There are many kinds of animals that live in the forest, such as mice, rabbits, squirrels, bears.

    Animals in the forest depend on（依靠）one another for food. Many small forest animals, such as mice, eat green plants for food, and then larger animals eat them. This is called food chain. A food chain begins with the sun. The green plants in the forest use the sun's energy to make food for themselves. It's called photosynthesis(光合作用). Mice eat flowers and seeds that forest plants produce(生产).The mice get their energy from the plants, and the mice become food for a larger animal, such as the hunting hawk. So the energy from the sun passes from the plants to the mice to the hawk. A break（中断）in any part of this food chain means some animals may not have enough food to eat.

    Life in the future will be different from life today.

    The population(人口) is growing fast. There will be more people in the world and most of them will live longer.

    Computer will be much smaller and more useful, and there will be at least one in each home. And computer science will be one of the most important subjects in school then. 

    People will work fewer hours than they do now, and they will have more free time for sports, watching TV and travel.

    Our food will be different, too. More land(土地) will be used for building new towns and houses for people. So there will be less land for cows and sheep, and meat will be more expensive. Maybe no one will eat it one day. They will eat more fruits and vegetables. 

    Work in the future will also be different. Robots will do dangerous and hard work. Because of this, many people will have no jobs to do. This will be a big problem in the future.  

根据短文内容，回答下列问题。

    We want to explore and try to better understand the world in which we live; Space exploration is one of the ways. Through the exploration of space, we can begin to unravel the mysteries of our universe, and to better know our living environment.

    Space exploration provides us with knowledge about the beginning of our solar system, our own planet and ourselves. It also helps answer the questions that have puzzled us for many years. Solar system exploration is important because it is good for us.

    Space technology has become an important part of our daily lives. Some technology uses satellites to communicate. Satellites are also used to examine the changes in the Earth's climate and seas, for weather report and for military. We also use satellites in food production. Because of the use of space technology in crops, fewer and fewer people will suffer hunger.

    The space program provides a chance for nations to work together. The cooperation(合作) promotes peace and understanding between governments and their people. Many governments have taken part in the space technology, including the United States, Russia, Japan, the European nations and India. In the near future, other nations will take part in it. In fact, the United States remains the leader in new space technology.

    The world's largest radio telescope was finished on Sept. 25, 2017 in China.

    FAST is a five-hundred-meter telescope. It is also called Tian-yan ("The Eye of Heaven"), with a dish the sire of 30 football grounds, deep in the mountains of southwest China's Guizhou Province. The giant dish is built on a howl-like valley.

    The surrounding area has "radio silence" as there are no towns and cities within a 5-kilometer radius (半径范围) and only one county center within 25 kilometers.

    FAST is made up of 4, 450 panels (面板). The second largest radio telescope is in Russia. The bigger dish will be able to pick up weaker signals (信号).

    The radio telescope is like an ear, listening to tell meaningful radio messages from white noise in the universe. With the help of the telescope, we can receive weaker and more radio messages far away in space. It will help us to search for intelligent life outside of the Galaxy (银河系) and explore the origins (起源) of the universe. "Any of its discoveries will lead to a Nobel Prize," said Joseph Taylor, a Noble Prize winner.

    The FAST project began in 2011. And the telescope is expected to remain the global leader for the next 10 to 20 years.

    Art, as we know, is subjective. What one person considers a priceless masterpiece others might see as nothing more than a giant black square. But there's one very specific kind of painting that almost everyone sees the same way-the kind with the" "strange" eyes that seem to follow you around the room. So what causes this optical illusion (视觉错觉) and how do artists achieve this effect?

    It turns out, for even a moderately skilled artist, this effect isn't a difficult thing to achieve, In fact, the artists need to use a little illusion of depth, making the person depicted on the canvas appears somewhat 3D on a 2D canvas, and to adjust .the gaze (凝视) of the eyes so that they would be looking at someone standing right in front of the picture.

    So what exactly is going on here in our brains that then makes it seem like the eyes follow you even if you move away from being front and center? As demonstrated by a team of researchers from Ohio State University, as you move to the side, the "near? and "far" points of the 2D image don't really change. These near and far points are defined as visible points that, if the image was 3D, would appear nearest and furthest away from the viewer at a given angle.

    The idea is simple. No matter what angle you look at a paining from, the painting itself doesn't change. You're looking at a flat surface. The key is that the near points and far points of the picture remained the same no matter the angle the picture was viewed from. When observing real surfaces in the natural environment the near and far points vary when we change viewing direction. When we observe a picture on the wall, the visual information that defines near and far points is unaffected by viewing direction. Still, we willingly accept and interpret the thing in the painting as if it were a real object.

    Thus, because the perspective, shadows, and light on the painting don't change as you move around, if the eyes in the painting would be staring directly at the observer who is standing in front of the painting, it creates something of an optical illusion in your brain so that the eyes will continue to seem to stare at you as you move to the side.

    In contrast to the eyes following you trick, if the artist tweaks the painting a bit, for example the artist adjusts the gaze of the eyes so that the eyes are looking off somewhere else instead of directly looking at a potential observer, no matter where you stand, the eyes will never seem to be looking at you.

    The technique first began popularly showing up in art around the 14th century when the artist and architect Fillipo Brunelleshi introduced the art world to the idea of "linear perspective", being painting with the idea of everything in the picture converging (聚集) on a specific point on the horizon, creating the illusion of depth. Linear perspective, combined with skilled use of light and shadow, allows artists to create masterfully realistic paintings, including sometimes of people that stare at you creepily no matter where you stand.