Lots of people buy books and products from Amazon, an online seller. They offer and pay over the Internet and the books are shipped through the mail or a delivery service like FedEx.

    One day, people could get their Amazon deliveries from an “unmanned aerial vehicle”—a timely vehicle that looks like a toy helicopter. And instead of waiting days to get the parcel, it could be at the buyer's home in half an hour or less. The company is working on a fleet of tiny vehicles they call “Prime Air”. The vehicles are also known as “octocopters”. On their website, Amazon says, “One day, Prime Air Vehicles will be as normal as seeing a mail trucks on the road today.”

    The U.S.'s Federal Aviation Administration (FAA) is working on safety regulations for unmanned flying vehicles like the Prime Air copters. Those regulations will make sure the copters are able to fly safely where they need to go. Once the FAA has put its rules in place, which could be as early as 2016, Amazon will be ready with its fleet of tiny flyers. The process could take as many as five years.

    The new delivery service would likely be available only in the United States, at first. The copters the company is testing now can handle packages up to five pounds (2.3kg) and they have a range of 10 miles (16 kilometers).

    Other companies are also looking at using unmanned flying vehicles to deliver their products. For instance, Domino's Pizza in the U.K. released a video showing a “DomiCopter”, delivering a pizza. That video may have been a publicity stunt（噱头）. In any case, just like Prime Air's octocopters, the DomiCopters don't have clearance（许可）to take off just yet.

    My youngest son Jack has begun to learn the cello (大提琴). Every night, he carefully gets his cello out of its case and begins practising. I won't lie; It's not pretty. While he's getting better every day, he has a long way from becoming the next Yo-Yo Ma.

    This led me to wonder what Yo-Yo Ma was like the first time he played the cello. Of course, we now know him as one of the most excellent artists in the world, but I'm sure that when he first tried, he wasn't much better than my son. I'm not suggesting that Jack is going to take the classical music world by storm one day. But he's got to start somewhere.

    Michael Jordan wasn't born playing basketball, but I'm sure that he had to start somewhere. Warren Buffett wasn't born making great investment choices, but he had to start somewhere. J. K. Rowling wasn't born a writer, but he had to start somewhere. Bruce Springsteen wasn't born a songwriter and performer, but he had to start somewhere. Each of these individuals is now famous as being at the top of their occupation. But when they first started, their skills would have been disappointing and their potential unrealized. It has taken years of hard work to realize their undoubted talents. But they had to start somewhere.

    I don't know what my kids are going to do with their lives, but they have a great opportunity to explore a wide range of experiences before focusing on one or two things that they can be crazy about and good at. It's my job as dad to encourage them not to be put off by their bad first efforts. Because everyone has to start somewhere.

    Two of the saddest words in the English language are "if only". I live my life with the goal of never having to say those words, because they convey regret, lost opportunities, mistakes, and disappointment.

    My father is famous in our family for saying "Take the extra minute to do it right." I always try to live by the "extra minute" rule. When my children were young and likely to cause accidents, I always thought about what I could do to avoid an "if only" moment, whether it was something minor like moving a cup full of hot coffee away from the edge of a counter, or something that required a little more work such as taping padding (衬垫) onto the sharp corners of a glass coffee table.

    I don't only avoid those "if only" moments when it comes to safety. It's equally important to avoid "if only" in our personal relationships. We all know people who lost a loved one and regretted that they had foregone an opportunity to say "I love you" or "I forgive you." When my father announced he was going to the eye doctor across from my office on Good Friday, I told him that it was a holiday for my company and I wouldn't be here. But then I thought about the fact that he was 84 years old and I realized that I shouldn't give up an opportunity to see him. I called him and told him I had decided to go to work on my day off after all.

    I know there will still be occasions when I have to say "if only" about something, but my life is definitely better because of my policy of doing everything possible to avoid that eventuality. And even though it takes an extra minute to do something right, or it occasionally takes an hour or two in my busy schedule to make a personal connection, I know that I'm doing the right thing. I'm buying myself peace of mind and that's the best kind of insurance for my emotional well-being.

    The final results of Best-Ever Teen Fiction vote are in. While it's no surprise to see Harry Potter and The Hunger Games series on top, this year's list also highlights some writers we weren't as familiar with. For example, John Green, author of The Fault in Our Stars, appears five times in the top 100.

    Summer, like youth, passes quickly. But the books we read when we're young can stay with us for a lifetime. The following are the top 4 on the list. Enjoy.

    ⒈Harry Potter series

    The Harry Potter books make up the popular series written by J. K. Rowing. The series includes seven books. The books concern a wizard (魔法师) called Harry Potter and his journey through Hogwarts School of Witchcraft and Wizardry. The stories tell of him over coming dangerous obstacles to defeat the dark wizard Lord Voldemort who killed his parents when Harry was 15 months old.

    ⒉The Hunger Games series

    In the ruins of a future North America, a young girl is picked to leave her poor district and travel to Capitol for a battle to the death in the cruel Hunger Games. But for Katniss Everdeen, the main character in this series by Suzanne Collins, winning the Games only puts her deeper in danger as the strict social order of Panem begins to unravel (瓦解).

    ⒊To Kill a Mockingbird

    Author Harper Lee explores racial tensions in the fictional “tired old town” of Maycomb, Ala., through the eyes of 6-year-old Scout Finch. As her lawyer father, Atticus, defends a black man accused of a crime, Scout and her friends learn about the unjust treatment of African-Americans – and their mysterious neighbor, Boo Radley.

    ⒋The fault in Our Stars

    Hazel Grace, a teenage girl, has got all sorts of cancer inside her body, and her lungs aren't working very well. She knows she is dying and doesn't live in hope any more. When a man named Augustus Waters suddenly appears at the Cancer Kid Support Group, Hazel's story is about to be completely rewritten.

    Your next car could have two seats, three wheels two in front and one in the back and a top speed of more than 100 miles per hour. Elio Motors plans to make such a tiny car named the Elio. Its two seats sit front and back instead of side by side. The driver is positioned in (he center with the passenger directly behind.

    The starting price for the car is just ＄6.800. It has only one door, on the left side, which cuts a few hundred dollars off the manufacturing costs. Having three wheels also makes it cheaper. It has air conditioning, power windows and door locks and an AM/FM radio. More features can be ordered through Elio's long list of suppliers. Elio will also sell the cars directly through its own stores and not through franchised dealers (特约经销商).

    Paul Elio dreamed as a kid that he would one day own a car company called Elio Motora. In 2008, tired of high gas prices, he started working on a car that burns gas in a more effective way. Equally important to him was creating US manufacturing jobs and making the car inexpensive enough to attract buyers who might otherwise be stuck in their old, unreliable cars. "Whatever matters to you, this can move the needle on," he said.

    Already, more than 27,000 people have reserved one. Paul hopes to make 250,000 cars a year by 2020. So far, reservation holders are those who will use the Elio as a second or third car for work. Paul Elio believes the car will interest college students as well as used-car drivers who want something newer and more reliable, though.

    The Largest World Fairs of All Time

    New York World Fair — New York, 1939

    The 1939 New York World Fair was the largest exposition (博览会) in US history with visitors over 14 million. The Fair was planned during the Great Depression and was aimed at relieving the city from economic depression by attracting foreign investment. Major inventions to emerge (出现) at the New York World Fair included nylon fabric, a streamlined pencil sharpener, and a futuristic car city imagined by General Moiors.

    Exposition liniverselle — Paris, 1900

    The Exposition Universelle was one of the earliest expositions to feature multiple countries with France inviting various countries to display their technological advancements and cultural heritage. Exposition Universelle was the birthplace of many inventions that we enjoy today including escalators (自动扶梯) and talking films.

    Expo' 70 — Osaka, Japan

    Expo' 70 was the biggest exposition of the 20th century and the second largest in history. Expo 70 had a record attendance of over 64 million visitors, a 40-year record that would not be broken until Expo 2010 in Shanghai. Notable exhibitions included a large piece of moon rock that was brought back from the Apollo 12 mission.

    Expo 2010 — Shanghai. China

    Expo 2010 goes down as the largest fair in history, having attracted 73 million people. It also had the highest international participation of any exposition in the world with 246 countries participating. The opening ceremony featured the biggest LED screen in the world as well as one of the biggest fireworks displays in history.