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[单项选择]Are genetically modified crops an environmental dream come true or a disaster in the making Scientists are looking for answers.
The world seems increasingly divided into those who favor genetically modified (GM) foods and those who fear them. Advocates assert that growing genetically altered crops can be kinder to the environment and that eating foods from those plants is perfectly safe. And, they say, genetic engineering—which can induce plants to grow in poor soils or to produce more nutritious foods— will soon become an essential tool for helping to feed the world’s burgeoning population. Skeptics contend that GM crops could pose unique risks to the environment and to health—risks too troubling to accept smoothly. Taking that view, many European countries are restricting the planting and importation of GM agricultural products. Much of the debate hinges on perceptions of safety. But what exactly does recent scientific research say about the hazards The answers, too often lost i
A. Being easy to survive.
B. Bigger production than traditional plants.
C. Enriching our food.
D. Benefiting the environment.
[填空题]Many experts who favor genetically modified foods believe that genetic engineering can help to meet the demands of the world’s increasing population.
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Five cloned piglets, genetically modified so that their organs are much less likely to be rejected by a human donor recipient, have been born in the US.
More than 62000 people in the US alone are waiting to receive donated hearts, lungs, livers, kidneys and pancreases. The number of human donors falls far short of demand. Pig organs are of a similar size to human organs, and some scientists hope they might be used to help meet the shortfall. But previous attempts to transplant unaltered pig tissue into humans have failed, due to immune rejection of the tissue.
The five piglets, born on Christmas Day, lack a gene for an enzyme that adds a sugar to the surface of pig ceils. The sugar would trigger a patient’s immune system into launching an immediate attack.
"This advance provides a near-time solution for overcoming the shortage of human organs for transplants, as well as insulin-producing cells to cure diabetes," says David Ayares, vice pres
A. To knock out one copy of the gene for the enzyme.
B. To study more genes in their program.
C. To test whether a virus from the pigs could infect human cells.
D. To transplant organs created from PPL pigs into patients
[单项选择] Genetically Modified Foods -- Feed the World
If you want to spark a heated debate at a dinner party, bring up the topic about 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.
In fact, genetically modified foods are already yew much a part of our lives. A third of the corn and more than half the soybeans and cotton grown in the US 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 US this year. The genetic is out of the bottle.
Yet there are clearly some very real issues that, need to be resolved, lake any new product entering the food chain, genetically modified foods
A. western countries
B. African countries
C. developed countries
D. developing countries