摘要：D Farmers in the United States sometimes plant switchgrass as a border crop．But could this tall grass lower the nation’s dependence on foreign oil? The Department of Energy plans to invest hundreds of millions of dollars to help produce fuels from materials that are not part of the food supply．Growing corn, or maize, for fuel has raised concerns about the supply and cost of corn available for food and animal feed． Fuel made from switchgrass or forestry waste like sawdust is known as cellulosic ethanol．Department officials say it contains more energy and produces fewer greenhouse gases than ethanol made from corn．Switchgrass is also easier to grow． Last month, the Proceedings of the National Academy of Sciences published a study of switchgrass grown on low-quality land．Government scientist Ken Vogel was the lead author．The study says the switchgrass produced five times more energy than was needed to grow it．Also, it says switchgrass, over its lifetime from crop to fuel, produces much less carbon compared to gasoline． Fossil fuels like oil take carbon from the ground and release it as waste gas when the fuel is burned．Biofuels like corn and cellulosic ethanol also produce greenhouse gases, through growing crops and making the fuel．The difference is that biofuels remove carbon from the atmosphere through the growth of the feedstock, the material for the fuel． Science magazine just published two studies of biofuels and the heat-trapping gases that scientists link to climate change．One of the reports notes that most studies have found that substituting biofuels for gasoline will reduce greenhouse gases． But it says the earlier studies failed to count the carbon released into the atmosphere as farmers worldwide react to higher prices．They are clearing forests and grasslands to make way for new cropland to replace the grain used for biofuels．Doing so can release much of the carbon stored in the plants and soil, and sacrifice future storage． The study found that corn-based ethanol could increase greenhouse gases for years from land use change．And it found that biofuels from switchgrass, if grown on American corn land, could also increase emissions, though by less． The study team, led by Timothy Searchinger at Princeton University, says the result shows the value of using waste products for fuel．The other report says carbon savings depend on how biofuels are produced． 76．Switchgrass is a better fuel than corn in all the following aspects except ． A．switchgrass grows on low – quality land B．switchgrass produces more energy than corn C．switchgrass produces fewer greenhouse gases than corn D．swiotchgrass is easier to grow 77．It is implied in the underlined sentence that ． A．an increasing number of people worry about the use of corn as fuel B．there will be an increase in price of corn for food if it is used as fuel C．there will be an decrease in quantity of corn for food if it is used as fuel D．all the above choices are right 78．Biofuels produces much less carbon compared to Fossil fuels in that ． A．biofuels produce less greenhouse gases than fossil fuels B．fossil fuels release carbon while biofuels not when burning C．biofuels take in carbon from the air when they are growing D．biofuels produce greenhouse gases only when they are burning 79．The passage indicates that ． A．we’d better make full use of biofuels to protect the environment B．the value of using biofuels remains to be further studied C．it’s costless to grow biofeuls D．biofuels are just switchgrass and corn Section C Directions: Read the following text and choose the most suitable heading from the list A – F for each paragraph．There is one extra heading which you do not need． A．How many people have participated in the well – received competition? B．Does the well – received competition of tall tales have an origin? C．Who was the constant winner of the annual competition of tall tales? D．Is there any secret to win the competition? E．Does the competition win the hearts of the people all over the world? F．Who is the annual competition of tall tales given to honour? 80． John Graham won the annual competition of tall tales, which is held at the Bridge．Inn in Santon Bridge, in Britain’s Lake District．The “world’s biggest liar has been crowned, after telling a tale about a German World War II submarine invading Britain to get digital television decoders．The 69 – year – old Graham, who has won the title five times before, insisted to BBC radio that “it was a true story ． 81． The annual World’s Biggest Liar Competition, which now draws tourists and competitors from around the world, dates back to the 19 th century when it was founded to honor a famous man called Will Ritson ． 82． The contest is always held at the Bridge Inn．Ritson was a popular pub owner who lived in the western Lake District．He always kept his customers interested with his funny stories．Of course, Ritson was a very honest and sincere man, who insisted that all his tales were true． 83． Each year, a contest is held to award the title of “The Biggest Liar in the World to the person who is worthy of following in Ritson’s footsteps．More than 120 people from across the country, and from as far away as Sweden and South Africa, have taken part in this interesting competition． 84． Competitiors have five minutes to tell the biggest lie．Last year’s winner Sue told the truth of “telling a successful lie , “I think you have got to keep that element of truth and then add some mad and fantastical elements．If you start off in a spaceship then you’ve lost people straight away． “Politicians and lawyers are banned from entering as they are judged to be too skilled at telling lies． 第Ⅱ卷 20080602

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