【正文】 or their system.Next, they had to decide on a natural length. They chose one tenmillionth (1/ 10,000,000) of the distance from the equator to the North Pole. They called this distance the meter. Then they chose the gram for weighing things. A cubic centimeter of water weighs 1 gram.Mathematicians and scientists worked for 20 years until they finally had a plete measuring system. The biggest problem was measuring the meter.The metric system was a wonderful gift to the world. There are only a few countries that don39。s races are similar except that the women do not kick a ball. They throw a wooden hoop in front of them with a stick. A hoop is a ring, or a circle.The Tarahumara play other games and sports. However, they are famous because they can run so fast and so far. (185 words)9 Olympic SportsThe first modern Olympic Games took place in Athens, Greece, in the year 1896.Athletes from only 13 countries participated in the Games that year. They peted in 43 different events in just 9 sports (track and field, swimming, cycling, fencing, gymnastics, shooting, tennis, weight lifting, and wrestling). In 2004, the summer Olympic Games took place once again in Athens, Greece. This time athletes from 202 countries peted in 300 events in 28 sports.Only five sports have been in every Olympic Games. They are track and field, swimming, fencing, cycling, and gymnastics. Other sports e and go in the Olympic Games. For example, tennis was an Olympic sport from 1896 until 1924.Then it disappeared from the Olympics until 1988. Baseball, badminton, and taekwondo are more recent additions to the Olympic Games.It is the job of the International Olympic Committee (IOC) to add and remove sports from the Olympic Games. A sport has to be popular in at least 50 countries on three continents before it can be added. However, the IOC doesn39。s true that many are. However, it39。t win just one gold medal. She won three. At the time, people called her the fastest woman in the world. As a young child, Wilma Rudolph could not participate in sports. She had a series of serious illnesses, and then, at the age of 4, she got polio. She lost the use of her left leg, and the doctors said she would never walk again.The people in Rudolph39。t want to get sick. However, there is one food that can be deadly, yet some people eat it on purpose. It39。s menu. Customers feel great after the meal. That39。s experiences with foreign food.Shao Wong is a student in France. He es from China. I never had cheese or even milk before I came to France. Cattle are rare in my part of China, so there are no dairy products. I drank some milk when I first arrived in France. I hated it ! I tried cheese, too, but I didn39。s made from milk. Birgit is from Sweden. She traveled to Australia on vacation. I was in a restaurant that specialized in fish, and I heard some other customers order flake. So I ordered some, too, and it was delicious. Later, I found out that flake is an Australian term for shark. Now, whenever I see a new food, I try it on purpose. You know why? I remember how much I enjoyed flake.Chandra is a dentist in Texas. She is from India. I39。m a Hindu, and my religion forbids me to eat meat from the cow. That39。t eat hamburgers or spaghetti with meatballs.Nathan is from the United States. He taught for a year in China. My friends gave me some 100yearold eggs to eat. I didn39。t really very old. Even so, I didn39。s an ingredient in the main course of a meal. Mexicans make a hot chocolate sauce called mole and pour it over chicken. The Mexicans also eat chocolate with spices like chili peppers.Chocolate is a product of the tropical cacao tree. Cacao beans taste so bitter that even monkeys say ugh! and run away. The word chocolate es from a Mayan word. The Mayas were an ancient people who once lived in Mexico. They valued the cacao tree. Some of the Mayas used cacao beans for money, while others ground them to make a bitter drink.When the Spaniards came to Mexico in the 16th century, they started drinking cacao, too. Because the drink was strong and bitter, they thought it was a medicine.When the Spaniards took the drink back to Europe, people discovered that sugar removed the bitter taste of cacao. Wealthy Spaniards heated the sweet drink and thought that it was good for their health.In the 19th century, an English pany made the first solid block of sweetened chocolate. Now people could both drink and eat chocolate. Later, a Swiss pany mixed milk and chocolate together. People liked the taste of milk chocolate even better.Besides the chocolate candy bar, one of the most popular American snacks is the chocolatechip cookie. Favorite desserts are chocolate cream pie and, of course, an ice cream sundae with hot fudge sauce.(280 words)14 The Blue RevolutionThe population of the world is increasing rapidly. By 2020, there could be people on earth. Will there be enough food for all these people, or will we have a food shortage? Some scientists think fish farming could solve this problem. However, other scientists worry that fish farming could cause serious environmental problems.Fish farming is not a new thing. There were fish farms in China 3,000 years ago. Today, about onethird of the fish we eat es from fish farms.Most fish farms raise planteating fish. Popular kinds of planteating fish are carp, tilapia, and catfish. Unfortunately, many fish farms are starting to raise meateating fish. A popular type of meateating fish is salmon. These meateating fish live on processed food made from wild fish. However, it takes up to 5 tons of wild fish to produce just 1 ton of farmraised salmon. The supply of wild fish is already decreasing. Eventually, many types of wild fish could bee extinct. What will we do then?Critics of fish farming also say that farmraised fish is unhealthy for humans. They say the fish contains dangerous chemicals. They also criticize fish farming because it pollutes the water. Another