Factory farming could soon enter a new era of mass production. Companies in the USare 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 copies³ , 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 theUS"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.

词汇:

Clone/ kləʊn /n. & v.克隆，无性繁殖

embryo / ˈembriəʊ /n.胚胎

implant / "ɪmplɑ:nt /v.植入；移植

chimera / kaɪˈmɪərə /n.嵌合体

embryonic / ˌembriˈɒnɪk /adj.胚胎的

fertilise / "fɜ:tɪlaɪz /v.使受精

pluripotent / plʊə"rɪpətənt /adj.多能的

vaccine / "væksi:n /n.疫苗

注释：

1. on a massive scale:大规模
2. genetically engineered：经过基因改造。genetical engineering：遗传工程
3. hatch into identical copies：孵出如出一辙的（小）鸡
4. help fund research： 资助研究。fund用作动词，research是它的宾语。
5. put off：意为 “discourage”（使……气馁）。
6. bulk-grow： 大量繁殖
7. stem cell：干细胞
8. culture：动词，意思是：培育。
9. a freshly laid, fertilized recipient egg:新产下的；已受精的；要接受细胞植入的鸡蛋
10. scale up： 提高，按比例增加。
11. team up with：与 合作。
12. up to 50,000 eggs：多达 5 万只鸡蛋。
13. different strains of chicken：不同品种的鸡。

The technology of freezing stem cells from different strains of chicken can do all the followingEXCEPT 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

诺西UltraSite基站的M6xx单元若用于GSM900，则称为：（）

A:M6Dx B:M6Gx C:M6Hx D:M6Lx

- Excuse me, Sir, is the swimming pool open all day
-（　）.Only from 6:00 p.m. to 10:00 p.m.

A:That’ s right B:Yes, of course C:Sorry, I’ m not sure D:Sorry, I’ m afraid not