When George W. Bush delivered his State of the Union Address this past Januar

游客2024-06-11  10

问题    When George W. Bush delivered his State of the Union Address this past January, three words appeared that had not previously been heard from the Oval Office: Switchgrass, stalks and woodchips.
    Bush’s signals on renewable energy have been decidedly mixed. Shortly before he visited the National Renewable Energy Laboratory (NREL) in Colorado last February, a $5 million funding shortfall forced the lab to lay off 32 workers. Bush blamed the layoffs, and NREL got its funding back.
    Switchgrass is a fast-growing perennial plant native to the central and eastern U.S. and tolerant of many different soil types. To make cellulosic ethanol, switchgrass -- or any cellulose-based plant -- is broken down to make sugar, then fermented to make the fuel. Supporters say that when blended with petroleum products, ethanol from switchgrass results in a net energy gain of 334 percent, compared to just 21 percent for corn- based ethanol.
    The cellulosic process has been invented and is being refined, but it hasn’t been commercialized, and that’ s what is preventing it from going into our tanks today, says former CIA Director James Woolsey, among switchgrass’ s biggest supporters.
Corn-based ethanol has made great strides. According to Tom Slunecka, executive director of the Ethanol Promotion and Information Council, the U.S. currently produces four billion gallons a year, or approximately three to four percent of the fuel supply. "It’ s growing rapidly," he says. "By 2012 we’ re projecting 7.5 billion gallons, but I think we’ 11 far surpass that." Automakers get federal tax credits for producing "bi-fuel" cars and trucks that can nm on ethanol, but until recently the lack of an ethanol refueling infrastructure (永久性设施) obstructed the actual use of the fuel. But now General Motors and other carmakers are promoting ethaonol vehicles with a new vigor. Even without bi-fuel technology, all cars today can burn a 10 percent ethanol blend
Slunecka says biobased ethanol production is still in its infancy: He cites a Canadian plant currenty producing 100,000 gallons per year. "It works, it’ s not science down the road," he says. "Private companies m trying to crack the cost barrier. But the feedstock potential is enormous. I can’ t wait until these cellulosic plants are bolted onto the front side of traditional ethanol plants."
    David Bransby, a professor in Auburn University’ s Agronomy Department, says we need to take action because we’ re in an international competition. "Europe is ahead of everybody in the use of biodiesel, and Brazil! is leading the world in the production and use of ethanol. We are behind. I hope that the President’ s address indicates that there is going to be a change, but he’ s fighting a war in Iraq and trying to recover from two, hurricanes. To be quite honest, these alternative fuels are just as important as those other things. It’s all part o national security and needs to be treated with the same priority." [br] From the passage we know switchgrass is ______.

选项 A、a biochemical product
B、a kind of animal
C、a kind of grass growing very fast
D、a kind of grass growing in a specific soil

答案 C

解析 细节理解题。本题考查对关键词汇的理解。虽然,我们没有学过该词,但从文章的介绍来看,switchgrass应是一种植物(根据第三段第一句a fast growing perennial plant ,答案选C 。本题选项中,B 项容易排除,因为整篇文章都没有谈到动物,有的同学可能认为文章主题就是说switch grass可以用作生产新型替代燃料的原材料,从而错误地选A ,但是细心的同学则会发现A 项里说的是化工产品(而非原材料 ,所以排除,D 项可根据第三段段首句(tolerant of many diff
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