第5练 阅读＋七选五＋完形＋书面表达
Ⅰ.阅读理解
体裁：科普文 话题：科学世界 词数：360 时间：7′
Sir John，a British scientist who won last year's Nobel Prize for medicine，said he had predicted at the time of his frog experiments that the successful cloning of a mammal would happen within 50 years，and that “maybe the same answer is appropriate” for the step to human cloning.Parents who lose children in accidents may be able to clone “copies” to replace them then.
Although any attempt to clone an entire human would raise complex moral issues，the biologist claimed people would soon overcome their concerns if the technique became medically useful.Cloning was regarded with extreme doubts when it was first developed but became widely accepted after the birth of Louise Brown，the first “test tube baby”．He said，“When my first frog experiments were done，an American reporter asked how long it will be before these things can be done in mammals or humans.I said，‘Well，it could be anywhere between 10 years and 100 years—how about 50 years？’It turned out that it wasn't far off the mark as far as Dolly was concerned.Maybe the same answer is appropriate.” Sir John added that cloning a human being effectively means making an identical twin，and doctors would therefore simply be “copying what nature has already produced”．
