晨讀英語美文60篇58 Feed the World

[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.

00:00

00:00

MP3下載 文本下載