No one knows for sure when advertising first started. It is possible that it grew out of the discovery that some people did certain kinds of work better than others did them. That led to the concept of specialization, which means that people would specialize, or focus, on doing one specific job.

    Let's take a man we'll call Mr. Fielder, for example. He did everything connected with farming. He planted seeds, tended the fields, and harvested and sold his crops. At the same time, he did many other jobs on the farm. However, he didn't make the bricks for his house, grind the wheat for his flour, or cut his trees into boards. He also did not make the plows(犁), the work boots, or any of the other hundreds of things a farm needs. Instead, he got them from people who specialized in doing each of those things.

    Suppose there was another man we shall call Mr. Plowright. Using what he knew about farming and working with iron, Mr. Plowright invented a plow that made farming easier. Mr. Plowright did not really like farming himself and wanted to specialize in making really good  plows. Perhaps, he thought, other farmers will trade what they grow for one of my plows.

    How did Mr. Plowright let people know what he was doing? Why, he advertised, of course. First he opened a shop and then he put up a sign outside the shop to attract customers. That sign may have been no more than a plow carved into a piece of wood and a simple arrow pointing to the shop door. It was probably all the information people needed to find Mr. Plowright and his really good plows.

    Many historians believe that the first outdoor signs were used about five thousand years ago. Even before most people could read, they understood such signs. Shopkeepers would carve into stone, clay, or wood symbols for the products they had for sale.

    A medium, in advertising talk, is the way you communicate your message. You might say that the first medium used in advertising was signs with symbols. The second medium was audio, or sound, although that term is not used exactly in the way we use it today. Originally, just the human voice and maybe some kind of simple instrument, such as a bell, were used to get people's attention.

    A crier, in the historical sense, is not someone who weeps easily. It is someone, probably a man, with a voice loud enough to be heard over the other noises of a city. In ancient Egypt, shopkeepers might hire such a person to spread the news about their products. Often this primitive form of advertising involved a newly arrived ship loaded with goods. Perhaps the crier described the goods, explained where they came from, and praised their quality. His job was, in other words, not too different from a TV or radio commercial in today's world.

    The fence was long and high. He put the brush into the whitewash and moved it along the top of the fence. He repeated the operation. He felt he could not continue and sat down.

    He knew that his friends would arrive soon with all kinds of interesting plans for the day.

    They would walk past him and laugh. They would make jokes about his having to work on a beautiful summer Saturday. The thought burned him like fire.

    He put his hand into his pockets and took out all that he owned. Perhaps he could find some way to pay someone to do the whitewashing for him. But there was nothing of value in his pockets—nothing that could buy even half an hour of freedom. So he put the bits of toys back into his pockets and gave up the idea.

    At this dark and hopeless moment, a wonderful idea came to him. It filled his mind with a great, bright light. Calmly he picked up the brush and started again to whitewash.

    While Tom was working, Ben Rogers appeared. Ben was eating an apple as he walked along the street. As he walked along it, he was making noises like the sound of a riverboat. First he shouted loudly, like a boat captain. Then he said “Ding－Dong－Dong”,“Ding－Dong－Dong” again and again, like the bell of a riverboat. And he made other strange noises. When he came close to Tom, he stopped.

    Tom went on whitewashing. He did not look at Ben. Ben stared a moment and then said: “Hello! I'm going swimming, but you can't go, can you？”

    No answer. Tom moved his brush carefully along the fence and looked at the result with the eye of an artist. Ben came nearer. Tom's mouth watered for the apple, but he kept on working.

    Ben said, “Hello, old fellow, you've got to work, hey？”

    Tom turned suddenly and said, “Why, it's you, Ben! I wasn't noticing.”

     “Say—I'm going swimming. Don't you wish you could? But of course you'd rather work—wouldn't you? Of course you would.”

    Tom looked at the boy a bit, and said, “What do you call work？”

     “Why, isn't that work？”

    Tom went back to his whitewashing, and answered carelessly.

     “Well, maybe it is, and maybe it isn't. All I know is, it suits Tom Sawyer.”

     “Oh come, now, you don't mean to say that you like it？”

    The brush continued to move.

     “Like it? Well, I don't see why I shouldn't like it. Does a boy get a chance to whitewash a fence every day？”

    Ben stopped eating his apple. Tom moved his brush back and forth, stepped back to look at the result, added a touch here and there, and stepped back again. Ben watched every move and got more and more interested. Soon he said，“Say, Tom, let me whitewash a little.”

    Tom thought for a moment, and was about to agree, but he changed his mind.

     “No—no—it won't do, Ben. You see, Aunt Polly wants this fence to be perfect. It has got to be done very carefully. I don't think there is one boy in a thousand, maybe two thousand, that can do it well enough.”

     “No—is that so? Oh come, now—let me just try. Only just a little.”

“Ben, I'd like to, but if it isn't done right, I'm afraid Aunt Polly ”

     “Oh, I'll be careful. Now let me try. Say—I'll give you the core of my apple.”

     “Well, here—No, Ben, now don't. I'm afraid …”

     “I'll give you all of it.”

    Tom gave up the brush with unwillingness on his face, but joy in his heart. And while Ben worked at the fence in the hot sun, Tom sat under a tree, eating the apple, and planning how to get more help. There were enough boys. Each one came to laugh, but remained to whitewash. By the time Ben was tired, Tom sold the next chance to Billy for a kite; and when Billy was tired, Johnny bought it for a dead rat—and so on, hour after hour. And when the middle of the afternoon came, Tom had won many treasures.

    And he had not worked. He had had a nice idle time all the time, with plenty of company, and the fence had been whitewashed three times. If he hadn't run out of whitewash, Tom would have owned everything belonging to his friends.

    He had discovered a great law of human action, namely, that in order to make a man or a boy want a thing, it is only necessary to make the thing difficult to get.

    In the United States, when one becomes rich, he wants people to know it. And even if he does not become very rich, he wants people to think that he is. That is what "keeping up with the Joneses" is about. It is the story of someone who tried to look as rich as his neighbors.

    The expression was first used in 1913 by a young American called Arthur Momand. He told this story about himself. He began earning $ 125 a week at the age of 23. That was a lot of money in those days. He got married and moved with his wife to a very wealthy neighborhood. When he saw that rich people rode horses, Momand went horseback riding every day. When he saw that rich people had servants. Momand and his wife also hired a servant and gave big parties for their new neighbors.

    It was like a race, but one could never finish this race because one was always trying to keep up. The race ended for Momand and his wife when they could no longer pay for their new way of life. They had to move back to an apartment in New York City. Momand looked around him and noticed that many people do things just to keep up with rich lifestyle of their neighbors. He saw the funny side of it and started to write a series of short stories. He called it "Keeping up with the Joneses" because "Jones" is a very common name in the United States. "Keeping up with the Joneses" came to mean keeping up with rich lifestyle of the people around you. Momand's series appeared in different newspapers across the country for over 28 years.

    People never seem to get tired of keeping up with the Joneses. And there are "Joneses" in every city of the world. But one must get tired of trying to keep up with the Joneses because no matter what one does, Mr. Jones always seems to be ahead.

    Some of Australian cyclists have used "GPS art" to turn a 202 km (125 mile) ride into the outline (轮廓) of a goat, which interests many people greatly.

    The four men marked their route on an app before using it track their journey around Perth. When uploaded to the computer, it was shown as a picture. Cyclist Ben Jones said the group settled on a goat because it was an easy animal to draw. He said the ride lasted more than six hours, with the four men stopping only for food, and flat tyres. "Except for riding 202km,' it's relatively simple," Mr. Jones told the BBC. "You mainly mark your route on the app and it plans directions out."

    GPS art has also been widely used by runners and other cyclists when they travel out. Mr. Jones said his group wanted to shake up their normal weekend ride. "We all ride 10, 000km to 15, 000km a year," he said. "Mostly we just ride together as mates and have a good time—that's what this was about."

    The group received much attention after posting their map to social media this week. Others described Mr. Jones as a goat guy in an interview on Australian television. For their next piece of GPS art, the group plans to draw a local animal such as the koala. "Certainly, there'll be something coming, for we are making our decisions to put more and more plans into practice. I'm sure of that," Mr. Jones said.

    Traveling by subway can sometimes be quite an adventure, especially during rush hour. There are the times when you have to avoid cups of coffee that could spill (溅) on you. The smells of some passengers' food are very strong, too. According to the Beijing subway passenger regulations, which went into effect on May 15th, passengers except babies and the sick are no longer allowed to eat or drink on the subway. Violators (违反者) who do not stop after being asked to will be asked to get off. The violation will also be recorded in the violators' credit record.

    Some support the rule. The reason is that the smell of food and drink can annoy other passengers. "The smell of food fills the carriage, causing people discomfort, especially in the hot summer. Besides, eating on the subway produces rubbish. And on subway trains, people often spill their drinks," said Zheng Yiou, 17, a student from Hefei.

    However, others question this rule. "Some citizens live so far from their work places that they have limited time to have breakfast before they go to work. Eating while they travel saves them time and decreases the chance that they will be late for work," He Songlin, a 17­year­old student from Chengdu said, "And some people, like those with low­ blood sugar levels, get sick if they can't eat when they must."

    Other Chinese cities like Nanjing and Chengdu have similar regulations. Some foreign cities also ban eating and drinking on the subway. For example, eating and drinking have long been banned on the subway in Washington DC. Singapore fines people who eat or drink on the subway up to 500 Singapore dollars, which is RMB 2,417 yuan.

    Chen Yanyan, a professor from Beijing University of Technology, believed we should consider the need of some people to eat or drink on the subway. "Commuters (上班族) and travelers are sometimes too busy to eat. Maybe we could learn from Tokyo, where there are many subway stations equipped with services, allowing passengers to eat and drink," she said.

    Compared with solar and wind energy, which are booming, tidal (潮汐的) power is a loser in the clean - energy competition. But if you did want to build a tidal power station, there are few better sites than the mouth of the River Severn, in Britain. Its tidal range, the difference in depth between high and low tides, of around 15 metres is among the largest in the world.

    Engineers and governments have been toying with the idea since at least 1925. But none of the suggested projects has materialised. Price is one objection. A study thought that tidal energy might cost between ￡216 and ￡368 ($306 - 521) per MWh of electricity by 2025, compared with ￡58 - 75 for seagoing wind turbines (轮机) and ￡55 - 76 for solar panels. Environmentalists also worry that any plant would change the tides, making life harder for wildlife.

    An engineer called Rod Rainey thinks he has a way around both problems. He plans to replace the conventional turbines of previous plans with a much older technology. Specifically, he plans to span (横跨) the river mouth with a line of water wheels. This is a design that dates back to the early days of the Industrial Revolution. Examples can be found fixed to the sides of old watermills (水磨).

    But there would be nothing old - fashioned about Mr Rainey's wheels. Thirty metres high and sixty wide, they would be made from ordinary steel. Two hundred and fifty of them, along with the supporting structures, would be floated into place and secured to the seabed, creating a line 15km long. Together, they could supply power at an avenge ate of 4GW. That is about as much as two biggish nuclear power stations would manage. Substituting one of the wheels with a set of locks would provide a shipping channel about twice the width of Panama Canal, permitting upstream ports such as Avonmouth and Cardiff to continue operating.