托福听力

🎧 听力原文

Listen to part of a lecture in an environmental science class. Professor: Now, many people assume that recycling is always the most environmentally friendly option for managing waste. However, this is not always the case. Consider the life cycle of a product, from raw material extraction to manufacturing, transportation, use, and final disposal. Recycling does reduce the need for new raw materials, which is good, but the recycling process itself consumes energy and water, and can produce pollution. For example, recycling aluminum cans requires only about 5% of the energy needed to produce new cans from bauxite ore, so that's clearly beneficial. But for some plastics, the energy and resources used to collect, sort, and reprocess them may be nearly as high as producing virgin plastic, especially if the plastic is contaminated or of low quality. In such cases, incineration with energy recovery, or even landfilling, might have a lower overall environmental impact. So the key is not to generalize, but to analyze each material and local infrastructure to determine the best option.