In recent years a new farming revolution has begun, one that involves the【21】______ of lif

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 suggests, it 【23】______ biology and modem technology through such techniques as genetic engineering. Some of the new biotech companies specialize 【24】______ agriculture and are working feverishly to duplicate seeds that give a high yield, that 【25】______ diseases, drought and frost, and that reduce the need for 【26】______ chemicals. 【27】______ such goals could be achieved, it would be most beneficial. But some have raised concerns about genetically engineered crops.

In nature, genetic diversity is created within certain space. A rose 【28】______ 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 【30】______ in an attempt to transfer a desired characteristic. This could mean, 【31】______ , selecting a gene which leads to the production of a chemical with anti-freeze quality from an arc- tic fish, and inserting 【32】______ into a potato or strawberry to make it frost-resistant. In essence, 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 that geneticists can employ techniques 【35】______ as cloning and 【36】______ culture, processes that produce perfectly 【37】______ copies. Concerns about the erosion of biodiversity, therefore, 【38】______ . Genetically altered plants, however, raise new issues, such as the effects that they may have 【39】______ us and the environment. "We are flying blindly into a new era of agricultural biotechnology with high hopes, few constraints, and 【40】______ idea of the potential outcomes," said science writer Jeremy Rifkin.

【21】

A．manipulation

B．management

C．manufacture

D．maturity