Long ago, people lived on wild animals, fruits and other plants and they didn't need to use money.
As time passed, families had more products(产品) than they needed, such as animals and crops. So they needed to trade(交易) with others. They began to use money to make it easier. However, it was not like the money we use today. They used shells, rice, salt or large stones.
During the 600s BC, people began using coins as money. Because they were easier to carry than goods(货物), countries began to make coins as their money.

The Chinese were the first to use paper money, probably in the 11th century. An Italian traveler, Marco Polo, saw the Chinese use paper money when he visited China in the 1200s. After his travel, he told the western people what he saw. But European countries didn't start using paper money till the1600s.
Today we have many ways to pay for things, such as coins, paper money and cards. Some prefer to pay by card. That's because paying with a card is easier and safer than carrying around a lot of “real” money.

Nearly all American students in colleges and universities pay for their education. There are many expenses. First of all, there is tuition (学费). At some schools, the tuition is very high, ten thousand dollars a year or more. At other schools, it may only be a few hundred dollars a year. At some community (社区) colleges, tuition is free. There are other expenses as well. Many students leave their homes to go to schools in other cities. They may live in dormitories or apartments (flats), and they must pay for it. Finally, students must buy textbooks for their courses. Some families start saving money for their children's education when the children are small. Many students work to save money for tuition. They can also get loans (贷款) from the government. They pay the money back to the government when they finish their education.

    People use their mouths for many things. They eat, talk, shout and sing. They smile and they kiss. In the English language, there are many expressions using the word “mouth.”

    For example, if you say bad things about a person, the person might protest and say “Do not bad mouth me.” Sometimes, people say something to a friend or family member that they later regret because it hurts that person's feelings. Or they tell the person something they were not supposed to tell. The speaker might say: “I really put my foot in my mouth this time.” If this should happen, the speaker might fee l down in the mouth. In other words, he might feel sad for saying the wrong thing.

    Another situation is when someone falsely claims another person said something. The other person might protest: “I did not say that. Do not put words in my mouth.”

    Some people have lots of money because they were born into a very rich family. There is an expression for this, too. You might say such a person, “was born with a silver spoon in his mouth.”

    This rich person is the opposite of a person who lives from hand to mouth. This person is very poor and only has enough money for the most important things in life, like food.

    Parents might sometimes withhold sweet food from a child as a form of punishment for saying bad things. For example, if a child says things she should not say to her parents, she might be described as a mouthy child. The parents might even tell the child to stop mouthing off.

    But enough of all this talk. I have been running my mouth long enough.

    The construction(建设)of high﹣speed railways in China began with the building of the Qinhuangdao﹣Shenyang High﹣Speed Railway（HSR）in 1999.Now the high﹣speed rail network in China is the largest in the world. So far, there have been about 1700 kilometers of HSR in service, along with trains of an average(平均)speed of 220 km/h.

    Now Chinese government plans to spend $300 million building the largest and fastest HSR system in the world by 2020. It's said that the trains can run 400 km/h and create new business for China and other countries through the Belt and Road.(一带一路)

    It's predicted that the HSR network in China will reach 30,000 kilometers and it will be like a grid, which is mainly made up of 8 long﹣distance high﹣speed rail lines:  four north﹣south HSR lines and four east﹣west HSR lines. Except for the Qingdao﹣Taiyuan HSR, all HSR lines of the railgrid are longer than 1,000 kilometers.

    Feng Hao, an expert, says "Many markets along the Belt and Road, especially in Central Asia, Southeast Asia, the Middle East and Eastern European countries, are planning to build HSR lines. They look forward to getting technological support from China".