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.

    The human brain contains 10 thousand million cells and each of these may have a thousand connections. Such enormous numbers used to discourage us and cause us to dismiss the possibility of making a machine with human-like ability, but now that we have grown used to moving forward at such a pace we can be less sure. Quite soon, in only 10 or 20 years perhaps, we will be able to assemble a machine as complex as the human brain, and if we can we will. It may then take us a long time to render it intelligent by loading in the right software (软件)or by altering the architecture but that too will happen.

    I think it certain that in decades, not centuries, machines of silicon (硅) will arise first to compete and then do better than their human ancestors. Once they do better than us they will be capable of their own design. In a real sense they will be able to reproduce themselves. Silicon will have ended carbon's long control. And we will no longer be able to claim ourselves to be the finest intelligence in the known universe.

    As the intelligence of robots increases to match that of humans and as their cost declines through economies of scale we may use them to improve environments. Thus, deserts may bloom and the ocean beds be mined. Further ahead, by a combination of the great wealth this new age will bring and the technology it will provide, the construction of a vast, man-created world in space, home to thousands or millions of people, will be within our power.

    Chris Thomas used to think of Facebook as just a platform to get in touch with his friends. He now believes the social networking service with saving his life. The 28－year－old was diagnosed with muscular dystrophy(肌肉萎缩症) nine years ago and has relied on a wheelchair ever since.

    On July 15，2015，Thomas was getting ready for bed in his apartment，when a shelving(架子) fell onto his wheelchair and knocked him over，causing him to fall and hit the back of his head. After waking up from a few minutes of coma(昏迷)，he realized he couldn't reach the string used to get the doorkeeper's attention.

    His phone was nearby and had the Facebook application conveniently open，so he posted a status update that immediately got his friends worried—even some he hadn't spoken to in years. “It was amazing，friends from six different states who didn't know each other were connecting with each other to get me help，” Thomas said. “Now that's the power of social media! You have hundreds of people at your fingertips.”

    Eight minutes after the status went up，an old friend，Leah，got in contact with Thomas' friend Brad，whose wife was in the neighborhood，and before you knew it there were 12 Facebook friends in his apartment，who took him to the hospital at once. They showed up to the rescue at the perfect time. Minutes before they arrived，Thomas thought he was going to have a panic attack，which he often suffers from because of his illness，but he's doing better now.

    “It felt good to know that my friends，even those I haven't spoken to in the past，came to save me，” Thomas said. “They all came together .I would've never imagined it.”

    My dad was in the Air Force. When I was a kid, we moved every few years. That meant a lot of good-byes. It also meant getting used to a whole new community and a whole new school each time we moved. I can still feel what it was like to have to walk into the new school—that sinking feeling in my belly, that heaviness in my throat. It would always take time for me to learn how everything worked, what was cool and what was not. It was always a struggle to find where I could fit in.

    Already shy, I didn't have much self-confidence in my friend-making abilities. I was the girl walking in the halls with her head down, panicking. When I spoke, you could hardly hear my soft voice. I was nervous and doubted myself a lot.

    It was very hard not having a history with everyone else. I was an outsider. But what I did have was soccer. Wherever I went, I knew that I could fit in with the soccer ball. The soccer team meant a familiar place and immediate friends for me. I could express myself and feel good about myself on the field. Playing hard helped to get rid of all my nervousness.

    Throughout our lives, our self-respect goes down when we feel like a failure, and it goes up when we feel successful. Doing something well, being praised, and feeling loved goes a long way. We all need to explore opportunities where we can be good at something and feel good about ourselves. Physical activity and sport participation is a terrific way to build up our sense of self-confidence and self-worth.

    Many people have long dreamed of being able to fly around as simply as riding a bicycle.

    Yet the safety and strength of a flying bike was always a big problem. Over the past 10 years' developments in technology have moved the dream of personal flying vehicle closer to reality. Now, two groups of inventors say such vehicles may be available very soon.

    Grant Stapleton from Malloy Aeronautics says the Hoverbike, which is able to get in and out of small spaces very quickly, will be a truly personal flying vehicle." It can be moved across continents very quickly because it can be folded and packed," he adds.

    Mr. Stapleton says safety was the company's main concern when developing the Hoverbike, He says the designers solved the safety issue by using overlapping rotors (折叠旋翼)to power the vehicle. The company is testing both a one-third size model and a full-size prototype (原型))of the Hoverbike.

    Inventors say their Hovebike will most likely be used first by the police and emergency rescue teams.

    In New Zealand, the Martin Aircraft Company is also testing a full-size prototype of its personal flying bike, called Jetpack. It can fly for more than 30 minutes, up to 1,000 meters high and reach a speed of 74 kilometers per hour.

    Peter Coker is the CEO of Martin Aircraft Company. He said Jetpack" is built around safety from the start" In his words, reliability is the most important part of it. We have safety built into the actual structure itself very similar to a Formula One racing car."

    Jetpack uses a gasoline-powered engine that produces two powerful jet streams. Mr. Coker says it also has a parachute (降落伞)that can be used should there be an emergency.

    "It opens at a very low altitude and actually saves both the aircraft and the pilot in an emergency," he adds.

    Much older than the Great Wall, Stonehenge is one of the world's most fascinating (迷人的), but least understood historical sites (遗址). Every year, thousands of tourists come to admire Stonehenge's beauty and to wonder about how and why it was built.

    Stonehenge was produced by a culture that left no written records. Though there are many guesses, it is still a mystery why stone-age man moved such heavy stones over 380 kilometers from where they were made.

    At that time, people had only basic wooden tools. To move the stones they probably used tree trunks (树干) to roll them along.

    Some historians believe that Stonehenge was a temple, the site of ancient sacrifice(祭祀). Others believe it was perhaps a giant sundial (日冕) to tell the time. Stonehenge could have been a burial ground(墓地) from its earliest beginnings, because human bone dating from as early as 3000 BC was found there. Whatever its ancient use was, the stones have always been a source of fascination for British people. One record from 1135 said the great stones were carried to England by giant magical creatures!

    In modern times Stonehenge has become a huge hit with tourists. When Stonehenge was first opened to the public it was possible to walk among and even climb on the stones, but the stones were circled with ropes in 1977 as a result of serious erosion(侵蚀). Visitors are no longer allowed to touch the stones, but are able to walk around from a short distance away. What's more, visitors can make special bookings to get into the stones throughout the year.