1. This substance has now been cloned by molecular biologists. 这种物质现已被分子生物学家克隆。
2. So far, he and his team have not succeeded, though they have cloned two cows and expect to clone a cat soon. 到目前为止，他和他的团队还没有成功，尽管他们已经克隆了两头牛，而且预计很快就会克隆一只猫。
3. For reasons that aren't yet well understood, cloned animals often abort spontaneously or are born with defects. 由于无法搞懂的原因，克隆动物通常会自行流产，或者具有天生缺陷。
4. The international trade in semen and embryos from cloned animals created in north and south America and beyond was effectively impossible to police. 在北美，南美以及其他一些地方生产的精子和克隆动物胚胎，其在国际范围内的交易已经无法加以有效监管。
5. She was cloned from a single cell of an adult female sheep, overturning long-held scientific dogma that had declared such a thing biologically impossible. 她是从一只成年母羊的单个细胞中克隆出来的，这推翻了长期以来一直坚持的科学教条，该教条宣称这样的事情在生物学上是不可能（发生）的。
