The introduction of the iPad,with its touch screen technology,has allowed even very young children to take advantage of a computer.So what if all children in a school were given an iPad to use in class and take home with them?

    Anne Laure Bazin works in a school where every child,teacher and teaching assistant is given a free iPad to use in and out of lessons.For her,the main advantage of everyone having an iPad had been the improvement in communication.Documents can be emailed straight over to workmates during a meeting.Children submit their homework by email,or through the school's learning environment.Teachers now take the register（点名）using their iPad,which means that there is a record of which children are in school,and which classroom they are in.

    The use of iPad has encouraged greater sharing of resources among teacher.All communication with parents is now done by email.Working as a group in class is much easier as children can share documents.The whole class can look at one child's work by attaching（连接）the iPad to the whiteboard.If a child has forgotten the textbook,the teacher can take a photograph of the relevant（相关的）page and send it to the student in class.

    While the use of the iPad in schools has revolutionized（变革）the way children are taught ,it hasn't completely replaced more traditional methods of teaching .Worksheets are still used in class as some children prefer the contact with paper.The children all have a textbook and exercise books.In Anne Laure's school,parents feared that the iPads would replace exercise books and children would lose handwriting skills.Anne Laure says,” The teacher are not ready to let go of the traditional style of teaching.We have welcomed the iPads in so much as they help communication and widen the resources available but we are not ready to let go of paper yet.The children themselves still value their exercise books and depend on them for review.”

    As the world's population grows, farmers will need to produce more and more food. And large farms are increasingly using precision farming to increase yields (产量), reduce waste, and reduce the economic and security risks that inevitably accompany agricultural uncertainty.

    Traditional farming relies on managing entire fields—making decisions related to planting, harvesting, irrigating, and applying pesticides and fertilizer (农药和化肥)—based on regional conditions and historical data. Precision farming, by contrast, combines sensors, robots, GPS, mapping tools and data-analytics software to customize（量身定制）the care that plants receive without increasing labor. Robot-mounted sensors and camera-equipped drones (无人机) wirelessly send images and data on individual plants to a computer, which looks for signs of health and stress. Farmers receive the feedback in real time and then deliver water, pesticide or fertilizer in adjusted doses（剂量）to only the areas that need it. The technology can also help farmers decide when to plant and harvest crops.

    As a result, precision farming can improve time management, reduce water and chemical use, and produce healthier crops and higher yields—all of which benefit farmers' bottom lines and conserve resources while reducing chemical runoff.

    Many small businesses are developing new software, sensors, and other tools for precision farming, as are large companies such as Monsanto, John Deere, Bayer, Dow and DuPont. The U.S. Department of Agriculture, NASA and the National Oceanic and Atmospheric Administration all support precision farming, and many colleges now offer course work on the topic.

    In a related development, seed producers are applying technology to improve plant characteristics. By following individual plants over time and analyzing which ones flourish in different conditions, companies can relate the plants' response to their environments with their genomics (基因组学). That information, in turn, allows the companies to produce seed varieties that will grow well in specific soil and weather conditions. This advanced technology may also help to improve crop nutrition.

    Farmers do not universally welcome precision agriculture for various reasons, such as high equipment costs and lack of access to the Internet. The technology may bring great challenges to experienced farmers who are not good at computers. And large systems will also be beyond the reach of many small farming operations in developing nations. But less expensive, simpler systems could potentially be applied. For others, though, cost savings in the long run may reduce the financial concerns. And however reticent some farmers may be to adopt new technology, the next generation of farmers are likely to warm to the approach.

    Some of the best things in life don't happen until you grow old enough to recognize them. I can say that about tea.

    I didn't start to drink tea until I was 35. What happened before that? The first time I felt a genuine urge to drink tea was in 2003, when I stayed briefly in the United Kingdom. After a time of consuming local food, I started to really like strong black tea. Although it was too strong to my tongue, I felt it was a necessity because it was comforting to my body.

    I took packs of green teas with me as gifts but was disappointed to find my British friends preferred much stronger black teas from Sri Lanka. Later I learned that although people know China for its teas, it ranks only third among the world's black tea exporters, after Sri Lanka and Kenya.

    After I came back to China and started to cover food stories, I met friends in the tea-drinking circle and learned more. Although the majority of the rest of the world drinks black tea, which the Chinese call“red tea”, China produces and drinks mostly green teas.

    I feel lucky to be Chinese because of the great variety of teas available in the country. It is estimated that there are more than 2,000 teas in China if you divide them geographically, including more than 600 locally famous brews. A more simple way to categorize (分类) is by color and extent of fermentation (发酵). That comes down to six main categories—green, white, yellow, dark-greenish (oolong), red and black teas.

    Tasting teas can be compared to our lives. They can be plain and predictable but sometimes they are full of pleasant surprises. Occasionally they can even seem too good to be true. The best thing is, you know there's always more to explore.

    One day, Mr. Arnold was teaching a lesson, and things were going as normally as ever. He was explaining the story of human being to his pupils. He told them that, in the beginning, men were nomads (游牧); they never stayed in the same place for very long. Instead, they would travel about, here and there, in search of food, wherever it was to be found. And when the food ran out, they would move off somewhere else.

    He taught them about the invention of farming and keeping animals. This was an important discovery, because by learning to cultivate (耕作) the land, and care for animals, mankind would always have food steadily. It also meant that people could remain living in one place, and this made it easier to set about tasks that would take a long while to finish, like building towns, cities, and all that were in them. All the children were listening attracted by this story, until Lucy jumped up:

    “And if that was so important and improved everything so much, why are we nomads all over again, Mr. Arnold?”

    Mr. Arnold didn't know what to say. Lucy was a very clever girl. He knew that she lived with her parents in a house, so she must know that her family were not nomads; so what did she mean?

    “We have all become nomads again,” continued Lucy, “The other day, outside the city, they were cutting the forest down. A while ago a fisherman told me how they fish. It's the same with everyone: when there's no more forest left the foresters go elsewhere, and when the fish run out the fishermen move on. That's what the nomads did, isn't it?

    The teacher nodded, thoughtfully. Really, Lucy was right. Mankind had turned into nomads. Instead of looking after the land in a way that we could be sure it would keep supplying our needs, we kept developing it until the land was bare. And then off we would go to the next place! The class spent the rest of the afternoon talking about what they could do to show how to be more civilized (文明的).

    The next day everyone attended class wearing a green T-shirt, with a message that said “I am not a nomad!”

    And, from then on, they set about showing that indeed they were not. Every time they knew they needed something, they made sure that they would get it using care and control. If they needed wood or paper, they would make sure that they got the recycled kind. They ordered their fish from fish farms, making sure that the fish they received were not too young and too small. They only used animals that were well cared for, and brought up on farms.

    And so, from their little town, those children managed to give up being nomads again, just as prehistoric men had done, so many thousands of years ago.

    For many people, the “golden years” are a time to slow down and recall past achievements. Nola Ochs—a Guinness record holder as the world's oldest college graduate at the age of 95—saw age as an opportunity to take on new challenges and satisfy unfulfilled goals.

    Born in 1911 in Illinois, Nola always loved learning. She was a good student who graduated from high school in 1929 and began college via correspondence course（函授课程）from Fort Hays State University in Kansas. After getting the degree of the college, she taught in county schools for four years before marrying her husband, Vernon Ochs.

    Soon, the realities of farming stopped any thoughts of furthering her education, though Nola lived a good, full life on the farm, raising four sons. She always yearned to learn more about the world she lived in, but not until after Vernon died in 1972, did Nola consider resuming her formal education.

    “I just thought something off the farm would be fun,” Nola explained. “Really, I had no thought of ever graduating. For 10 years, I just took classes that were of interest to me, mostly history and composition. And then one of the professors came to me and told me if I would take college algebra, I would have enough credit hours to graduate. And I finally made it.”

    For most people, graduating at the age of 95 with a 3.7 GPA might be enough of an accomplishment, but not for Nola. In May 2010, at the age of 98, Nola Ochs received her master's degree, making her the oldest person to receive that distinction.

By the time Nola passed away in 2016, at the incredible age of 105, she had achieved her goal of writing a book about her life experiences. At one point in the process, when asked for her life advice, she said, “Buy the plane ticket!” She meant that people should take advantage of life's opportunities and not wait until tomorrow.

Tropical cyclones (热带气旋), including hurricanes and typhoons, are now moving at a slower speed than they did decades ago, new research shows.

While having a cyclone travel with less speed may seem like a good thing, it's actually just the opposite. Wind speeds within the storm remain high, but the whole system itself moves slower, allowing punishing rains to stay longer over communities. "Nothing, good comes out of a slowing storm," says James Kossin, author of the paper. "It can increase the amount of time that buildings suffered from strong wind. And it increases rainfall."

In his paper, Kossin showed that from 1949 to 2016, tropical cyclones across the globe slowed their movement by 10 percent on average. In some regions (地区), the speed of those storms slowed even more as they hit land. In the western North Pacific, the decrease was much more manifest ― almost a third. That means a storm that may already hold more moisture (水分) will have time to drop more of it in each spot.

Kossin's work was based on details of almost 70 years' worth of storms, but he didn't try to determine what was causing the slowdown. Still, the change is exactly what he and other cyclone experts said, which would be expected from climate change. With the polar regions warming fester than other parts of the globe, that is changing the pressure and reducing the winds that push these storms.

Christina Patricola, a scientist, called Kossin9s work important and new and said she found it reliable. "I was not surprised by his findings," she says. "But I was surprised by the speed of the slowdown."

Kossin hopes that scientists will begin building models that show which places are likely to face the most risk. Given that storms in some regions are moving towards polar regions and already increasing in intensity (强度), cyclones causing unusually powerful rain may threaten places not normally in their paths. Scientists must take action to make those places suffer less from the disasters.