You use her as a shoulder to cry on. She texts you back with casual jokes. But she, Xiaoice, is only a virtual chatbot（虚拟聊天机器人）.

    Xiaoice, Microsoft's latest artificial intelligence robot, was briefly released in 2014, and returned to WeChat in 2015, where she became a big hit. Millions of young Chinese now exchange messages with her daily, The New York Times reported. On WeChat, Xiaoice is an official account. After following it, users can start text-based conversations with Xiaoice.

    “Her incredible learning ability was why people loved to talk with Xiaoice,” Liu Jinchang, a researcher at High-tech Research and Development Center under the Ministry of Science and Technology, told China Daily. Apart from her ability to identify photos and send emojis（表情符号） in conversations, Xiaoice gains 45 percent of her knowledge from interacting with users, China Daily reported.

    Chatbot programs first appeared in the mid-1960s in the US. Driven by top tech companies, they are becoming smarter and more common. For instance, IBM's latest artificial intelligence program served as an academic consultant at Australia's Deakin University, answering students' questions about course schedules and financial aid. Apple's Siri and Amazon's Alexa have been used as voice assistants who can read news, play music and even make jokes for their users.

    These programs are expected to move beyond smartphones, into televisions, cars and living rooms, The New York Times pointed out. However, it may take decades before scientists develop a “Samantha”, the advanced chatbot seen in the fiction film Her. In the film, Samantha has a romantic relationship with her user played by US actor Joaquin Phoenix. Many viewers were enthusiastic about this fantasy of virtual soul mates.

    Nowadays more and more people like to travel, especially when vacations come. A great number of people rush out of their homes or companies to travelling spots. They either drive or take a bus, a train, a ship and so on. Some even ride bikes.

    However, there is another way of travelling—poorism. People have a tour in the poorest areas of the world. Some people may take one-day poorest tour, and some even pay to stay in very poor neighborhoods to experience the lowest living standards in the world. Poorism tours take place around the world, and not just in the third world countries. You can, for instance, tour New York neighborhoods in the Bronx, in the Bund of Shanghai. Such tours can take people into the heart of poor areas within large and in some rich cities. These tours may awaken people to pay more attention to long-standing poverty, or the effects of war.

    Some suggest that tours in the poor areas can raise social care. And the money from the tour can be donated to help the people there.

    Modern lifestyles are generally quite different from those of our hunter-gatherer ancestors, a fact that some claim as the cause of the current rise in global obesity, but new results published July 25 in the open access journal PLOS ONE find that there is no difference between the energy expenditure(耗费) of modern hunter-gatherers and Westerners, casting doubt on this theory.

    The research team behind the study, led by Herman Pontzer of Hunter College in New York City, along with David Raichlen of the University of Arizona and Brian M. Wood of Stanford measured daily energy expenditure among the Hadza, a population of traditional hunter-gatherers living in the open Savannah of northern Tanzania. Despite spending their days hiking long distances to seek for wild plants and game, the Hadza burned no more calories each day than adults in the U.S. and Europe. The team ran several analyses accounting for the effects of body weight, body fat percentage, age, and gender. In all analyses, daily energy expenditure among the Hadza hunter-gatherers was indistinguishable(难以区分的) from that of Westerners. The study was the first to measure energy expenditure in hunter-gatherers directly; previous studies had relied entirely on estimates.

    These findings overturn the long-held assumption that our hunter-gatherer ancestors expended more energy than modern populations, and challenge the view that obesity in Western populations results from decreased energy expenditure. Instead, the similarity in daily energy expenditure across a broad range of lifestyles suggests that habitual metabolic(新陈代谢的) rates are relatively constant among human populations. This in turn supports the view that the current rise in obesity is due to increased food consumption, not decreased energy expenditure. It means we have more to learn about human physiology(生理学) and health, particularly in non-Western settings.

    "These results highlight the complexity of energy expenditure. It's not simply a function of physical activity," says Pontzer.” Our metabolic rates may be more a reflection of our shared evolutionary past than our diverse modern lifestyles."

    Golden Gate Bridge

    Located in San Francisco, the Golden Gate Bridge started in the year 1933 to connect the San Francisco Peninsula with Marin County. It was finally thrown open to public traffic in 1937. It cost $25.7 million in the construction. Till the year 1957, the Golden Gate Bridge, at a length of 2,737 meters, was the longest suspension bridge in the world.

    Brooklyn Bridge

    The Brooklyn Bridge is located in Brooklyn. It is one of the oldest suspension bridges in the United States, having been opened in the year 1883. The length of the bridge is 1,843 meters. The bridge has been featured in several Hollywood movies.

    George Washington Bridge

    Also known as the Hudson River Bridge and the Columbus Bridge, the George Washington Bridge which connects Fort Lee to Manhattan came into use in 1931 after a construction period of almost 4 years. It is a two level suspension bridge that cost about $52 million to build.

    Mackinac Bridge

    This is the third biggest suspension bridge in the world at a length of 8,038 meters. The architect of this bridge was Dr. David B. Steinman, who directed the construction of the bridge which started in the year 1954 and opened to the public in 1958. People using this bridge are charged a certain amount of money.

Navajo Bridge

    Located in Arizona, this bridge crosses the Colorado River and is almost 250 meters long. The construction of this bridge started in the year 1927, ending two years later, costing $390,000. In the 1990s, a second bridge was built which was opened to the public in 1994. The first bridge is now used only by pedestrians.

    In the space of just two years, the app Douyin, created by Beijing-based company ByteDance, has gathered more than half a billion users—around 40%of them outside China—who share short videos of themselves lip-syncing (假唱), cooking, dancing or just being silly. What sets ByteDance apart is its success in the social media category, which is controlled by Facebook, Twitter and Snap—all Western companies.

    ByteDance calls itself an artificial intelligence company. It uses machine learning and algorithms (算法) to figure out what people like most and give them more of what they want to see. On Douyin, people can edit and beautify 15-second videos before posting them online. The app has even made a phrase to describe people glued to their customized feeds: "shua Douyin" or "scrolling through Douyin". Last year, the company released TikTok, the overseas version of Douyin. ByteDance's growing video empire has made it the world's fifth biggest app maker. ByteDance says TikTok and Douyin together have more than 500 million monthly active users.

    Investors like ByteDance because its hundreds of millions of users attract a lot of advertising money. The video apps are lucrative because they attract a lot of users in their teens and 20s, who are more generous with the money. ByteDance also makes money through income sharing deals. People on TikTok, for example, can buy digital coins to give to other people on the app—like throwing money in a performer's tip jar. ByteDance takes a cut of those earnings.

    ByteDance's founder and CEO is Zhang Yiming, a 35-year-old former Microsoft employee. People who have worked with Zhang describe him as someone who thinks deeply about technology and spends much of his free time writing code.

    Like Facebook and Twitter, ByteDance is also battling fake news and inappropriate content. ByteDance promises to add thousands more employees to review content on Douyin.