22、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（蒸餾）into alcohol to power cars and farm machinery．

　　And because sellers reject 360,000 tons of  “substandard”fruit annually in America alone they 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 annual 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 per cent of the fruit was fermentable（可發(fā)酵的）into alcohol which could provide valuable fuel．

　　“We’ve shown that the juice of these melons 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 per cent 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 per cent of the fuel sold at the pump by 2010 to be biofuel．

1．The passage mainly tells us ______．

A． western countries aim at producing biofuels

    B． watermelons could be used to make fuel

    C． the advantages of fuel made from watermelons

    D． watermelon juice will be the largest source of renewable energy

2．Which of the following is NOT the reason why so many watermelons are deserted in America each year?

    A． They are substandard．                             B． They are imperfect．

    C． They are misshapen．               D． They are oversupplied．

3．It can be learned from the text that ______．

    A． sellers in the world throw away 360,000 tons of watermelons every year

    B． about two gallons of fuel could be made from rejected fruit per acre

    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 2010 in Britain

4．The underlined word “cosmetic” in Paragraph 5 probably means ______．

    A． inside             B． flavor             C． surface          D． freshness

5．We can infer from the passage that ______．

    A． western countries are engaged in biofuel study but still have a long way to go

    B． the EU is likely to meet its target of transport fuels from biological sources

    C． it will cost a lot to make biofuel from watermelons

    D． watermelon juice has been used as a source of sugars to produce alcohol biofuel