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  3. Across the United States, scientists are mounting what may become the most i

Across the United States, scientists are mounting what may become the most i

游客2024-06-09  45
问题     Across the United States, scientists are mounting what may become the most innovative agricultural research drive since the 1920’s, when hybrid corn was developed. Surprisingly, the new genetic revolution is not taking place in America’s fields. Instead, it is occurring in biology laboratories, for it involves the deliberate manipulation in test tubes of the genes of crop plants. This genetic engineering may prove the biggest boon to agriculture since plant breeding began.
    The new concepts grew out of the bioengineering of bacteria for the production of such things as human hormones and vaccines for viral diseases. Plant cells, however, are far more complex than bacteria, and it will probably take many years for today’s encouraging laboratory results to have a major impact on the farm. In fact the payoff may not come until the next century.
    But although bio-technologists are still in the earliest phases of this new field of science, they are already actively exploring ways to redesign plants so they will use sunlight mere efficiently, resist viruses and other pests, grow in hot or dry areas, in saline soils or in the presence of pesticides, and perhaps even make their own fertilizer out of nitrogen in the air. In addition, scientists have had early success in making wholly new plants that are unavailable by conventional plant breeding-a potato-tomato combination, for example.
    The new technology holds the promise of virtually limitless horizons in food production. Only imagination sets the limits: frost-resistant wheat, tropical potatoes, saltwater rice, a plant producing a combination of a pea and a carrot-all may be with us one day. [br] What will be one effect of the new biotechnology on plants?
选项 A、They will grow anywhere in the world.
B、Some will be able to grow in salty soils.
C、They will become poisonous to pests.
D、Using nitrogen from the air they will be able to cress fertilize.
答案 B
解析 此题问及新的生物工艺学对植物的影响，关键在于对文章第三段第一句话的理解。这句话讲到科学家们已积极地探索以生物技术培植作物使之能更有效地利用太阳光照，抵抗病毒及虫害，耐炎耐寒，能在盐碱土壤中生存，不怕杀虫剂，甚至可以自己从空气氮中取得肥料等。选项A扩大了生物技术对农作物的作用；选项C曲解了“pesticide”的作用。选项D中的“cross- fertilize”的意思是使异花受精。原文中的“fertilizer”是指的肥料。
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