新SAT官方指南阅读第十八篇全解析This passage is adapted from Emily Anthes,Frankenstein's Cat.©2013by Emily Anthes.
When scientists first learned how to edit the genomes of animals,they began to imagine all the ways they could u this new power.Creating brightly colored novelty pets was not a high
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priority.Instead,most rearchers envisioned far more conquential applications,hoping to
create genetically engineered animals that saved human lives.One enterpri is now delivering on 5
this dream.Welcome to the world of“pharming,”in which simple genetic tweaks turn animals into living pharmaceutical factories.
Many of the proteins that our cells crank out naturally make for good medicine.Our bodies’own enzymes,hormones,clotting factors,and antibodies are commonly ud to treat cancer,
goddamnitdiabetes,autoimmune dias,and more.The trouble is that it’s difficult and expensive to make 10
the compounds on an industrial scale,and as a result,patients can face shortages of the
medicines they need.Dairy animals,on the other hand,are expert protein producers,their udders swollen with milk.So the creation of the first transgenic animals—first mice,then other
species—in the1980s gave scientists an idea:What if they put the gene for a human antibody or enzyme into a cow,goat,or sheep?If they put the gene in just the right place,under the control of the right molecular switch,maybe they could engineer animals that produced healing human
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proteins in their milk.Then doctors could collect medicine by the bucketful.
Throughout the1980s and’90s,studies provided proof of principle,as scientists created transgenic mice,sheep,goats,pigs,cattle,and rabbits that did in fact make therapeutic compounds in their milk.At first,this work was merely gee-whiz,scientific geekery,lab-bound thought
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experiments come true.That all changed with ATryn,a drug produced by the Massachutts firm GTC Biotherapeutics.ATryn is antithrombin,an anticoagulant that can be ud to prevent
life-threatening blood clots.The compound,made by our liver cells,plays a key role in keeping our bodies clot-free.It acts as a molecular bouncer,sidling up to clot-forming compounds and
escorting them out of the bloodstream.But as many as1in2,000Americans are born with a
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genetic mutation that prevents them from making antithrombin.The patients are prone to clots, especially in their legs and lungs,and they are at elevated risk of suffering from fatal
complications during surgery and childbirth.Supplemental antithrombin can reduce this risk,and GTC decided to try to manufacture the compound using genetically engineered goats.
To create its special herd of goats,GTC ud microinjection,the same technique that
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produced GloFish and AquAdvantage salmon.The company’s scientists took the gene for human antithrombin and injected it directly into fertilized goat eggs.Then they implanted the eggs in the wombs of female goats.When the kids were born,some of them proved to be transgenic,the
human gene nestled safely in their cells.The rearchers paired the antithrombin gene with a
promoter(which is a quence of DNA that controls gene activity)that is normally active in the 35
goat’s mammary glands during milk production.When the transgenic females lactated,the
promoter turned the transgene on and the goats’udders filled with milk containing antithrombin.
All that was left to do was to collect the milk,and extract and purify the protein.Et voilà—human medicine!And,for GTC,liquid gold.ATryn hit the market in2006,becoming the world’s first
transgenic animal drug.Over the cour of a year,the“milking parlors”on GTC’s300-acre farm 40
in Massachutts can collect more than a kilogram of medicine from a single animal.
22、The primary purpo of the passage is to
A)prent the background of a medical breakthrough.
B)evaluate the rearch that led to a scientific discovery.
C)summarize the findings of a long-term rearch project.
D)explain the development of a branch of scientific study.
zhimei正确答案：A
分析：文章的重点是介绍基因工程发展的背景（注：pharming在这里应理解成基因工程或基因改造）。在第6-7行，作者使用了如下语言：welcome to the world of pharming,in which simple genetic tweaks turn animals into living pharmaceutical factories.紧接着，文章讨论了这种技术的逐年发展，描述了一种有用的药物ATryn.
23、The author’s attitude toward pharming is best described as one of
A)apprehension.
B)ambivalence.
conveyed
C)appreciation.
D)astonishment.
正确答案：C
分析：通篇文章讲述的是如何通过基因改造，帮助人类治疗疾病。文章开头段落也提到：基因工程将动物变成了一个医药工厂。因此作者态度应该是积极赞赏的。
24、As ud in line12,“expert”most nearly means
A)knowledgeable.
B)professional.
C)capable.venus什么意思
D)trained.
正确答案：C
frisby分析：文章原句的意思是：奶畜是有能力的蛋白生产者。
25、What does the author suggest about the transgenic studies done in the1980s and1990s?
A)They were limited by the expensive nature of animal rearch.
B)They were not expected to yield products ready for human u.
C)They were completed when an anticoagulant compound was identified.
D)They focud only on the molecular properties of cows,goats,and sheep.
正确答案：B
分析：文章20行，作者提到：this work was merely gee-whiz,scientific geekery,lab-bound thought experiments come true.翻译成中文是：这项工作（转基因研究）是夸大其词的，有科学极客范儿的，受限于实验室的想法的实验。换言之，转基因技术还没有能够为人所用。
rice是什么意思26、Which choice provides the best evidence for the answer to the previous question?
A)Lines9-11(“d”)
B)Lines14-16(“ilk”)
C)Lines19-20(“ue”)
D)Lines20-22(“lots”)
正确答案：C
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分析：见25题分析。
27、According to the passage,which of the following is true of antithrombin?
A)It reduces compounds that lead to blood clots.
B)It stems from a genetic mutation that is rare in humans.
C)It is a quence of DNA known as a promoter.
D)It occurs naturally in goats’mammary glands.
正确答案：A
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分析：文章23-24行解释到：ATryn“acts as a molecular bouncer,sidling up to clot-forming compunds and escorting them out of the bloodstream.”因此，抗凝血酶antithrombin能够减少血液循环中危险血块的数量。
28、Which choice provides the best evidence for the answer to the previous question?shirt是什么意思中文
A)Lines7-9(“”)
B)Lines23-24(“bloodstream”)
C)Lines24-25(“antithrombin”)
D)Lines33-35(“production”)
正确答案：B
分析：见27题解释。
29、Which of the following does the author suggest about the“female goats”mentioned in line 33?
