2014
高考英语阅读理解基础精品练习题(71)及答案阅读理解 dna(deoxyribonucleic acid)is one of the most important discoveries in science. dna is the plan for the human being, as a blueprint is the plan for a building. dna makes a person look the way he does. a person’s dna comes from a mixing of his parents’ dna. that’s why a child looks like his parents. but, besides controlling things such as height and hair color, dna can also give people diseases. scientists are now studying dna to cure diseases. in the seventies, scientists deve