2014
高考英语阅读理解基础精品练习题(58)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 no