In recent years a new farming revolution has begun, one that involves the【1】of life at a fundamental level-the gene. The study o

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问题     In recent years a new farming revolution has begun, one that involves the【1】of life at a fundamental level-the gene. The study of genetics has【2】a new industry called biotechnology. As the name suggests, it【3】biology and modern technology through such techniques as genetic engineering. Some of the new biotech companies specialize in agriculture and are working feverishly to【4】seeds that give a high yield, that【5】disease, drought and frost, and that reduce the need for【6】chemicals. If such goals could be achieved, it would be most【7】. But some have raised concerns about genetically engineered crops.
    In nature, genetic diversity is created within certain【8】. A rose can be crossed with a different kind of rose, but a rose will never cross with a potato. Genetic engineering【9】usually involves taking genes from one species and inserting them into another【10】to transfer a desired characteristic. This could mean, for example, selecting a gene which leads to the production of a chemical with anti-freeze【11】from an arctic fish, and inserting it into a potato or strawberry to make it frost-resistant.【12】, then, biotechnology allows humans to【13】the genetic walls that separate species.Like the green revolution,【14】some call the gene revolution contributes to the problem of genetic uniformity-some say even more【15】geneticists can employ techniques such as cloning and【16】culture, processes that produce perfectly【17】copies. Concerns about the erosion of biodiversity, therefore, remain. Genetically altered plants, however, raise new【18】, such as the effect they may have on us and environment. ".We are flying blindly into a new【19】of agricultural biotechnology with high hopes, few constraints and little idea of the potential【20】," said science writer Jemery Rifkin.

选项 A、after all
B、on the other hand
C、in any case
D、as a result

答案B

解析 考查短语辨析与上下文逻辑关系。After all意为“毕竟”;on the other hand意为“另一方面”in any case意为“无论如何”;as a result意为“结果”。上文中的句子说,一朵玫瑰可以同一朵不同种类的玫瑰杂交,但是一朵玫瑰永远不可能同一个土豆杂交;本句话说,基因工程通常涉及从一个物种提取基因并植入另一物种,这说明前后两句话的意思是相对应的,故选项B正确。
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