Once upon a time the colors of the world started to quarrel.

    Green said, “Clearly I am the most important. I am the sign of life and hope. I was chosen for grass, trees and leaves. Look over the countryside and you will see that I am in the majority.”

    Blue interrupted, “You only think about the earth, but consider the sky and the sea. It is the water that is the basis of life.”

    Yellow chuckled(咯咯地笑). “The sun is yellow, as well as the moon and the stars. Every time you look at a sunflower, the whole world starts to smile.”

    Red could bear it no longer. “I am the ruler of all of you. I am blood-life's blood! I am the color of danger and bravery. I bring fire into the blood. I am the color of passion and love.”

    Purple stood at his full height. “I am the color of royalty(皇室) and power. I am the sign of authority (权力) and wisdom. People do not question me! They listen and obey.”

    Finally Indigo(靛蓝) spoke with determination, “Think of me and I am the color of silence. I represent thought and reflection. You need me for balance and contrast(对比), for prayer and inner peace.”

    The colors went on boasting(吹嘘), each showing off his or her own advantages. Suddenly there came a flash of bright lightening. Thunder rolled and boomed. Rain started to pour down. The colors were scared to death.

    In the midst of the quarrelling, rain began to speak, “You foolish colors. Don't you know that you were each made for a special purpose, unique and different? Join hands with one another and come to me.”

    Doing as they were told, the colors united and joined hands.

    From then on, when it rains, colors will stretch across the sky in a great bow of color.

    Whenever a rainbow appears in the sky, let us remember to appreciate one another.

    You may be familiar with the following famous people, but have you heard of their graduation speeches, in which they either share their unforgotten experiences or give you some great inspiration(启迪).

    Michael Dell, University of Texas at Austin

    And now you've accomplished something great and important here, and it's time for you to move on to what's next. And you must not let anything prevent you from taking those first steps. ... You must also commit to the adventure. Just have faith in the skills and the knowledge you've been blessed (赐予)with and go.

    J.K. Rowling, Harvard University

    Half my lifetime ago ,I was striking an uneasy balance between my ambition and the expectation from my parents who were not rich...But what I feared most for myself at your age was not poverty(贫穷), but failure. The fact that you are graduating from Harvard suggests that you know little about failure, you might be driven by a fear of failure quite as much as a desire for success.

    Steve Jobs, Stanford University

    Sometimes life's going to hit you in the head with a brick. Don't lose faith...Your work is going to fill a large part of your life, and the only way to be truly satisfied is to do what you believe is great work, and the only way to do great work is to love what you do. If you haven't found it yet, keep looking, and don't settle.

    Bill Gates, Harvard University

    We need as many people as possible to have access to the advanced technology to lead to a revolution in what human beings can do for one another. They are making it possible not just for national governments, but for universities ,smaller organizations, and even individuals to see problems, see approaches and deal with the world's inequities（不公平）like hunger, poverty, and so on.

    If you could have one superpower, what would it be?

    Dreaming about whether you would want to read minds, see through walls, or have superhuman strength may sound silly, but it actually gets to the heart of what really matters in your life.

    Every day in our work, we are inspired by the people we meet doing extraordinary things to improve the world.

    They have a different kind of superpower that all of us possess: the power to make a difference in the lives of others.

    We're not saying that everyone needs to contribute their lives to the poor. Your lives are busy enough doing homework, playing sports, making friends, seeking after your dreams. But we do think that you can live a more powerful life when you devote some of your time and energy to something much larger than yourself. Find an issue you are interested in and learn more. Volunteer or, if you can, contribute a little money to a cause. Whatever you do, don't be a bystander. Get involved. You may have the opportunity to make your biggest difference when you're older. But why not start now?

    Our own experience working together on health, development, and energy the last twenty years has been one of the most rewarding parts of our lives. It has changed who we are and continues to fuel our optimism about how much the lives of the poorest people will improve in the years ahead.

    Whenever we see a button on a doorbell or on a remote, we may press it. This is true in most cases. But some buttons are actually fake(假的), like the "close" button on an elevator.

    Many people are in the habit of pressing the "close" button because they don't have the patience to wait for the elevator doors to shut. But according to experts, the buttons are a complete trick—the doors will not close any faster however hard you press.

    It started in the 1990s when the Americans with Disabilities Act was passed, making sure that all elevators stayed open long enough so that people with disabilities could enter. Only firefighters and maintenance workers(维修工) can use the buttons to speed up the door-closing process if they have a code or special keys. But to normal elevator riders, the buttons aren't completely useless.

    According to psychologists, fake buttons can actually make you feel better by offering you a sense of control. Experts have showed that a lot of buttons that don't do anything exist in our lives for this same purpose. For example, pedestrian crosswalk buttons don't live up to their names. Pressing them used to help make the traffic signals change faster, but that was before computer-controlled traffic signals were introduced.

    But psychologists found it interesting that even when people are aware of these little "white lies". They still continue to push fake buttons because as long as the doors eventually close, it is considered to be worth the effort.

    That habit is here to stay, John Kounios, a psychology professor at Drexel University in the US, told The New York Times. "After all, I've got nothing else to do while waiting. So why not try the chance?"

    When a leafy plant is under attack, it doesn't sit quietly. Back in 1983, two scientists, Jack Schultz and Ian Baldwin, reported that young maple trees getting bitten by insects send out a particular smell that neighboring plants can get. These chemicals come from the injured parts of the plant and seem to be an alarm. What the plants pump through the air is a mixture of chemicals known as volatile organic compounds, VOCs for short.

    Scientists have found that all kinds of plants give out VOCs when being attacked. It's a plant's way of crying out. But is anyone listening? Apparently. Because we can watch the neighbors react.

    Some plants pump out smelly chemicals to keep insects away. But others do double duty. They pump out perfumes designed to attract different insects who are natural enemies to the attackers. Once they arrive, the tables are turned. The attacker who was lunching now becomes lunch.

    In study after study, it appears that these chemical conversations help the neighbors. The damage is usually more serious on the first plant, but the neighbors, relatively speaking, stay safer because they heard the alarm and knew what to do.

    Does this mean that plants talk to each other? Scientists don't know. Maybe the first plant just made a cry of pain or was sending a message to its own branches, and so, in effect, was talking to itself. Perhaps the neighbors just happened to "overhear" the cry. So information was exchanged, but it wasn't a true, intentional back and forth.

    Charles Darwin, over 150 years ago, imagined a world far busier, noisier and more intimate (亲密的) than the world we can see and hear. Our senses are weak. There's a whole lot going on.

    The following are four famous malls in the world where you can not only purchase things but also enjoy entertainment.

    Mall of America (Minnesota, USA)

    This Mall has a theme park and a wedding church, where more than 5,000 couples have been married since its opening. The mall of America opened in 1992 and is the third largest mall in North America.

    The mall of America is the most visited shopping mall in the world, with more than 40 million visitors annually. Spending 10 minutes in every store would take shopper more than 86 hours to complete their visit to the Mall of America.

    Mall of the Emirates (Dubai)

    The mall of the Emirates is an entertainment and shopping resort located in Dubai. It offers a full range of shopping, leisure and entertainment facilities.

    This shopping center is home to over 450 retailers（零售商）and also features a complete range of entertainment options, including Ski Dubai, the first indoor ski destination in the middle East.

    West Edmonton Mall (Alberta, Canada)

    The fifth largest mall in the world and the largest in North America, it has the largest indoor water park, which has the biggest wave pool in the world.

    The mall has a theme park called Galaxyland, with a number of attractions, including a roller coaster. In addition, the mall has an indoor lake, which is home to four sea lions.

    The Dubai Mall (Dubai)

    The Dubai Mall is the world's largest mall in total area.

    The mall has 1,200 shops and houses an aquarium（水族馆）which earned the Guinness World Record for the world's "largest Acrylic Panel". The mall is also home to an ice rink（溜冰场）, a 250-room luxury hotel and 22 cinema screens, plus 120 restaurants and cafes. It's also famous for the unique "malls-within-a-mall" concept, with themed shopping area like Gold Souk, Fashion Island and The Grove, an indoor-outdoor streetscape with a fully retractable（可缩回的）roof.