Almost every machine with moving parts has wheels, yet no one knows exactly when the first wheel was invented or what it was used for. We do know, however, that they existed over 5,500 years ago in ancient Asia.

    The oldest known transport wheel was discovered in 2002 in Slovenia. It is over 5,100 years old. Evidence suggests that wheels for transport didn't become popular for a while, though. This could be because animals did a perfectly good job of carrying farming tools and humans around.

    But it could also be because of a difficult situation. While wheels need to roll on smooth surfaces, roads with smooth surfaces weren't going to be constructed until there was plenty of demand for them. Eventually, road surfaces did become smoother, but this difficult situation appeared again a few centuries later. There had been no important changes in wheel and vehicle design before the arrival of modem road design.

    In the mid-1700s, a Frenchman came up with a new design of road—a base layer (层) of large stones covered with a thin layer of smaller stones. A Scotsman improved on this design in the 1820s and a strong, lasting road surface became a reality. At around the same lime, metal hubs (the central part of a wheel) came into being, followed by the pneumatic tyre(充气轮胎) in 1846. Alloy wheels were invented in 1967, sixty years after the appearance of tarmacked roads (柏油路). As wheel design took off, vehicles got faster and faster.

    Every week in China, millions of people will sit in front of their TVs watching teenagers compete for the title Character Hero, which is a Chinese­style spelling bee (拼写大赛). In this challenge, young competitors must write Chinese characters by hand. To prepare for the competition, the competitors usually spend months studying dictionaries.

    Perhaps the show's popularity should not be a surprise. Along with gunpowder and paper, many Chinese people consider the creation of Chinese calligraphy (书法) to be one of their primary contributions. Unfortunately, all over the country, Chinese people are forgetting how to write their own language without computerized help. Software on smart phones and computers allows users to type in the basic sound of the word using the Latin alphabet(字母). The correct character is chosen from a list. The result? It's possible to recognize characters without remembering how to write them.

    But there's still hope for the paint brush. China's Education Ministry wants children to spend more time learning how to write.

    In one Beijing primary school we visited, students practice calligraphy every day inside a specially decorated classroom with traditional Chinese paintings hanging on the walls. Soft music plays as a group of six­year­olds dip brush pens into black ink. They look up at the blackboard often to study their teacher's examples before carefully trying to reproduce those characters on thin rice paper.＂If adults can survive without using handwriting, why bother to teach it now?＂we ask the calligraphy teacher, Shen Bin.＂The ability to write characters is part of Chinese tradition and culture,＂she reasons.＂Students must learn now so they don't forget when they grow up.＂says the teacher.

    The 90-minute documentary, Amazing China, which is co-produced by China Central Television and China Film Corp, opened in theaters nationwide on Friday.

    The film focuses on the major achievements the country has made since the 18th National Congress of the Communist Party of China in 2012 under Xi Jinping Thought on Socialism with Chinese Characteristics for a New Era（时代）.

    The documentary focuses on key Chinese infrastructure（基础设施）projects in aerospace, high-speed rail, the Hong Kong-Zhuhai-Macao Bridge and the world's largest single-dish telescope FAST.

    The documentary also informs viewers that seven of the world's 10 biggest sea ports are now in China. And that the country now has the longest high-speed rail network in the world.

    Speaking of the significance of the new documentary for the Chinese, La Peikang, the head of China Film Corp, says: “It's not only about showing the achievements, but presenting the status quo of China.

    “The film will help people to know our country better. The moving stories behind the Chinese miracles reflect the people's endeavors and spirit.”

A good documentary is usually a vivid portrayal（描绘）of individual stories rather than slogans, and Amazing China is no exception.

    One of the most touching moments in the film is probably footage from an interview of Nan Rendong, often called the “father of FAST”.

    Amazing China also focuses on common people.

    In the film, you see a young Tibetan woman volunteering in rural areas to help people poverty.

    The movie shows that their work is not easy, but their spirit and unwavering belief make it possible to achieve their targets. And, they are just representative of the many Chinese who work as hard.

    China is the world's second-largest economy. But the country still faces “the contradiction between unbalanced and inadequate development and the people's ever-growing needs for a better life”, as stated in the CPC's 19th National Congress in November. However, as this cinematic production proves, the documentary is a good way for country to boost self-confidence and to aspire for a brighter future.

    Taxi-booking app Uber agreed to sell its business in China to Didi Chuxing. The two firms had been fierce competitors, but Didi Chuxing had controlled the Chinese market with an 87% share.

    Uber China launched in 2014, but it had failed to make any profit for a long time. Cheng Wei, founder and chief executive of Didi Chuxing, said the two companies had learned a great deal from each other over the past two years in China. He added that the deal would set the mobile transportation industry on a healthier path of growth at a higher level. As part of the deal, Mr. Cheng would join the board of Uber, while Uber chief executive Travis Kalanick would also join Didi's board.

    Uber's China business would own its separate branding while US-based Uber Technologies would hold about 17.5% in the combined company. Didi Chuxing is backed by Chinese Internet giants Tencent and Alibaba.

    Uber had been struggling to break into the Chinese market despite having Chinese search engine Baidu as an investor. Last February, the company admitted it was losing more than $1 billion a year in China. “Funding their Chinese dreams was becoming too expensive for Uber,” Duncan Clark, chairman of Beijing-based consultancy BDA, told the BBC. Travis Kalanick said, “As a businessman, I've learned that being successful is about listening to your head as well as following your heart.”

    The fierce competition had led both companies to spend much more on their journeys. The combination is likely to see fewer such subsidies（补贴）. “One thing to watch carefully is how quickly consumers feel the impact as subsidies are withdrawn.” Mr. Clark added.

    The deal with Didi Chuxing came just days after China had agreed to provide a legal framework for taxi-ordering apps. Both Uber and Didi welcomed the decision. The new rules took effect last November and could, among other things, forbid such platforms to operate below cost.

    Many animals recognize their food because they see it. So do humans. When you see an apple or apiece of chocolate you know that these are things you can eat. You can also use other senses when you choose your food. You may like it because it smells good or because it tastes good. You may dislike some types of food because they do not look, smell or taste very nice. Different animals use different senses to find and choose their food. A few animals depend on only one of their senses, while most animals use more than one sense.

    Although there are many different types of food, some animals spend their lives eating only one type. The giant panda eats only one particular type of bamboo. Other animals eat only one type of food even when given the choice. A land of white butterfly will stay on the leaves of a cabbage, even though there are plenty of other vegetables in the garden. However, most animals have a more varied diet. The bear eats fruits and fish. The fox eats small animals, birds and fruits. The diet of these animals will be different depending on the season.

    Humans have a very varied diet. We often eat food because we like it and not because it is good for us. In countries such as France and Britain, people eat foods with too much sugar. This makes them overweight, which is bad for their health. Eating too much red meat and animal products, such as butter, can also be bad for the health Choosing the right food, therefore, has become an area of study in modern life.

    The world we live in gets more mechanized every year. Some countries which were mainly agricultural a hundred years ago have now become industrial. New factories and towns have been built on good agricultural land. There are now fewer farms to serve a much greater population, so these farms must be more efficient in order to produce as much food as possible. There is no place in the modern agricultural world for the inefficient farmer. Unfortunately, many of the picturesque aspects of farming are disappearing in the search for efficiency. The more tractors are used, the fewer horses are needed. Everyone agrees that horses are far more pleasant to look at than tractors. But they are less efficient. Cows are usually milked by machinery nowadays, and even pigs are fed automatically. There is not much art or poetry on the modern farm, and the old traditional idea of a farm as a slow, peaceful, romantic place is totally wrong nowadays.

    The modern farmer has to be a mechanic, a scientist, an accountant and a gambler. The more mechanized farming becomes, the more expert the farmer has to be. He must understand what machinery is necessary for his kind of farm, and he must know how to use it efficiently. He must also understand the new technical advances in agriculture, and how to use chemical and synthetic products to improve his crops. The more workers a farmer employs, the more he must know about the problems of wages and taxes. As in any other industry, most modern farmers find it necessary to employ office staff to deal with these. But although he has more modern equipments and far more scientific aids than his grandfather had, the farmer is still dependent upon the weather. As he can never be sure what the weather will do, he must be prepared to take risks, and face the possibility of losing everything.