特别广播英语第 335 课：Is Cloning the Future? 克隆一个你？-1

Saving lives has always been an important mission of science. 挽救生命一直是科学研究的一项重要使命。

Now science, and indeed all society, is facing a new dilemma:whether or not to try and save more lives through human cloning. 如今，科学研究，其实是整个社会，正面临着一个新的困境：是否要设法通过克隆人类来挽救更多的生命。

The first cloning experiments in the 1950s involved frogs and toads. 克隆实验开始于20世纪50年代，对象为青蛙和蟾蜍。

It was not until 1997 that scientists successfully cloned the first mammal, the now world-famous sheep known as Dolly. 直到1997年，科学家才成功地克隆了哺乳类动物，即世界闻名的“多莉羊”。

Cloning techniques have continued to improve since then, and today there are cloned mice, salmon, and cattle. 克隆技术从那时起得到了持续的进展，今天已有了克隆老鼠、克隆鲑鱼和克隆牛。

Some scientists want to apply the methods used in cloning animals to produce skin, organs, and other body parts for humans. 一些科学家想用克隆动物的方法，来为人类制造人类使用的皮肤、器官与其它的身体构造。

One of these methods involves taking adult cells from the brain or blood and growing them into new tissues. 其方法之一是从脑内或血液中提取成熟细胞，把它们培养成新组织。

Another, more complex, technique takes embryo cells and develops them into a wide variety of cell types and tissues. 另外一种较为复杂的技术，则是把胚胎细胞培养成各式各样的细胞种类及组织。

It is this planned use of human embryos that has resulted in controversy and criticism. 正是这个有计划的使用人类胚胎引起了争议与批评。