14．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 360，000tons 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 50percent 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 20gallons 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 2010that 5.75percent of transport fuels should come 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 2010to be biofuel．
53．The passage mainly tells usD．
A．watermelon juice will be the largest source of renewable energy
B．the advantages of fuel made from watermelons
C．Western countries aim at producing biofuels
D．watermelons could be used to make fuel
54．It can be learned from the text thatC．
A．about two gallons of fuel could be made from rejected fruit per acre
B．sellers in the world throw away 360，000tons of watermelons every year
C．half of the watermelons were fermentable into alcohol to provide energy
D．five percent of fuel is required to be biofuel from watermelons by 2010in Britain
55．The underlined word"cosmetic"in Paragraph 3probably meansC．
A．fresh B．sweet C．surface D．inside
56．We can infer from the passage thatB．
A．it will cost a lot to make biofuel from watermelons
B．Western countries are engaged in biofuel study but still have a long way to go
C．watermelon juice has been used as a source of sugars to produce alcohol biofuel
D．the European Union is likely to meet its target of transport fuels from biological sources．
分析 本文介绍了西瓜可以用作生物燃料的研究．科学家把西瓜里的糖分蒸馏成酒精，从而给汽车提供燃料．这种技术利用因为表面的瑕疵被仍在地里这些西瓜，百分之五十的西瓜被发酵成酒精，这酒精能提供宝贵的燃料．虽然西方国家进行生物燃料的研究，但是他们仍旧有很长的路要走．
解答 53．答案：D．主旨大意题．根据第一段中the latest source of biofuel could be watermelons可以知道最新的生物燃料来源是西瓜，而后面几段介绍了这个研究的过程，所以选择D．watermelons could be used to make fuel（西瓜能够被用来制作燃料）．
54．答案：C．细节题．根据第四段中50percent of the fruit was fermentable （可发酵的） into alcohol which could provide valuable fuel（百分之五十的西瓜被发酵成酒精，这酒精能提供宝贵的燃料．）．
可以知道答案是C，而第六段中watermelons could produce around 20gallons of fuel per acre from fruit that otherwise would go to waste（每亩被扔掉的西瓜可以产出20加仑的燃料）证明A项是错的；第二段中 sellers reject 360，000tons of"substandard"fruit every year in America alone（单单在美国，销售者每年都扔掉360000吨的不合格水果） 证明B项是错的；末段中的five percent of the fuel sold at the pump by 2010to be biofuel．（到2010年，加油站卖的油要有百分之五是生物燃料．）证明D项是错的，外延大了．
55．答案：C．词义猜测题．根据划线单词的下一句About a fifth of each yearly watermelon crop is left in the field because of surface blemishes 可以知道这些西瓜被仍在地里是因为表面的瑕疵，所以选择C urface（表面的）．
56．答案：B．推理判断题．根据倒数第二段but the target is unlikely to be met．可以知道这个目标很难实现，所以选择B．Western countries are engaged in biofuel study but still have a long way to go（西方国家进行生物燃料的研究，但是他们仍旧有很长的路要走．）
点评 考查科技类阅读．
要做好阅读理解，必须找出一定的方法，但每一个方法不一定适合所有的阅读理解题，所以必须要多读，多练，要勤于思考，更要学会巧读，这样才能达到事半功倍的效果，要不断扩大词汇量，拓宽阅读面，提高阅读速度，同时也要探索和总结适合自己方法或，实践出真知，多练出效益，才能在高考中立于不败之地．
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