【導(dǎo)讀】本文是由中大職稱英語考試網(wǎng)編輯整理的職稱英語衛(wèi)生類相關(guān)復(fù)習(xí)題，更多免費(fèi)精選職稱英語考試練習(xí)題盡在中大職稱英語考試網(wǎng)，敬請關(guān)注！

Clone Farm

Factory farming could soon enter a new era of mass production. Companies in the US are developing the technology needed to "clone" chickens on a massive scale1. Once a chicken with desirable traits has been bred or genetically engineered2, tens of thousands of eggs, which will hatch into identical copies , could roll off the production lines every hour. Billions of clones could be produced each year to supply chicken farms with birds that all grow at the same rate, have the same amount of meat and taste the same.

This, at least, is the vision of the US's National Institute of Science and Technology, which has given Origen Therapeutics of Burlingame, California, and Embrex of North Carolina $4.7 million to help fund research4. The prospect has alarmed animal welfare groups, who fear it could increase the suffering of farm birds.

That's unlikely to put off5 the poultry industry, however, which wants disease-resistant birds that grow faster on less food. "Producers would like the same meat quantity but to use reduced inputs to get there," says Mike Fitzgerald of Origen. To meet this demand, Origen aims to "create an animal that is effectively a clone", he says. Normal cloning doesn't work in birds because eggs can't be removed and implanted. Instead, the company is trying to bulk-grow6, embryonic stem cells7 taken from fertilized eggs as soon as they're laid. "The trick is to culture8 the cells without them starting to distinguish, so they remain pluripotent," says Fitzgerald.

Using a long-established technique, these donor cells will then be injected into the embryo of a freshly laid, fertilized recipient egg9, forming a chick that is a "chimera". Strictly speaking a chimera isn't a clone, because it contains cells from both donor and recipient. But Fitzgerald says it will be enough if, say, 95 percent of a chicken's body develops from donor cells. "In the poultry world, it doesn't matter if it's not 100 percent," he says.

Another challenge for Origen is to scale up10 production. To do this, it has teamed up with11 Embrex, which produces machines that can inject vaccines into up to 50,000 eggs12 an hour. Embrex is now trying to modify the machines to locate the embryo and inject the cells into precisely the right spot without killing it.

In future, Origen imagines freezing stem cells from different strains of chicken13. If orders come in for a particular strain, millions of eggs could be produced in months or even weeks. At present, maintaining all the varieties the market might call for is too expensive for breeders, and k takes years to breed enough chickens to produce the billions of eggs that farmers need.

詞匯：

clone 克隆，無性繁殖 implant 植入；移植

embryonic胚胎的 fertilise 使受精

pluripotent 多能的 embryo 胚胎

chimera 嵌合體 vaccine 疫苗

注釋：

1. on a massive scale:大規(guī)模

2. genetically engineered：經(jīng)過基因改造。genetical engineering：遺傳工程

3. hatch into identical copies：孵出如出一轍的（?。╇u

4. help fund research： 資助研究。fund用作動詞，research是它的賓語。

5. put off：意為 “discourage”（使……氣餒）。

6. bulk-grow： 大量繁殖

7. stem cell：干細(xì)胞

8. culture：動詞，意思是：培育。

9. a freshly laid, fertilized recipient egg:新產(chǎn)下的；已受精的；要接受細(xì)胞植入的雞蛋

10. scale up： 提高，按比例增加。

11. team up with：與 合作。

12. up to 50,000 eggs：多達(dá) 5 萬只雞蛋。

13. different strains of chicken：不同品種的雞。

練習(xí)：

1. Which statement is the best description of the new era of factory farming according to the first paragraph?

A. Eggs are all genetically engineered.

B. Thousands of eggs are produced every hour.

C. Cloned chickens are bulk-produced with the same growth rate, weight and taste.

D. Identical eggs can be hatched on the production lines.

2. Which institution has offered $4.7 million to fund the research?

A. The US’s National Institute of Science and Technology.

B. Origen therapeutics of Burlingame, California.

C. Embrex of North Carolina.

D. Animal welfare groups.

3. In the third paragraph, by saying “Producers would like the same meat quantity but to use reduced inputs to get there.” Mike Fitzgerald means that he wishes

A. chickens’ quality could be maintained but with less investment.

B) chickens' taste could be improved but at less costs.

C) chickens' growth rate could be quickened but with less inputs.

D) chickens could grow to the same weight but with less feed.

4. Which of the following statements about Origen and Embrex is correct according to the fifth paragraph?

A) Origen and Embrex will jointly invent machines to increase production.

B) Origen wants to purchase an efficient donor cells injecting machine.

C) Origen has joined hands with Embrex in producing cell-injecting machines.

D) Origen is the leading company in producing embryo-locating machines.

5. The technology of freezing stem cells from different strains of chicken can do all the following EXCEPT that

A) farmers can order certain strains of chicken only.

B) Origen can supply all the strains of chicken the market might need.

C) chicken farmers order certain strains of chicken for economic reasons.

D) chicken farmers can be supplied with whatever strain they need.

答案與題解：

1. C 第一段最后一句提供了直接的答案。 .

2. A 第二段共提到三個研究機(jī)構(gòu)和一個民間組織。The US's National Institute of Science and Technology為研究提供了經(jīng)費(fèi)，被資助的研究機(jī)構(gòu)是Origen Therapeutics of Burlingame, California 禾口 Embrex of North Carolina.因此，A 是答案。

3. D 原句的意思有兩點(diǎn)是關(guān)鍵的，即每只雞提供的肉量不變，但飼料（inputs)要減 少。只有D符合原意。

4. C 該段第二個句子中which引導(dǎo)的從句表明，是Embrex生產(chǎn)疫苗注射裝置，而 不是兩家研究單位共同研制。Embrex在此基礎(chǔ)上將裝置改造為細(xì)胞注射裝置。所以， 只有C最接近原意。

5. A 最后一段的大意是，如果能冷凍所有品種的雞的干細(xì)胞，那么，無論需要什么 品種的雞或多少數(shù)量，都不是問題。但是，目前儲備所有品種是非常昂貴的。B、C、 D從幾方面表達(dá)了這層意思。因此，只有A是答案。

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