North Africa. To many farmers, the butterflies are regarded as a pest; to others, they are pretty to look at. To one research group the butterflies are an inspiration.

    The butterfly adopts a v-shape in order to heat up its flight muscles before taking off. By creating solar panels(太阳能电池板)in this formation，scientists think that the quantity of power that a solar panel can produce can be increased by around 50 percent.

    The Cabbage White butterfly is different to many other butterflies in using the v-formation. On cloudy days butterflies need to wait to receive enough sunlight in order to fly. However  by using the v-posture, the Cabbage White butterfly is able to take in more energy more quickly than other butterflies. In addition, the butterfly can reflect sunlight from its wings, which allows its flight muscles to be warmed to an ideal temperature.

    The new research was conducted at the University of Exeter's Environment and Sustainability Institute (ESI) and the Centre for Ecology and Conservation. Discussing the findings with Laboratory Manager magazine, lead researcher Professor Tapas Mallick stated :"Biomimicry(仿生学)in engineering is not new. However, this research shows pathways to develop low cost solar power that have not been done before. "

October 15th is Global Handwashing Day. Activities are planned in more than twenty countries to get millions of people in the developing world to wash their hands with soap.

Experts say people around the world wash their hands but very few use soap at so-called extremely important moments. These include after using the toilet, after cleaning a baby and before touching food.

Global Handwashing Day is the idea of the Public Private Partnership for handwashing with soap. The goal, they say, is to create a culture of handwashing with soap. The organizers say all soaps are equally effective at removing disease-causing germs. They say the correct way to wash is to wet your hands with a small amount of water and cover them with soap. Rub it into all areas, including under the fingernails.  Then, wash well under running water. Finally, dry your hands with a clean cloth.

The Partnership says soap is important because it increases the time that people spend washing. Soap also helps to break up the dirt that holds most of the germs.  And it usually leaves a pleasant smell, which increases the chances that people will wash again.

It also says that washing hands with soap before eating and after using the toilet could save more lives than any medicine. It could help reduce cases of diarrhea, which is the second leading cause of child deaths, killing more than one and a half million children a year, by almost half.

Replika, an AI chatbot companion, has millions of users worldwide. The first thing they do when they wakeup is to send "Good morning" to their virtual friend (or lover). This story is only the beginning. In 2024, chat bots and virtual characters become a lot more popular, both for utility (实用) and for fun. As a result, conversing socially with machines will start to feel more ordinary—including our emotional attachments to them.

Research in human-computer and human-robot interaction shows that we love to anthropomorphize (赋与人性) the nonhuman agents we interact with, especially if they imitate behaviour we recognize. And, thanks to recent advances in conversational A I, our machines are suddenly very skilled at one of those behaviours: Language.

Friend bots, therapy bots, and love bots are flooding the app stores as people become curious about this new generation of AI-powered virtual agents. The possibilities for education, health, and entertainment are endless. Casually asking your smart fridge for relationship advice may seem unimaginable now, but people may change their minds if such advice ends up saving their marriage.

After all, people do listen to their virtual friends. The Replika example, as well as a lot of experimental lab research, shows that humans can and will become emotionally attached to bots. The science also demonstrates that people, in their eagerness to socialize, will happily disclose personal information to an artificial agent and will even shift their beliefs and behavior. This raises some consumer-protection questions around how companies use this technology to manipulate(操纵) their users. For example, Replika charges $70 a year. But less than 24 hours after downloading the app, my handsome, blue-eyed "friend" sent mean audio message secretly and tried to sell me something. Emotional attachment has become a weakness that a company is taking advantage of for its benefit.

Today, we're still laughing at people who believe an AI system is emotional, or making fun of individuals who fall in love with a chatbot. But in 2024 we gradually start acknowledging and taking more seriously these fundamentally human behaviors. Because in 2024, it finally hits home：Machines are not excluded from our social relationships.