The expression “a thirst for knowledge" may soon have a new meaning for millions of people who have no way to get clean water. Researchers have developed a book with specially treated pages that can turn dirty water into clean and drinkable water. They say their invention could improve the lives of many in the developing world.

    About 700 million people around the world are at risk of disease or even death because their drinking water is not clean. The water is polluted by harmful bacteria.

    The book contains 25 pages. Each page is about one millimeter thick. The pages contain very small particles (微粒) of silver. The pages can be used as filters（过滤器）to remove harmful microorganisms (微生物) that can pollute drinking water. The filter kills the organisms that pass throughit.

    Pictures on the pages show the dangers of dirty water and how to use the book for those unable to read. The pages aremade of filter paper. They are designed to be torn from the book. Water can bepoured through the paper to be cleaned.

    Ms. Dankovich, the inventor, says eachpage can treat up to 100 liters of water. She recently presented her invention at the meeting of the American Chemical Society in Boston, Massachusetts. She was asked whether she had considered adding classic literature on the book's pages.

    "The idea of classic texts—that's of interest maybe later. We have discussed a little bit more exciting text. But we really haven't had the time to go through that part," she says.

    Teri Dankovich and another researcher tested the drinkable book in Bangladesh, Ghana and South Africa. The tests proved to be successful.

    Water for Life, a non-government alorganization, has provided financial support for the project.

    People aren't walking any more—if they can figure out a way to avoid it.

    I felt superior about this matter until the other day I took my car to mail a small parcel. The journey is a matter of 281 steps. But I used the car. And I wasn't in any hurry, either, I had merely become one more victim of a national sickness: motorosis.

    It is an illness to which I had thought myself immune（免疫的）, for I was bred in the tradition of going to places on my own two legs. At that time, we regarded 25 miles as good day's walk and the ability to cover such a distance in ten hours as sign of strength and skill. It did not occur to us that walking was a hardship. And the effect was lasting. When I was 45 years old I raced—and beat—a teenage football player the 168 steps up the Stature of Liberty.

    Such enterprises today are regarded by many middle-aged persons as bad for the heart. But a well-known British physician, Sir Adolphe Abrhams, pointed out recently that hearts and bodies need proper exercises. A person who avoids exercise is more likely to have illnesses than one who exercises regularly. And walking is an ideal form of exercise—the most familiar and natural of all.

    It was Henry Thoreau who showed mankind the richness of going on foot. The man walking can learn the trees, flower, insects, birds and animals, the significance of seasons, the very feel of himself as a living creature in a living world, He cannot learn in a car.

    The car is a convenient means of transport, but we have made it our way of life. Many people don't dare to approach Nature any more; to them the world they were born to enjoy is all threat.To them security is a steel river thundering on a concrete road. And much of their thinking takes place while waiting for the traffic light to turn green.

    I say that the green of forests is the mind's best light. And none but the man on foot can evaluate what is basic and everlasting.

    These hotels don't have all the necessary facilities(设施),but each of them offers something different. Don't miss them if you travel to Canada.

    Sleep on a train at the Train Station Inn. This hotel is in an old train station in Nova Scotia. The owners, James and Shelley Le Fresne, use the station and the train as rooms. There are seven old train cars and there is also a restaurant in the dining car. Prices are from $89 to $169 per room or train car.

    Sleep in a jail(监狱) in the Canadian capital, Ottawa. Here, you can sleep in the old downtown Ottawa Jail Hostel. There are group or private bedrooms. There are still bars on the doors! Prices are from $ 25 to $ 65. Don't worry, there aren't any criminals(犯人）there !

    Sleep in a tepee (a tent of the American Indians) at a UNESCO World Heritage site in Alberta. At this hotel, there are guided tours and lessons in local culture. The best part: sleeping in a real tepee outside. The price is around $ 300, or $ 620 for a full package.

    Sleep in a lighthouse at the Quirpon Lighthouse Inn. This hotel is on Newfoundland's Quirpon Island. There are great views of the ocean from the windows. There are 11 private rooms in total. Prices are from $ 225 for a single to $ 350 for a suite(套房). Meals are included in the restaurant. The hotel has the traditional look and feel of the lighthouse, so there is no Internet, TV or telephones in the rooms. There are tours available, and boat tours to the island are included.

    Age has never been a problem for 16­year­old Thessalonika Arzu­Embry. After all, she's already got her master's degree.

    The North Chicago­area teen started homeschooling at the age of 4. She began having an influence on others soon after. When she was 6 years old, she was an inspirational speaker at an organization called Tabitha House Community Service, a shelter for people who were forced to leave their homes due to the situations such as earthquake, flood and other natural disasters.

    At the age of 11, she graduated from high school and then earned her bachelor's degree in psychology in 2013. She completed those classes online as she was traveling for church events and leadership meetings.

    She doesn't stop there, though. The teen plans to focus on aviation psychology(航空心理学) for her further study, a decision inspired by her father who is a pilot. She grew up around airplanes and took fights all the time. Her goal is to use it to determine whether pilots are dealing with problems that could have deadly results once the plane takes off­a topic that has been in the news lately. For her, it's a mix of two of her interests.

    In her free time, Thessalonika enjoys playing tennis, swimming and being active in her youth group at church. She also has three self­published books, which are on her site. Jump the Education Barrier is written to help students finish college, and in the future aims to help business owners with trends. Her third book The Genius Race, has a wider appeal. It is designed to help people to be geniuses in various areas of life.

    Imagine a school where self-awareness is celebrated, students are encouraged to solve maths problems by writing on the walls and applying learned lessons to real life is more important than homework. These are a few of the concepts that makes Space of Mind School unique.

    Located in a home built in 1896 in Florida, US, the program serves students in grades 2 through 12 and will accept kindergarten students next year. It also offers an after-school program for students who attend traditional schools, as well as evening programs for adults and educators and weekend events for families.

    There is a different atmosphere from that of a traditional school building. Tables and brightly colored walls are white boards. In the science room, students are studying climate changes at a weather station, while in the music room, a student is solving an equation (等式) with his academic coach while he connects music theory and maths.

    The daily schedule at the school also stands out. "We don't assign boring or exhausting homework." said Space of Mind founder and CEO Ali Kaufman. "Instead of homework, we ask that they go home and take a video of themselves applying a lesson they learned or cooking a meal for their family that they learned how to make at school."

    For lunch, instead of traditional cafeteria dishes such as pizza, the school offers organic meals made out of products from local gardens and farms. "Our students also run a business at the Delray Beach Green Market on Saturdays so they can understand sustainable living practices and how to run a business," Kafman said.

    " We are also the first school program in Florida to start and end each day with 15 minutes of meditation (冥想)," Kaufman said. "The positive results we have been seeing in the students from meditation are amazing. We are really about infusing social, emotional and creative skills with academic and life skills."