For its supporters, the idea of growing single-celled algae on exhaust gas piped from power stations is the ultimate in recycling. For its detractors, it is a mere pipe dream. Whoever turns out to be right, though, it is an intriguing idea: instead of releasing the carbon dioxide produced by burning fossil fuels into the atmosphere, why not recapture it by photosynthesis? The result could then be turned into biodiesel (since many species of algae store their food reserves as oil), or even simply dried and fed back into the power station. Of course, if it were really that easy, someone would have done it already. But although no one has yet commercialised the technology, several groups are trying.

One of them is GS CleanTech, which has developed a bioreactor based on a patent held by a group of scientists at the Ohio Coal Research Centre, at the University of Ohio. The GS CleanTech bioreactor uses a parabolic mirror to funnel sunlight into fibre-optic cables that carry the light to acrylic “glow plates” inside the reactor. These diffuse the light over vertical sheets of polyester that form the platform on which the algae grow. Eventually the polyester is unable to support the weight of the algae, and they fall off into a collection duct positioned underneath.

GreenFuel Technologies, based in Cambridge, Massachusetts, has a different approach. Its reactor is composed of a series of clear tubes, each with a second, opaque tube nested inside. This arrangement makes it possible to bubble the exhaust gas down through the outer compartment and then bubble it back up through the opaque middle. The bubbling gas causes turbulence and circulates the algae around the reactor. The constant shift between light and darkness as the algal cells circulate increases the amount of carbon that they fix, probably by promoting chemical reactions that occur naturally only at night.

A preliminary test of GreenFuel’s reactor design, which was performed at the Massachusetts Institute of Technology’s campus power plant, suggested that it can remove 75% of the carbon dioxide from a power station’s exhaust. A more serious test is now being carried out by Arizona Public Service, that state’s power utility, at its Redhawk plant. Another test is planned in Louisiana.

GreenFuel claims that over the course of a year, a hectare (2.5 acres) of its reactors should be able to produce 30,000 litres (8,000 American gallons) of oil, which could be used as biodiesel, and enough carbohydrates to be fermented into 9,000 litres of ethanol, which can be used as a substitute for petrol.

There is, of course, no free lunch. As Rob Carlson of the University of Washington points out, if money is to be made selling products made from exhaust gas, then that gas goes from being waste matter to being a valuable resource. Far from giving it away, power companies might even start charging for it. That would, indeed, be a reversal of fortune.

1.The word “intriguing” (Line 3, Paragraph 1) most probably means_____

[A] challenging.

[B] promising.

[C] complicated.

[D] alluring.

2. Which one of the following statements is TRUE of the bioreactor developed by GS CleanTech?

[A] No exhaust gas is used in this bioreactor.

[B] The “glow plates” are used to conduct the sunlight.

[C] Sunlight comes into the fibre-optic cables through holes in the parabolic mirror.

[D] Photosynthesis is carried out by the algae in the collection duct.

3.The collection duct positioned underneath is used to_____

[A] hold the vertical sheets of polyester that fall off.

[B] substitute the platform on which the algae grows.

[C] obtain the overweight algae.

[D] take the place of polyester after light is diffused on it.

4. The approach developed by the GreenFuel Technologies is different from that by GS CleanTech in that_____

[A] there is no photosynthesis in the reactor of GreenFuel Technologies.

[B] the light used for photosynthesis is produced by the reactor itself.

[C] the algal cells fix carbon in the process.

[D] the exhaust gas acts as the motive force.

5.The reactors of GreenFuel could produce the following fuels except_____

[A] biodiesel.

[B] ethanol.

[C] alcohol.

[D] fossil fuel.

篇章剖析：

这篇文章讲述了绿色燃料的生产情况。第一段讲述了人们希望可以利用光合作用来生成燃料;第二、三段讲述有两家公司都在生产绿色燃料，但是使用了技术不同;第四、五段讲述绿色燃料开发使用的地点和规模;第六段讲述将来电力公司可能会对绿色燃料实行收费。

词汇注释：

detractor n. 恶意批评者 pipe dream 白日梦

biodiesel n. 生物燃料parabolic mirror n. 抛物柱面镜

acrylic adj. 丙烯酸的 duct n. 管

carbohydrate n. 碳水化合物 ferment v. 发酵

ethanol n. 乙醇; 酒精

难句突破：

(1) The constant shift between light and darkness as the algal cells circulate increases the amount of carbon that they fix, probably by promoting chemical reactions that occur naturally only at night.

[主体句式] The constant shift as the algal cells circulate increases …

[结构分析] 这是一个复合句，as引导的是时间状语从句，that引导的是定语从句修饰carbon， by promoting…作方式状语。

[句子译文] 随着藻类的运动，光亮和黑暗交替出现，把碳固定住并不断增加其数量，这可能是通过促成只在晚上进行的化学反应而产生的。

(2) A preliminary test of GreenFuel’s reactor design, which was performed at the Massachusetts Institute of Technology’s campus power plant, suggested that it can remove 75% of the carbon dioxide from a power station’s exhaust.

[主体句式] A preliminary test suggested that …

[结构分析] 这是一个复合句，which引导的是design的定语从句;that引导的是宾语从句。

[句子译文] 绿色燃料公司称该设计的最初试验是在麻省理工大学校园的发电厂里进行的，该实验证明可以将发电厂排出废气的75%清除掉。

题目分析：

[答案] D

[难度系数] ☆☆☆

[分析] 猜词题。根据上下文“Whoever turns out to be right, though, it is an intriguing idea: instead of releasing the carbon dioxide produced by burning fossil fuels into the atmosphere, why not recapture it by photosynthesis”，尽管有支持者和反对者，但是可见这个主意还是非常吸引人的，令人向往的，因此选项中D最为符合。

[答案] B

[难度系数] ☆☆☆☆

[分析] 细节题。根据第二段，A选项，没有废气就不能进行光合作用;B选项，白炽盘是用来漫射光的，因此也是用来传导光的;C选项，阳光是通过柱面镜的反射进入到纤维光缆中，而不是抛物柱面镜的洞;D选项，光合作用在聚酯片上进行的。因此，答案为B选项。

[答案] C

[难度系数] ☆☆☆

[分析] 细节题。根据第二段“These diffuse the light over vertical sheets of polyester that form the platform on which the algae grow. Eventually the polyester is unable to support the weight of the algae, and they fall off into a collection duct positioned underneath”，这个收容器是用来接住那些经过光合作用后掉下来的藻类的，其中“unable to support the weight of the algae”说明藻类开始变得过重，因此C选项为正确答案。

[答案] D

[难度系数] ☆☆☆

[分析] 细节题。根据第三段，绿色燃料公司是使用了废气作为让藻类活动的动力，而与清洁技术相同的是在这个过程中也有光合作用，光也来自外部，也有碳固定下来。因此，不同之处就是D选项。

[答案]D

[难度系数] ☆

[分析] 细节题。根据倒数第二段“GreenFuel claims that over the course of a year, a hectare (2.5 acres) of its reactors should be able to produce 30,000 litres (8,000 American gallons) of oil, which could be used as biodiesel, and enough carbohydrates to be fermented into 9,000 litres of ethanol, which can be used as a substitute for petrol”，反应器只可以制造酒精作为石油的替代品，不能制造石油。因此，D是正确答案。

参考译文：

对于支持者来说，用发电厂废气来养殖单细胞藻类是个能实现循环利用这个终极目标的办法。而那些反对者认为，这只是个白日梦而已。不管最后谁是正确的，这个主意确实很吸引人，如果燃料燃烧后产生的二氧化碳排放到空气中，那么为什么不用光合作用来将其消耗掉呢?其生成物可以转化为生物燃料(因为许多藻类都以石油的形式储存食物)，或只需脱水后再送回发电厂。当然，如果真的有这么简单，早就会有人这么做了。不过，尽管还没有人将这项技术商业化，有一些公司已经开始试验了。

GS清洁技术就是这样的一家公司，它利用俄亥俄大学俄亥俄州煤炭研究中心科学家们的一项专利而研制出一种生物反应器。该反应器用一个抛物柱面镜将阳光射到纤维光缆上，光缆把将阳光传到反应器里面的丙烯酸“白炽盘”上。这就将光漫射到垂直的聚酯片上，而聚酯片是藻类生长的平台。最后聚酯不能支持藻类的重量了，就会落到安在下面的管子里。

绿色燃料技术公司的总部设在马萨诸塞的剑桥，该公司采用了另外一种技术。它的反应器由一系列干净的管子构成，每个官子里面都有另外一个不透明的管子。这种安置方法可以使沿着外层下来的废气起泡，然后再通过不透明的中间层向上起泡。起泡的气体引起紊乱，使得藻类在反应器内活动。随着藻类的运动，光亮和黑暗交替出现，把碳固定住并不断增加其数量，这可能是通过促成只在晚上进行的化学反应而产生的。

绿色燃料公司称该设计的最初试验是在麻省理工大学校园的发电厂里进行的，该实验证明可以将发电厂排出废气的75%清除掉。亚利桑那公共服务部门目前正在红鹰工厂进行一项更为重要的试验——国家公共电力。此外路易斯安那州也在计划进行一个试验。

绿色燃料公司声称在一年中，一公顷(2.5英亩)的反应堆应该可以产出三万升(八千美国加仑)的石油，可以用作生物燃料，还能产生足够的碳水化合物并通过发酵生成九千升的乙醇，作为石油的替代品。

当然，世上没有免费的午餐。正如华盛顿大学的Rob Carlson指出的，如果废气制造的产品可以出售盈利的话，那么废气就会从一种废品变成一种宝贵的资源。电力公司不仅不会排放出去，而且可能会收费。这样实际上是财富的逆转。