Nowadays people are putting our water supply in danger, because they use too much water or throw rubbish into the river. You may wonder how paving(铺砌) a road can lead to less usable fresh water. A major part of thewaterweuse every day is groundwater. Groundwater does not come from lakes or rivers. It comes from underground. The more roads and parking lots we pave，the less water can flow into the ground to become groundwater.

    Human activity is not responsible for all water shortages(短缺). Drier climates are of course more likely to have droughts(干旱) than areas with morerainfall，but in any case, good management can help to make sure there is enough water to meet our basic needs.

    Thinking about the way we use water every day can make a big difference，too. In the United States，a family of four can use 1.5 tons of water a day! This shows how much we depend on water to live，but there's a lot we can do to lower the number.

    You can take steps to save water in your home. To start with，use the same glass for your drinking water all day. Wash it only once a day. Run your dishwasher (洗碗机)only when it is full. Help your parents fix any leaks in your home. You can even help to keep our water supply clean by recycling batteries instead of throwing them away.

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    A student was one day taking a walk with his teacher. As they went along, they saw a pair of old shoes lying in the path. They were a poor farmer's, who was working in the nearby field.

    The student turned to the teacher, saying: “we will hide his shoes, and hide ourselves behind those trees, and wait to see what he will do.”

    “My young friend,” answered the teacher, “we should never make fun of the poor. Why not put a coin in each shoe, and then we will hide ourselves and watch?” The student did so and they both hid themselves behind the trees. The poor man soon finished his work, and came across the field to the path where he had left his coat and shoes.

    After putting on his coat, he put his foot into one of his shoes, and felt something hard. Then he bent (弯腰) down to feel what it was, and found the coin. Surprised, he looked at the coin, turned it around and looked at it again. He then looked around, but no person was seen. He put the money into his pocket, and continued to put on the other shoe. His surprise was doubled on finding the other coin.

    He couldn't control his feelings and fell to his knees, looked up to the sky and expressed his thanks. Then he spoke of his wife, sick and helpless, and his children without bread. He said the help would save them from dying.

    The student stood there deeply moved, and his eyes filled with tears. “Now,” said the teacher, “are you not much happier than if you had hidden the shoes?”

    It's such a happy-looking library, painted yellow, decorated with palm-tree stickers and sheltered from the Florida sun by its own roof. About the size of a microwave oven, it's pedestrian-friendly, too, waiting for book lovers next to a sidewalk in Palm Beach country Estates, along the northern boundary of Palm Beach Gardens.

    It's a library built with love.

  A year ago, shortly after Janey Henriksen saw a Brian Williams report about the Little Free Library organization, a Wisconsin-based nonprofit that aims to promote literacy and build a sense of community in a neighborhood by making books freely available, she announced to her family of four, “That's what we're going to do for our spring break!”

    Son Austin, now a 10th-grader, didn't see the point of building a library that resembles a mailbox. But Janey insisted, and husband Peter unwillingly got to work. The 51-year-old owner of a ship supply company modified a small wooden house that he'd built years earlier for daughter Abbie's toy horses, and made a door of glass.

    After adding the library's final touches (装点), the family hung a signboard on the front, instructing users to “take a book, return a book,” and making the Henriksen library, now one of several hundred like it nationwide and among more than 2,500 in the world, the only Little Free Library in Palm Beach County.

    They stocked it with 20 or so books they'd already read, a mix of science fiction, reference titles, novels and kids' favorites. “I told them, keep in mind that you might not see it again,” said Janey, a stay-at-home mom.

    Since then, the collection keeps replenishing (补充) itself, thanks to ongoing donations from borrowers. The library now gets an average of five visits a day.

    The project's best payoff, says Peter, are the thank-you notes left behind. “We had no idea in the beginning that it would be so popular.”  (317 words)

    Few of us make money by losing sleep. But three graduate students at Brown University in Providence built a company around sleep deprivation(睡眠不足).

    Jason Donahue, Ben Rubin and Eric Shashoua were working late nights in Brown's business and engineering schools. They began thinking about ways to sleep better. They discovered they weren't alone in burning the midnight oil. Around 20% of Americans get less than six hours of rest a night.

    The friends imagined a smart alarm clock that could track how much time people spend in the most restorative(有恢复作用的) stages of the sleep cycle: REM (rapid eye movement) and deep sleep. What would it cost to design such a thing? Five years of research, 20 employees, $14 million and a whole lot of doubting from investors and scientists.

    Their company, Zeo, based in Newton, Mass, launched its product in June, 2009. The Zeo device uses a headband with tiny sensors(传感器) that scan your brain for signs of four sleep states-REM, light, deep and waking sleep. The smart alarm clock displays a graph of your sleep pattern and wakes you as you're not in REM sleep. In the morning you can upload the data to the company's Web site, and so track your sleep over time. Most of the feedback(反馈) comes in the form of Zeo's ZQ score showing how well you've slept.

    “Zeo allows people to unlock this black box of sleep,” says Dave Dickinson, a health-care CEO.

    Whether any of this actually improves sleep is up to the consumer, who will also need to make lifestyle changes like cutting out alcohol before bedtime or caffeine after 3 P.M.

    For now the company is selling Zeo online only. Dickinson also plans to spread it to countries such as Australia, where sleep deprivation approaches US levels.

    There's a good chance something you've bought online has been in the hands of a "picker" first. These are the workers in warehouses(仓库)who pick, pack and ship all those things we're ordering.

    At Amazon and other companies, they're working side by side with robots. Experts say while the robots are replacing some human workers, the machines aren't quite ready to take over completely.

    When a robot finds its storage unit, it slides underneath, lifts it up and then delivers it to a worker 一 they're called pickers. On a recent day, the computer told a picker to grab what looked like a fantasy board (棋盘)game. The picker found it, canned it and placed it on the conveyor belt.

    ^"In a traditional fulfillment center where the associate would walk to the different items, it can take hours to fulfill a customer order." Robinson says.

    Now, with the help of robots, that task takes minutes 一 and fewer humans.

So is this a sign we're entering a new industrial revolution?

    "It's definitely going to take over a lot of jobs." says Karen Myers, a scientist at SRI, one of Silicon Valley's oldest research centers.

    At the same time, she says, we're running against the limits of technology. Take "the picker" at the Amazon fulfillment center. Myers says those skills are proving to be uniquely human.

    "Our fingers are incredibly flexible and the current generation of robotic operators, they're getting much_, much better," she says. "But they're just not quite there yet."

    There's also the robot's brain.

    Remember that board game the Amazon worker was looking for? She could barely see the box filled into the storage bin — but she could tell it was a board game. Robots can't do that.

    Technologists say that, increasingly, humans will work side by side with robots — instead of robots working alone.

    Amazon says robots and humans enabled the Tracy warehouse to fulfill customer orders faster. That means more customers and more human workers.

    Did you know that Albert Einstein could not speak until he was four years old, and could not read until he was seven? His parents and teachers worried about his mental ability.

    Beethoven's music teacher said about him, "As a composer (作曲家) he is hopeless." What if this young boy had believed it?

    When Thomas Edison was a young boy, his teachers said he was so stupid that he could never learn anything. He once said, "I remember I used to never be able to get along at school. I was always at the foot of my class ... My father thought I was stupid, and I almost decided that I was a stupid person." What if young Thomas had believed what they said about him?

    When the sculptor (雕刻家) Auguste Rodin was young, he had difficulty learning to read and write. Today, we may say he had a learning disability. His father said of him, "I have an idiot (白痴) for a son." His uncle agreed. "He's uneducable," he said. What if Rodin had doubted his ability?

    Walt Disney was once fired by a newspaper editor because he was thought to have no "good ideas". Enrico Caruso was told by one music teacher, "You can't sing. You have no voice at all." And an editor told Louisa May Alcott that she was unable to write anything that would have popular appeal.

    What if these people had listened and become discouraged? Where would our world be without the music of Beethoven, the art of Rodin or the ideas of Albert Einstein and Walt Disney? As Oscar Levant once said, "It's not what you are but what you don't become that hurts."

    You have great potential. When you believe in all you can be, rather than all you cannot become, you will find your place on earth.