【F1】The agricultural sciences deal with the challenges of food and fibre production and processing. They include the technologie

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问题     【F1】The agricultural sciences deal with the challenges of food and fibre production and processing. They include the technologies of soil cultivation, crop cultivation and harvesting, animal production, and the processing of plant and animal products for human consumption and use.
    Food is the most basic human need.【F2】The domestication and cultivation of plants and animals beginning almost 10,000 years ago were aimed at ensuring that this need was met, and then as now these activities also fit with the relentless human drive to understand and control the Earth ’s biosphere. Over the last century and a half, many of the world’s political leaders have recognized what India’s Jawaharlal Nehru did, that "Most things except agriculture can wait. " Scientific methods have been applied widely, and the results have revolutionized agricultural production. Under the conditions of prescientific agriculture, in a good harvest year, six people can produce barely enough food for themselves and four others. Advanced technologies have made it possible for one farmer in the United States, for example, to produce food for more than 100 people.【F3】The farmer has been enabled to increase yields per acre and per animal; reduce losses from diseases, pests, and spoilage; and augment net production by improved processing methods.
    Until the 1930s, the benefits of agricultural research derived mostly from labour-saving inventions. Once the yield potentials of the major economic crops were increased through agricultural research, however, crop production per acre increased dramatically.【F4】Between 1940 and 1980 in the United States, for example, per-acre yields of corn tripled, those of wheat and soybeans doubled, and farm output per hour of farm work increased almost 10-fold as capital was substituted for labour.【F5】New techniques of preserving food products made it possible to transport them over greater distances, in turn facilitating adjustments among locations of production and consumption, with further benefits to production efficiency.
    From a global perspective, the international flow of agricultural technology allows for the increase of agricultural productivity in developed and developing countries alike. From 1965 to 1985, for example, world trade in grains tripled, as did net exports from the United States. In fact, by the 1980s more than two-fifths of U. S. crop production was exported, making U. S. agriculture heavily dependent upon international markets.
【F5】

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答案有了保存食品的新技术,使远距离运输食品成为可能;进而有助于调节食品生产地点和消费地点,更有利于提高生产效率。

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