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.

    A city child's summer is spent in the street in front of his home, and all through the long summer vacations I sat on the edge of the street and watched enviously the other boys on the block play baseball. I was never asked to take part even when one team had a member missing—not out of special cruelty, but because they took it for granted I would be no good at it. They were right, of course.

    I would never forget the wonderful evening when something changed. The baseball ended about eight or eight thirty when it grew dark. Then it was the custom of the boys to retire to a little stoop(门廊) that stuck out from the candy store on the corner and that somehow had become theirs. No grownup ever sat there or attempted to. There the boys would sit, mostly talking about the games played during the day and of the game to be played tomorrow. Then long silences would fall and the boys would wander off one by one. It was just after one of those long silences that my life as an outsider changed. I can no longer remember which boy it was that summer evening who broke the silence with a question: but whoever he was, I nod to him gratefully now. “What's in those books you're always reading?” he asked casually. “Stories,” I answered. “What kind?” asked somebody else without much interest.

    Nor do I know what drove me to behave as I did,for usually I just sat there in silence, glad enough to be allowed to reain among them; but instead of answering his question, I told them for two hours the story I was reading at the moment. The book was Sister Carrie. They listened bug-eyed and breathless. I must have told it well, but I think there was another and deeper reason that made them to keep an audience. Listening to a tale being told in the dark is one of the most ancient of man's entertainments, but I was offering them as well, without being aware of doing it, a new and exciting experience.

    The books they themselves read were the Rover Boys or Tom Swift or G.A.Henty. I had read them too, but at thirteen I had long since left them behind. Since I was much alone I had become an enthusiastic reader and I had gone through the books-for-boys series. In those days there was no reading material between children's and grownups'books or I could find none. I had gone right fromTome Swift and His Flying Machine to Theodore Dreiser and Sister Carrie. Dreiser had hit my young mind, and they listened to me tell the story with some of the wonder that I had had in reading it.

    The next night and many nights thereafter, a kind of unspoken ritual (仪式) took place. As it grew dark, I would take my place in the center of the stoop and begin the evening's tale. Some nights, in order to taste my victory more completely, I cheated. I would stop at the most exciting part of a story by Jack London or Bret Harte, and without warning tell them that that was as far as I had gone in the book and it would have to be continued the following evening. It was not true, of course; but I had to make certain of my new-found power and position. I enjoyed the long summer evenings until school began in the fall. Other words of mine have been listened to by larger and more fashionable audiences, but for that tough and athletic one that sat close on the stoop outside the candy store, I have an unreasoning love that will last forever.

    On Sunday, May 25th, 2014, India's Malavath Poorna, became the youngest female to climb to the summit of the world's highest peak—Mount Everest. The 13-year-old girl surpassed (超越) the previous record holder, Nepal's Nima Chemji Sherpa, who accomplished the same achievement in 2012, at the age of 16.

    Unlike many young climbers who come from wealthy families, Malavath comes from a poor farming family living in a small village named Pakala in southern India.

    Most Pakala girls have never seen the inside of a school all their lives. Malavath is one of the fortunate ones that managed to realize their dreams thanks to Swaeroes, a welfare organization whose mission is to help India's poor children reach their full potential. They helped enroll (使入学) the young girl in a nearby boarding school. Then about nine months ago, Swaeroes provided her with the opportunity to achieve this dream by offering mountaineering training. Not one to pass up (错过) an exciting adventure, the athletic girl signed up.

    At the end of the two-week period, only two youngsters were selected for the dangerous climb—Malavath was one of them!

    Then came the big day. On April 15th, 2014, Malavath and 16-year-old Anand Kumar along with their guide Shekhar Babu and a team of Sherpas (夏尔巴人) began the dangerous 8,848-meter trek (艰苦跋涉). While most climbers attempt the peak from the slightly easier Nepalese side, this team had to go via the harder Tibetan side. That's because the government of Nepal does not allow anyone younger than 16 to climb up the route.

    It was not easy. In fact, Malavath was sent back to the base camp after she experienced altitude sickness when she got to the advanced base camp set up at an altitude of 6,400 meters. However, the youngster returned three days later, and insisted on continuing. It took 52 days, but on May 25th, 2014, Malavath, who made it to the summit a few minutes ahead of 16-year-old Anand, proudly raised her country's flag at the top of the world. The young girl hopes that her achievements will inspire poor girls all over the world to try to achieve their dreams.

    Have you ever noticed tiny raised areas on the branches of a tree? These may have been insects. These small insects feed on tree sap (汁液). Insects on urban trees are notably more abundant than those on rural trees. As a result, urban trees suffer from heavy infestations (害虫横行), and are often unhealthy or die. To protect and restore urban trees' health, we need to determine the factors that make these tree pests more successful in urban habitats.

    Living organisms interact closely with their environment. The warmer, more drought-stressed trees harbor more successful pests than cooler, less drought-stressed trees. As cities and natural habitats become hotter and drier, damaging insects will become more abundant on urban trees.

    Trees within urban forests are valuable economically and for the environmental sustainability (可持续性) of the region. More than half of the world's population lives in cities. Across the globe, people are moving into cities at a faster rate than ever. Rapid growth may turn cities into places with harder conditions. Although cities are primarily made of buildings, roads, parking lots, and vehicles, there are still plants in them. The trees within a city are referred to as the urban forest. Urban forests offer very big benefits to human and environmental health. They improve air and water quality, provide habitat for wildlife, cool down temperatures and beautify our environment. They make cities livable.

    However, being a city tree is not easy. Heat released by human activities is trapped in cities. As a result, temperatures in urban areas are often warmer than their surrounding rural areas. We call this urban warming or the urban heat island effect. Urban habitats are mostly made of surfaces of asphalt (沥青) and concrete. These surfaces reduce the amount of rainwater that reaches tree roots. As a result, urban forests may suffer, which can negatively affect people and the environment.

    What can we do to restore urban forests? Regular irrigation when possible may help keep pest populations under control. Planting tree species that are suitable to handle heat and drought stress would also reduce the occurrence of insect pest outbreaks.

    Staying up late is a potential battle between parents and kids. But the solution could be as simple as changing your meal time.

    Researchers at the University of Surrey, UK, found that delaying (延迟) meals could help change one of the internal (内部的) body clocks. Besides a “master” clock in the brain, there are clocks in other parts of the body. They are usually synchronized (同步的) according to factors including light.

    During the study, researchers tested 10 participants to study the effect of changing meal times on their body clocks. The participants were given three meals – breakfast, lunch and dinner. In the first stage, participants received breakfast 30 minutes after waking. Lunch and dinner followed, after 5-hour intervals (间隔). In the second stage, each meal was delayed by 5 hours. Right after each stage, blood and fat samples (样本) were collected.

    Results showed that later meal times greatly influenced blood sugar levels. A 5-hour delay in meal times caused a 5-hour delay in the internal blood sugar rhythms (规律性变化).

    The discovery showed that meal times are in line with (与……一致) the body clock that controls blood sugar levels.

    This is a small study but the researchers believed the findings could help jet lag (飞行时差反应) sufferers and night-shift (夜班的) workers.

    In a study by the University of Surrey in 2013, researchers explored what happened when a person's body was changed from a normal pattern to that of a night-shift worker's.

    After people work through the night, over 97 percent of the body's rhythmic genes are disrupted (扰乱).

    These findings explain why we feel so bad following a long flight, or after working at night, according to Simon Archer, one of the study's researchers.

    “It's like living in a house. There's a clock in every room in the house and in all of those rooms those clocks are now disrupted, which of course leads to chaos (混乱) in the household,” fellow researcher Derk-Jan Dijk told the BBC.

    Changing meal times didn't affect the “master” body clock – the one controlling when we get sleepy – but it can reset the body clock that controls blood sugar levels.

    This wouldn't necessarily cure jet lag completely, but it might reduce the negative effects.

    A study published earlier this year suggested that just a weekend camping trip could be enough to reset our body clocks. And now this latest research shows regular food schedules could play a key part too.

    The U.S. has countless secret swimming holes throughout most states, many of which you've likely never heard of unless you're from the area.