Listen to part of a lecture in an environmental science class. Professor: Today we're discussing the concept of 'carbon footprint'—the total amount of greenhouse gases, especially carbon dioxide, that are emitted by human activities. But it's not just about driving cars or flying planes. Consider the food you eat. The production of a single kilogram of beef, for example, can generate more than 27 kilograms of CO2, due to land clearing, fertilizer production, and methane from cattle. In contrast, growing vegetables like potatoes has a much lower footprint. However, there's a catch: transport and packaging can add significantly to the footprint of any food, especially if it's out of season and shipped from far away. So, the idea of 'food miles' matters. But recent research suggests that what you eat matters more than where it comes from, because agricultural practices dominate emissions. For instance, a locally raised beef still has a huge footprint compared to imported beans. So, in your projects, I want you to analyze not just transportation, but the entire lifecycle of a food product.
❓ 题目 What is the professor's main point about food and carbon footprints?
A. A. Transportation is the most significant factor in a food's carbon footprint.
B. B. The type of food consumed has a greater impact than its transportation distance.
C. C. Local food always has a smaller carbon footprint than imported food.
D. D. Beef production is less damaging to the environment than vegetable farming.
✅ 正确答案
B. The type of food consumed has a greater impact than its transportation distance.