Part A Note-taking And Gap-filling Directions: In this part of the test you will hear a short talk. You will hear the talk ONLY ONCE. While listening to the talk, you may take notes on the important points so that you can have enough information to complete a gap-filling task on a separate ANSWER BOOKLET. You will not get your ANSWER BOOKLET until after you have listened to the talk. 听力原文： Extinction is gaining speed. One of the most demanding environmental tasks is trying to preserve at least some of the 10 million life forms on the planet. The world's remaining rain forests are being logged at a rate of 5000 acres an hour. Oceans are being emptied of fish and filled with toxic waste. Wetlands are being dried out. Pastures are being turned into dust bowls or concrete jungles. Species have nowhere to and so they die. The simplest thing we can do to support biodiversity is to eat sensibly. The plants and animals that we eat reflect our relationship with nature and bind us to her. The greater the diversity we maintain in our diet, the greater the diversity we nurture in the fields and the oceans. Fast food is a remarkable and tragic phenomenon. It is indeed fast; it is also portable, hygienic and consistent. On the other hand, it is also an ecological nightmare. It is environmentally devastating, nutritionally inadequate and shuns biodiversity. Fast food chains often fatten beef in rain forests. Rainforests are cleared for cattle grazing. As a result, a medium size hamburger represents approximately five square meters of rain forests and all the hundreds and thousands of species that passed through and benefited from that five square meters. The land beneath rain forests is very poorly suited to grazing and it has to be abandoned within a couple of years and the whole process repeated somewhere else. It already takes a lot of rainforests to keep hamburger eaters happy in Japan and America. It will take even more to keep them happy in China, Vietnam and all the other destinations on multinational corporations' itineraries. Fast food chains serve the same food all over the world. That means they strive and mostly succeed in serving the same French fries made from the same type of potatoes and the same salads made from the same type of lettuce and tomatoes in every country. With biogenetic tampering heavy doses of agrochemical, almost anything is possible. Fast food chains move into countries where the fast food ingredients are quite different from traditional local ingredients. Local farmers abandon their traditional crops and try to grow the ingredients needed for the very limited international menus. Supermarkets appear to have everything. Indeed in many developed countries a large supermarket will stock an average of 22,000 items on its shelves. The diversity, however, is only in the packaging. The content is pretty much all the same. Nearly everything that you can buy to eat at a supermarket comes from a meager 30 plants and 6 animals. We are being forced to rely on fewer and fewer varieties of breeds of plants and animals. Although throughout history human beings have used more than 10,000 edible plant species for good health, now barely 150 species are grown for the human diet, and most people live off no more than 12 species. Food choices are being dangerously narrowed simply to suit monoculture, mass production, market performance and greed. Multinational corporations have already succeeded in patenting many plants and animals. They have even patented breast milk—lest in case anyone should think of selling it. We can help preserve biodiversity by eating vegetarian and by eating as wide a selection of ingredients as possible. We can choose to eat in local restaurants rather than fast food chains. We can shop in season, buy local organic produce, favor less common types of food, and avoid buying imported fruits and vegetables. We try to simplif