Forget chip fat, sugar cane or rapeseed oil — the latest source of biofuel could be watermelons. Scientists have discovered that the fruit is a great source of sugar that can be readily distilled (蒸馏) into alcohol to power cars and farm machinery.
And sellers reject 360,000 tons of “substandard” fruit every year in America alone which could be used as an economical way to make fuel. The waste from US growers could produce nearly two million gallons (nine million litres) of biofuel per year.
In the study, researchers at the United States Department of Agriculture set out to determine the biofuel potential of juice from rejected watermelons —those not sold due to cosmetic imperfections, and currently ploughed back into the field. About a fifth of each yearly watermelon crop is left in the field because of surface blemishes (瑕疵) or because they are misshapen.
Dr. Wayne Fish, who led the team, found that 50 percent of the fruit was fermentable (可发酵的) into alcohol which could provide valuable fuel.
“We’ve shown that the juice of these watermelons is a source of readily fermentable sugars, representing an unexploited raw material for alcohol biofuel production,” he said.
The study, published in the journal Biotechnology for Biofuels, discovered that watermelons could produce around 20 gallons of fuel per acre from fruit that otherwise would go to waste.
Production of biofuels has been targeted by Western governments as a way to support renewable energy targets.
The European Union has a target for 2010 that 5.75 percent of transport fuels should e from biological sources, but the target is unlikely to be met.
The British government’s Renewable Transport Fuel Obligation requires five percent of the fuel sold at the pump by 2010 to be biofuel.
【小题1】The passage mainly tells us .A．watermelon juice will be the largest source of renewable energyB．the advantages of fuel made from watermelonsC．Western countries aim at producing biofuelsD．watermelons could be used to make fuel【小题2】 It can be learned from the text that .A．about two gallons of fuel could be made from rejected fruit per acreB．sellers in the world throw away 360,000 tons of watermelons every yearC．half of the watermelons were fermentable into alcohol to provide energyD．five percent of fuel is required to be biofuel from watermelons by 2010 in Britain【小题3】The underlined word “cosmetic” in Paragraph 3 probably means . A．freshB．sweetC．surfaceD．inside【小题4】We can infer from the passage that .A．it will cost a lot to make biofuel from watermelonsB．Western countries are engaged in biofuel study but still have a long way to goC．watermelon juice has been used as a source of sugars to produce alcohol biofuelD．the European Union is likely to meet its target of transport fuels from biological sourcesD
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(答案→)D
解析：小题1 这篇文章主要讲的是西瓜可以被用来当做燃料。A、B答案不完全 C应该是“The European Union has a target for 2010 that 5.75 percent of transport fuels should e from biological sources”目标是实现运输燃料来自生物源。
小题2 A原文倒数第二段watermelons could produce around 20 gallons of fuel per acre；
B第二段第一句话sellers reject 360,000 tons of “substandard” fruit every year而不是throw away；C正确原文第四段found that 50 percent of the fruit was fermentable into alcohol which could provide valuable fuel.；D在原文最后一段意思与原文不符。
小题3 通过后面“is left in the field because of surface blemishes (瑕疵) or because they are misshapen.”可知文章是说由于外表有瑕疵，故为C
小题4 原文倒数第二段说“but the target is unlikely to be met”故C、D错误；文章第二段可找出专家使用“substandard”fruit，这是一种经济的方式，故A错误；B是说西方国家所从事的生物燃料研究仍有很长的路要走。