单选题 In recent years a new farming revolution has begun, one that involves the manipulation of life at a fundamental level—the gene. The study of genetics has (51) a new industry called biotcehnology. As the name suggests, it (52) biology and modern technology through such techniques as genetic engineering. Some of the new biotech companies specialize in agriculture and are working feverishly to (53) seeds that give a high yield, that (54) diseases, drought and frost, and that reduce the need for hazardous chemicals, If such goals could be achieved, it would be most (55) . But some have raised concerns about genetically engineered crops.
In nature, genetic diversity is created within certain (56) . A rose can be crossed with a different kind of rose, but a rose will never cross with a potato. Genetic engineering, (57) usually involves taking genes from one species and inserting them into another in an attempt to transfer a desired characteristic. This could mean, for example, selecting a gene which leads to the production of a chemical with anti-freeze (58) from an artic fish, and inserting it into a potato or strawberry to make it frost, resistant, in essence, then, biotechnology allows humans to (59) the genetic walls that separate species.
Just like the green revolution, (60) some call the gene revolution contributes to the problem of genetic uniformity-some say even more so (61) geneticists can employ techniques such as cloning and (62) culture (培养) and processes that produce perfectly (63) copies. Concerns about the erosion of biodiversity, therefore, remain. Genetically altered plants, however, raise new (64) ,such as the effects that they may have on us and the environment. "We are tlying blindly into a new era of agricultural biotechnology with high hopes, few constraints, and little idea of the potential (65) ," said science writer Jeremy Rifkin.