Transparent animals let light pass through their bodies the same way light passes through a window. These animals typically live between 

the surface of the ocean and a depth of about 3,300 feet—as far as most light can reach. Most of them are extremely delicate and can be 

damaged by a simple touch. Sonke  Johnsen, a scientist in biology, says, “These animals live through their life alone. They never

touch anything unless they're eating it, or unless something is eating them.”

And they are as clear as glass. How does an animal become see-through? It's trickier than you might think.

      The objects around you are visible because they interact with light. Light typically travels in a straight line. But some materials slow and

 scatter(散射) light, bouncing it away from its original path. Others absorb light, stopping it dead in its tracks. Both scattering and absorption

 make an object look different from other objects around it, so you can see it easily.

But a transparent object doesn't absorb or scatter light, at least not very much, Light can pass through it without bending or stopping.

That means a transparent object doesn't look very different from the surrounding air or water. You don't see it —you see the things

behind it.

   To become transparent, an animal needs to keep its body from absorbing or scattering light. Living materials can stop light because they

contain pigments(色素) that absorb specific colors of light. But a transparent animal doesn't have pigments, so its tissues won't absorb

 light. According to  Johnsen, avoiding absorption is actually easy. The real challenge is preventing light from scattering.

Animals are built of many different materials—skin, fat, and more—and light moves through each at a different speed. Every time light

moves into a material with a new speed, it bends and scatters.Transparent animals use different tricks to fight scattering. Some animals are

simply very small or extremely flat. Without much tissue to scatter light, it is easier to be see--through. Others build a large, clear mass of

 non-living jelly-lie(果冻状的)material and spread themselves over it .

    Larger transparent animals have the biggest challenge, because they have to make all the different tissues in their bodies slow down light 

exactly as much as water does. They need to look uniform. But how they're doing it is still unknown. One thing is clear for these larger animals, staying transparent is an active process. When they die, they turn a non-transparent milky white.

    Every time we get behind the wheel of a car, we put our lives and the lives of others at risk. Self-driving cars are designed to reduce those risks by letting technology control our vehicles.

    Accident rates for self-driving cars have been much lower than the rate, for human-driven cars. {#blank#}1{#/blank#}

    As humans, we can make moral choices in avoiding accidents. To avoid hitting a child, for example, human drivers might sharply turn a car away from the child even if others may be injured. {#blank#}2{#/blank#} Researchers studied this issue. They have developed the Moral Machine website to help explore the choices self-driving cars should make.

    {#blank#}3{#/blank#} You are shown two possible traffic situations and you choose between them. An accident will take place. You choose how many living beings would be hurt or killed.

    In one situation there may be a female doctor, a child, two dogs and a homeless person who would be killed. In the other situation, you might have two babies and a cat who would be killed. {#blank#}4{#/blank#}

    The Moral Machine website has many situations and many possible outcomes. When you click on the situation of your choice, it will be highlighted. {#blank#}5{#/blank#} At the end of the situation, you are shown the results, based on the choices you made. The results show which character you were most likely to save and which character you were most likely to have die.

    Did you know that, in 2016, over 18 million people attended classical concerts in Germany? That's more people than those who went to main league football matches! Earlier this year, Germany continued its celebration of classical music with the opening of a new concert hall in the heart of Hamburg. Germans are incredibly proud of it and it's the first thing I show to my friends when they come to visit.

    Known as the 'Elphi' by the locals, the Elbphilharmonie is a beautiful tower of glittering glass sitting atop an old warehouse by the banks of the river Elbe. The plaza(露天广场)is open to the public an from the middle of the city's tallest building, you can gaze across the harbour, miles of rooftops and passing ships below.

    The main concert hall seats over 2000 people and is one of the most advanced music venues in the world. Two smaller concert halls are used for jazz, world and contemporary music. In addition, if you're unbelievably rich, you can buy one of the 45 luxurious apartments lying within the building.

    Construction began in 2007 with a budget of €241 million and a two-year period. Fast forward ten years, the building eventually opened with a final price tag of over 800 million!

    I consider myself very lucky that the Elbphilharmonie opened during my time living in Hamburg, but unfortunately I haven't yet been able to attend a concert. Everything is sold out for six months! For now, I'm content to visit the plaza to enjoy the impressive view over the docks and see the innovative architecture up close. Hopefully one day soon, I'll be lucky enough to grab a last-minute concert ticket!

    Standing desks have become common across Silicon Valley, offering health benefits to those willing to work on their feet. However, due to their high price, they have failed to catch on until now. Recently, Ikea has brought out Bekant convertible（可变换的） standing desk that can become a normal desk at the touch of a button. The $500 adjustable desk can transform from a standard desk to a standing one, and Ikea hopes it could make the standing desk mainstream.

    Experts say that changing from a seated to a standing desk can improve productivity. Similar desks have become a common sight at tech firms such as Google, where some employees have even installed treadmill (跑步机) and bicycle desks.

    The desk is not the first “convertible” on the market. As early as 2013, Stir Kinect brought out an adjustable desk. The $3,890 Stir Kinect desk has a motor to raise and lower itself, changing it into a standing desk or a traditional desk. The desk can even be programmed to move up and down slightly, making it appear to take a gentle breath to remind the user to change their positions. To move between sitting and standing positions, owners simply double tap on the screen. The desk can learn the user's preferences over time and suggest the best seating position.

    The Stir Kinect desk was created by a team of ex-Apple and Disney engineers. It has a built-in touch screen to control and track movement, and can tell users exactly how many calories they burn by standing during their working day. It also has devices containing power points and USB ports for charging phones, to keep cables hidden.

    “Ikea's height-adjustable desk is great for opening up the lower end of the market, '' said JP Labrosse, founder and CEO of Stir.

    From the first use of the rocket to carry satellites into space to the setting up of space stations, human beings have been putting great effort into space research. And so far, we have achieved many successes. But there are still numerous tasks in front of us and we should not stop trying to progress.

    The international space station （ISS） is an important step we should take in space exploration. It is not only helpful but also essential. It provides a proper space environment for many experiments that we have wanted to do for a long time. It is also a base for the observations of the earth and the universe. It could also be an important base for later travel to the moon and Mars. In a word, if we want to explore space more, the first thing we should do is to set up a space station.

    As the space station costs a lot of money, it is hard for one country alone to establish one. The USA seem to be the only country that has the ability to build a space station alone, and it has tried to do so, but not very successful. So it aggregated many other countries to work on it together. Though it is still extremely expensive, it is much cheaper than doing it alone. It is really a job that needs everyone's effort and will benefit everyone.

    Led by the U. S. and Russia, the ISS is a joint project between six space agencies involving 16countries. Called the greatest achievement in human cooperation, the ISS has come to the end of a ten﹣year's hard work in construction. China has applied for participation in （taking part in） the project many times. Unfortunately all the applications were rejected, which drove China onto the path of independent development. As the Long March Ⅱ﹣F/T1 carrier rocket blasted off （leave the ground） and successfully carried the Tiangong﹣1into space on September 29, 2011, China takes a big step toward its Space Station Era.

    Some West media suggested that the successful launch of Tiangong﹣1 would disturb the balance of global space power, raising concerns about "China threat". China's space project is not designed for military purpose but for developing space technology to explore space resources and make use of them for mankind's well﹣being.

    A few weeks ago, I sat with a California farmer named Dave Ribeiro. I asked him what he wished to know about farmers. He smiled and said, "That we walk among you. We look like you and talk like you. We have advanced degrees and hobbies, just like you."

    Take Dave for example: He's a young man with a music degree. And if you walked past him on the street, you'd never think, "There goes a farmer."

    Is someone like Dave who you picture when you think of a farmer? Probably not. I think that most people would picture a man in his overalls(工作服). I can tell you, that does not represent Dave or any of the many other farmers I have gotten to know.

    Not only do we have to throw out our previous impression of farmers, but farming as a whole doesn't look much like it used to either. We recently sent a team out to see what modern farming looks like, and they found farmers to be completely different from our usual ideas about them and also came across them in some unexpected places.

    In a parking lot in a neighborhood of Brooklyn, they met a new crop of young farmers who were trying to bring fresh greens closer to eaters in the city by growing them in high-tech indoor vertical(垂直的) farms. In a Florida field under the fight path of an airport, they discovered farmers with university degrees growing plants that might someday fuel our cars. And in a modern farm in California, they observed how farmers were using technology to take the best possible care of their animals.

    These farmers all spend their days in very different ways—none of them looks like the previous farmer we have in our mind—but they're all working on new ways to feed our planet. Not only do we need to change our idea of what farming looks like, but we also need to change our view of where solutions can come from. Feeding all of us is going to take all of us working together.