What do Tom Sawyer and jumping frogs have in common? Stories about both of them were created by one man：Mark Twain. Born Samuel Langhorne Clemens, Mark Twain was his pen name. When Twain was 4, his family moved to Hannibal, Missouri, lying on the west bank of the Mississippi. Twain grew up there and was attracted greatly with life along the river - the steamboats, the big wooden boats, and the people who worked on them.

    The Celebrated Jumping Frog of Calaveras Country is one of Twain's best-loved short stories, and The Adventures of Tom Sawyer is one of his most famous novels. Both these works are celebrated by events held during National Tom Sawyer Days. There's also a fence-painting competition to see who can paint the fastest. The idea for this competition comes from a scene in Tom Sawyer, in which Tom has been told to paint the fence in front of the house he lives in. It's a beautiful day, and he would rather be doing anything else. As his friends walk by, he persuades them to paint with him for fun, and they all join in the "fun". By the end of the day, the fence has three coats of paint!

    Although the story of Tom Sawyer is not true, it's based on fact. If you go to Hannibal,, you'll see the white fence, which still stands at Twain's boyhood home.

    Peter Thiel,the billionaire co-founder of PayPal,plans to live to be 120.Compared with some other tech billionaires,he doesn't seem particularly ambitious.Dmitry Itskov,the “godfather” of the Russian Internet,says his goal is to live to 10.000;and Sergey Brin,co-founder of Google,hopes to someday "cure death.

    They aren't being ridiculous.Their search is based on real science that could fundamentally change what we know about life and about death.It's hard to believe,though,since the human search for immortality is both ancient and filled with disastrous failures.Around 200 B.C.,the first emperor of China,Qin Shi Huang,accidentally killed himself trying to live forever;he poisoned himself by eating mercury（水银）pills.Centuries later, the search for eternal life wasn't much safer: In J492,Pope Innocent VIII died after blood transfusions from three healthy boys whose youth he believed he could absorb.

    But historical examples haven't discouraged some of the biggest names in Silicon Valley.Thiel,for example,has given $3.5 million to the Methuselah Foundation.Aubrey de Grey,Methuselah's co-founder,says SENS,the nonprofit's main research is devoted to finding drugs that cure several types of age-related damage:"Loss of cells, excessive（过多的）cell division,inadequate cell death,garbage inside the cell,garbage outside the cell,...The idea is that the human body,being a machine,has a structure that determines all aspects of its function,so if we can restore that structure—at the molecular（分子的）and cellular（细胞的）level—then we will restore function too,so we will have comprehensively renewed the body."

    But SENS,which has an annual operating budget of $5 million,is small,compared with the Brin-led Project Calico,Google's attempt to “cure death,”which is planning to pump billions into a partnership with medicine giant AbbVie.Google is secretive,but it's said to be building a drug to copy a gene associated with exceptional life span.

    Then there's the Glenn Foundation for Medical Research,started by Paul F.Glenn in 1965.Since 2007,the foundation has distributed annual "Glenn Awards,"$60,000 to independent researchers doing promising work on aging.The Glenn Foundation also works closely with the Ellison Medical Foundation,a far younger institution (founded in 1997).Ellison's passion project gives out hundreds of thousands of dollars each year to scholars seeking research on aging.Their decision to fund independent research may be paying off.Research projects funded by Ellison and Glenn appear to be developing into a testable means to stave off old age—for lab mice.The question is: Can those lab results be repeated in humans?

    There are 5.25 trillion pieces of plastic trash in the world's oceans, and each year, 8 million tons of plastic are added to the figure. Though the oceans seem vast enough to stomach a lot of plastic, the level of waste is starting to reach a crisis point: According to a new report by the Ocean Conservancy, by 2025, the ocean could contain one ton of plastic for every three tons of finfish.

All these floating bits of plastic not only disrupt marine ecosystems, but they also poison the global supply of seafood. “It's reaching crisis proportions,” says Andreas Merkl, CEO of the Ocean Conservancy. “Plastic breaks down into small pieces that look like plankton and is eaten by everyone from plankton to whales.” Plastic acts as a pollution sponge in the ocean, so when wildlife swallow pieces, the plastic might as well be a poison pill.

    The new report calls for a focus on improving waste management systems in a handful of developing countries that are most responsible for the plastic leakage into the ocean. China, Indonesia, the Philippines, Thailand and Vietnam contribute more than half of the oceans' plastic since their waste facilities hasn't kept up with rapid industrialization.

    On average, only about 40% of waste in these countries is actually picked up for disposal. But it's not just uncollected waste floating around-though that is three-fourths of the problem. The other quarter of the oceans' plastic came from post-collection activities. Even when a waste management company picks up waste to landfill it, poorly equipped landfills or illegal dumping mean that trash still ends up in the ocean.

    But how can countries stop the leakage of waste into the ocean? The Ocean Conservancy report suggests five “levers”: waste collection services, closing the leakage points within the collection system, gasification and burning of waste, and recycling facilities. The average waste ends up as litter. Just by expanding collection systems and plugging up their leakage points, the report says plastics leakage could by cut by 50% by 2020.

    It's not just an environmentalist's daydream. Coca-Cola and Dow Chemical, along with some other multinational companies have joined forces with Ocean Conservancy to fight ocean pollution. “We're committed to working toward a future of a plastic-free ocean. Companies don't make plastic with the intent of it ending up in the ocean, and we acknowledge the strong role industry must play in order to help eliminate ocean plastic waste by 2035.” Says Dow Packaging and Speciality Plastics' global sustainability director in a press release.

    Merkl emphasized that the countries can't recycle their way out of the problem. Only about 20% of the waste is valuable enough to be worth recycling: the rest, needs to be sent to sanitary landfills or waste-to-energy plants. “You have to concentrate on the fundamentals of waste management,” he says. And while building landfills and incinerators(焚化炉)across these developing countries might not be pretty, it's far more environmentally friendly than letting waste slide into the world's oceans.

    Buttons are found on all sorts of clothing. They are usually small and round and made of metal or plastic. They fasten, or connect, one piece of clothing to another. They make sure your clothes don't fall off. When we are speaking or writing m English, buttons can be just as useful.

    Men or women often wear button-down clothes to the office. Button-down as an adjective means to be conservative（保守的）or traditional. People who are described as buttoned-down stay close as possible to the normal way of dressing and behaving. They don't wear crazy clothing or do unusual things. People and events can both be described as buttoned-down.

    If someone is buttoned-up, he or she seems very business-like. In personal relationships, a buttoned-up person is cold and standoffish, meaning they physically and emotionally keep away from others. Buttoned-up people are not warm or friendly. And they do not share their inner thoughts and feelings with others.

    In the expression “button up”, button is a verb. It means to stop talking. Now, let's say you find yourself buttonholed in a conversation at a party. The person just keeps talking and talking and talking! Finally, you can't take it any longer. You tell the person to button it! This is a direct, but unacceptable way of saying “stop talking”. Button you lip is another equally rude but effective to stop a person who talks too much.

    Another kind of difficult person is someone who pushes your buttons. To push someone's buttons means to know exactly how to get that person angry or upset. People who like to push other people s buttons usually do it for selfish reasons. First they find a person's weak point. Then they use it to upset him.

    Travelling can be a way to gain life experiences, especially during Spring Break — a week long school vacation in the United States. But what if you're a student and don't have enough money for a trip? Don't worry. Here are some useful suggestions.

    Save: This probably is the most important preparation for travelling. Cut expenses to fatten your wallet so you'll have more choices about where to go and how to get there.

    Plan ahead: Don't wait until the last minute to plan your trip. Tickets may cost more when bought on short notice. Giving yourself several months to get ready can mean security(安全) and savings.

    Do your homework: No matter where you go, research the places you will visit. Decide what to see. Travel books will provide information on the cheapest hotels and restaurants.

    Plan sensibly: Write down what you expect to spend for food and hotels. Stick to your plan or you may not have enough money to cover everything.

    Travel in groups: Find someone who is interested in visiting the same places. By travelling with others you can share costs and experiences.

    Work as you go: Need more money to support your trip? Look for work in the places you visit.

    Go off the beaten path: Tourist cities may be expensive. You may want to rethink your trip and go to a lesser－known area. Smaller towns can have many interesting activities and sights.

    Pack necessary things: The most important things to take are not always clothes: Remember medicine in case you get sick and snacks in case you cannot find a cheap restaurant.

    Use the Internet: The Net can help to save money. Some useful websites include www. Travelocity.com, www. bargains－lowest－fare.com and www. Economic－travel.com.

    By planning sensibly, even students can enjoy the travel.  Your travel experiences will be remembered for a lifetime.

    When Jenny Benson was eight, her mother took her to soccer practice for the first time.

    "She's never played soccer before," Mrs. Benson told the coach." I'm not sure how she'll do."

    Jenny ran onto the field and joined the other players. Over the next hour, Mrs. Benson and the coach watched as Jenny out­ran many of the more experienced players.

    "I knew then that soccer would be Jenny's sport." Mrs. Benson recalls. And she was right.

    It may have helped that Jenny had spent much of her time trying to keep up with her three brothers." I wanted to be just like them," Jenny says." My family has inspired me for my entire life."

    Jenny has retired from the United States women's national soccer team. She started out on her professional career in the Philadelphia Charge, a team in the Women's United Soccer Association (WUSA)．Later on, she joined FC Energy Voronezh, and then New Jersey Wildcats.

    When the WUSA was being formed, league officials watched many college soccer games, looking for players good enough to join the league. They were very interested in Jenny, who played for the University of Nebraska.

    "Throughout that college season, I knew I was being watched," Jenny says, "I knew I couldn't be perfect, so I just tried to be very consistent and have fun."

    As a professional, Jenny relied on her focused but fun­loving attitude. "In a game, I try never to put too much pressure on myself. The more I concentrate on having fun, the better I play." She says. "I have good and bad days, just like everyone else, but I know the sun will always come up after a bad day. So all I have to do is to adjust myself, either to the change of my inner feelings or to the change of circumstances. That helps me get through anything."