A busy public square in the Chinese city of Nanjing is home to an unusual experiment.

    For almost two months, the country's first “honesty bookshop” has occupied（占据） a sidewalk on HanZhong Road in the city's Gulou District.

    With no cashier or other staff, the store relies on trust for payment.

    Making money isn't the company's main goal and they don't punish those who take books without paying.

    “If they can really finish the books, it doesn't matter if they took the books for free,” Zhu Yu, the marketing director of the company says.

    “In fact, we are really happy to witness so many people taking books from the honesty bookshop.” After browsing the four wooden bookshelves, customers must drop their money in a locked box.

    Prices are set at 30% of the usual cover price. Zhu hopes that his sidewalk store, which sells, on average, 60 books a day, will make more people interested in reading. Like elsewhere, e-books are affecting sales of traditional books, and traditional books and many independent booksellers are struggling.

    Zhu got permission from the city government to use the sidewalk and says he's determined to make it a long-term project.

    He says the store is open every day, except when it rains, and it's locked up each night.

    In September last year, the company laid out 1,000 books and reading lamps on the ground and encouraged people “to go on a date” with a book.

    “Independent bookshops represent the well-being of the city.” Zhu told CNN in 2013, “when a city is losing its bookshops, it's actually losing something in its soul.”

If the success of the Honesty Bookstore is any guide, Nanjing's soul is in pretty good shape.

    Walk down the drinks section at the supermarket.Look in the drink cooler in your local convenience store.A new drink is taking up more and more space on the shelves，and that drink is water.Bottled water sales in the US rose to 1.7 billion gallons in 2010 for plastic bottles alone，compared to total sales of only 700 million gallons in 1990. Whereas bottled water was once associated only with the rich and the privileged (特权阶层)，it is now regularly drunk by people at all income levels despite the fact that the price of bottled water can be between 240 and 10,000 times higher per gallon than tap water.What accounts for this surprising increase in demand?

    Traditionally，people have drunk bottled water for health reasons.The practice of “taking the waters” originated with the Romans，who believed that a person developed a healthy mind by building a healthy body.Across Europe，drinking or bathing in mineral water has been associated with the power to cure various diseases.Health spas at Evian in France and Pellegrino in Italy began bottling water so that their consumers could continue their treatments at home.The consumers in the 21st century are also concerned about health.However，in America，where the habit of drinking bottled water is relatively new，the concern is often more related to the purity or sterilization (消毒) of the water than to its mineral contents.Americans are often worried about the effects of the chemical pollution and other contaminants on the water supply.Many Americans view bottled water as a safe alternative to tap water.

    Further reasons for drinking bottled water are its usefulness as an aid to digestion，as a complement to a good meal in a restaurant，and for taste.City tap water is often treated with chlorine (氯) to guard against harmful micro­organisms.Chlorine，as well as metals from pipes and tanks used to distribute and store tap water，can leave behind an unpleasant taste.

    Two new studies suggest that modem running shoes could increase the risk of injuries to runners.

    One study involved sixty-eight healthy young women and men who ran at least twenty-four kilometers a week. The runners were observed on a treadmill machine (跑步机). Sometimes they wore running shoes. Other times they ran barefoot.

    Researchers from the JKM Technologies Company in Virginia, the University of Virginia and the University of Colorado did the study.

They found that running shoes create more stress that could damage knees, hips and ankle joints than running barefoot. They observed that the effect was even greater than the effect reported earlier for walking in high heels.

    The study appeared in the official scientific journal of the American Academy of Physical Medicine.

    The other study appeared in the journal Nature. It compared runners in the United States and Kenya. The researchers were from Harvard University in Massachusetts, Moi University in Kenya and the University of Glasgow in Scotland.

    They divided the runners into three groups. One group had always run shoeless. Another group had always run with shoes. And the third group had changed to shoeless running.

    Runners who wear shoes usually come down heel first. That puts great force on the back of the foot. But the study found that barefoot runners generally land on the front or middle of their foot. That way they ease into their landing and avoid striking their heel.

    Harvard's Daniel Lieberman led the study. He says the way most running shoes are designed may explain why those who wear them land on their heels. The heel of the shoe is bigger and heavier than other parts of the shoe, so it would seem more likely to come down first. Also, the heel generally has thick material under it to soften landings.

    But the researchers do not suggest that runners immediately start running barefoot. They say it takes some training. And there can be risks, like running when your feet are too cold to feel if you get injured.

    The study was partly supported by Vibram, which makes a kind of footwear that it says is like running barefoot. The findings have gotten a lot of attention. But the researchers say there are many problems in the way the press has reported in their paper. So they have tried to explain their findings on a Harvard Website.

    Polish President Andrzej Duda has signed a bill into law that largely limits trade on Sundays, saying it will benefit family life.

    The legislation（立法）, worked out by the government and the Polish trade union, is expected to draw protests from large western supermarket chains that are the main target of the law. A large part of their profit is earned on weekends.

    As of March 1, shops and markets are closed on two Sundays per month; in 2019 only one Sunday a month will be open for shopping; and starting in 2020, there will be no Sunday shopping with a few exceptions.

    Duda praised the law as giving children a chance to be with parents and giving shop workers some needed time off. He also said big traders will need to adjust their practices to the new system and asked them for "understanding". But critics say some of them make employees work long hours for modest pay.

    "A family should be together on Sundays," Olszewska said after buying some food at a local Biedronka, a large discount supermarket chain. She said that before she retired she served cold cuts in a grocery store, and was grateful she never had to work on Sundays.

    There are some exceptions to the ban. For instance, gas stations, cafes, pharmacies and some other businesses are allowed to keep operating on Sundays.

    Anyone breaking the new rules faces a fine of up to 100,000 zlotys （$ 29,500）, while repeat offenders may face a prison sentence. Polish trade union appealed to people to report any violators to the National Labor Inspectorate, a state body.

Teachers across America are struggling to decide whether to view artificial intelligence (AI) tools like ChatGPT as friends or enemies in the classroom. Our study on whether AI affects student creativity shows that the answer isn't always simple. 

In the study, we asked college students to brainstorm — without technology — all the ways a paper clip can be used. A month later, we asked them to do the same, but using ChatGPT. We found that AI can be a useful brainstorming tool, quickly generating ideas that can spark creative exploration. But there are also potential negative effects on students' creative thinking skills and self-confidence. While students reported that it was helpful to "have another brain", they also felt that using AI was "the easy way out" and didn't allow them to think on their own. 

The results call for a thoughtful approach to using AI in classrooms and striking a balance that inspires students' creativity while utilizing AI's capabilities. The good news is that the students in our study generated more diverse and detailed ideas when using AI. They found that AI was useful for kick-starting brainstorming sessions. 

When it comes to brainstorming with AI, some students voiced concerns about over-reliance on the technology, fearing it might hurt their own thoughts and, consequently, confidence in their creative abilities. Some students reported a "fixation of the mind", meaning that once they saw the AI's ideas, they had a hard time coming up with their own. Some students also questioned the originality of ideas generated by AI. Our research noted that while using ChatGPT improved students' creative output individually, the AI's ideas tended to be repetitive overall. 

The study results indicate that allowing students to practice creativity independently first will strengthen their belief in themselves and their abilities. Once they complete this, AI can be useful in furthering their learning, much like teaching long division to students before introducing a calculator. That's to say, teaching students to be creative thinkers rather than rely on AI for answers is the key to answering the question mentioned above.