【正文】 ed with HIV!AIDS. For the same reason, some AIDS patients cannot find anyone to look after them when they are sick. You can get HIV/AIDS from . There is no evidence of this.選修6 Unit 4 Global warmingReadingTHE EARTH IS BECOMING WARMERBUT DOES IT MATTER? During the 20th century the temperature of the earth rose about one degree Fahrenheit. That probably does not seem much to you or me, but it is a rapid increase when pared to other natural changes. So how has this e about and does it matter? Earth Care’s Sophie Armstrong explores these questions. There is no doubt that the earth is being warmer (see Graph 1) and that it is human activitythat has caused this global warming rather than a random but natural phenomenon. All scientists subscribe to the view that the increase in the earth39。greenhouse effect39。greenhouse effect39。t predict the climate well enough to know what to expect, but it could be very serious. Others who agree with her think there may be a rise of several metres in the sea level, or predict severe storms, floods, droughts, famines, the spread of diseases and the disappearance of species. On the other hand, there are those, like George Hambley, who are opposed to this view, believe that we should not worry about high levels of carbon dioxide in the air. They predict that any warming will be mild with few bad environmental consequences. In fact, Hambley states, More carbon dioxide is actually a positive thing. It will make plants grow quicker。 it will encourage a greater range of animals all of which will make life for human beings better. Greenhouse gases continue to build up in the atmosphere. Even if we start reducing the amount of carbon dioxide and other greenhouse gases, the climate is going to keep on warming for decades or centuries. No one knows the effects of global warming. Does that mean we should do nothing? Or, are the risks too great?WHAT CAN WE DO ABOUT GLOBAL WARMING?Dear Earth Care,I am doing a project on behalf of my school about global warming. Sometimes I feel that individuals can have little effect on such huge environmental problems. However, 1 still think people should advocate improvements in the way we use energy today. As I39。t mind because danger excites me and makes me feel alive. However, the most important thing about my job is that I help protect ordinary people from one of the most powerful forces on earth the volcano. I was appointed as a volcanologist working for the Hawaiian Volcano Observatory (HVO) twenty years ago. My job is collecting information for a database about Mount Kilauea, which is one of the most active volcanoes in Hawaii. Having collected and evaluated the information, I help other scientists to predict where lava from the volcano will flow next and how fast. Our work has saved many lives because people in the path of the lava can be warned to leave their houses. Unfortunately, we cannot move their homes out of the way, and many houses have been covered with lava or burned to the ground. When boiling rock erupts from a volcano and crashes back to earth, it causes less damage than you might imagine. This is because no one lives near the top of Mount Kilauea, where the rocks fall. The lava that flows slowly like a wave down the mountain causes far more damage because it buries everything in its path under the molten rock. However, the eruption itself is really exciting to watch and I shall never forget my first sight of one. It was in the second week after I arrived in Hawaii. Having worked hard all day, I went to bed early. I was fast asleep when suddenly my bed began shaking and I heard a strange sound, like a railway train passing my window. Having experienced quite a few earthquakes in Hawaii already, I didn39。s largest nature reserve and it is kept in its natural state for the people of China and visitors from all over the world to enjoy. The height of the land varies from 700 metres above sea level to over 2,000 metres and is home to a great diversity of rare plants and animals. Among the rare animals are cranes, black bears, leopards and tigers. Many people e to Changbaishan to study its unique plants and animals. Others e to walk in the mountains, to see the spectacular waterfalls or to bathe in the hot water pools. However, the attraction that arouses the greatest appreciation in the reserve is Tianchi or the Lake of Heaven. Tianchi is a deep lake that has formed in the crater of a dead volcano on top of the mountain. The lake is 2,194 metres above sea level, and more than 200 metres deep. In winter the surface freezes over. It takes about an hour to climb from the end of the road to the top of the mountain. When you arrive you are rewarded not only with the sight of its clear waters, but also by the view of the other sixteen mountain peaks that surround Tianchi. There are many stories told about Tianchi. The most wellknown concerns three young women from heaven. They were bathing in Tainchi when a bird flew above them and dropped a small fruit onto the dress of the youngest girl. When she picked up the fruit to smell it, it flew into her swallowed the fruit, the girl became pregnant and later gave birth to a handsome boy. It is said that this boy, who had a great gift for languages and persuasion, is the father of the Manchu people. If you are lucky enough to visit the Lake of Heaven with your loved one, don3