Putting Plants to Work

Using the power of the sun is nothing new. People have had solar-powered calculators and buildings with solar panels for decades. But plants are the real experts: They’ve been using sunlight as an energy source for billions of years.

Ceils in the green leaves of plants work like tiny factories to convert sunlight, carbon dioxide, and water into¹ sugars and starches, stored energy that the plants can use. This conversion process is called photosynthesis. Unfortunately, unless you’re a plant, it’s difficult and expensive to convert sunlight into storable energy. That’s why scientists are taking a closer look at exactly how plants do it.

Some scientists are trying to get plants, or biological cells that act like plants, to work as miniature photosynthetic power stations. For example, Mafia Ghirardi of the National Renewable Energy Laboratory in Golden, Colo.², is working with green algae³. She’s trying to trick them into producing hydrogen⁴ instead of sugars when they perform photosynthesis. Once the researchers can get the algae working efficiently, the hydrogen that they produce could be used to power fuel cells in cars or to generate electricity.

The algae are grown in narrow-necked glass bottles to produce hydrogen in the lab. During photosynthesis, plants normally make sugars or starches. “But under certain conditions, a lot of algae are able to use the sunlight energy not to store starch, but to make hydrogen,” Ghirardi says. For example, algae will produce hydrogen in an air free environment. It’s the oxygen in the air that prevents algae from making hydrogen most of the time.

Working in an air free environment, however, is difficult. It’s not a practical way to produce cheap energy. But Ghirardi and her colleagues have discovered that by removing a chemical called sulfate from the environment that the algae grow in, they will make hydrogen instead of sugars, even when air is present.

Unfortunately, removing the sulfate also makes the algae’s cells work very slowly, and not much hydrogen is produced. Still, the researchers see this as a first step in their goal to produce hydrogen efficiently from algae. With more work, they may be able to speed the cells" activity and produce larger quantities of hydrogen.

The researchers hope that algae will one day be an easy-to-use fuel source. The organisms are cheap to get and to feed, Ghirardi says, and they can grow almost anywhere: “You can grow them in a reactor, in a pond. You can grow them in the ocean. There’s a lot of flexibility in how you can use these organisms.”

 

词汇:

panel /5pAnl/ n.嵌板，发热板，仪器板  

starch /stB:tF/ n. 淀粉

miniature /5minjEtFE/ adj.口巧．微型的

sulfate /5sQlfeit/ n. 硫酸盐，硫酸酯

carbon dioxide 二氧化碳  

photosynthesis /7fEutEu5sinWEsis/ n. 光合作用

algae /5AldVi:/ n. 水藻，海藻  

 

注释:    

1. convert … into…：将……转换为 ……     

2. Colo.：Colorado，（美国科罗拉多州）的缩写形式  

3. Green algae: 绿藻       

4.trick them into producing hydrogen: 想方设法使它们产生氢。 trick作为动词，有 “欺骗、哄骗 ”的意思，但是在这里的意思是 “设法”或“采取措施 ”。

Researchers have met with difficulties when trying to make algae produce hydrogen efficiently. Which one of the following is one such difficulty?

A:It is not possible to remove sulfate from the environment. B:It is not possible to work in an airfree environment to produce hydrogen. C:It is not easy to make sugars instead of hydrogen. D:It is too slow for algae to produce hydrogen when the sulfate is removed.

Ancient Greek philosopher Aristotle viewed laughter as “a bodily exercise precious to health.” But (1) some claims to the contrary, laughing probably has little influence on physical fitness Laughter does (2) short-term changes in the function of the heart and its blood vessels, (3) heart rate and oxygen consumption But because hard laughter is difficult to (4) , a good laugh is unlikely to have (5) benefits the way, say, walking or jogging does.
(6) ，instead of straining muscles to build them, as exercise does, laughter apparently accomplishes the (7) , studies dating back to the 1930’s indicate that laughter (8) muscles, decreasing muscle tone for up to 45 minutes after the laugh dies down.
Such bodily reaction might conceivably help (9) the effects of psychological stress. Anyway, the act of laughing probably does produce other types of (10) feedback, that improve an individual’s emotional state. (11) one classical theory of emotion, our feelings are partially rooted (12) physical reactions. It was argued at the end of the 19th century that humans do not cry (13) they are sad but they become sad when the tears begin to flow.
Although sadness also (14) tears, evidence suggests that emotions can flow (15) muscular responses. In an experiment published in 1988,social psychologist Fritz Strack of the University of würzburg in Germany asked volunteers to (16) a pen either with their teeth-thereby creating an artificial smile-or with their lips, which would produce a(n) (17) expression. Those forced to exercise their enthusiastically to funny catoons than did those whose months were contracted in a frown, (19) that expressions may influence emotions rather than just the other way around (20) , the physical act of laughter could improve mood.

（2）（）

A:reflect B:demand C:indicate D:produce

Richard Wagner Richard Wagner (1813 ~ 1883) is regarded by many 【51】 "The Revolutionist of Opera, "who demolished all old forms, and who reconstructed the music drama 【52】 principles entirely his own. In the strictest 【53】 , this belief is not justified, for Wagner simply returned to the oldest version of the music drama. He found that the ideal construction of the opera in Florence had been to produce work in which the music, drama and interpretation should be 【54】 equal importance. Wagner studied the changes and abuses which Gluck had 【55】 correct, and found that the opera 【56】 of the nineteenth century had 【57】 back into many of the old customs, with the result, that there was no longer a complete 【58】 of the three fundamentals of opera. Wagner tells us in his autobiography that his early life was influenced by the dramas of Shakespear, the symphonies of Beethoven, and the operas of Von Weber. His first operas were constructed on the lines of the French grand opera. The first two were absolute failures, but with the 【59】 of "Rienzi" in 1842, Wagner was proclaimed the equal, if not the superior, 【60】 Bellini, Donizetti and Meyerbeer. In the writing of this work he had discovered the dramatic absurdities of the form, 【61】 in his next work, "The Flying Dutchman," he attempted his first important use of the "leit motif," or characteristic 【62】 , for his different personages , and also used these themes, in anticipation of the advent of his characters, in a manner he later described as" making the audience a part of the being. 【63】 his way to Dresden to conduct" Rienzi," Wagner visited the Wartburg Castle, and there he became familiar 【64】 the legendary stories which he used in all his later works. "Tannhauser" gives an actual description of the Minnesinger Knights, who inspired Wagner 【65】 Teutonic versions of "The Ring of the Nibelungs", "Lohengrin" ,"Tristan and Isolde" and "Parsifal".

A:produce B:production C:product D:productivity

 

The“standard of living”of any country means the average person’s share of the goods and services the country produces．A country’s standard of living，therefore， (51) first on its capacity to produce wealth．“Wealth”in this (52) is not money，for we do not live on money but on things that money can buy：“goods”such as food and clothing，and“services”such as transport and entertainment．
A country’s capacity to (53) wealth depends upon many factors，most of (54) have an effect on one another．Wealth depends (55) a great extent upon a country’s natural resources．Some regions of the world are well supplied with coal and minerals，and have fertile(肥沃的)soil and a favorable climate；other regions (56) none of them． Next to natural resources comes the ability to (57) them to use．China is perhaps as rich as the USA in natural resources，but suffered for many years (58) civil and external wars，and for this and other (59) was unable to develop her resources．Sound and stable political conditions，and (60) from foreign invasions，enable a country to develop its natural resources peacefully and steadily，and to produce more (61) than another country equally welt favored by nature but less well ordered． A country’s standard of living does not only depend upon the wealth that is produced and (62) within its own borders，but also upon what is directly produced through international trade．For example，Britain’s wealth in foodstuffs and other agricultural (63) would be much less if she had to depend only on those grown at home．Trade makes it possible for her surplus(剩余的) manufactured goods to be traded abroad for the agricultural products (64) would otherwise be lacking．A country’s wealth is，therefore，much influenced by its manufacturing capacity， (65) that other countries can be found ready to accept its manufactures．

53（）

A:distribute B:produce C:contain D:buy

The "standard of living" of any country means the average person’s share of the goods and services the country produces. A country’s standard of living, therefore (51) first on its capacity to produce wealth. "Wealth" in this (52) is not money, for we do not live on money but on things that money can buy: "goods" such as food and clothing, and "services" such as transport and entertainment.
A country’s capacity to (53) wealth depends upon many factors, most of (54) have an effect on one another. Wealth depends (55) a great extent upon a country’s natural resources. Some regions of the world are well supplied with coal and minerals, and have fertile soil and a favorable climate; other regions (56) none of them. Next to natural resources comes the ability to (57) them to use. China is perhaps as rich as the USA in natural resources, but suffered for many years (58) civil and external wars and for this and other (59) was unable to develop her resources. Sound and stable political conditions, and (60) from foreign invasions, enable a country to develop its natural resources peacefully and steadily, and to produce more (61) than another country equally well favored by nature but less well ordered.
A country’s standard of living does not only depend upon the wealth that is produced and (62) within its own borders, but also upon what is directly produced through international trade, for example, Britain’s wealth in foodstuffs and other agricultural (63) would be much less if she had to depend only on those grown at home. Trade makes it possible for her surplus (过剩的) manufactured goods to be traded abroad for the agricultural products (64) would otherwise be lacking. A country’s wealth is, therefore, much influenced by its manufacturing capacity (65) that other countries can be found ready to accept its manufactures.

A:distribute B:produce C:contain D:buy

Richard Wagner Richard Wagner (1813 ~ 1883) is regarded by many 【51】 "The Revolutionist of Opera, "who demolished all old forms, and who reconstructed the music drama 【52】 principles entirely his own. In the strictest 【53】 , this belief is not justified, for Wagner simply returned to the oldest version of the music drama. He found that the ideal construction of the opera in Florence had been to produce work in which the music, drama and interpretation should be 【54】 equal importance. Wagner studied the changes and abuses which Gluck had 【55】 correct, and found that the opera 【56】 of the nineteenth century had 【57】 back into many of the old customs, with the result, that there was no longer a complete 【58】 of the three fundamentals of opera. Wagner tells us in his autobiography that his early life was influenced by the dramas of Shakespear, the symphonies of Beethoven, and the operas of Von Weber. His first operas were constructed on the lines of the French grand opera. The first two were absolute failures, but with the 【59】 of "Rienzi" in 1842, Wagner was proclaimed the equal, if not the superior, 【60】 Bellini, Donizetti and Meyerbeer. In the writing of this work he had discovered the dramatic absurdities of the form, 【61】 in his next work, "The Flying Dutchman," he attempted his first important use of the "leit motif," or characteristic 【62】 , for his different personages , and also used these themes, in anticipation of the advent of his characters, in a manner he later described as" making the audience a part of the being. 【63】 his way to Dresden to conduct" Rienzi," Wagner visited the Wartburg Castle, and there he became familiar 【64】 the legendary stories which he used in all his later works. "Tannhauser" gives an actual description of the Minnesinger Knights, who inspired Wagner 【65】 Teutonic versions of "The Ring of the Nibelungs", "Lohengrin" ,"Tristan and Isolde" and "Parsifal".

A:produce B:production C:product D:productivity

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A:distribute B:produce C:contain D:buy