2. 外语
  3. In recent years a new farming revolution has begun, one that involves the 【21】______ of life at a fundamental level—the gene.

In recent years a new farming revolution has begun, one that involves the 【21】______ of life at a fundamental level—the gene.

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问题      In recent years a new farming revolution has begun, one that involves the  【21】______   of life at a fundamental level—the gene. The study of genetics has  【22】______   a new industry called biotechnology. As the name suggest, it  【23】______   biology and modem technology through such techniques as genetic engineering. Some of the new biotech companies specialize in agriculture and are working feverishly to  【24】______   seeds that give a high yield, that  【25】______   diseases, drought and frost, and that reduce the need for  【26】______   chemicals. If such goals could be achieved, it would be most  【27】______   . But some have raised concerns about genetically engineered crops.
     In nature, genetic diversity is created within certain  【28】______   . A rose can be crossed with a different kind of rose, but a rose will never cross with a potato. Genetic engineering,  【29】______   usually involves taking genes from one species and inserting them into another  【30】______   to transfer a desired Characteristic. This could mean, for example, selecting a gene which leads to the production of a chemical with antifreeze  【31】______   from an artic fish, and inserting it into a potato or strawberry to make it frost-resistant.  【32】______   , then, biotechnology allows humans to  【33】______   the genetic walls that separate species.
     Like the green revolution,  【34】______   some call the gene revolution contributes to the problem of genetic uniformity—some say even more so  【35】______   geneticists can employ techniques such as cloning and  【36】______   culture(培养), processes that produce perfectly  【37】______   copies. Concerns about the erosion of biodiversity, therefore, remain. Genetically altered plants, however, raise new  【38】______   , such as the effects that they may have on us and the environment. "We are flying blindly into a  【39】______   of agricultural biotechnology with high hopes, few constraints, and little idea of the potential  【40】______   ," said science writer Jeremy Rifkin.
【29】
选项 A、after all
B、on the other hand
C、in any case
D、as s rest
答案B
解析 空格处的上文已经指出了基因工程其中的一个方面的情况，那么下文就是从另一个方面来说明它的情况。on the other hand“另—个方面”在写作中经常遇到。
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