|
导语：以下英语网为大家整理了全面的职称英语考试历年真题及答案解析，《职称英语考试试题汇总：历年真题及答案解析》供大家参考学习。更多职称英语考试试题敬请关注英语网！ 【推荐】关注英语网微信：yingyuwang2013，更快获取真题答案及成绩查询信息。 第4部分：阅读理解 (第31-45题，每题3分，共45分)． 下面有3篇短文，每篇短文后有5道题.请根据短文内容，为每题确定l个最佳选项. Genetic Engineering Genetic engineering began when the DNA molecule(分子), the most basic unit of life, was first described in 1953 by James Watson and Francis Crick. An understanding of DNA led to the altering of normal cell reproduction. Experiments with altering human cells began in 1970. In one of the first experiments, patients were injected with a virus that would produce a life-saving enzyme, but their bodies would not accept it. In 1980 patients with a rare but fatal blood disease were injected with a purified gene that was cloned through DNA technology. Another failure. Genetic engineering got a legal boost(激励) in 1980. The U.S. Supreme Court said that a patent could be granted on a genetically engineered oil-eating bacterium(细菌). This bacterium would help clean up oil spills. The ruling encouraged companies to invent new life forms, and three important medical products were quickly developed. | 
