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Saving lives has always been an important mission of science. Now science, and indeed all society, is facing a new dilemma:whether or not to try and save more lives through human cloning. The first cloning experiments in the 1950s involved frogs and toads. It was not until 1997 that scientists successfully cloned the first mammal, the now world-famous sheep known as Dolly. Cloning techniques have continued to improve since then, and today there are cloned mice, salmon, and cattle.

挽救生命一直是科学研究的一项重要使命。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。克隆实验开始于20世纪50年代，对象为青蛙和蟾蜍。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”。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。