2. 外语
  3. In recent years a new farming revolution has begun, one that involves the【C1】______of life at a fundamental level--the gene. The

In recent years a new farming revolution has begun, one that involves the【C1】______of life at a fundamental level--the gene. The

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问题     In recent years a new farming revolution has begun, one that involves the【C1】______of life at a fundamental level--the gene. The study of genetics has【C2】______a new industry called biotechnology. As the name suggest, it【C3】______biology and modern technology through such techniques as genetic engineering. Some of the new biotech companies specialize in agriculture and are working feverishly to【C4】______seeds that give a high yield, that【C5】______diseases, drought and frost, and that reduce the need for【C6】______chemicals. If such goals could be achieved, it would be most【C7】______. But some have raised concerns about genetically engineered crops.
    In nature, genetic diversity is created within certain【C8】______. A rose can be crossed with different kind of rose, but a rose will never cross with a potato. Genetic engineering,【C9】______usually involves taking genes from one species and inserting them into another【C10】______to transfer a desired characteristic. This could mean, for example, selecting a gene which leads to a production of a chemical with anti-freeze【C11】______from an arctic fish, and inserting it into a potato or strawberry to make it frost-resistant.【C12】______, then, biotechnology allows humans to【C13】______the genetic walls that separate species.
    Like the green revolution,【C14】______some call the gene revolution contributes to the problem of genetic uniformity--some say even more so【C15】______geneticists can employ techniques such as cloning and【C16】______culture (培养), processes that produce perfectly【C17】______copies. Concerns about the erosion of biodiversity, therefore, remain. Genetically altered plants, however, raise new【C18】______such as the effects that they may have on us and the environment. "We are flying blindly into a new【C19】______of agricultural biotechnology with high hopes, few constraints, and little idea of the potential【C20】______," said science writer Jeremy Rifkin.
【C15】
选项 A、that
B、because
C、if
D、when
答案A
解析
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