If humans were truly at home under the light of the moon and stars, we would go in darkness happily, the midnight world as visible to us as it is to the vast number of nocturnal(夜间活动的) species on this planet. Instead, we are diurnal creatures, with eyes adapted to living in the sun's light. This is a basic evolutionary fact, even though most of us don't think of ourselves as diurnal beings. Yet it's the only way to explain what we've done to the night: We've engineered it to  receive us by filling it with light.

    The benefits of this kind of engineering come with consequences 一 called light pollution 一 whose effects scientists are only now beginning to study. Light pollution is largely the result of bad  lighting design, which allows artificial light to shine outward and upward into the sky. III-designed lighting washes out the darkness of night and completely changes the light levels 一 and light  rhythms — to which many forms of life, including, ourselves, have adapted. Wherever human light spills into the natural world, some aspect or life is affected.

    In most cities the sky looks as though it has been emptied of stars, leaving behind a vacant haze(霾) that mirrors our fear of the dark. We've grown so used to this orange haze that the original glory of an unlit nigh, - dark enough for the planet Venus to throw shadow on Earth, is wholly beyond our experience, beyond memory almost.

    We've lit up the night as if it were an unoccupied country, when nothing could be further form the truth. Among mammals alone, the number of nocturnal species is astonishing, Light is a powerful biological force, and on many species it acts as a magnet(磁铁). The effect is so powerful that scientists speak of songbirds and seabirds being “captured” by searchlights on land or by the light from gas flares on marine oil platforms. Migrating at night, birds tend to collide with brightly lit tall buildings.

    Frogs living near brightly lit highways suffer nocturnal light levels that are as much as a million times righter than normal, throwing nearly every aspect of their behavior out of joint including most other creatures ,we do need darkness. Darkness is as essential to our biological welfare, to our internal clockwork, as light itself.

    Living in a glare of our making,we have cut ourselves off from our evolutionary and cultural heritage—the light of the stars and the rhythms of day and night .In a very real sense light pollution causes us to lose sight of our true place in the universe, to forget the scale of our being, which is best measured against the dimensions of a deep night with the Milky Way—the edge of our galaxy arching overhead.

    To develop one's taste in English，the most effective way is to read English books extensively. However, one may be at a loss to choose the appropriate books，especially as a beginner.I would like to share some of my experience.

    My first English novel was Jane Austen's Pride and Prejudice，recommended by many English teachers and professors as an ideal book for English learners. But I had great difficulty in understanding the novel，let alone enjoying it. It's not the vocabulary that troubled me，but rather the way Austen constructs sentences，and her way of thinking，which seemed too remote to me at that time. My fading enthusiasm was much recovered after reading Hemingway's novel Farewell to Arms. I particularly liked his brief and lively style. So my first suggestion is，as a beginner, you'd better choose contemporary novels instead of classical ones.

    However，reading novels is not the only way to improve your English. English essays can at once inform you，entertain you, and improve your taste in English. The best example is Bertrand Russell's work. Its language is plain, yet you cannot help feeling the elegance and the unique sense of humor. His simple language enables his philosophy(哲理) within the reach of ordinary people. Here comes my second suggestion—essays are indispensable.

    Never follow other's opinions blindly，however famous or influential the person might be. As a saying goes，one man's meat is another man's poison. With that in mind，we are sure to find out our favorite writers through reading and develop our fine taste in English.

    “Plants were expected to get larger with increased carbon dioxide in atmosphere, but changes in temperature, humidity and nutrient availability seem to trumped the benefits of increased carbon dioxide,” said researchers from the National University of Singapore.

    45 percent of the species studied now reach smaller adult sizes than they did in the past. The researchers pointed out that warmer temperatures and changing habitats, caused by climate change, are possible reasons for shrinking creatures.

    “We do not yet know the mechanisms involved, or why some organism are getting smaller while others are unaffected,” the researchers said. “Until we understand more, we could be risking negative consequences that we can' t yet quantify.”

    The change was big in cold-blooded animals. Only two decades of warmer temperatures were enough to make reptiles smaller. An increase of 1 degree centigrade caused nearly a 10 percent increase in metabolism(新陈代谢). Greater use of energy resulted in tiny tortoises and little lizards. Fish are smaller now too. Though overfishing has played a part in reducing numbers, experiments show that warmer temperatures also stop fish growth. There is a recent report on warmer temperatures' negative effects on plankton, the base of the marine ecosystem.

    Warm-blooded animals weren't immune from the size change caused by climate change. Many birds are now smaller. Mammals have been miniaturized too. Soay sheep are thinner. Red deer are weaker. And polar bears are smaller, compared with historical records.

    This is not the first time this has happened in Earth' s history. 55 million years ago, a warming event similar to the current climate change caused bees, spiders and ants to shrink by 50 to 75 percent over several thousand years. That event happened over a long time than the current climate change.

    The speed of modem climate change could mean organisms may not respond or adapt quickly enough, especially those with long generation times. So, it is likely that more negative influences of climate change will be shown in future.

    Larry was on another of his underwater expeditions(探险)but this time, it was different. He decided to take his daughter along with him. She was only ten years old. This would be her first trip with her father on what he had always been famous for.

    Larry first began diving when he was his daughter's age. Similarly, his father had taken him along on one of his expeditions. Since then, he had never looked back. Larry started out by renting diving suits from the small diving shop just along the shore. He had hated them. They were either too big or too small. Then, there was the instructor. He gave him a short lesson before allowing him into the water with his father. He had made an exception. Larry would never have been able to go down without at least five hours of theory and another similar number of hours on practical lessons with a guide. Children his age were not even allowed to dive.

    After the first expedition, Larry's later diving adventures only got better and better. There was never a dull moment. In his black and blue suit and with an oxygen tank fastened on his back, Larry dived from boats into the middle of the ocean. Dangerous areas did not prevent him from continuing his search. Sometimes, he was limited to a cage underwater but that did not bother him. At least, he was still able to take photographs of the underwater creatures.

    Larry's first expedition without his father was in the Cayman Islands. There were numerous diving spots in the area and Larry was determined to visit all of them. Fortunately for him, a man offered to take him around the different Spots for free. Larry didn't even know what the time was, how many spots he dived into or how many photographs he had taken. The diving spots afforded such a wide array of fish and sea creatures that Larry saw more than thirty varieties of creatures.

    Larry looked at his daughter. She looked as excited as he had been when he was her age. He hoped she would be able to continue the family tradition. Already, she looked like she was much braver than had been then. This was the key to a successful underwater expedition.

    Elizabeth Blackwell was born in England in 1821, and moved to New York City when she was ten years old. One day she decided that she wanted to become a doctor. Thai was nearly impossible for n woman in the middle of the nineteenth century. After writing many tellers asking for admission (录取) to medical schools, she was finally accepted by a doctor in Philadelphia. She was so determined that she taught school and gave music lessons to get money for the cost of schooling.

    In 1849, after graduation from medical school. She decided to further her education in Paris. She wanted to be a surgeon (外科医生), but a serious eye problem forced her to give up the idea.

    Upon returning to the United States, she found it difficult to start her own practice because she was a woman. By 1857 Elizabeth and her sister, also n doctor, along with another woman doctor, managed to open a new hospital, the first for women and children. Besides being the first woman physician and founding her own hospital, she also set up the first medical school for women.

    Many years ago, there lived a poor fisherman. His only companion was his dog. They might be seen walking on the white sandy beach.

    The dog was always beside his master as the fisherman made his little boat ready to sail. When the man pulled out to sea each morning, the dog would run up on the high ridge (山岭). There he would sit and watch all day. The dog never moved until late afternoon when he saw the little boat return. Then he would race back to the shore to greet his master.

    As the years went by, the fisherman grew older. So did the faithful dog. The fisherman still went out to sea. The dog still watched for his return, sitting on the high ridge.

    One early morning in September, the fisherman was getting his little boat ready. All at once the dog began to bark. He circled around the fisherman and tugged at his trousers. The fisherman could not remember when he had seen his dog act so strangely. He patted the dog's back, thinking the dog wanted to play. But nothing made any difference. Then the man climbed into the boat and sailed away. The dog went to his watching place, still barking.

    There were other fishing boats out that morning. Suddenly the soft wind changed. It began to blow wildly. The fisherman's boat was seized by the wind and whirled around (随风旋转) .The sky darkened. Rain began to fall.

    "It's a hurricane!" said the fisherman." The man thought of his dog at once. Had the dog left the ridge and run home? Or was he still sitting there? The fisherman tried to drive his boat and turn it toward the shore. Suddenly a great wave swept over his head and tossed the boat away (卷走).

    The next morning, the hurricane was over. The families of the other fishermen ran to the shore. They watched for the return of the boats. They waited and waited, but no one returned. Then the people went slowly back to their homes and started a new life. As they rebuilt their village, no one gave a thought to the fisherman's dog.

    Several months later a group of villagers was out gathering sea grapes (海葡萄). They noticed what appeared to be the figure of a dog sitting high on the ridge.

    "Look" said one." Isn't that the old fisherman's dog?"

    "How could it be, after all this time?" said another.

    When the man reached the spot, he found only a rock—a rock shaped like a dog. But as soon as the people looked up again, they saw the stone dog. He just sat there on top of the ridge, waiting, waiting…