A long time ago people thought that the sun went round the earth. In some countries people even said that the sun was a god(神). They thought the god drove across the sky each day on a golden horse. Now we know the earth goes round the sun. It takes the earth a year to go a circle(圈) round the sun. Today men even know how far it is for the earth to go round the sun. They tell us that the earth travels over a thousand miles a minute on its journey round the sun.

    The sun is really a star. It is much bigger than the earth and it is very hot. Some people have been to the moon but we know that no one can ever go to the sun. It is far too hot for people to live anywhere near it. The sun is three hundred thousand times heavier than the earth and more than million times larger.

    People aren't walking any more—if they can figure out a way to avoid it.

    I felt superior about this matter until the other day I took my car to mail a small parcel. The journey is a matter of 281 steps. But I used the car. And I wasn't in any hurry, either, I had merely become one more victim of a national sickness: motorosis.

    It is an illness to which I had thought myself immune（免疫的）, for I was bred in the tradition of going to places on my own two legs. At that time, we regarded 25 miles as good day's walk and the ability to cover such a distance in ten hours as sign of strength and skill. It did not occur to us that walking was a hardship. And the effect was lasting. When I was 45 years old I raced—and beat—a teenage football player the 168 steps up the Stature of Liberty.

    Such enterprises today are regarded by many middle-aged persons as bad for the heart. But a well-known British physician, Sir Adolphe Abrhams, pointed out recently that hearts and bodies need proper exercises. A person who avoids exercise is more likely to have illnesses than one who exercises regularly. And walking is an ideal form of exercise—the most familiar and natural of all.

    It was Henry Thoreau who showed mankind the richness of going on foot. The man walking can learn the trees, flower, insects, birds and animals, the significance of seasons, the very feel of himself as a living creature in a living world, He cannot learn in a car.

    The car is a convenient means of transport, but we have made it our way of life. Many people don't dare to approach Nature any more; to them the world they were born to enjoy is all threat.To them security is a steel river thundering on a concrete road. And much of their thinking takes place while waiting for the traffic light to turn green.

    I say that the green of forests is the mind's best light. And none but the man on foot can evaluate what is basic and everlasting.

    See a cell phone cover that you like on Taobao? Forget about placing an order, paying the bill online and waiting for days for it to be delivered to you. In the near future, you'll be able to get it in minutes just by hitting "print" on your computer. You might find it hard to believe that you could actually "print" an object as you would a picture. But it is not that hard to understand how it would work. Just as a traditional printer sprays (喷) ink onto paper line by line, modem 3-D printers spread material onto a surface layer by layer, from the bottom to the top, gradually building up a shape.

    Instead of ink, the materials the 3-D printer uses are mainly plastic, resin (树脂) and certain metals. The thinner each layer is — from a millimeter to less than the width of a hair —the smoother and finer the object will be. This may sound like a completely new technology, but the truth is that 3-D printing has been around since the late 1980s. Back then, it was barely affordable for most people, so few knew about it.

Last year, though, saw a big change in the 3-D printing industry — printers became much cheaper. For example, 10 years ago a desktop 3-D printer might have cost £20,000, while now they cost only about £ 1,000, according to the BBC. Taken out of the factory and introduced to more diverse and common uses, 3-D printing can create just about anything you can think of — flutes (笛子), bikinis, jewelry, aircraft parts and even human organs. In fact, scientists from Cornell University in New York have just made an artificial ear using a 3-D printer, according to Science Daily. The fake ear looks and acts exactly like a natural one.

    However, as 3-D printing becomes more common, it may bring about certain problems —such as piracy. "Once you can download a coffee maker, or print out a new set of kitchen utensils (餐具) on your personal 3-D printer, who will visit a retail (零售的) store again?", an expert in 3-D printing told Forbes News. Even more frightening, what if anyone in the world could use a 3-D printer to print out a fully functioning gun?

    He may not have an "S" across his chest but this dog is most certainly a hero.

    Harley, who was rescued from a puppy mill four years ago, was named the American Humane Association's 2015 American Hero Dog. Harley, who is missing an eye and has other medical issues from his time at the mill, is now a "spokes-dog" against puppy mills. He serves as the adorable furry face of the "Harley to the Rescue" campaign, which raises funds for the National Dog Mill Rescue, according to a press release.

    The pup was rescued back in 2011 and adopted by Rudi and her husband, Dan. "It was just four years ago that he was pulled from the cage in the puppy mill and left to die," Harley's owner, Rudi, said during the awards show at the Beverly Hilton Hotel in Los Angeles this past weekend, according to Today. com. "We never would have ever thought he would live this long and make such a difference for so many puppies."

    The dog was one of eight finalists up for the American Hero Dog and was chosen as the winner through public votes. The finalists all won $ 1,500 to be donated to one of American Humane Association's charity partners, with Harley receiving another $ 5, 000 to go toward his charity partner, New Leash On Life.

    According to the release, Harley spent 10 years at the puppy mill, and endured rough treatment there, which led to his many medical issues. He lost his eye as a result of his cage being power-washed with him inside.

    The dog isn't just the face of his campaign, he also goes on rescue missions and makes public appearances at events and schools to raise awareness for puppy mills.

    This incredible work is all due to the dog's fighting spirit. That spirit is allowing him now to be the voice for dogs who cannot speak for themselves and give everybody hope that tomorrow's going to be a better day.

China' Forbidden City—-traditionally off-limit at night for anyone except emperors and visiting dignitaries (显要人物)—- was decorated with lanterns as China celebrated the end of the Chinese New Year holiday. The complex, home to Chinese emperors for five centuries, was opened at night for the first time since it was reopened as the Palace Museum 94 years ago.

    The complex and palace walls were illuminated with red lanterns and a light show, designed to recreate the feelings of the royal court, while the China National Traditional Orchestra and the Peking Opera performed. An image of a treasured scroll called A Thousand Li of Rivers and Mountains was cast onto the palace roof.

    Most of China's 1.3 billion people, however, had to watch the show on television. Only 3,000 people were allowed in: 2,500 invited guests and 500 people who booked their tickets online. "The 3,000 visitors can show off for the whole year," one person said on Weibo. When booking for the second day opened at midnight, the booking system crashed for more than an hour due to great demand. The free tickets were quickly taken when it reopened. A lively secondary market soon appeared. Scalpers were selling tickets for as much as 9,999 yuan on online trading sites.

    The Palace Museum is now on a campaign to attract more visitors, with its former curator Shan Jixiang saying he wants to make traditional Chinese culture more accessible to the general public. More than 80 percent of the palace is now accessible to visitors, up from 30 percent in 2012. Shan has set a target of 85 percent by 2020 to mark the palace's 600^th anniversary. Creativity today has made the Palace Museum younger and drawn traditional culture closer to the public.

    Once a teacher was giving her young students a lesson on how the government works. She was trying to explain the principle of income tax(所得税).

    "You see," she began speaking slowly and carefully, "each person who works must pay part of his or her salary to the government. If you make a high salary, your taxes are high. If you don't make much money, your taxes are low."

    "Does it make sense?" she asked. "Does everyone understand the meaning of income tax?" The students nodded.

    "Are there any questions?" she asked. The students shook their heads.

    "Very good!" she said. "Now, I would like you to take a piece of paper and write a short composition on the subject of income tax."

    Little Joe was a slow learner. He had lots of problems with spelling and grammar, but at least this time he seemed to understand the task. He took his pen and after a few minutes, he handed the teacher the following composition: Once I had a dog. His name was Tax. I opened the door and in come Tax.