Experiments under way in several labs aim to create beneficial types of genetically modified foods, including starchier potatoes and caffeine-free coffee beans. Genetic engineers are even trying to transfer genes from a cold-winter fish to make a frost-resistant tomato.

    A low-sugar GM strawberry now in the works might one day allow people with health problems such as diabetes (糖尿病) to enjoy the little delicious red fruits again. GM beans and grains rich in protein(蛋白质) might help people at risk of developing kwashiorkor. Kwashiorkor, a disease caused by severe lack of protein, is common in parts of the world where there are severe food shortages.

    Commenting on GM foods, Jonathon Jones, a British researcher, said: "The future benefits will be enormous（巨大的）, and the best is yet to come". To some people, GM foods are no different from unmodified foods. "A tomato is a tomato," said Brian Sansoni, an American food manufacturer.

    Critics of GM foods challenge Sansoni's opinion. They worry about the harm that GM crops might do to people, other animals, and plants.

    In a recent lab study conducted at Cornell University, scientists tested pollen(花粉) made by BT corn, which makes up one-fourth of the U.S. corn crop. The scientist dropped the pollen onto milkweed, a plant that is the only known food source of a butterfly caterpillar(毛虫). Within four days of feeding on the leaves, almost half of a test group of caterpillars died. "This is a warning bell." said Cornell researcher Linda Raynor.

    Some insects that are not killed by GM foods might find themselves made stronger. How so? The insecticides are used on the crops to kill the pests. But GM plants produce a continuous level of insecticide. Insects relying on those crops may develop resistance to the plants and they may also develop a resistance to the insecticide.

    At the forum on GM food held last year in Canada. GM crops that have been made resistant to the herbicide might crossbreed with wild plants, creating "superweeds" that could take over whole fields.

    So where do you stand? Should GM food be banned in the United States, as they are in parts of Europe? Or do their benefits outweigh（胜过） any of the risks they might carry?

    As computers become all the more popular in China, Chinese people are increasingly relying on computer keyboards to input Chinese characters. But if they use the computer too much, they may end up forgetting the exact strokes （笔画）of each Chinese character when writing on paper. Experts suggest people, especially students, write by hand more.

    Do you write by hand more or type more? In Beijing, students start using a computer as early as primary school. And computer dependence is more wide-spread among university students. Almost all their writings are typed on a computer.

    All the students interviewed say they usually use a computer.

    It's faster and easier to correct if using a computer. And that's why computers are being used more and more often to modern education. But when people are taking stock in computers increasingly, problems appear. "When I'm writing with a pen, I find I often can't remember how to write a character, though I feel I'm familiar with it."

    "I'm not in the mood to write when faced with a pen and paper."

    Many students don't feel this is something to worry about. Now that it's more convenient and efficient to write on a computer, why bother to handwrite?

    Many educators think differently. Shi Liwei, the headmaster of a famous primary school in the capital said "Chinese characters enjoy both practical and aesthetic(审美的) value. But those characters typed with computer keyboards only maintain their practical value. All the artistic beauty of the characters is lost. And handwriting contains the writer's emotion. Through one's handwriting, people can get to know one's thinking and personality.

    Beautiful writing will give people a better first impression of them."

    To encourage students to handwrite more, many primary schools in Beijing have made writing classes compulsory(必修的)and in universities, some professors are asking students to turn in their homework and essays written by hand.

    Not many years ago, a wealthy and rather strange old man named Johnson lived alone in a village in the south of England. He had made a lot of money in trading with foreign countries. When he was seventy-five, he gave 12,000$ to the village school to buy land and equipment for a children's playground.

    As a result of his kindness, many people came to visit him. Among them was a newspaperman. During their talk, Johnson said that he was seventy-five and expected to live to be a hundred. The newspaperman asked him how he managed to be healthy at seventy—five. Johnson had a sense of humor. He liked whisky(威士忌)and drank some each day. "I have an injection(注射)in my neck each evening." he told the newspaperman, thinking of his evening glass of whisky. The newspaperman did not understand what Johnson meant. In his newspaper he reported that Johnson was seventy-five and had a daily injection in his neck. Within a week Johnson received thousands of letters from all over Britain asking him for the secret of his daily injection.

    Humans and many other mammals have unusually efficient internal temperature regulating systems that automatically maintain stable core body temperatures in cold winters and warm summers. In addition, people have developed cultural patterns and technologies that help them adjust to extremes of temperature and humidity (湿度).

In very cold climates, there is a constant danger of developing hypothermia, which is a life-threatening drop in core body temperature to below normal levels. The normal temperature for humans is about 37.0℃. However, differences in persons and even the time of day can cause it to be as much as 6℃ higher or lower in healthy individuals. It is also normal for core body temperature to be lower in elderly people. Hypothermia begins to occur when the core body temperature drops to 34.4℃. Below 29.4℃, the body cools more rapidly because its natural temperature regulating system usually fails. The rapid decline in core body temperature is likely to result in death. However, there have been rare cases in which people have been saved after their temperatures had dropped to 13.9-15.6℃. This happened in 1999 to a Swedish woman who was trapped under an ice sheet in freezing water for 80 minutes. She was found unconscious, not breathing, and her heart had stopped beating, yet she was eventually saved despite the fact that her temperature had dropped to 13.7℃.

In extremely hot climates or as a result of uncontrollable infections, core body temperatures can rise to equally dangerous levels. This is hyperthermia. Life-threatening hyperthermia typically starts in humans when their temperatures rise to 40.6-41.7℃. Only a few days at this extraordinarily high temperature level is likely to result in the worsening of internal organs and death.

    "The history of the world is but the biography (传记) of great men," argued Thomas Carlyle, the advocate of what has come to be known as the "Great Man Theory of History." This theory suggests that the broader movements and outline of history all go back to the leadership of great individuals who had unique influence on their times. Whether or not Carlyle's theory proves true is debatable, but that certain individuals cast long shadows is not.

    As one who is entrusted with a leadership position, I find it profitable to read of others who have led. Wherever you find me, you'll likely find a good biography nearby. Why is this the case? First, I find good biographies fascinating. I'll occasionally read a novel, but I've never been overly drawn to fiction. I have found myself unable to sleep while in the struggle of the Battle of Britain in William Manchester's The Last Lion. For me, not to read biographies would rob me of pleasure in my life.

    Second, I find good biographies informative. A good biographer tells not only the story of a person, but also of their times. Reading a good biography is like wandering through an intellectual shopping mall. The first store is what drew you there, but you will be pleasantly surprised along the way at what other items grab your attention. You'll find no better account of the British Empire at its peak than the opening chapters of Manchester's Visions of Glory, volume one of his The Last Lion. Strictly speaking, a biography is but a slice of history.

    Third, I find good biographies relaxing. Winston Churchill once noted a man who works with his hands should have a hobby that engages his mind, and a man who works with his mind should have a hobby that engages his hands. Another way to apply Churchill's saying is to combine technical, pen-in-hand vocational reading with leisurely biographical reading. Indeed, few things are more relaxing to me than winding down the evening and entering into another world.

    This is why I love reading good biographies, and why I pity the person who neglects them. Don't be counted among their number.

    If you feel sick or uncomfortable, you might seek out a doctor. But what to do if you don't quite know where you fit into this world and you're tired of carrying that burden alone?

    I answered strangers' questions on life puzzles at the entrance to the New York City subway at 57th and 8th. A group of strangers had stopped by because they were carrying around some deep, meaningful questions that had long gone unanswered, like "why can't I be happier in my life?"

    And then I spotted her, who would be my toughest questioner of the day. She was about 6 years old and held her mother's hand as she craned (伸长脖子) her neck to stare at us. Her mother stopped, but the girl hesitated. "It's OK," I offered. "Do you have a question?" The girl smiled at her mother, then let go of her hand to walk over towards us. She looked me dead in the eye and said: "How do I know I'm real?"

    Suddenly I was back in graduate school. Should I talk about the French philosopher Rene Descartes to prove our existence, with the phrase "I think, therefore I am?" Or, mention English philosopher G. E. Moore and his famous "here is one hand, here is the other," to prove the existence of the external world? But then the answer came to me. I remembered that the most important part of philosophy was feeding our sense of wonder. "Close your eyes," I said. She did. "Well, did you disappear?" She smiled and shook her head, then opened her eyes. "Congratulations, you're real."

    She grinned (露齿而笑) broadly and walked over to her mother, who looked back at us and smiled.