听力原文 国际交流英语视听说4 第八单元

Unit 6 Food Concerns

Analytical

Listening 1

Lecturer: Let me just get my first slide up. Great. OK, everyone, today we’re going to talk about genetically-modified foods—GM foods for short. These are foods with modified genes. Nowadays, scientists can modify the genes of any animal or plant to make them grow faster, grow bigger, or even produce their own pesticides. Genetic engineers can take a gene from virtually any animal or plant and insert it into virtually any other animal or plant. For example, they can put a rat gene into lettuce to make it produce vitamin C, or put moth genes into apple plants to help them resist diseases. Some GM plants produce chemicals that fight insects. This means that insects would not be able to destroy any crops.

Lecturer: Scientists have modified the genes of Atlantic salmon to make them grow twice as fast. They’ve modified the genes of cattle and sheep so they produce medicines in their milk. Many scientists feel that GM foods could be the key to the next advances in agriculture and health. OK so far? OK. Onto the next slide. On the other hand, there’s another side to GM foods, too. Critics fear that these new foods are being rushed to market before their effects are fully understood. Scientists think that some weeds could pick up modified genes from other plants and become “superweeds”. Superweeds could spread over wide areas of land and be very hard to kill. Scientists are also worried about possible harmful effects of GM plants on insects and animals.

Lecturer: In North America and Europe, the value and impact of GM foods has become the subject of intense debate. Are you following me? Yes, you have a question?

Student 1: Yes, um, are any of these GM foods in restaurants today?

Lecturer: Oh, sure. Most people don’t even realize that they’ve been eating genetically-modified foods. In the United States, for instance, genetically modified vegetables have been sold since the mid-1990s. More than 60 percent of all processed foods on U.S. supermarket shelves—including pizza, ice cream, salad dressing, and baking powder—contain ingredients from GM soybeans, corn, or canola. And the U.S. is certainly not alone.

Lecturer: Argentina, Canada, China, South Africa, Australia, Germany, and Spain all plant plenty of genetically-modified vegetable crops. On the other hand, while scientists have created various GM animals, no GM animals have been approved for use as food yet. Any other questions?

Student 2: I have a question. Genetically modifying plants and animals sounds dangerous to me. Is it?

Lecturer: There are things to be concerned about, no question. But corporations try to offset risks by doing thorough testing—more than any other food we eat—that’s according to one of the leading developers of GM products.