Touring Cenotes

    My parents and I traveled to Mexico to visit my grandparents last summer, and we visited the cenotes (say-NO-tays), the natural swimming holes located on the Yucatán Peninsula. The term "swimming hole" might make you think that cenotes are just average, but cenotes are truly {#blank#}1{#/blank#}. I had the most exciting experience of my life exploring these wonders of nature.

    Thousands of years old, the cenotes formed and created sinkholes underneath. Though the ancient Mayans (玛雅人) used the cenotes as water {#blank#}2{#/blank#}, people can now swim, dive, take photographs, and admire local trees and {#blank#}3{#/blank#} life, all through water as clear as liquid diamond.

    In Cenote Azul, my parents, my grandparents, and I swam through water that seemed too blue to be real. I {#blank#}4{#/blank#} countless younger kids diving into the water from a small cliff, but I dared not to jump at first. I finally worked up the courage, and my {#blank#}5{#/blank#} try instantly put all my worries to rest.

    A few days later, we went to Cenote Ponderosa. We stayed in the sun-covered pond, where we {#blank#}6{#/blank#} floated while others did diving and took underwater photographs. Being surrounded by a valley of trees made everything else in the world seem to disappear.

    Grutas de Loltún were definitely the most magnificent of all the cenotes, even though there was no swimming involved. Grutas are caves, and the Grutas de Loltún are among the biggest caves on the entire Peninsula. Our guide, Carolina, walked us through several caves, where we saw many drawings thousands of years old on the cave walls! Just one brief look at those drawings made me feel like I had stepped back in time to a(n) {#blank#}7{#/blank#} era of history. Our group thought Carolina was joking when she claimed she could make the stalagmites(石笋) sing for us, but when she {#blank#}8{#/blank#} them, we heard what sounded like the words "Lol" and "Tun"—the name of the caves! I cannot imagine that a(n) {#blank#}9{#/blank#} played at a concert at Carnegie Hall would have been any better.

    Mexico's Yucatán Peninsula is filled with beauty, but the cenotes are a one-of-a-kind opportunity to commune with nature in a way that is impossible anywhere else on Earth, and I would not {#blank#}10{#/blank#} to do it all again.

    For several decades, various types of artificial intelligence kept shocking the world. Robots could {#blank#}1{#/blank#} people in highly competitive games and then quickly destroyed their human competitors.

    AI long ago mastered chess, the Chinese board game Go and even the Rubik's cube, which it managed to solve in just 0. 38 second.

    Now machines have a new game that will allow them to {#blank#}2{#/blank#} humans: Jenga, the popular game in which players {#blank#}3{#/blank#} remove pieces from an increasingly unstable tower of 54 blocks, placing each one on top until the entire structure would {#blank#}4{#/blank#}.

    A newly released video from MIT shows a robot developed by the school's engineers playing the game with surprising accuracy. The machine is equipped with a soft gripper (夹子), a force-sensing wrist and an external camera, allowing the robot to detect the tower's {#blank#}5{#/blank#} the way a human might do

    Unlike in purely recognitive tasks or games such as chess or Go, playing the game of Jenga also requires mastery of physical acts such as pushing, pulling, placing, and arranging pieces. It must {#blank#}6{#/blank#} interactive physical operation, where you have to touch the tower to learn how and when to move blocks.

    Imitating it is rather difficult, so the robot has to learn in the real world, by working with the real Jenga tower. Recently, a relevant research was published in the journal Science Robotics. Researchers say the robot demonstrates that machines can learn how to perform certain tasks through actual touching instead of relying heavily on visual {#blank#}7{#/blank#}. That physical {#blank#}8{#/blank#} is significant, researchers say, because it provides further proof that robots can be used to perform {#blank#}9{#/blank#} tasks, such as separating recyclable objects from landfill trash and assembling consumer products.

    In a cellphone assembly line, the felling of any component is coming from force and touch rather than vision. To become an accomplished Jenga player, the robot did not require as much repetitive practice as you might imagine. Hoping to avoid reconstructing a Jenga tower thousands of times, researchers developed a method that allowed the robot to be trained on about 300 games. Researchers say the robot has already begun facing off against humans, who remain {#blank#}10{#/blank#} players—for now.

Bad News for Apple; Good News for Humanity

    When Apple cut its revenue estimate(收益预期) for the last quarter of 2018 because of unexpectedly slow sales of iPhones, markets trembled. The company's share price, which had been {#blank#}1{#/blank#} for months, fell by a further 10% on January 3rd, the day after the news came out. Apple's suppliers' shares were also hit.

    Analysts assume that the number of smartphones sold in 2018 will be slightly lower than in 2017, the industry's first ever annual decline. All this is terrible news for investors who had {#blank#}2{#/blank#} on continued growth. But step back and look at the bigger picture. That smartphone sales have peaked, and seem to be {#blank#}3{#/blank#} off at around 1.4billion units a year, is good news for humanity. The slowdown is actually the result of market saturation (饱和), which hits Apple the hardest because, despite a relatively small market share (13% of smartphone users), it captures almost all of the industry's {#blank#}4{#/blank#}. But Apple's pain is humanity's gain. The fact that the benefits of these magical devices are now so widely {#blank#}5{#/blank#} is something to be celebrated.

    Now many phones are used for longer than three years, often as hand-me-downs. Replacement cycles are lengthening as new models offer only {#blank#}6{#/blank#} improvements. So even with flat sales, the longer {#blank#}7{#/blank#} between upgrades mean people who already have phones benefit. For all but the most addicted device fans, the slowing pace of upgrades comes as a welcome {#blank#}8{#/blank#}.

    Does that mean innovation is slowing? No. As computers become smaller, still more {#blank#}9{#/blank#} and closer to people's bodies, many technicians expect that wearable devices, from smart watches to AR headsets, will be the next big thing. Even so, finding another product with the scope of the smartphone is a tall order. The smartphone holds its {#blank#}10{#/blank#} as the device that will make computing and communications worldwide. The recent slowing of smartphone sales is bad news for the industry, obviously. But for the rest of humanity it is a welcome sign that a transformative technology has become almost universal.

    Thank you for choosing me as the best{#blank#}1{#/blank#}. In our school, I'm really happy to share with you how passionate I am about sports and what I do to{#blank#}2{#/blank#}. I'm a big{#blank#}3{#/blank#}of many sports, including basketball, football and gymnastics. I love to watch these events on TV at the weekend. I also{#blank#}4{#/blank#}regularly, too. In the morning. I often {#blank#}5{#/blank#}on the running{#blank#}6{#/blank#}for about half an hour. I don't run too fast or for too long so that I have enough{#blank#}7{#/blank#}for the day. In the afternoon, I usually play football or basketball. I'm on the school football team. The training is always {#blank#}8{#/blank#}, but we all do our best, since we all want to{#blank#}9{#/blank#}on the team when playing against other schools. Believe it or not, we also occasionally do yoga in the{#blank#}10{#/blank#}! It helps relax our muscles and focus our minds. If you want to become fit and healthy, my advice is to try different sports and activities to see which one you enjoy the most.

The Floating School

    Life on the islands can feel a bit isolated due to a lack of electricity and internet connectivity.

    Although some of the islands have primary schools, most young people must travel to the larger islands or to the mainland to attend high school. Schools on the islands follow the {#blank#}1{#/blank#} curriculum (课程). They don't teach subjects such as maritime skills, swimming or local fishing traditions, and so the curriculum isn't always {#blank#}2{#/blank#} with students' everyday life.

    So, we {#blank#}3{#/blank#} the Floating School after winning funding through a US State Department grant competition called Seeds for the Future. Before we started the school, we spoke with young people, community leaders and teachers on the islands to find out the topics young people are most interested in. We also learned about the various {#blank#}4{#/blank#} of students and young people who don't go to school. Thus, we {#blank#}5{#/blank#} our own non-formal educational programme that fits with the context of life on the islands. For example, those working in fishing have responsibility {#blank#}6{#/blank#} the marine life, so we teach environmental protection and discourage destructive fishing practices.

    The Floating School is a wooden boat that can {#blank#}7{#/blank#} up to twenty people and it goes to the students, not the other way around -- we use it to transport educational materials, tools, and teachers to young people living on the islands. Our teachers are local young {#blank#}8{#/blank#}— so far we have had journalists, photographers, computer engineers and musicians — and students who want to {#blank#}9{#/blank#} their skills.

    At first, many of the young people thought the Floating School would be the same as their schools on the islands. They had thought of the teachers to be {#blank#}10{#/blank#}. But our students learn through art, media and literature. They don't have to wear uniforms or shoes, and the teachers treat the students as equals, without judging them. This means our students can be themselves.