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1、microscopic mess 9 Climate Change Poses Major Risks for Unprepared Cities A new examination of urban policies has been carried out recently by Patricia Romero Lankao. She is a sociologist specializing in climate change and urban development. She warns that many of the world’s fast-growing

2、 urban areas, especially in developing countries, will likely1 suffer from the impacts of changing climate. Her work also concludes that most cities are failing to reduce emissions of carbon dioxide and other greenhouse gases. These gases are known to affect the atmosphere. “Climate change is

3、a deeply local issue and poses profound threats to the growing cities of the world,” says Romero Lankao. “But too few cities are developing effective strategies to protect their residents. ” Cities are major sources of greenhouse gases. And urban populations are likely to be among those most sever

4、ely affected by future climate change. Lankao’s findings3 highlight ways in which city-residents are particularly vulnerable, and suggest policy interventions that could offer immediate and longer-term benefits The locations and dense construction patterns of cities often place their populations a

5、t greater risk for natural disasters. Potential threats associated with climate include storm surges and prolonged hot weather. Storm surges can flood coastal areas and prolonged hot weather can heat heavily paved cities more than surrounding areas. The impacts of such natural events can be more ser

6、ious in an urban environment. For example, a prolonged heat wave can increase existing levels of air pollution, causing widespread health problems. Poorer neighborhoods that may lack basic facilities such as drinking water or a dependable network of roads, are especially vulnerable to natural disast

7、ers. Many residents in poorer countries live in substandard housing without access to reliable drinking water, roads and basic services. Local governments,therefore,should take measures to protect their residents. “Unfortunately, they tend to move towards rhetoric rather than meaningful responses,”

8、 Romero Lankao writes. “They don’t impose construction standards that could reduce heating and air conditioning needs. They don’t emphasize mass transit and reduce automobile, use. In fact, many local governments are taking a hands-off approach.” Thus, she urges them to change their idle polic

9、ies and to take strong steps to prevent the harmful effects of’ climate change on cities. Free Statins With Fast Food Could Neutralize Heart Risk Fast food outlets could provide statin drugs free of charge so that customers can reduce the heart disease dangers of fatty food, researchers at Imperia

10、l College London suggest in a new study. Statins reduce the amount of unhealthy “LDL” cholesterol in the blood. A wealth of trial data4 has proven them to be highly effective at lowering a person’s heart attack risk In a paper published in the American Journal of Cardiology, Dr Darrel Francis and

11、colleagues calculate that the reduction in heart attack risk offered by a statin is enough to offset the increase in heart attack risk from eating a cheeseburger and drinking a milkshake. Dr Francis, from the National Heart and Lung Institute at Imperial College London, who is the senior author of

12、the study, said: “Statins don’t cut out all of the unhealthy effects of cheeseburgers and French fries. It’s better to avoid fatty food altogether. But we’ve worked out that in terms of your possibility of having a heart attack, taking a statin can reduce your risk to more or less the same d

13、egree as a fast food meal increases it. ” It’s ironic that people are free to take as many unhealthy condiments in fast food outlets as they like, but statins, which are beneficial to heart health, have to be prescribed. It makes sense to make risk-reducing statins available just as easily a

14、s the unhealthy condiments that are provided free of charge. It would cost less than 5 pence per customer —— not much different to a sachet of sugar, “ Dr Francis said. When people engage in risky behaviours like driving or smoking, they’re encouraged to take measures that lower their risk,

15、 like wearing a seatbelt or choosing cigarettes with filters. Taking a stain is a rational way of lowering some of the risks of eating a fatty meal. Better Solar Energy Systems: More Heat, More Light Solar photovoltaic thermal energy systems, or PVTs, generate both heat and electricity, but until

16、now they haven’t been very good at the heat-generating part compared to a stand-alone solar thermal collector. That’s because they operate at low temperatures to cool crystalline silicon solar cells, which lets the silicon generate more electricity but isn’t a very efficient way to gather heat.

17、 That’s a problem of economics. Good solar hot-water systems can harvest much more energy than a solar-electric system at a substantially lower cost. And it，s also a space problem：photovoltaic cells can take up all the space on the roof, leaving little room for thermal applications. In a pair of s

18、tudies, Joshua Pearce, an associate professor of materials science and engineering, has devised a solution in the form of a better PVT made with a different kind of silicon. His research collaborators are Kunal Girotra from ThinSilicon in California and Michael Pathak and Stephen Harrison from Que

19、en’s University, Canada." Most solar panels are made with crystalline silicon， but you can also make solar cells out of amorphous silicon,commonly known as thin-film silicon. They don’t create as much electricity, but they are lighter, flexible, and cheaper. And, because they require much less sil

20、icon, they have a greener footprint. Unfortunately，thin-film silicon solar cells are vulnerable to some bad-news physics in the form of the Staebler-Wronski effect. “That means that their efficiency drops when you expose them to light — pretty much the worst possible effect for a solar cell,” Pea

21、rce explains，which is one of the reasons thin- film solar panels make up only a small fraction of the market. However, Pearce and his team found a way to engineer around the Staebler-Wronski effect by incorporating thin-film silicon in a new tpye of PVT. You don’t have to cool down thin-film silic

22、on to make it work. In fact，Pearce’s group discovered that by heating it to solar-thermal operating temperatures，near the boiling point of water, they could make thicker cells that largely overcame the Staebler-Wronski effect. When they applied the thin-film silicon directly to a solar thermal ene

23、rgy collector, they also found that by baking the cell once a day，they boosted the solar cell’s electrical efficiency by over 10 percent. Sharks Perform a Service for Earth’s Watersy It is hard to get people to think of sharks as anything but a deadly enemy. They are thought to attack people

24、 frequently. But these fish perform a valuable service for earth’s waters and for human beings. Yet business and sport fishing3 are threatening their existence. Some sharks are at risk of disappearing from earth. Warm weather may influence both fish and shark activity. Many fish swim near coas

25、tal areas because of their warm waters. Experts say sharks may follow the fish into the same areas,where people also swim. In fact, most sharks do not purposely charge at or bite humans. They are thought to mistake a person for a sea animal, such as a seal or sea lion. That is why people should

26、 not swim in the ocean when the sun goes down or comes up. Those are the times when sharks are looking for food. Experts also say that bright colors and shiny jewelry may cause sharks to attack. A shark has an extremely good sense of smell4. It can find small amounts of substances in water, such a

27、s blood, body liquids and chemicals produced by animals. These powerful senses help sharks find their food. Sharks eat fish, any other sharks, and plants that live in the ocean. Medical researchers want to learn more about the shark’s body defense and immune systems against disease. Researche

28、rs know that sharks recover quickly from injuries. They study the shark in hopes of finding a way to fight human disease. Sharks are important for the world’s oceans. They eat injured and diseased fish. Their hunting activities mean that the numbers of other fish in ocean waters do not become too g

29、reat. This protects the plants and other forms of life that exist in the oceans. “Liquefaction” Key to Much of Japanese Earthquake Damage The massive subduction zone earthquake in Japan caused a significant level of soil “l(fā)iquefaction” that has surprised researchers with its widespread severity, a

30、 new analysis shows. We’ve seen localized examples of soil liquefaction as extreme as this before, but the distance and extent of damage in Japan were unusually severe,” said Scott Ashford, a professor of geotechnical engineering at Oregon State University. “Entire structures were tilted and si

31、nking into the sediments,” Ashford said. “The shifts in soil destroyed water, drain and gas pipelines, crippling the utilities and Infrastructure these communities need to function. We saw some places that sank as much as four feet. ” Some degree of soil liquefaction is common in almost any major

32、earthquake. It’s a phenomenon in which soils soaked with water, particularly recent sediments or sand, can lose much of their strength and flow during an earthquake. This can allow structures to shift or sink or collapse. But most earthquakes are much shorter than the recent event in Japan, Ashford

33、 said. The length of the Japanese earthquake, as much as five minutes, may force researchers to reconsider the extent of liquefaction damage possibly occurring in situations such as this. “With such a long-lasting earthquake, we saw how structures that might have been okay after 30 seconds just

34、 continued to sink and tilt as the shaking continued for several more minutes,” he said. “And it was clear that younger sediments, and especially areas built on recently filled ground, are much more vulnerable.” The data provided by analyzing the Japanese earthquake, researchers said, should make i

35、t possible to improve the understanding of this soil phenomenon and better prepare for it in the future. Ashford said it was critical for the team to collect the information quickly,before damage was removed in the recovery efforts. There’s no doubt that we’ll learn things from what happened in

36、 Japan that will help us to reduce risks in other similar events,” Ashford said. “Future construction in some places may make more use of techniques known to reduce liquefaction, such as better compaction to make soils dense, or use of reinforcing stone columns.” Ashford pointed out that northern

37、 California have younger soils vulnerable to liquefaction – on the coast, near river deposits or in areas with filled ground. The “young” sediments, in geologic terms, may be those deposited within the past 10,000 years or more. In Oregon, for instance, that describes much of downtown Portland, the

38、Portland International Airport and other cities. Anything near a river and old flood plains is a suspect, and the Oregon Department of Transportation has already concluded that 1100 bridges in the state are at risk from an earthquake. Fewer than 15 percent of them have been reinforced to prevent c

39、ollapse. Japan has suffered tremendous losses in the March 11 earthquake, but Japanese construction standards helped prevent many buildings from collapse – even as they tilted and sank into the ground. Batteries Built by Viruses病毒電池 What do chicken pox, the common cold 水痘、普通感冒、流感和艾滋病有哪些相似之處呢？這些都是

40、由病毒引起的疾病。病毒是能夠在人與人之間傳染的微生物。難怪大部分人一提到病毒，首先想到的是如何躲避病毒。然而，并不是每個人都躲避這些疾病攜帶者。在馬薩諸塞州劍橋市，科學家發(fā)現(xiàn)有些病毒能起到非同尋常的作用。他們使病毒開始工作，使病毒構(gòu)成世界上最小的充電電池。病毒和電池的搭檔似乎并不常見，但這對于工程師安吉拉，貝爾徹來說卻并不陌生。安吉拉，貝爾徹最早產(chǎn)生了這一想法。在位于劍橋市的麻省理工學院，她和合作者一起用新方式融合了不同的科學領(lǐng)域。在由病毒構(gòu)成的電池里，科學家融合了他們在生物、技術(shù)和生產(chǎn)工藝方面的知識。貝爾徹的團隊包括幫助組裝微型電池的寶拉，哈蒙德和以電池形式存儲能量的專家蔣業(yè)明。哈蒙德說，“

41、我們現(xiàn)在從事的行業(yè)是傳統(tǒng)中不會想到的。”許多電池已經(jīng)很小了。A型、C型和D型電池都可以握在手里。硬幣形狀的手表電池通常比分幣還小。然而，個人音樂播放器和手機等新型電子設(shè)備變得越來越小。這些設(shè)備變小了，普通理想的電池應當體積小、儲能多。目前，貝爾徹的電池模型是完全由病毒構(gòu)成的金屬圓盤，看起來就像普通手表電池。但里面的部件卻非常小——小到用高倍望遠鏡才能看到。這些電池部件到底有多小呢？從頭上拔一根頭發(fā)，把它放到白紙上，看看頭發(fā)的寬度——是不是很細呢？盡管每個人的頭發(fā)寬度不同，每個頭發(fā)上可以并列排放大約10個病毒電池部件。這些微電池可能會改變我們對病毒的看法。 the way we look at

42、 viruses 1.According to the first paragraph, people try to -Stay away from viruses because they are causes of various diseases. 2.What is Belcher’s team doing at present?-It is making batteries with viruses 3.What expression below. is opposite in meaning to the word “shrink” appearing in paragra

43、ph 5?-Expand 4.Which of the following is true of Belcher’s battery mentioned in paragraph 6?-It is a metallic disk with viruses inside it. 5.How tiny is one battery part?-Its width is one tenth of a hair. Putting Plants to Work植物效能 Using the power of the sun is nothing new 太陽能的使用已經(jīng)不足為奇。幾十年前，人們就

44、開始使用太陽能計算器，制造太陽能電熱板鑲嵌的建筑。但是植物當屬應用太陽能的專家：十億年來，植物一直把陽光作為能源資源。綠葉植物細胞的工作就像微型加工廠一樣，將陽光，二氧化碳和水轉(zhuǎn)化為糖和淀粉，并且同時儲存植物本身所需的能量。這種轉(zhuǎn)換過程叫做光合作用?？上悴皇且恢曛参?，必須困難的并且花上大價錢將陽光轉(zhuǎn)換為穩(wěn)定的能源。因此，科學家們正在對植株進行準確細致的研究。一些科學家正試圖像植物的作用過程一樣，將植物，或生物的細胞活動看做微型光合發(fā)電站。例如，瑪麗亞奇若蒂在美國科羅拉多州的國家可再生能源實驗室里對綠藻進行研究。她正想方設(shè)法地通過植物的產(chǎn)生氫來取代光合作用產(chǎn)生的糖。一旦研究人員了解藻類如何有效

45、率的進行工作，由此產(chǎn)生的氫氣可用于燃料電池動力汽車和發(fā)電。在實驗室里，藻類生長通過狹窄的頸玻璃瓶生產(chǎn)氫氣的環(huán)境下。在光合作用下，植物通常產(chǎn)生糖類或淀粉。奇若蒂說： “但在一定條件下，有很多藻類能夠利用日光能源產(chǎn)生氫氣而不是儲存淀粉?！崩纾孱悤诳諝獯嬖诃h(huán)境下產(chǎn)生氫氣。這是因為空氣中的氧氣，氧阻止綠藻制造氫。藻類在空氣中雖然可以工作，但是充滿困難。這種方式不能切實可行的生產(chǎn)廉價的能源。但是奇若蒂和她的同事們已經(jīng)發(fā)現(xiàn)，即使在目前的空氣條件下，他們從藻類生長的環(huán)境中，除去所謂的硫酸化學品，能夠產(chǎn)生氫來代替糖。只可惜消除硫酸鹽不僅使藻類細胞的工作速度減慢，而且大大減少了氫的數(shù)量。盡管如此，研究人

46、員認為，對于實現(xiàn)有效率的利用藻類產(chǎn)生氫這一目標，他們已經(jīng)邁出了第一步。隨著工作量的加大，他們可以加速細胞的活動，從而產(chǎn)生大量的氫氣。研究人員們希望，總有一天藻類會成為很容易使用的燃料來源。藻類這種生物極易存活，他們可以在幾乎任何地方成長。奇若蒂說：“你可以將它放在一反應堆或是池塘里，也可以在海洋中找到它們，人們可以靈活的使用藻類的用途廣泛?！? in how you can use these organisms 1.What does the writer say about plants concerning solar energy?-Plants have been using so

47、lar energy for billions of years. 2.Why do some scientists study how plants convert sunlight carbon dioxide, and water into sugars and starches?-Because they want green plants to become a new source of energy 3.According to the fifth paragraph, under what conditions are algae able to use solar ene

48、rgy to make hydrogen?-When there is no oxygen in the air 4.Researchers have met with difficulties when trying to make algae produce hydrogen efficiently. Which one of the following is one such difficulty?-It is too slow for algae to produce hydrogen when the sulfate is removed. 5.What is NOT true

49、of algae?-They are cheap to eat. Listening Device Provides Landslide Early Warning聽覺儀器提供早期山崩預警 A device that provides early warning 英國研究者們正在測試一種儀器，它可以通過監(jiān)測土壤振動提供早期山崩預告?？茖W家們說，這種儀器通過警報某處有險情需要撤離，每年可以拯救成千上萬的生命。經(jīng)歷過驟降大雨，地震甚至土壤侵蝕的國家，山崩這樣的自然災害是很常見的。當同一個山坡上的一些土壤或石塊開始移動時，山崩就開始了，但早期很難發(fā)現(xiàn)。接著這個初始運動，“山坡在數(shù)分鐘或數(shù)小時

50、內(nèi)變得不穩(wěn)定，”英國拉夫堡大學尼爾迪克森說。他說，一個監(jiān)控這種運動的警報系統(tǒng)“足以疏散一個街區(qū)的人或清出一條馬路，拯救生命”。監(jiān)視迫近的山崩，最常見的辦法就是觀察這座山Jp狀的變化。研究者們可以直接測量，也可以在鉆孔中或者地表面上探測山坡形狀的變化?？墒?，山坡改變形狀也未必就導致山崩。所以任何一種方法都可能導致誤警?，F(xiàn)在，迪克森的團隊已發(fā)明了一種儀器，它在一個山坡內(nèi)的顆粒開始移動時可以接收到振動。這個儀器是鋼管形狀，探人山坡上的一個鉆孔中。鉆孔中儀器的四周填滿沙礫，有助于傳導山坡內(nèi)顆粒產(chǎn)生的高頻振動波。振動波順著鋼管上傳，被地表傳感器接收。通過軟件分析振動信號，判斷是否馬上要發(fā)生山崩。目前這種

51、儀器正在英國紐卡斯爾一座6米高人造石灰大壩中接受測試。先期結(jié)果顯示它比現(xiàn)有的儀器提供較少的判斷誤差。一旦這種儀器通過了認真徹底的檢測，它將成為一個完善的山崩早期預警系統(tǒng)?！笆苌奖绹乐赝{的地區(qū)一定會從這樣的儀器中得益，”英國紅十字會的專家艾登，保特說，“只要它不是太貴?！钡?，保特又說一個早期預警系統(tǒng)本身并不足以防災，“你需要建立人際交流，”他說，“使系統(tǒng)發(fā)射的預警送達到需要的人群是不容易的事?！? who need them can be difficult 1.What does “Such natural disasters” in the first paragraph refer

52、to -Landslides. 2.Which of the following statements is true of landslides?-All of the above. 3.Why do researchers develop a new device to monitor signs of landsides?-Because the common methods can cause false alarms. 4.Which of the following statements is NOT true of the device, according to Par

53、agraph 4?-It is filled in with gravel. 5.According to the context, what does the word “positives” in the fifth paragraph mean?-Evidences. “Don’t Drink Alone” Gets New Meaning“不要在就餐時間以外飲酒”有了新含義 In what may be bad news for 一定程度上，這對酒吧可能是一個壞消息，歐洲的一個研究小組發(fā)現(xiàn)人們在就餐時間以外飲酒會使患口腔和頸部癌癥的幾率比就餐時飲酒更高。Luigino Dal

54、Maso和他的同事們研究了取自四項癌癥研究的1，500個病例的飲酒習慣模式和另外3500個從沒患癌癥的成年人的飲酒習慣模式。在研究者分析了飲酒的總量后，他們發(fā)現(xiàn)和只在就餐時飲酒的人相比，在就餐時間以外灌下大量烈酒的人面臨至少50%~80%的患口腔癌、咽癌和食道癌的危險。在就餐時間外飲酒也會使患喉癌的可能性增加至少20%?！氨谎芯空叩那闆r說明大約95%患以上四種癌癥的原因就是抽煙或飲酒?！盌al Maso說。他的研究小組提供的報告中令人沮喪的消息是就餐時飲酒不會消除患以上任何一種癌癥的危險。為了進行新的分析，歐洲科學家根據(jù)每星期平均飲酒量將被研究者分為4組。飲酒量最少的一組包括每周平均飲酒量達2

55、0杯的人，飲酒量最高的一組每周飲酒至少56杯，平均每天8杯以上。患口腔癌和頸部癌的危險隨著飲酒量而穩(wěn)定上升，即使是那些只在就餐時飲酒的人。例如，和低飲酒量的人相比，每周飲酒21~34杯的人患除喉癌以外其他部位的癌癥的危險增加了一倍。如果這幾組中的人在就餐時間以外飲酒，那些屬于高飲酒量組的人會使他們患口腔癌和食道癌的危險至少增加3倍。和每周只在就餐時平均飲酒至多20杯的人相比，高飲酒量組的人在就餐時間飲酒患口腔癌的危險是低飲酒量組的10倍，咽癌是其7倍，食道癌是16倍。相反，酒精高攝入且僅在就餐時飲酒的人患喉癌的危險是酒精低攝人且僅在就餐時飲酒的人的3倍?！熬凭苁菇M織發(fā)炎，一段時間后，炎癥可引

56、發(fā)癌癥?！盌al Maso說。他認為食物降低了患癌癥的危險，或是通過覆蓋在消化道組織上或是通過將酒精從那些組織上擦掉。他推測所有被研究者患喉癌的幾率比其他癌癥低很多的原因是喉部組織被酒精侵害到的部分少得多。 tissue’s lower exposure to alcohol. 1.Researchers have found that the risk of cancer in the mouth and neck is higher with people -who drink alcohol outside of meals 2.Which of the following is

57、 NOT the conclusion made by the researchers about “drinking with meals”?-It increases by 20 percent the possibility of cancer in all sites 3.Approximately how many drinks do the lowest-intake group average per day?-3 drinks 4.Which cancer risk is the lowest among all the four kinds of cancer menti

58、oned in the passage?-Laryngeal cancer 5.According to the last paragraph, tissue’s lower exposure to alcohol -reduces the risk of laryngeal cancer. “Life Form Found” on Saturn’s Titan土衛(wèi)六上發(fā)現(xiàn)了生命跡象 Scientists say they have discovered hints 科學家們說，在土衛(wèi)六上發(fā)現(xiàn)了外星生命跡象并宣布了這一發(fā)現(xiàn)。美國國家航空航天局( NASA)的研究者們對卡西尼號探測器

59、所傳回來的數(shù)據(jù)進行了分析，數(shù)據(jù)表明，土星衛(wèi)星中最大的一顆衛(wèi)星有以甲烷為基礎(chǔ)的生命的存在跡象。據(jù)報道，科學家們已經(jīng)找到了在土衛(wèi)六高濃度氫氣大氣層里“呼吸”的原始外星生命的線索。他們認為，氫氣在到達布滿甲烷河流湖泊的土衛(wèi)六類似行星一樣的表層前就已經(jīng)被吸收了。這就證明在這個不及半個地球大小的衛(wèi)星表面有某種微生物在依靠氫氣生存。美國國家航空航天局的科學家Chris Mckay說，“我們提出有氫氣的消耗，是由于它是土衛(wèi)六上生命賴以生存的顯而易見的氣體，就像我們地球上用氧氣呼吸一樣。如果這些跡象最終證明是生命的跡象，它會加倍令人興奮，因為它會代表完全不同于地球上水基生命的第二種生命?！睍r至今日，盡管地球上

60、的依賴液體水的微生物在甲烷里生長良好或把它作為廢物排出，科學家在任何地方都沒有探測到這種生命的形式。在土衛(wèi)六上，絕對溫度達到90度（相當于攝氏-273.15度），依賴于甲烷的微生物不得不用某種液體物質(zhì)作為生存的介質(zhì)，這種液體不是水，水在土衛(wèi)六上會凍成冰塊，不能融化。我們知道，冰塊太冷不能維持生命。科學家們原指望太陽與大氣層中的化學物質(zhì)相互作用會在土衛(wèi)六上產(chǎn)生一層乙炔。但卡西尼號在它的表面沒有探測到乙炔。Mark Allen是美國宇航局土衛(wèi)六項目組的主要負責人，他說道，既然在土衛(wèi)六的表面沒有探測到乙炔，那就充分說明上面沒有生物。Allen說：“科學界的保守主義者們建議，要做出土衛(wèi)六上有生物的結(jié)論

61、，首先必須對土衛(wèi)六上所有沒有生物的觀點做出回應；要排除土衛(wèi)六上可能沒有生物的觀點，我們?nèi)沃氐肋h。極為可能的是，一種化學過程而非生物學能解釋這些結(jié)果?！? can explain these results. 1.What have scientists found about Saturn?-They have found methane-based life on Titan 2.What do scientists say about Titan?-There are life clues there 3.To date, scientists have not yet detect

62、ed this form of life...(paragraph 5) What does “this form of life” refer to?-Methane-based life. 4.What can be inferred from what Allen said?-Scientists have different arguments over whether there is life on Titan. 5.Which of the following can replace the title of this passage?-A different Life Fo

63、rm, a Possibility Clone Farm克隆農(nóng)場 Factory farming could soon enter a new 工業(yè)化農(nóng)場很快會進入一個大產(chǎn)量的新領(lǐng)域。美國的公司正在開發(fā)一項需要大規(guī)?？寺⌒‰u的技術(shù)。一旦一個具有所期望特性的小雞被孵化出來或被基因改造，每小時成千上萬的雞蛋就會滾下生產(chǎn)線，這些雞蛋將孵出如出一轍的小雞。每年數(shù)以十億只計的克隆小雞能被孵化出來，從而為雞場提供以相同比例生長、重量相同并且味道相同的小雞。這至少是美國國家科技院的夢想，科技院給Origen Therapeutics of Burlingame，California，以及Embrex

64、of North Carolina 470萬基金以資助研究。這個預想為擔憂增加雞場小雞痛苦的動物福利組織拉響了警報。那好像并沒有令家禽養(yǎng)殖業(yè)氣餒，然而，他們想使抗病小雞吃得更少，長得更快?！梆B(yǎng)殖者希望減少投入但仍獲得相同的產(chǎn)量，”Mike Fitzgerald of Origen說。為了達到這個要求，Origen致力于“制造一個有效克隆體的小雞，”他說。正常的克隆技術(shù)對禽類無效，因為卵不能被移動或移植。然而，公司正試圖從剛產(chǎn)下的受精卵中大量繁殖胚胎干細胞。 “訣竅是在細胞開始顯示其差別前對其進行培育，這樣它們還保持發(fā)育靈活性，”Fitzgerald說。運用早已成熟的技術(shù)，這些干細胞會被注入剛

65、產(chǎn)出、已經(jīng)受精的雞蛋的胚胎中，形成一個嵌合體的小雞。嚴格地說，嵌合體的小雞不是克隆雞，因為它既有植入的細胞又有本身的細胞。但Fitzgerald說，如果小雞身體的95%是由被植入的細胞發(fā)展而來的就足夠了。 “在家禽界，不是100%也沒關(guān)系。”O(jiān)rigen面臨的另一個挑戰(zhàn)是提高生產(chǎn)量。為了做到這點，他和Embrex合作研制了一個可將疫苗在一小時內(nèi)注入50000個雞蛋中的儀器。 Embrex正試圖改造那個儀器，從而使胚胎和注射的細胞落在準確的位置而不殺死它。在將來，Origen設(shè)想將不同品種小雞的干細胞冷凍，如果訂單要某一種小雞，成百萬的卵能在幾個月甚至幾個星期被生產(chǎn)出來。目前，維持市場可能需要

66、的所有品種小雞對養(yǎng)殖者來說太昂貴了，而且要花數(shù)年的時間才能培育足夠多的小雞以生產(chǎn)出農(nóng)民需要的數(shù)以十億只計的雞蛋。billions of eggs that farmers need 1.Which statement is the best description of the new era of factory farming according to the first paragraph?-Cloned chickens are bulk-produced with the same growth rate, weight and taste 2.Which institution has offered $4.7 million to fund the research?-The US’s National Institute of Science and Technology 3.In the third paragraph, by saying “Producers would like the same meat quantity but