It was a village in India. The people were poor. However, they were not unhappy. After all, their forefathers had lived in the same way for centuries.

    Then one day, some visitors from the city arrived. They told the villagers there were some people elsewhere who liked to eat frog's legs. However, they did not have enough frogs of their own, and so they wanted to buy frogs from other place.

    This seemed like money for nothing. There were millions of frogs in the fields around, and they were no use to the villagers. All they had to do was catch them. Agreement was reached, and the children were sent into the fields to catch frogs. Every week a truck arrived to collect the catch and hand over the money. For the first time, the people were able to dream of a better future.

    But the dream didn't last long. The change was hardly noticed at first, but it seemed as if the crops were not doing so well. More worrying was that the children fell ill more often, and, there seemed to be more insects around lately.

    The villagers decided that they couldn't just wait to see the crops failing and the children getting weak. They would have to use the money earned to buy pesticides(杀虫剂) and medicines. Soon there was no money left.

    Then the people realized what was happening. It was the frog. They hadn't been useless. They had been doing an important job—eating insects. Now with so many frogs killed, the insects were increasing more rapidly. They were damaging the crops and spreading diseases.

    Now, the people are still poor. But in the evenings they sit in the village square and listen to sounds of insects and frogs. These sounds of the night now have a much deeper meaning.

    When Hai started college, he weighed over 250 pounds Healthy food choices were difficult for him, and he was emotionally distraught (忧心忡忡). However, when he left home for college, he was able for the first time to start taking his life and weight into his own hands.

    He started by shopping at a local farmers' market, an experience that inspired him profoundly. The idea that a farmer's market represents local, sustainable, healthy food with a human connection where you can interact with the people that grow your produce was extremely appealing to him, and he began to think about the food that people at his university were eating. From what he saw at farmers' markets, Hai realized that dining hall food was not “real” food.A lot of it is frozen or processed, and has unhealthy additives. His ideas continued to develop as he started taking classes about food sustainability at university, and after the summer of 2014 during which he cooperated with other students9 he launched into his senior year at the University of California full force with the Real Food Challenge (RFC) campaign, a project he co-founded that aims to reinvest university spending in food that is “real”: ecologically-sound, community-based, humane, and fair; as opposed to those traditional purchases with those unhealthy additives and processed products.

    Not only has Hai started a movement of change across the university dining system, but he has also grown extremely as an individual，now with strong leadership abilities and great vision. In addition, after he started learning about food sustainability and taking action at university, Hai has lost over 100 pounds, and has been able to start enjoying activities such as backpacking and swimming that were not a possibility for him previously. He is confident instead of distraught now.

    In my bag I always carry the same essential items: my keys, my purse, some loose change, my mobile phone and my little blue vocabulary notebook. This year I am living abroad in Germany and I am trying to learn as much German as possible. I always knew that living abroad would be a great way to learn a foreign language but one thing I didn't realize was how many new words and phrases I would come across every day! I see and hear new words everywhere; the announcements in the train station; menus in cafes; on social media; on the local newspaper and of course from my German-speaking friends.

    At first I was slightly upset by the large amounts of German I didn't understand. Speaking German in Germany is definitely very different from that in the classroom; I kept on looking up new words and by the end of the day I had forgotten most of them already. It was very frustrating. After a month of worrying that I would never be able to improve my language skills, I went to the stationery shop and bought a small notebook which easily fit into my handbag or even into my back pocket! I set myself the goal of writing five new words or phrases a day into my little blue book and soon enough it became one of my most valuable language-learning tools.

    I don't have any rules about which words I write down. Most days I write down words that I learn from my colleagues at work, words that I don't understand in reading or words that I have learned from seeing them in context. For example, I have learned the names of many fruits and vegetables from looking at their labels in the supermarket (a very unexpected source of vocabulary!) and I have learned many words that I have heard on TV or on the radio. It doesn't even matter if I know how to spell a new word straight away. If I hear a word but I don't know how to spell it, I write down how I think it sounds and look it up later.

    My little blue vocabulary book is now like my close friend. We go everywhere together. Setting this small daily goal has made me feel much more in control of my language teaming and I am already seeing an improvement. I will continue to use it for the rest of my stay in Germany and also when I return to university at home in September.

    Ten minutes of gentle exercise can immediately change how certain parts of the brain communicate and coordinate (协调) with one another and improve memory function, according to an encouraging new study.

    The scientists invited 36 people of different ages to the lab and had them sit quietly on a fixed bicycle for 10 minutes or, on a separate visit, pedal the bicycle at a pace so gentle that it barely raised their heart rates. It also was short, lasting for only 10 minutes. Immediately after each session of the sitting or slow pedaling, the people completed a computerized memory test during which they would see a brief picture of, for instance, a tree, followed by a variety of other images and then a new image of either the same tree or a similar one. The people would press buttons to show whether they thought each image was new or the same as an earlier shot. The test is difficult, since many of the images closely resemble one another. It requires rapid, skillful scanning recent memories to decide whether a picture is new or known. Next, the scientists had each people repeat this process--riding or sitting on the bike for 10 minutes and then completing memory testing--but the testing now took place inside an M. R. I. machine(磁共振成像仪)that scanned the people's brains while they responded to the images.

    Then the researchers compared results. The effects of the exercise were clear. The people were better at remembering images after they had ridden the bike, especially when the images most closely resembled one another. In other words, the harder their memories had to do their best, the better they performed after the exercise. The M. R. I. scans showed that memory parts of each people's brain lit up at the same time with parts of the brain associated with learning, indicating that these physically separate parts of the brain were better connected now than when the people had not first exercised.

    It was a cold winter. The wind blew all night and the snow was blinding. When morning came, my three children and I got up and made our way to the windows. As we looked out of the window, we saw that the henhouse was gone. Our three hens had been blown away by the cold wind.

    I looked at the emptiness outside. Then I saw all three chickens sitting around the edge of a white bucket. I couldn't believe my eyes! How was this violent wind not blowing them into the field beyond？I quickly pulled on long snow pants and heavy winter coat, wrapped a scarf around my neck and stuck my feet into large boots.

    I shouted at the wind as it blew. I was alone, struggling in the snow. They stared out the window into the vast white sea of snow, peering at any sign of movement. Outside I heard the sound of my boots as I walked against the wind.

    As the snow circled around me, I steadily made my way to the soft cluck-cluck-cluck sound my hens always made. When I reached them, I saw that their little feet were holding on to the edge of the bucket, heads bent forward and away from the wind. I gently lifted each hen and put it carefully into the warm inside. Then I began the freezing walk back to the small shed directly behind our house. One by one I laid my chickens on the cold floor, and they began to cluck softly.

    As I shut the shed doors, my eyes went directly to the window where my children were watching. They jumped up and down cheering, and so did I! I wasn't some dragon slayer(屠龙者) from a fairy tale. I was simply a mom, but the look on my children's faces told me that they thought I was a hero mom.

    Tim Berners-Lee is not the most famous inventor in the world. However, his invention has changed our lives.

    He was born in London, England in 1955.When he was a small boy, Tim was interested in playing with electrical things. He studied science at Oxford University. He made his first computer from an old television at the age of 21.

    Tim started working on early computers. At that time, they were much bigger than now. He worked in England then Switzerland. Tim was really interested in two things, computers and how the brain works. How could the brain connect so many facts so quickly? He had to work with people all over the world. They shared information about computers. It was hard to manage all the information. He answered the same questions again and again. It took a lot of time. It was even difficult for computers in the same office in Switzerland to share information. Tim also forgot things easily. Could a computer work like a brain? Could it "talk" to other computers?

    There was an Internet already but it was difficult to use. In 1989, Tim Berners-Lee invented the World Wide Web (WWW) all by himself. This had a special language that helped computers talk to each other on the Internet. When people wanted to share information with others, they used the World Wide Web. The Internet grew quickly after that.

    Tim Berners-Lee doesn't think he did anything special. He says that all of the ideas about the Internet were already there. All he did was to put them together. He says that many other people worked together to make the Internet what it is today.

    Most inventors want to become rich. But Tim gave away the World Wide Web for nothing. He now works in America. He helps people share technology and wants the Internet to be free for everyone to use. Maybe he is the most important but least famous inventor in the world today!