Modern graffiti began in big cities in the United States in the 1970s. In New York, young people wrote their names, or 'tags', in pen on walls around the city.

    One of the first 'taggers' was a teenager called Demetrius. His tag was TAKI 183. He wrote his tag on walls and in stations in New York. He did it just for fun and he had never imagined his behavior would have launched an amazing art campaign. Other teenagers saw Demetrius's tag and started writing their tags too. Soon, there were tags on walls, buses and trains all over New York.

    Then, some teenagers started writing their tags with aerosol paint. Their tags were bigger and more colourful. Aerosol paint graffiti became very popular in the 1970s and 1980s. It appeared on trains, buses and walls around the world.

    In the 1990s and 2000s, a lot of graffiti artists started painting pictures. Some artists' pictures were about politics. Other artists wanted to make cities beautiful and painted big, colorful pictures on city walls.

    In some countries, writing or painting on walls is a crime. Sometimes, graffiti artists have problems with the police. In other countries, artists can draw and paint in certain places. For example, in Taiwan, there are 'graffiti zones' where artists can paint on walls. In São Paulo in Brazil, street artists can paint pictures on walls and houses. Their pictures are colorful and beautiful. Some tourists visit São Paulo just to see the street art!

    In Bristol in the UK, there is a street art festival in August every year. Artists paint all the buildings in a street. Lots of people come to watch the artists and take photos. You can see exhibitions of street art in some galleries too. There have been exhibitions of street art in galleries in Paris, London and Los Angeles.

    Businesses are witnessing a difficult time, which has in turn produced influence on consumers, desire to go green. However, shoppers are still laying stress on environmental concerns.

    Two thirds of customers say that environmental considerations inform their purchases to the same degree as they did a year ago, while more than a quarter say that they are now even better aware of the environmental effect on what they buy.

    This may help to influence how shops store goods on their shelves. And the companies should still make efforts to become more environmentally friendly. Two out of three people think it is important to buy from environmentally responsible companies, with about one in seven saying that they had even decided to take their custom elsewhere if they felt a company's environmental reputation was not good enough.

Harry Morrison, chief executive (主管) of the Carbon Trust, sympathizes: "I understand this situation where survival is very important now. But from environmental considerations, the clock is ticking—we don't have much time. In addition, cutting carbon has an immediate effect as costs drop and a medium-term benefit for the brand."

    Larger companies have an extra motivation to look at reducing their carbon footprint, as new rules next year will require businesses to buy carbon allowances to make up for their emissions (排放). Those that have taken early action will have a head start. More than two thirds of consumers are not clear about which companies are environmentally responsible. This suggests that firms that are able to relay clearly their message to the public will be in a pole position to attract shoppers.

The Carbon Trust believes that it can help by informing customers about the good work companies are doing. "When companies are granted (授予) the standard, they can use a logo (标识) in all their marketing which makes it clear that they are working towards cutting emissions," Mr. Morrison said.

    Many of the world's most well-known people were once successful failures. Here are the stories of a few of them.

    Abraham Lincoln(1809-1865)

    Abraham Lincoln was one of America's greatest leaders, taking the country through the Civil War(from 1860 to 1865). However, his life was never easy. He started numerous businesses that failed. He went bankrupt twice, and was defeated in 26 campaigns for public office. He later said, “My great concern is not whether you have failed, but whether you are content with your failure. ”

    Vincent Van Gogh(1853-1890)

    Van Gogh is one of the most famous and influential painters in the history of Western Art. He's renowned for paintings such as TheStarryNight, ThePotatoEaters and Sunflowers. However, during his lifetime, Van Gogh sold only one painting for a very small amount of money. Despite this, he carried on painting, sometimes even going without food so he could complete his collection of over 800 known works.

    Albert Einstein(1879-1955)

    Albert Einstein won the Noble Prize in Physics in 1921. However, he wasn't always considered as a “genius”. He didn't speak until he was four, and couldn't read until he was seven. His teachers and parents thought he was slow, so he was expelled from school and couldn't get into the Zurich Polytechnic School. He later famously said, “Success is failure in progress. ”

    Stephen King(born 1947)

    Stephen King is one of the best-selling authors of all time, but his first book,  Carrie, was rejected by about 30 publishers. Eventually, Stephen threw it in the bin,  but his wife fished it out and encouraged him to resubmit it, which he did successfully this time!

    There are many places to go on safari in Africa, but riding a horse through the flooded waters of Botswana's Okavango Delta must rank as one of the world's most exciting wildlife journeys.

    Several safari camps operate as the base for this adventure, providing unique rides twice a day to explore deep into the delta. The camps have excellent horses, professional guides and lots of support workers. They have a reputation for providing a great riding experience.

    The morning ride, when the guides take you to beautiful, shallow lakes full of water lilies, tends to be more active. It is unlike any other riding experience. With rainbows forming in the splashing water around you and the sound of huge drops of water bouncing off your body and face. It is truly exciting. You are very likely to come across large wild animals, too. On horseback it is possible to get quite close to elephants, giraffes and many other animals. The sense of excitement and tension levels rise suddenly though, as does your heart rate, as you move closer to them.

    In the evening, rides are usually at a more relaxed and unhurried pace. With golden light streaming across the grassy delta and the animals coming out to eat and drink. Sedate though they are, rides at this time of day are still very impressive. As the sun's rays pass through the dust kicked up by the horses, the romance of Africa comes to life.

    Back at the camp you can kick off your boots and enjoy excellent food and wine. Looking back on your day, you will find it hard to deny that a horseback Safari is as close as you will ever come to answering the call of the wild.

    One morning more than thirty years ago, I entered the Track Kitchen, a restaurant where everyone from the humblest(卑微的) to the most powerful came for breakfast. I noticed an empty chair next to an elderly, unshaven man, who looked somewhat disheveled. He was wearing a worn-out hat and was alone. I asked if I might join him. He agreed quietly and I sat down to have my breakfast.

    We cautiously began a conversation and spoke about a wide range of things. We never introduced ourselves. I was concerned that he might have no money and not be able to afford something to eat. So as I rose to go back to the counter and buy a second cup of coffee, I asked,

    “May I get you something?”

    “A coffee would be nice.”

    Then I bought him a cup of coffee. We talked more, and he accepted another cup of coffee, Finally, I rose to leave, wished him well, and headed for the exit. At the door I met one of my friends. He asked,

    “How did you get to know Mr. Galbreath?”

    “Who?”

    “The man you were sitting with. He is chairman of the Board of Churchill Downs.”

    I could hardly believe it. I was buying, offering a free breakfast, and feeling pity for one of the world's richest and most powerful men!

    My few minutes with Mr. Galbreath changed my life. Now I try to treat everyone with respect, no matter who I think they are, and no matter another human being with kindness and sincerity.

    I was in the middle of the Amazon (亚马逊) with my wife, who was there as a medical researcher. We flew on a small plane to a faraway village. We did not speak the local language, did not know the customs, and more often than not, did not entirely recognize the food. We could not have felt more foreign.

    We were raised on books and computers, highways and cell phones, but now we were living in a village without running water or electricity It was easy for us to go to sleep at the end of the day feeling a little misunderstood.

    Then one perfect Amazonian evening, with monkeys calling from beyond the village green, we played soccer. I am not good at soccer, but that evening it was wonderful. Everyone knew the rules. We all spoke the same language of passes and shots. We understood one another perfectly. As darkness came over the field and the match ended, the goal keeper, Juan, walked over to me and said in a matter-of-fact way, "In your home, do you have a moon too?" I was surprised.

    After I explained to Juan that yes, we did have a moon and yes, it was very similar to his, I felt a sort of awe (敬畏) at the possibilities that existed in his world. In Juan's world, each village could have its own moon. In Juan's world. the unknown and undiscovered was vast and marvelous. Anything was possible.

    In our society, we know that Earth has only one moon. We have looked at our planet from every angle and found all of the wildest things left to find. I can, from my computer at home, pull up satellite images of Juan's village. There are no more continents and no more moons to search for, little left to discover. At least it seems that way.

    Yet, as I thought about Juan's question, I was not sure how much more we could really rule out. I am, in part, an ant biologist, so my thoughts turned to what we know about insect life and I knew that much in the world of insects remains unknown. How much, though? How ignorant (无知的) are we? The question of what we know and do not know constantly bothered me.

    I began collecting newspaper articles about new species, new monkey, new spider…, and on and on they appear. My drawer quickly filled. I began a second drawer for more general discoveries: new cave system discovered with dozens of nameless species, four hundred species of bacteria found in the human stomach. The second drawer began to fill and as it did I wondered whether there were bigger discoveries out there, not just species, but life that depends on things thought to be useless, life even without DNA. I started a third drawer for these big discoveries. It fills more slowly, but all the same, it fills.

    In looking into the stories of biological discovery, I also began to find something else, a collection of scientists, usually brilliant occasionally half-mad, who made the discoveries. Those scientists very often see the same things that other scientists see, but they pay more attention to them, and they focus on them to the point of exhaustion (穷尽), and at the risk of the ridicule of their peers. In looking for the stories of discovery, I found the stories of these people and how their lives changed our view of the world.

    We are repeatedly willing to imagine we have found most of what is left to discover. We used to think that insects were the smallest organisms (生物), and that nothing lived deeper than six hundred meters. Yet, when something new turns up, more often than not, we do not even know its name.