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  3. With rapid growth of world population, mainly in developing countries, the available cultivable land per person has declined ste

With rapid growth of world population, mainly in developing countries, the available cultivable land per person has declined ste

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问题     With rapid growth of world population, mainly in developing countries, the available cultivable land per person has declined steadily since 1960 and will decease by half over the next 50 years. Besides, about 400 million women of childbearing age are iron deficient, leaving their babies exposed to various birth defects. As many as 100 million children suffer from vitamin A deficiency. Tens of millions of people suffer from other major ailments (疾病) and nutritional deficiencies caused by lack of food.
    How can biotech help? Biotechnologists have developed genetically modified rice that is fortified with beta-carotene(β胡萝卜素) and additional iron, and they are working on other kinds of nutritionally improved crops. Biotech can also improve farming productivity in places where crop failures are caused by pests, drought, poor soil and crop viruses or bacteria. Genetically modified, virus-resistant crops can reduce that damage, as can drought-tolerant seeds in regions where water shortages limit the amount of land under cultivation. Biotech can also help solve the problem of soil that contains excess aluminum, which damages roots and causes crop failures.
    Many scientists believe biotech could raise overall crop productivity in developing countries as much as 25% and help prevent the loss of those crops after they are harvested. Yet for all that promise, biotech is far from being the whole answer. In developing countries, lost crops are only one cause of hunger. Poverty plays the largest role. Making genetically modified crops available will not reduce hunger if farmers cannot afford to grow them or if the local population cannot afford to buy the food those farmers produce.
    Nor can biotech overcome the challenge of distributing food in developing countries. Taken as a whole, the world produces enough food to feed everyone—but much of it is in the wrong place. Especially in countries with undeveloped transport infrastructures, geography restricts food availability as dramatically as genetics promises to improve it.
    Biotech has its own "distribution" problems. Private-sector biotech companies in rich countries carry out much of the leading-edge research. Their products are often too costly for poor farmers in the developing world, and many of those products won’t even reach the regions where they are most needed. Biotech firms have a strong financial incentive to target rich markets first to help them rapidly recoup (收回) the high costs of product development. But some companies are responding to the needs.
Biotech can’t solve the problem of distributing food in developing countries because______.
选项 A、enough food can be produced to feed the world population
B、the transport infrastructures in some countries are backward
C、biotech itself can not play its role in those countries
D、farmers in those countries have no right to use the technology
答案B
解析 细节辨认题。文章提出，从整体上看，世界生产的粮食总量足够养活所有人，但大部分粮食却不是在需要的地方。尤其在道路运输基础设施落后的国家，生物科技为食物供给带来的希望有多大，地理条件对食物供给的限制就有多大。由此可得B)为答案。
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