We produce 500 billion of plastic bags in a year worldwide and they are thrown away polluting oceans, killing wildlife and getting dumped in landfills where they take up to 1,000 years to decompose. Researchers have been unsuccessfully looking for a solution.

    The 16-year-old Canadian high school student, Daniel Burd, from Waterloo Collegiate Institute, has discovered a way to make plastic bags degrade(降解) in as few as 3 months, a finding that won him first prize at the Canada Wide Science Fair, a ＄10,000 prize, a ＄20,000 scholarship, and a chance to revolutionize a major environmental issue.

    Burd's strategy was simple: Since plastic does eventually degrade, it must be eaten by microorganisms(微生物)．If those microorganisms could be identified, we could put them to work eating the plastic much faster than under normal conditions.

    With this goal in mind, he grounded plastic bags into a powder and concocted(调制) a solution of household chemicals, yeast(酵母) and tap water to encourage microbes growth．Then he added the plastic powder and let the microbes work their magic for 3 months．Finally, he tested the resulting bacterial culture on plastic bags, exposing one plastic sample to dead bacteria as a control．Sure enough, the plastic exposed(暴露) to the live bacteria was 17% lighter than the control after six weeks.

    The inputs are cheap, maintaining the required temperature takes little energy because microbes produce heat as they work, and the only outputs are water and tiny levels of carbon dioxide.

    “Almost every week I have to do chores and when I open the closet door, I have piles of plastic bags falling on top of me．One day, I got tired of it and I wanted to know what other people are doing with these plastic bags．The answer: not much．So I decided to do something myself.” Said Daniel Burd.

    What might the future be like? Here are some predictions: things to come, things to go.

    Spring Festival, the most important Chinese holiday when everyone returns home has caused headaches for millions of Chinese. More than 2 billion people travel at the same time, making getting travel tickets and the journey difficult. But in 28 years, Spring Festival travel may not be a problem at all. China plans to build more than 120,000 kilometers of railway and a fast transportation network that will serve 90% of the population by 2020.

    And because most of China will be cities, people will not have to go to other places to find a job, so it will no longer be a problem.

Newspapers will come to an end in 2043. In the future, digital newspapers will be sent to personal web tools through Internet. Readers can discuss topics with journalists and editors. Information will move faster.

    Oil is running out faster than expected. But scientists have found something else for oil as fuel. Coal, natural gas, solar power, nuclear power and even water can take the place of oil as sources of energy.

    Schools will go electronic. Computers will be important and popular among the students. Everything will be in the computer and students will not need to bring books to school. They will find information on the Internet. A computer will be the students ‘library, schoolbag and connection to the outside world. There will be robot teachers, who will check homework on computers and communicate with the students' parents through e-mail. And school buses will be like spaceships, comfortable and safe.

    Today we talk about a time when half the world is waking from the dark, cold winter months. Spring! We often describe “spring” as a time of rebirth, renewal and awakening. Many trees are blossoming and early flowers are pushing through the earth. Things are coming to life!

    But the word “spring” is not just a season. It is also a verb that means something going on or coming out quickly. When you put “spring” and “life” together, you will get “spring to life”. This expression means something suddenly becomes very active or perhaps seems more alive! You may “spring to life” after hearing that a distant friend will be visiting you. Or maybe your favorite soccer team finally “sprang to life” in the second half, played well and won the match.

    Now, besides being a season and a verb the noun “spring” refers to a metal coil (线圈) that is wound tightly. When the coil unwinds, it often jumps. So, we often say a person “has a spring in his step” if he is lively and active. He might even appear to jump, or bounce a little when he walks.

    There is another way we use “spring” as a description. In the case of a “spring chicken”, “spring” means young. However, “spring chicken” is also an informal, humorous way to refer to someone who isn't young at all. So, we use this expression in the negative form, as in “no spring chicken”. For example, let's say you know an 85-year-old man who decides to run a marathon, even though he has never exercised before. You could say, “That's amazing! After all, he's no spring chicken.”

    But be careful when using this expression. It could be a little disrespectful. Let's say your boss shows you a picture of his wife, and you say, “Wow, she's no spring chicken.” That response would be disrespectful and a bad career move.

    Four years ago your friends congratulated you and your father talked big continuously. Four years ago you walked among the gothic towers and weathered traditions that sew our community together. But what's next, will I make friends, or I will measure up? And maybe you quietly wondered why a place like Yale, a place that sparked the drive of presidents, a place that raised the world-famous scholars, a place that trained Pulitzer Prize winners, would ever want you? I hope you had these questions because otherwise I might have embarrassed myself. I admit I asked all of these and more.

    I took an unconventional path to Yale. Five years ago I was working the evening shift at a clothing store in the suburbs of Virginia. My family had moved every year for the past five years and our finances were so consumed that retirement was not a possibility. Worse yet, my son was a junior at an Ivy League college in New Jersey and hearing about his privileged friends often reminded me of all the things I wanted to give him but couldn't.

    When I told him this he relied, “If you really want to spoil me, spoil yourself. ”Then he took my hands and told me I had a brilliant mind and deserved better than everything I had ever known.

    That summer I started community college while working full-time. Education was my second chance. I awoke my curiosity, vitality( 活力) and dignity that I never knew I could feel. When I read Eliot, Miller and Morrison, it was as if I were the first person to have ever read them, as if they were secret insights into the human soul and situations and I knew I couldn't stop.

    Walking among these gothic towers, among these traditions, and among this brilliant, vibrant and unapologetically eclectic Class of 2014 has been inspiring. Whether debating issues in class, or chatting over coffee, I have enjoyed, learned and loved every moment I have shared with you. You have made me a better person and I only hoped I have helped in some way to do the same for you.

    And yet even now this is dreamlike. Four years ago I was convinced no one would want me, I wouldn't measure up and as far as knowing what was next, I supposed I had resigned myself to more of the same. But I've come to learn that nothing great can really be accomplished without a healthy dose of terror. No one ever wrote epic(史诗般的) poems, built monuments or told bedtime stories about people who played it safe.

    I was terrified when I came to Yale. A big part of me thought I wasn't good enough. But a big part of life is ignoring the naysayers(反对者) especially the one inside you. Most people are stopped from doing great things by no one but themselves. I learned to tell myself to shut up. Sometimes in the mirror in the morning and others times in the dark before I went to bed. I came to realize once I could overcome my own fear I could overcome just about anything. If you haven't felt this yet I recommended it: it's the greatest joy you'll ever know.

    You've likely all met your own fear and misgivings(担忧、害怕). I charge you to tell that voice to shut up when necessary because in the end your greatness will not be about IQ but about the sincerity of your ambitions, the toughness of your character and your unwillingness to compromise in the face of difficulty, fear and uncertainty.

    And should someone tell you that it can't be done, or you're not good enough or it's not worth the trouble? Should others ask you to take the safe route, or stick to the path of least resistance? Should people say it's too late or your dreams are impractical? Look them in the eye, laugh a little and let them know “Nothing is impossible”.

Dear Mr. Whitacre,

I fell in love with a "flying Dutchman"…literally. In the summer of 2011, I moved to the Netherlands not knowing anyone except my husband, not knowing how to speak the language, and leaving behind my friends, family, and everything I knew that represented me. But as they say, "Love is blind."

In the beginning, I spent many months "alone in my head." My mother-in-law didn't speak English (or Italian). This, however, didn't stop her from trying to communicate with me. At first, sounds of vague meanings coupled with hand gestures was our way of having a conversation.

It wasn't until I discovered she was a choral (合唱的) director for a women's group in the community that we then began communicating on a whole different level. From my early days in school, I was always part of a school choir for over a decade.

We shared a love of music! Dien (my mother-in-law's name) taught me many beautiful Dutch songs. I sang in her choir throughout the years that followed. And then by chance, I came across a TED-Talk featuring you, Mr. Whitacre discussing your music and the virtual (虚拟合唱团) choir. Within minutes, I researched when the next project would start and to my surprise, it was Virtual Choir4" Fly To Paradise." I couldn't wait to tell my mother-in-law!

The next 2 weeks we spent practicing our parts and perfecting our video submissions. It was pure joy for us. Something we shared a love for, encouraging each other, spending hours together, and making a permanent bond as a mother and daughter-in-law.

Music has always been a part of my life. Its significance is greater than anything most people are aware of. Our participation in your virtual choir is one I will never forget. And it goes without saying, I am grateful for you, your music, and its ability to connect us all.