题目内容
Many people consider the wider use of biofuels a promising way of reducing the amount of surplus carbon dioxide (CO2) being pumped into the air by the world’s mechanized transport. The theory is that plants such as sugar cane, maize (corn, to Americans), oilseed rape and wheat take up CO2 during their growth, so burning fuels made from them should have no net effect on the amount of that gas in the atmosphere.Theory, though, does not always translate into practice, and just as governments have committed themselves to the greater use of biofuels, questions are being raised about how green this form of energy really is. The latest comes from the International Council for Science (ICSU) based in Paris.The ICSU report concludes that, so far, the production of biofuels has aggravated rather than ameliorated global warming. In particular, it supports some controversial findings published in 2007 by Paul Crutzen of the Max Planck Institute for Chemistry in Germany. Dr. Crutzen concluded that most analyses had underestimated the importance to global warming of a gas called nitrous oxide (N2O). The amount of this gas released by farming biofuel crops such as maize and rape probably negates by itself any advantage offered by reduced emissions of CO2.Although N2O is not common in the Earth’s atmosphere, it is a more potent greenhouse gas than CO2 and it hangs around longer. The result is that, over the course of a century, its ability to warm the planet is almost 300 times that of an equivalent mass of CO2.N2O is made by bacteria that live in soil and water and, these days, their raw material is often the nitrogen-rich fertiliser that modern farming requires. Since the 1960s the amount of fertiliser used by farmers has increased sixfold, and not all of that extra nitrogen ends up in their crops. Maize, in particular, is described by experts in the field as a “nitrogen-leaky” plant because it has shallow roots and takes up nitrogen for only a few months of the year. This would make maize (which is one of the main sources of biofuel) a particularly bad contributor to global N2O emissions.But it is not just biofuels that are to blame. The ICSU report suggests N2O emissions in general are probably more important than had been realised. Previous studies, including those by the International Panel on Climate Change (IPCC), a United Nations-appointed body of experts, may have miscalculated their significance — and according to Adrian Williams of Cranfield University, in Britain, even the IPCC’s approach suggests that the global-warming potential of most of Britain’s annual crops is dominated by N2O emissions. It can be inferred from the third paragraph that（）
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Jim always says silly something.
In 1999, the price of oil hovered around $16 a barrel. By 2008, it had (1) the $100 a barrel mark. The reasons for the surge (2) from the dramatic growth of the economies of China and India to widespread (3) in oil-producing regions, including Iraq and Nigeria’s delta region. Triple-digit oil prices have (4) the economic and political map of the world, (5) some old notions of power. Oil-rich nations are enjoying historic gains and opportunities, (6) major importers — including China and India, home to a third of the world’s population — (7) rising economic and social costs.Managing this new order is fast becoming a central (8) of global politics. Countries that need oil are clawing at each other to (9) scarce supplies, and are willing to deal with any government, (10) how unpleasant, to do it.In many poor nations with oil, the profits are being, lost to corruption, (11) these countries of their best hope for development. And oil is fueling enormous investment funds run by foreign governments, (12) some in the west see as a new threat.Countries like Russia, Venezuela and Iran are well supplied with rising oil (13) , a change reflected in newly aggressive foreign policies. But some unexpected countries are reaping benefits, (14) costs, from higher prices. Consider Germany. (15) it imports virtually all its oil, it has prospered from extensive trade with a booming Russia and the Middle East. German exports to Russia (16) 128 percent from 2001 to 2006.In the United States, as already high gas prices rose (17) higher in the spring of 2008, the issue cropped up in the presidential campaign, with Senators McCain and Obama (18) for a federal gas tax holiday during the peak summer driving months. And driving habits began to (19) , as sales of small cars jumped and mass transport systems (20) the country reported a sharp increase in riders. Read the following text. Choose the best word (s) for each numbered blank and mark A, B, C or D on ANSWER SHEET 1.9（）
Many people consider the wider use of biofuels a promising way of reducing the amount of surplus carbon dioxide (CO2) being pumped into the air by the world’s mechanized transport. The theory is that plants such as sugar cane, maize (corn, to Americans), oilseed rape and wheat take up CO2 during their growth, so burning fuels made from them should have no net effect on the amount of that gas in the atmosphere.Theory, though, does not always translate into practice, and just as governments have committed themselves to the greater use of biofuels, questions are being raised about how green this form of energy really is. The latest comes from the International Council for Science (ICSU) based in Paris.The ICSU report concludes that, so far, the production of biofuels has aggravated rather than ameliorated global warming. In particular, it supports some controversial findings published in 2007 by Paul Crutzen of the Max Planck Institute for Chemistry in Germany. Dr. Crutzen concluded that most analyses had underestimated the importance to global warming of a gas called nitrous oxide (N2O). The amount of this gas released by farming biofuel crops such as maize and rape probably negates by itself any advantage offered by reduced emissions of CO2.Although N2O is not common in the Earth’s atmosphere, it is a more potent greenhouse gas than CO2 and it hangs around longer. The result is that, over the course of a century, its ability to warm the planet is almost 300 times that of an equivalent mass of CO2.N2O is made by bacteria that live in soil and water and, these days, their raw material is often the nitrogen-rich fertiliser that modern farming requires. Since the 1960s the amount of fertiliser used by farmers has increased sixfold, and not all of that extra nitrogen ends up in their crops. Maize, in particular, is described by experts in the field as a “nitrogen-leaky” plant because it has shallow roots and takes up nitrogen for only a few months of the year. This would make maize (which is one of the main sources of biofuel) a particularly bad contributor to global N2O emissions.But it is not just biofuels that are to blame. The ICSU report suggests N2O emissions in general are probably more important than had been realised. Previous studies, including those by the International Panel on Climate Change (IPCC), a United Nations-appointed body of experts, may have miscalculated their significance — and according to Adrian Williams of Cranfield University, in Britain, even the IPCC’s approach suggests that the global-warming potential of most of Britain’s annual crops is dominated by N2O emissions. Biofuels are appreciated by governments because（）
In 1999, the price of oil hovered around $16 a barrel. By 2008, it had (1) the $100 a barrel mark. The reasons for the surge (2) from the dramatic growth of the economies of China and India to widespread (3) in oil-producing regions, including Iraq and Nigeria’s delta region. Triple-digit oil prices have (4) the economic and political map of the world, (5) some old notions of power. Oil-rich nations are enjoying historic gains and opportunities, (6) major importers — including China and India, home to a third of the world’s population — (7) rising economic and social costs.Managing this new order is fast becoming a central (8) of global politics. Countries that need oil are clawing at each other to (9) scarce supplies, and are willing to deal with any government, (10) how unpleasant, to do it.In many poor nations with oil, the profits are being, lost to corruption, (11) these countries of their best hope for development. And oil is fueling enormous investment funds run by foreign governments, (12) some in the west see as a new threat.Countries like Russia, Venezuela and Iran are well supplied with rising oil (13) , a change reflected in newly aggressive foreign policies. But some unexpected countries are reaping benefits, (14) costs, from higher prices. Consider Germany. (15) it imports virtually all its oil, it has prospered from extensive trade with a booming Russia and the Middle East. German exports to Russia (16) 128 percent from 2001 to 2006.In the United States, as already high gas prices rose (17) higher in the spring of 2008, the issue cropped up in the presidential campaign, with Senators McCain and Obama (18) for a federal gas tax holiday during the peak summer driving months. And driving habits began to (19) , as sales of small cars jumped and mass transport systems (20) the country reported a sharp increase in riders. Read the following text. Choose the best word (s) for each numbered blank and mark A, B, C or D on ANSWER SHEET 1.11（）
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