On Monday, the Centers for Disease Control and Prevention predicted that 42% of Americans could be overweight by 2030. Our expanding waistlines lead to not only a medical problem, but according to a recent article In The New York Times, it could also endanger personal safety in some situations—in an airplane crash, for example.

    The New York Times' Christen Negroni reports that engineers and scientists are questioning whether airplane seats are adequately constructed to protect overweight travelers. Government standards for airplane seat strength（强度）— first set moe than 60 years ago — require that the seats be made for a passenger weighing 170 pounds (77kg). Today, the average American man weighs nearly 194 pounds (88kg) and the average woman 165 pounds (75kg). Negroni reports:

    “If a heavier person completely fills seat, the seat is not likely to behave as intended during a crash,” said Robert Salazar, the leading scientist at the Center for Applied Biomechanics at the University of Virginia. “The energy absorption that is built into the aircraft seat is likely to be overpowered and the passengers will not be protected properly.”

    “Nor would the injury be limited to that passenger only,” Dr. Salzar said. “If a seat or a seat belt fails,” he said, “those people who are seated nearby could be endangered from ‘the uncontrolled movements of the passenger'.”

    Most complaints about airplane seats focus on their lack of comfort and high ticket price, and whether overweight passengers should be made to buy two seats. But The New York Times' article brings up another reason to feel anxious about flying. Investigators of the issue got in touch with the airplane seat and seat belt makers, but they refused to comment on the problem. Experts agreed that crash testing should be done with overweight dummies （人体模型）. Both airplane seats and seat belts should be tested, they said.

    Fortunately, however, according to Nora Marshall, a senior adviser at the National Transportation Safety Board, the board's investigators have never seen an accident involving a commercial plane in which the weight of a passenger was a problem.

    Bill Gates recently predicted that online learning will make place-based colleges less significant, and five years from now, students will be able to find the best lectures in the world online. I applaud Mr. Gates. But what's taking us so long?

    As early as 1997, MIT(麻省理工) decided to post videos of all university lectures online. for free, for all people. But today, how many students have you met who mastered advanced mathematics or nuclear physics from an MIT online video? Unfortunately, the answer is not many. The problem is the poor quality of online education websites and the experience they provide to students. Those who go to the MIT website and watch courses online are surely very smart people, but it's not like playing a video game such as World of Warcraft. Only the most ardent students, those who are highly motivated, will devote themselves to studying these boring online videos.

    The real question is why we aren't spending more to develop better online education platforms. Where is the Avatar of education? Think about this. The market for Hollywood films per year is worth around 30 billion USD. Education in the world is a trillion-dollar-a-year market, hundreds of times bigger than Hollywood movies. Yet the most expensive digital learning system ever built cost well under 100 million dollars.

    Bill Gates' prediction is going to happen. There is no doubt about it. But it will only happen when we create high level educational content and experiences that engage and excite more than has ever been possible in the real world.

根据短文内容，选择最佳答案，并将选定答案的字母标号填在题前括号内。

    There are many differences between country life and city life in many ways. One person even does different things in the two places.

    Julia lived in the countryside, but one year she decided to visit the capital city to do some shopping and to see the sights. She stayed at a hotel near the central market. She had seldom been to the city before, and was very excited about what she would find.

    On the first morning of her visit, as she walked from the hotel to the market, she passed a beggar(乞丐). He was holding up a notice, which said, “Blind from birth. Please give generously(慷慨地).”

    Julia felt sorry for the blind beggar and she bent down and put a dollar coin into his bowl. “Thank you.” he said.

    The same thing happened again the following day.

    On the third day, however, Julia did not have a dollar coin. She had only fifty cents, so she dropped this into the beggar's bowl.

    “What have I done wrong?” the beggar said, “Why are you so stingy today? ”

    Julia was very surprised at what the beggar said. “How do you know I haven't given you a dollar?” she said, “If you're blind you can't know what coin I put into your bowl.”

    “Ah, ” explained the beggar, “The truth is that I'm not blind. I'm just looking after this place for the regular beggar while he's on holiday.”

    “On holiday?” Julia said, “And what exactly does your blind friend do on holiday?”

    “He goes into the countryside,” the man said, “and takes photographs. He's a very good photographer.”

Dear Customers,

    I love slipping into a comfortable chair for a long read－as I relax into the chair; I also relax into the author's words, stories and ideas. The physical book is so elegant that it disappears into the background and what remains is the author's world.

    Today, we, at Amazon, are excited to announce Mindle, a wireless, portable reading device with instant access to more than 90, 000 books, magazines and newspapers.

    We've been working on Mindle for more than three years. Our top design goal was for Mindle to disappear in your hands―to get out of the way－so you can enjoy your reading, also wanted to go beyond the physical book. Mindle is wireless, so whether you're lying in bed or riding a train, you can think of a book and have it in less than 60 seconds. No computer is needed－you do your reading directly from the device.

    We chose the same wireless technology used in advanced mobile phones. But unlike phones there are no monthly wireless bills, no service or data plans, and no yearly contracts. There is no software to install. We want you to get lost in your reading and not in the technology.

    Mindle uses a new kind of display called electronic paper. Sharp and natural with no strong light reading on Mindle is nothing like reading from a computer screen. Mindle weighs only 10.3 ounces－less than a paperback, but can carry two hundred books.

    Enjoy learning about Mindle and many thanks!

    Jeff Bezos Founder CEO

    Dreaming of summer picnics filled with family and fun? We've come up with 4 of the top picnic areas across the US.

    Cumberland Islands, Georgia

    Just a few hours south of Savannah, this national seashore is a picnic paradise. It's an unspoiled place in the Deep South with over 50 miles of hiking trails (小径). Covered in Spanish moss, the trails are lined with trees and since it's still a rural area, the stars line up for a spectacular show at night and create the perfect evening starlit picnic opportunity.

    Grant Park, Chicago

    If you are looking for delicious food in Chicago, go for a taste of a 20-day, lake-front, foodie festival that happens in October each year. Grab a spot near the fountain to enjoy your picnic, appreciate the city scenery and lake views and relax with family and friends. If you are there on July 4^th, be sure to plan the day to include the fireworks display at the Navy Pier.

    Cranberry Islands, Maine

    Here, you'll enjoy natural picnics with island views. The islands are a delightful group of islands about 20 minutes offshore from Acadia National Park. You can visit the islands by private boat or ferry (渡船) service. Bring a picnic basket along for the ride as it's a romantic picnic area to take your special someone or go for a family outing to visit the islands.

    Big Sur, California

    The Point Lobos State Reserve is a small gem. Besides the coastal wildlife there are rare plant communities, and unique geological formations. It's good to have a picnic there. We recommend bringing a telescope, because much of the wildlife can be seen only at a distance.

    Addyson Moffitt is an 8-year-old from Kansas City, Missouri. Maurine Ghelagat is a 9-year-old from a village in Kenya called Bartabwa. It might not seem as if the girls have much in common, but when they met at a dinner two years ago, in Kansas City, they immediately hit it off.

    "We had this one little red ball to play with," Addyson told TIME for Kids. "We didn't have any electronics or phones, no iPads or TV. It was just us playing." Addyson and Maurine still keep in touch now.

    The dinner was hosted by the nonprofit group World Vision International, which builds wells, pipelines, and rain catchers in communities where people find it hard to get clean water. Addyson, was at the dinner because her family supports World Vision. Maurine was there because her village had been without clean water. World Vision fixed that by building a water station there.

    "People helped Maurine so she could have clean water, and kids are dying because they don't have it," Addyson says. "I want to help."

    Races are one way World Vision raises money to pay for its water projects. Runners run a race, often a 26-mile marathon or 13-mile half marathon. They ask people to support them by donating(捐赠) to World Vision.

    Addyson decided to run the 2017 Kansas City Half Marathon for World Vision. At age 7, she was one of the youngest-ever runners in the race, and had to get special permission to take part.

    Addyson spent four months training with her parents, waking up before 6 a.m. to run. Meanwhile, she started fundraising(募捐)by asking friends to make donations as birthday presents and clearing tables at a restaurant for tips.

    By October 2017, when Addyson ran the race, she'd raised more than $20,000. She's the youngest person in World Vision history to raise more than $10,000. In 2018, she ran again and raised $36.000.

    But Addyson's work is not finished. "My goal is for every kid to have clean water," she says.