Depending on whom you ask, the experiment announced at a Texas medical conference last week was a potential breakthrough for infertile women, a tragic failure or a dangerous step closer to the nightmare scenario of human cloning.

　　There's truth to all these points of view. Infertility was clearly the motivation when Chinese doctors used a new technique to help one of their countrywomen get pregnant. Unlike some infertile women, the 30-year-old patient produced eggs just fine, and those eggs could be fertilized by sperm. But they never developed properly, largely because of defects in parts of the egg outside the fertilized nucleus. So using a technique developed by Dr. James Grifo at New York University, Dr. Zhuang Guanglun of Sun Yat-sen University in Guangzhou took the patient's fertilized egg, scooped out the chromosome-bearing nuclear material and put it in a donated egg whose nucleus had been removed. In this more benign environment, development proceeded normally, and the woman became pregnant with triplets who carried a mix of her DNA and her husband's--pretty much like any normal baby.

　　What has some doctors and ethicists upset is that this so-called nuclear-transfer technique has also been used to produce clones, starting with Dolly the sheep. The only significant difference is that with cloning, the inserted nucleus comes from a single, usually adult, cell, and the resulting offspring is genetically identical to the parent. Doing that with humans is ethically repugnant to many. Besides, for reasons that aren't yet well understood, cloned animals often abort spontaneously or are born with defects; Dolly died very young, though she had seemed healthy. And because the Chinese woman's twins were born prematurely and died (the third triplet was removed early on to improve chances for the remaining two), critics have suggested that cloning and nuclear transfer are equally risky for humans.

　　Not likely, says Grifo. "The obstetric outcome was a disaster," he admits, "but the embryos were chromosomally normal. We have no evidence that it had anything to do with the procedure." Even so, concern over potential risks is why the Food and Drug Administration created a stringent approval process for such research in 2001--a process that Grifo found so onerous that he stopped working on the technique and gave it to the researchers in China, where it was subsequently banned (but only this month, long after Zhuang's patient became pregnant).

　　The bottom line, say critics, is that perfecting a technique that could be used for human cloning, even if it were developed for another purpose, is just a bad idea--an assertion Zhuang rejects. "I agree that it makes sense to control these experiments," he says. "But we've developed an effective technology to help people. We understand how to do it. We need it."

1.What is implied in the first paragraph?
　　[A]Some people regard it as a tragic failure.
　　[B]The new experiment means a breakthrough for some people.
　　[C]People have different reactions to the new experiment.
　　[D]The new experiment means a step further to the dangerous human cloning.

2.The author uses the case of Dolly and the Chinese pregnant woman to show that _________.
　　[A]both nuclear-transfer and cloning are dangerous for humans and animals
　　[B]both of them benefit from the new technique
　　[C]both of them are the examples of technical failure
　　[D]both of them are the fruits of the new technology

3.Zhuang’s attitude toward the critics’ conclusion is one of __________.
　　[A]reserved consent
　　[B]strong disapproval
　　[C]slight contempt
　　[D]enthusiastic support

4.The only difference existing between nuclear-transfer and cloning technique is ________.
　　[A]whether it is used for research or for helping the infertile
　　[B]whether the offspring looks like the parent
　　[C]whether it is used in animals or human beings
　　[D]whether the inserted nucleus comes from a single and usually adult cell

5.The text intends to express the idea that _________.
　　[A]research of cloning has potential risks
　　[B]the research of cloning should be stopped totally
　　[C]ethics and research of cloning are in contradiction
　　[D]researchers should have the right to continue the study of cloning

　　答案：CABDC

　　篇章剖析

　　本文采用提出问题——分析问题的模式，指出细胞核移植和克隆技术上存在的伦理方面的争议以及研究人员本人对此事的看法。在第一段指出人们对一项新成果的不同看法；第二段指出这一技术对一名中国不孕妇女的帮助；第三段指出细胞核移植和克隆技术的区别以及都存在的危险性；第四段和第五段指出研究人员的一些做法和看法。

　　词汇注释

　　ethical[5eWIk(E)l]adj.与伦理有关, 民族的, 民族特有的

　　impregnate[5Impre^neIt; (?@) Im5pre^net]vt.使怀孕, 使受精, 使充满, 注入, 灌输

　　deem[di:m]v.认为, 相信

　　infertile[In5f\:taIl]adj.不肥沃的, 贫瘠的, 不毛的, 不结果实的

　　breakthrough[5breIkWru:]n.突破

　　scenario[sI5nB:rIEJ]n.想定；游戏的关,或是某一特定情节

　　clone[klEJn]n.无性系, 无性繁殖, 克隆v.无性繁殖, 复制

　　fertilize[5f\:tIlaIz]vt.施肥, 使丰饶, 使受精, 使肥沃, 使多产

　　sperm[sp\:m]n.精液, 精子, 鲸油

　　nucleus[5nju:klIEs; (?@) 5nu:-]n.核子

　　scoop out v.接应, 舀出

　　chromosome[5krEJmEsEJm]n.[生物]染色体

　　benign[bI5naIn]adj.(病)良性的, (气候)良好的, 仁慈的, 和蔼的

　　triplet[5trIplIt]n.三个一幅, 三个一组, 三份

　　triplets n.三胞胎

　　repugnant[rI5pQ^nEnt]adj. 引起厌恶或反感的；讨厌的或可憎的；不一致的

　　obstetric[Cb`stetrIk]adj.产科的

　　stringent[5strIndVEnt]adj.严厉的, 迫切的, 银根紧的

　　onerous[5RnErEs, 5EJnErEs]adj.繁重的, 费力的, 负有法律责任的

　　bottom line n. 结果，结局,最后结果或声明；

　　难句突破

　　Even so, concern over potential risks is why the Food and Drug Administration created a stringent approval process for such research in 2001--a process that Grifo found so onerous that he stopped working on the technique and gave it to the researchers in China, where it was subsequently banned (but only this month, long after Zhuang's patient became pregnant).

　　主体句式：…concern over potential risks is why …

　　结构分析：“a process”在句子中的语法成分是同位语；后面又跟了一个“that”引导的定语从句；在从句中又使用了“so…that”句式；在从句中又使用了“where”引导的从句。

　　句子译文：尽管如此，由于担心潜在的危险，美国食品药物管理局2001年就类似研究制定了较为严格的批准程序——这是一套令葛瑞佛觉得太过于烦琐而终止了这一技术的研究工作，并将其转给了中国研究人员的程序。这项研究工作后来在中国也被禁止（在本月才刚被禁止，这是发生在庄的病人怀孕后很久以后的事了）。