【正文】 ourse, they hit with their hands, too.Each round is three minutes long. Then the boxers have a twominute rest. Most boxers can fight only five rounds because this kind of fighting is very difficult.Thai boxing began over 500 years ago. If a soldier lost his weapons in a battle, he needed to fight with just his body. The soldiers learned how to use all the parts of their bodies. In 1560, the Burmese army captured Naresuen, the King of Thailand, in a war. King Naresuen was a very good boxer. He won his freedom from Burma by defeating all the best Burmese fighters. When he returned to Thailand, his people were very proud of him. Thai boxing became a popular sport.(237 words)7 Sumo WrestlingSumo wrestling is a national sport in Japan. Every year there are six tournaments, and millions of Japanese watch them on television. A tournament is a series of matches.Sumo is almost as old as the nation of Japan itself. Stories say that there was sumo wrestling over 2,000 years ago. There are written records of national sumo tournaments in the 8th century.In many sports, athletes are thin and can move very quickly. However, sumo wrestlers weigh from 100 to 160 kilos (kilograms). One famous wrestler weighed 195kilos. Sumo wrestlers do not move quickly, and sumo wrestling is a very slow sport.Sumo wrestlers start training when they are boys. They exercise to make their bodies strong. They also eat a lot.They wrestle in a round ring with a sand floor. A wrestler loses the match if he leaves the ring. He is also the loser if any part of his body except his feet touches the floor. Each wrestler tries to push the other down on the floor or out of the ring.Sometimes one wrestler just steps aside when the other wrestler rushes toward him.Then, the wrestler who is rushing falls down or moves out of the ring.Sumo is not very popular in other countries, but the Japanese think that it is a very exciting sport.(223 words)8 Tarahumara Foot RacesThe Tarahumara live in the mountains in the state of Chihuahua in northern Mexico. This is an area of high mountains and deep tropical valleys. It sometimes snows in the mountains in winter. There are not many roads.The Tarahumara walk wherever they need to go. They carry heavy baskets on their backs. Perhaps this is why the Tarahumara can run many kilometers without getting tired. They are excellent runners, and they like to organize races.When the men race, they kick a wooden ball ahead of them while they run. Before they start racing, they plan where and how long they will run. They might run just a few minutes, or they might run for several hours. Sometimes they run in teams, and sometimes each person runs as an individual.The women39。t popular, and people continued to write with pens. They used bird feathers as pens.Then, in 1795, someone started making pencils from graphite, and they became very popular. Graphite is like coal. (Coal is black, and we burn it for heat and energy.) Today, people make pencils in the same way. They grind the graphite, make it into the shape of a stick, and bake it. Then they put it inside a piece of wood. One pencil can write 50,000 English words or make a line 55 kilometers long.People wrote with feather pens and then used pens with metal points. They had to dip the point into ink after every few letters. Next, someone invented a fountain pen that could hold ink inside it. A fountain pen can write several pages before you have to fill it again.Two Hungarian brothers, Ladislao and Georg Biro, invented the ballpoint pen.They left Hungary and started making ballpoint pens in England in 1943, during World War II. English pilots liked the pens. They couldn39。t stay closed very well. This was embarrassing, and people didn39。 Notions01 The Zipper02 The Postage Stamp03 Pencils and Pens04 The Umbrella05 The Metric System06 Thai Boxing07 Sumo Wrestling08 Tarahumara Foot Races09 Olympic Sports10 Great athletes11 The Puffer Fish12 Foods from Around the World13 Chocolate14 The Blue Revolution15 TwentyOne Days Without Food16 The Marie Celeste17 The Roanoke Settlement18 The Easter Island Statues19 The Tunguska Fireball20 Mystery of the Monarchs21 The History of Money22 Mass Marketing23 Inflation24 Doing Business Around the World25 Credit Cards1 The ZipperThe zipper is a wonderful invention. How did people ever live without zippers?They are very mon, so we forget that they are wonderful. They are very strong, but they open and close very easily. They e in many colors and sizes.In the 1890s, people in the United States wore high shoes with a long row of buttons. Clothes often had rows of buttons, too. People wished that clothes were easier to put on and take off.Whitb L. Judson, an engineer from the United States, invented the zipper in 1893. However, his zippers didn39。t have to pay anything. The postage was prepaid.Postage stamps became popular in Great Britain immediately. Other countries started making their own postage stamps very quickly.There were still problems with international mail. Some countries did not want to accept letters with stamps from other countries. Finally, in 1874, a German organized the Universal Postal Union (UPU). Each country in the UPU agreed to accept letters with prepaid postage from the other members. Today, the offices of the UPU are in Switzerland. Almost every country in the world is a member of this organization. It takes care of any international mail problems.Today, post offices in every country sell beautiful stamps. Collecting stamps is one of the most popular hobbies in the world, and every stamp collector knows about the Penny Black and the Twopence Blue.(250 words)3 Pencils and PensNo one knows who invented pencils or when it happened. A Swiss described a pencil in a book in 1565. He said it was a piece of wood with lead inside it. (Lead is a very heavy, soft, dark gray metal.) Pencils weren39。t use them. They