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  3. Genetically Modified Foods—Feed the World? A)If you want to spark a heated debate at a dinner party, bring up the topic of genet

Genetically Modified Foods—Feed the World? A)If you want to spark a heated debate at a dinner party, bring up the topic of genet

admin2016-10-18  31
问题                  Genetically Modified Foods—Feed the World?
A)If you want to spark a heated debate at a dinner party, bring up the topic of genetically modified foods. For many people, the concept of genetically altered, high-tech crop production raises all kinds of environmental, health, safety and ethical questions. Particularly in countries with long agrarian traditions— and vocal green lobbies—the idea seems against nature.
B)In fact, genetically modified foods are already very much a part of our lives. A third of the corn and more than half the soybeans and cotton grown in the U. S. last year were the product of biotechnology, according to the Department of Agriculture. More than 65 million acres of genetically modified crops will be planted in the U. S. this year. The genetic is out of the bottle.
C)Yet there are clearly some very real issues that need to be resolved. Like any new product entering the food chain, genetically modified foods must be subjected to rigorous testing. In wealthy countries, the debate about biotech is tempered by the fact that we have a rich array of foods to choose from—and a supply that far exceeds our needs. In developing countries desperate to feed fast-growing and underfed populations, the issue is simpler and much more urgent: do the benefits of biotech outweigh the risks?
D)The statistics on population growth and hunger are disturbing. Last year the world’s population reached 6 billion. And by 2050, the U.N. estimates, it will probably near 9 billion. Almost all that growth will occur in developing countries. At the same time, the world’s available cultivable land per person is declining. Arable land has declined steadily since 1960 and will decease by half over the next 50 years, according to the International Service for the Acquisition of Agri-Biotech Applications(ISAAA).
E)The U. N. estimates that nearly 800 million people around the world are undernourished. The effects are devastating. About 400 million women of childbearing age are iron deficient, which means their babies are exposed to various birth defects. As many as 100 million children suffer from vitamin A deficiency, a leading cause of blindness. Tens of millions of people suffer from other major ailments and nutritional deficiencies caused by lack of food.
F)How can biotech help? Biotechnologists have developed genetically modified rice that is fortified with be-la-carotene- which the body converts into vitamin A--and additional iron, and they are working on other kinds of nutritionally improved crops. Biotech can also improve farming productivity in places where food shortages are caused by crop damage attribution to pests, drought, poor soil and crop viruses, bacteria or fungi(真菌).
G)Damage caused by pests is incredible. The European corn borer, for example, destroys 40 million tons of the world’s corn crop annually, about 7% of the total. Incorporating pest-resistant genes into seeds can help restore the balance. In trials of pest-resistant cotton in Africa, yields have increased significantly. So far, fears that genetically modified, pest-resistant crops might kill good insects as well as bad appear unfounded.
H)Viruses often cause massive failure in staple crops in developing countries. Two years ago, Africa lost more than half its cassava(木薯)crop—a key source of calories—to the mosaic virus. Genetically modified, vims-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 can damage roots and cause many staple-crop failures. A gene that helps neutralize aluminum toxicity in rice has been identified.
I)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.
J)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. Today more than 1 billion people around the globe live on less than $ 1 a day. 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.
K)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 simply in the wrong place. Especially in countries with undeveloped transport infrastructures, geography restricts food availability as dramatically as genetics promises to improve it.
L)Biotech has its own "distribution" problems. Private-sector biotech companies in the rich countries cany out much of the leading-edge research on genetically modified crops. Their products are often too costly for poor fanners 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 in order to help them rapidly recoup the high costs of product development. But some of these companies are responding to needs of poor countries. A London-based company, for example, has announced that it will share with developing countries technology needed to produce vitamin-enriched "golden rice".
M)More and more biotech research is being carried out in developing countries. But to increase the impact of genetic research on the food production of those countries, there is a need for better collaboration between government agencies—both local and in developed countries—and private biotech firms. The ISAAA, for example, is successfully partnering with the U. S. Agency for International Development, local researches and private biotech companies to find and deliver biotech solutions for farmers in developing countries.
N)Will "frankenfoods" feed the world? Biotech is not a panacea, but it does promise to transform agriculture in many developing countries. If that promise is not fulfilled, the real losers will be their people, who could suffer for years to come.
It has already been proved that a gene can help alleviate aluminum toxicity in rice.
选项
答案H
解析 定位句提到“目前，研究人员已经识别出一种有助于中和水稻里铝的毒性的基因”，题干中的it has already been proved that是对论述中的has been identified的同义转述。因此选项H)正确。
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