【正文】 from “black carbon”the anic particles from camp fires and charred (燒成炭的 ) wood left over from thousands of years of slashandburn farming. ”The soils, known as Terra Preta, contained up to 70times more black carbon than the surrounding soil, ”says Glaser. Unburnt vegetation rots quickly, but black carbon persists in the soil for many centuries. Radiocarbon dating shows that the charred wood in Terra Preta soils is typically more than 1,000 years old. “Slashandburn farming can be good for soils provided it doesn’t pletely burn all the vegetation, and leaves behind charred wood,” says Glaser. “It can be better than manure (糞肥 ).” Burning the forest just once can leave behind enough black carbon to keep the soil fertile for thousands of years. And rainforests easily regrow after smallscale clearing. Contrary to the conventional view that human activities damage the environment, Glaser says: ”Black carbon bined with human wastes is responsible for the richness of Terra Preta soils.” Terra Preta soils turn up in large patches all over the Amazon, where they are highly prized by farmers. All the patches fall within 500 square kilometers in the central Amazon. Glaser says the widespread presence of pottery (陶器 ) confirms the soil’s human origins. The findings add weight to the theory that large areas of the Amazon have recovered so well from past periods of agricultural use that the regrowth has been mistaken by generations of biologists for “virgin” forest. During the past decade, researchers have discovered hundreds of large earth works deep in the jungle. They are up to 20 meters high and cover up to a square kilometer. Glaser claims that these earth works, built between AD 400 and 1400, were at the heart of urban civilizations. Now it seems the richness of the Terra Preta soils may explain how such civilizations managed to feed themselves. 11. We learn from the passage that the traditional view of slashandburn farming is that . A) it does no harm to the topsoil of the rainforest B) it destroys rainforest soils C) it helps improve rainforest soils D) it diminishes the anic matter in rainforest soils 12. Most rainforest soils are thin and poor because . A) the position of the topsoil is rather unstable B) black carbon is washed away by heavy rains C) anic matter is quickly lost due to heat and rain D) longterm farming has exhausted the ingredients essential to plant growth 13. Glaser made his discovery by . A) studying patches of fertile soils in the central Amazon B) examining pottery left over by ancient civilizations C) testburning patches of trees in the central Amazon D) radiocarbondating ingredients contained in forest soils 14. What does Glaser say about the regrowth of rainforests? A) They take centuries to regrow after being burnt. B) They cannot recover unless the vegetation is burnt pletely. C) Their regrowth will be hampered by human habitation. D) They can recover easily after slashandburn farming. 15. From the passage it can be inferred that . A) human activities will do grave damage to rainforests B) Amazon rainforest soils used to be the richest in the world C) farming is responsible for the destruction of the Amazon rainforests D) there once existed an urban civilization in the Amazon rainforests Passage Two Questions 16 to 20 are based on the following passage. As a wise man once said, we are all ultimately alone. But an increasing number of Europeans are choosing to be so at an ever earlier age. This isn’t the stuff of gloomy philosophical contemplations, but a fact of Europe’s new economic landscape, embraced by sociologists, realestate developers and ad executives alike. The shift away from family life to solo lifestyle, observes a French sociologist, is part of the “irresistible momentum of individualism” over the last century. The munications revolution, the shift from a business culture of stability to one of mobility and the mass entry of women into the workforce have greatly wreaked havoc on(擾亂 ) Europeans’ private lives. Europe’s new economic climate has largely fostered the trend toward independence. The current generation of homealoners came of age during Europe’s shift from social democracy to the sharper, more individualistic climate of American style capitalism. Raised in an era of privatization and increased consumer choice, today’s techsavvy(精通技術(shù)的 ) workers have embraced a free market in love as well as economics. Modern Europeans are rich enough to afford to live alone, and temperamentally independent enough to want to do so. Once upon a time, people who lived alone tended to be those on either side of marriagetwentysomething professionals or widowed senior citizens. While pensioners, particularly elderly women, make up a large proportion of those living alone, the newest crop of singles are high earners in their 30s and 40s who increasingly view living alone as a lifestyle choice. Living alone was conceived to be negativedark and cold, while being together suggested warmth and light. But then came along the idea of singles. They were young, beautiful, strong! Now, young people want to live alone. The booming economy means people are working harder than ever. And that doesn’t leave much room for relationships. Pimpi Arroyo, a 35yearold poser who lives alone in a house in Paris, says he hasn’t got time to get lonely because he has too much work. “I have deadlines which would make life with someone else fairly difficult.” Only an Ideal Woman would make him change his lifestyle, he says. Kaufmann, author of a recent book called “The Single Woman and Prince Charming,” thinks this fierce new individualism means that people expect more and more of mates, so relationships don’t last longif they start at all. Eppendorf, a blond Berliner with a deep tan, teaches grade