新视野大学英语读写教程听力 第三册 te-unit08-a
日期:2012-05-06
[by:恒星英语学习网|//www.julie-photo.com|恒星英语||恒星英语学习网]
[00:00.00]喜欢hxen.com，就把hxen.com复制到QQ个人资料中！Legal and Moral Implications of Cloning
[00:04.43]1 At first it was just plain surprising.
[00:09.25]Word last week that a scientist named Ian Wilmut
[00:14.29]had succeeded in cloning an adult mammal
[00:17.64]— an achievement long thought impossible
[00:20.88]— caught the imagination of everyone.
[00:23.90]The laboratory process that produced Dolly,
[00:28.37]an unremarkable-looking sheep,
[00:31.21]theoretically would for humans as well.
[00:35.21]A world with human clones was suddenly within reach.
[00:41.08]It was science fiction coming to life.
[00:44.60]2 In the wake of Wilmut's announcement,
[00:49.64]governments hurried to draft guidelines for the unknown,
[00:54.04]a future filled with incredible possibilities.
[00:58.36]President Clinton ordered a national commission to study
[01:03.00]the legal and moral implications of cloning.
[01:06.67]Leaders in Europe,
[01:09.52]where most nations already prohibit human cloning,
[01:13.30]began examining the moral implications of cloning other species.
[01:18.88]3 Like the Theory of Relativity, the splitting of the atom,
[01:24.42]and the first space flight,
[01:26.29]Dolly's appearance has generated a long list of difficult puzzles
[01:31.58]for scientists, politicians, and philosophers.
[01:35.94]And we wild questions on the topic of cloning continue to mount.
[01:42.10]4 Why would anyone want to clone a human being in the first place?
[01:48.83]5 The human cloning situations that experts consider
[01:54.23]most frequently fall into two broad categories:
[01:58.91]1) parents who want to clone a child,
[02:03.01]either to provide transplants for a dying child or to replace that child,
[02:09.10]and 2) adults who for a variety of reasons might want to clone themselves.
[02:17.09]6 Will it be possible to clone the dead?
[02:21.84]7 Perhaps, if the body is fresh, says one experts.
[02:26.99]The cloning method used by Wilmut's lab requires combining an egg cell
[02:33.25]with the nucleus of a cell containing the DNA of the person to be cloned.
[02:40.24](DNA is a very long,
[02:44.77]ribbon-like molecule that contains our genetic information.)
[02:50.17]And that means that the nucleus must be intact.
[02:55.93]Cells die and the cell nucleus begins to break apart after death.
[03:02.95]But, yes, in theory at least it might be possible.
[03:07.99]8 Would a cloned human be identical to the original?
[03:13.97]9 Identical genes don't produce identical people,
[03:19.76]as anyone who knows a set of identical twins can tell you.
[03:24.84]In fact, twins are more alike than clones would be,
[03:30.31]since they have at least shared the same environment within the mother,
[03:35.35]are usually raised in the same family, and so forth.
[03:39.89]parents could clone a second child
[03:43.49]who resembled their first in appearance,
[03:46.66]but all the evidence suggests
[03:49.28]the two would have very different personalities.
[03:53.06]Twins separated at birth do sometimes share personality characteristics,
[04:01.74]but such characteristics in a cloned son or daughter
[04:06.64]would only be reminders of the child who was lost.
[04:11.32]10 Even in terms of biology,
[04:14.95]a clone would not be identical to the "master copy".
[04:20.03]The clone's cells, for example,
[04:24.06]would have energy-processing machinery that came from the egg,
[04:29.14]not from the person who was cloned.
[04:31.91]But most of the physical differences
[04:35.44]between originals and copies are so minor that detection
[04:40.51]of them would require a sophisticated laboratory.
[04:44.69]The one possible exception is bearing children.
[04:48.12]Wilmut and his coworkers are not sure that Dolly will be able to have lambs.
[04:56.22]They will try to find out once she's old enough to breed.
[05:02.27]11 What if parents decided to clone a child in order to harvest organs?
[05:11.88]12 Most experts agree that it would be psychologically harmful
[05:17.46]if a child sensed he had been brought into the world
1/2 1 2 下一页 尾页
[00:00.00]喜欢hxen.com，就把hxen.com复制到QQ个人资料中！Legal and Moral Implications of Cloning
[00:04.43]1 At first it was just plain surprising.
[00:09.25]Word last week that a scientist named Ian Wilmut
[00:14.29]had succeeded in cloning an adult mammal
[00:17.64]— an achievement long thought impossible
[00:20.88]— caught the imagination of everyone.
[00:23.90]The laboratory process that produced Dolly,
[00:28.37]an unremarkable-looking sheep,
[00:31.21]theoretically would for humans as well.
[00:35.21]A world with human clones was suddenly within reach.
[00:41.08]It was science fiction coming to life.
[00:44.60]2 In the wake of Wilmut's announcement,
[00:49.64]governments hurried to draft guidelines for the unknown,
[00:54.04]a future filled with incredible possibilities.
[00:58.36]President Clinton ordered a national commission to study
[01:03.00]the legal and moral implications of cloning.
[01:06.67]Leaders in Europe,
[01:09.52]where most nations already prohibit human cloning,
[01:13.30]began examining the moral implications of cloning other species.
[01:18.88]3 Like the Theory of Relativity, the splitting of the atom,
[01:24.42]and the first space flight,
[01:26.29]Dolly's appearance has generated a long list of difficult puzzles
[01:31.58]for scientists, politicians, and philosophers.
[01:35.94]And we wild questions on the topic of cloning continue to mount.
[01:42.10]4 Why would anyone want to clone a human being in the first place?
[01:48.83]5 The human cloning situations that experts consider
[01:54.23]most frequently fall into two broad categories:
[01:58.91]1) parents who want to clone a child,
[02:03.01]either to provide transplants for a dying child or to replace that child,
[02:09.10]and 2) adults who for a variety of reasons might want to clone themselves.
[02:17.09]6 Will it be possible to clone the dead?
[02:21.84]7 Perhaps, if the body is fresh, says one experts.
[02:26.99]The cloning method used by Wilmut's lab requires combining an egg cell
[02:33.25]with the nucleus of a cell containing the DNA of the person to be cloned.
[02:40.24](DNA is a very long,
[02:44.77]ribbon-like molecule that contains our genetic information.)
[02:50.17]And that means that the nucleus must be intact.
[02:55.93]Cells die and the cell nucleus begins to break apart after death.
[03:02.95]But, yes, in theory at least it might be possible.
[03:07.99]8 Would a cloned human be identical to the original?
[03:13.97]9 Identical genes don't produce identical people,
[03:19.76]as anyone who knows a set of identical twins can tell you.
[03:24.84]In fact, twins are more alike than clones would be,
[03:30.31]since they have at least shared the same environment within the mother,
[03:35.35]are usually raised in the same family, and so forth.
[03:39.89]parents could clone a second child
[03:43.49]who resembled their first in appearance,
[03:46.66]but all the evidence suggests
[03:49.28]the two would have very different personalities.
[03:53.06]Twins separated at birth do sometimes share personality characteristics,
[04:01.74]but such characteristics in a cloned son or daughter
[04:06.64]would only be reminders of the child who was lost.
[04:11.32]10 Even in terms of biology,
[04:14.95]a clone would not be identical to the "master copy".
[04:20.03]The clone's cells, for example,
[04:24.06]would have energy-processing machinery that came from the egg,
[04:29.14]not from the person who was cloned.
[04:31.91]But most of the physical differences
[04:35.44]between originals and copies are so minor that detection
[04:40.51]of them would require a sophisticated laboratory.
[04:44.69]The one possible exception is bearing children.
[04:48.12]Wilmut and his coworkers are not sure that Dolly will be able to have lambs.
[04:56.22]They will try to find out once she's old enough to breed.
[05:02.27]11 What if parents decided to clone a child in order to harvest organs?
[05:11.88]12 Most experts agree that it would be psychologically harmful
[05:17.46]if a child sensed he had been brought into the world
1/2 1 2 下一页 尾页