公共英語PETS二級閱讀復習(33)

　　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.

　　克隆實驗開始于20世紀50年代，對象為青蛙和蟾蜍。直到1997年，科學家才成功地克隆了哺乳類動物，即世界聞名的“多莉羊”�？寺〖夹g從那時起得到了持續(xù)的進展，今天已有了克隆老鼠、克隆鮭魚和克隆牛。

　　公共英語PETS二級閱讀復習(34)

　　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.

　　挽救生命一直是科學研究的一項重要使命。如今，科學研究，其實是整個社會，正面臨著一個新的困境：是否要設法通過克隆人類來挽救更多的生命。