It is said that if you want to stay young, sit down and have a good think. This is the research finding of a team of Japanese doctors, who say that most of our brains are not getting enough exercise — and as a result, we are growing old unnecessarily soon.

    Professor Taiju Matsuzawa wanted to find out why otherwise healthy farmers in northern Japan appeared to be losing their ability to think and reason at a relatively early age, and how the process of aging could be slowed down. With a team of colleagues at Tokyo National University, he set about measuring brain volumes of a thousand people of different ages and varying occupations. Computer technology enabled the researchers to obtain precise measurements of the volume of the front and side parts of the brain, which controls functions like eating and breathing, does not contract with age, and one can continue living without intellectual on economical faculties. Contraction of front and side parts — as cells die off — was observed in some subjects in their thirties, but it was still not evident in some sixty-and seventy-year-olds. Matsuzawa concluded from his tests that there is a simple way to the contraction normally connected with age — using the head.

    The findings show in general terms that contraction of the brain begins sooner in people in the country than in the town. Those least at risk, says Matsuzawa, are lawyers, followed by university professors and doctors. White collar workers doing routine work in government offices are, however, as likely to have shrinking (萎缩) brains as the farm worker, bus driver and shop assistant.

    Matsuzawa's findings show that thinking can prevent the brain from shrinking. Blood must circulate properly in the head to supply the fresh oxygen the brain cells need. “The best way to maintain, good blood circulation is through using the brain.” he says. “Think hard and engage in conversation. Don't rely on pocket calculators.”

根据短文内容，选择最佳答案，并将选定答案的字母标号填在题前括号内。

    Did you know that the color of uniforms can influence the performance of an athlete? It may sound strange, but a study suggests this might be true.

    Two British scientists studied the results of four sports in the 2004 Athens Olympic Games where the athletes had been given either a red or a blue uniform. They discovered that when there was a big difference in the score, color had no influence on the result. But if it was a close match, the athlete in a red uniform was more likely to win. Then they looked at the uniforms of the soccer teams at the Euro 2004 tournament. Again, teams wearing red won more games.

    The two scientists got their idea from earlier studies of wild animals. It had been discovered that when a male show red on its body, it sends a signal of its power and strength. For example, in many kinds of monkey, the more the male shows off its red scare, the more females it can attract

    Based on this fact, the British scientists thought that the idea might work for humans, too. According to them, when an athlete sees a competitor in a red uniform, he gets a feeling that his competitor could be stronger than him. And that kind of feeling may have a bad influence on the player's performance in the actual game.

    Although the idea is Interesting, most people don't accept that color signals in the animals world can really be useful to humans in sports. They think that it is unreasonable to develop an Idea based on such a small number of examples. Much more research has to be done to prove the influence of uniform colors on the performance of athletes.

    It is popular to travel by bike in China. China has a huge population. And it is said that there is at least one bike for every two people. Of course, many people in China ride bikes for sport or exercise, but it is also a much more commonly accepted means of everyday transportation, as compared to countries such as the United States.

    If you are living for a long time in China, chances are that you will want to buy your own bike so that you can use it whenever you want. Even if you don't use a bike for everyday transportation, owning one can be a great way to enjoy the sights in the countryside. However, if you are just visiting China, renting a bike can be a more convenient choice.

    It is important to choose the correct bike for your use. You will find that in China, the one-speed style of bike is popular. These bikes are great if you want to ride around in the city to see the sights. They are quite comfortable and easy to ride. You can often rent a bike for a day for about 15 dollars.

    However, if you wish to ride on some of the rural paths, a mountain bike style would be a better choice. They are great for different kinds of road surfaces, providing for a safer ride. If you are planning to have a wish to tour and still be able to carry packages with you, then a touring bike would be the best choice. These are the most expensive to rent, but are very suitable for carrying packages and even some of your luggage along with you.

    Language is always changing. In a society where life continues year after year with few changes, the language does not change either. The earliest known languages had difficult grammar but a small, limited vocabulary. Over the century, the grammar changed, and the vocabulary grew. For example, the English and Spanish people who came to America during the sixteenth century gave names to all the new plants and animals they found. In this way, hundreds of new words were introduced into English and Spanish vocabularies. Today life is changing very fast, and language is changing fast too.

     There are several major(主要) language families in the world. Some scientists say there are nine main families, but other scientists divide them differently. The languages in each family are connected, and scientists think that they came from the same parent language. About 3 percent of the people in the world speak languages that are not in these major families.

    Last year, I worked in a middle school near my mother's house, and I stayed with her for a month. During that time, I helped her do some housework and buy some food.

    After the first week, I noticed that the food was eaten up very quickly. Then I began keeping an eye on my mum. To my surprise, I found that she would put some of the food into a paper bag and go out with it at about nine every morning. And finally, I decided to follow her. I saw her taking the food to the street children. She would also spend a lot of time talking and playing with them.

One day, I talked to a neighbor and found out that my mum was well-known in the area. The children were very friendly with her and even thought of her as their own mother. Then it hit me —why wouldn't she want to tell me about it? Was she worried that I would stop buying food if I found out?

    When my mum got home, I gave her a big hug. I told her she didn't need to keep it a secret from me. She told me something about the children. Some of them lived with an old lady in a small house. Others slept on the street. For years, she was helping the poor street children by giving them food. After she told me everything, I was so moved by how selfless she was. She helped others in need. As her son, I was so proud of my mum.

    I continued to buy food for my mum after that. But I always added one more bag for her other children.

    If you're a yoga lover, you've probably noticed the ways yoga works — you're sleeping better, getting fewer colds or just feeling more relaxed and at ease. But if you've ever tried telling a beginner how it works, you might find explanations like "It increases the flow of prana" or "It brings energy up your spine" fall on skeptical ears.

    As it happens, Western science is starting to provide some concrete clues about how yoga works to improve health, heal aches and pains, and prevent sicknesses. Once you understand them, you'll have even more motivation to step onto your mat.

    I myself have experienced yoga's healing power in a very real way. Weeks before a trip to India in 2002 to investigate yoga therapy, I developed numbness and tingling (刺痛) in my right hand. After first considering scary things like a brain tumor and multiple sclerosis, I figured out that the cause of the symptoms was thoracic outlet syndrome, a nerve blockage in my neck and chest.

    Despite the uncomfortable symptoms, I realized how useful my condition could be during my trip. While visiting various yoga therapy centers, I would submit myself for evaluation and treatment by the various experts, try their suggestions and see what worked for me.

    Thanks to the techniques I learned in India, advice from teachers in the United States, and my own exploration, my chest is more flexible than it was, my posture has improved, and for more than a year, I've been free of symptoms.

    My experience inspired me to dig into the scientific studies that I'd collected in India as well as the West to identify and explain how yoga can both prevent disease and help you recover from it.