晨读英语美文60篇(含lrc字幕)Feed the World?
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[00:00.00]Genetically Modified Foods—Feed the World?
[00:03.67]If you want to spark a heated debate at a dinner party,
[00:08.68]bring up the topic of genetically modified foods.
[00:11.75]For many people, the concept of genetically altered,
[00:15.46]high-tech crop production raises all kinds of environmental,
[00:19.73]health, safety and ethical questions.
[00:22.70]Particularly in countries with long agrarian traditions—
[00:26.62]and vocal green lobbies—
[00:28.71]the idea seems against nature.
[00:30.77]In fact, genetically modified foods are already very much a part of our lives.
[00:36.46]A third of the corn and more than half the soybeans
[00:40.18]and cotton grown in the US last year were the product of biotechnology,
[00:44.99]according to the Department of Agriculture.
[00:47.63]More than 65 million acres of genetically modified crops
[00:52.32]will be planted in the US this year.
[00:54.53]The genetic is out of the bottle.
[00:57.03]The issue is simple and urgent:
[00:59.54]Do the benefits of biotech outweigh the risks?
[01:02.72]The statistics on population growth and hunger are disturbing.
[01:07.09]Last year the world’s population reached 6 billion.
[01:10.58]And by 2050, the UN estimates,
[01:13.77]it will probably near 9 billion.
[01:16.30]almost all that growth occer in developing countries.
[01:20.00]At the same time,
[01:20.82]the world’s available cultivable land per person is declining.
[01:25.40]The UN estimates that nearly 800 million people
[01:29.45]around the world are undernourished.
[01:31.53]The effects are devastating.
[01:33.40]How can biotech help?
[01:35.57]Biotechnologists have developed genetically modified rice
[01:39.73]that is fortified with beta-carotene --
[01:42.04]which the body converts into vitamin A—
[01:44.54]and additional iron,
[01:46.30]and they are working on other kinds of nutritionally improved crops.
[01:50.78]Biotech can also improve farming productivity in places
[01:54.71]where food shortages are caused by crop damage attribution to pests,
[01:59.65]drought, poor soil and crop viruses, bacteria or fungi.
[02:04.47]Damage caused by pests is incredible.
[02:07.19]The European corn borer, for example,
[02:09.71]destroys 40 million tons of the world’s corn crop annually,
[02:14.20]about 7% of the total.
[02:16.37]Incorporating pest-resistant genes into seeds can help restore the balance.
[02:21.51]In trials of pest-resistant cotton in Africa,
[02:24.59]yields have increased significantly.
[02:27.20]So far, fears that genetically modified,
[02:30.50]pest-resistant crops might kill good insects as well as bad appear unfounded.
[02:36.50]Viruses often cause massive failure in staple crops in developing countries.
[02:41.97]Two years ago, Africa lost more than half its cassava crop—
[02:46.01]a key source of calories—
[02:47.88]to the mosaic virus.
[02:49.52]Genetically modified,
[02:51.06]virus-resistant crops can reduce that damage,
[02:53.78]as can drought-tolerant seeds in regions
[02:57.17]where water shortages limit the amount of land under cultivation.
[03:00.69]Biotech can also help solve the problem of soil that contains excess aluminum,
[03:06.24]which can damage roots and cause many staple-crop failures.
[03:10.09]A gene that helps neutralize aluminum toxicity in rice has been identified.
[03:16.00]Many scientists believe biotech could raise overall crop productivity in developing countries
[03:22.10]as much as 25% and help prevent the loss of those crops after they are harvested.