Listen to part of a lecture in an environmental science class. The professor is discussing the concept of urban heat islands.
"Now, urban areas tend to be warmer than surrounding rural areas, a phenomenon we call the urban heat island effect. This happens because concrete, asphalt, and buildings absorb and re-emit solar heat more than natural landscapes do. Additionally, human activities like driving cars and running air conditioners generate waste heat. But here's an interesting point: not all urban surfaces contribute equally. Dark roofs, for instance, can reach temperatures up to 80 degrees Celsius on a hot day, while green roofs—covered with vegetation—stay much cooler. Green roofs also help with stormwater management by absorbing rainwater, which reduces runoff and the strain on drainage systems. Moreover, they provide insulation, cutting energy costs for heating and cooling. Some cities, like Chicago, have implemented green roof initiatives, offering incentives to building owners. However, the initial cost can be a barrier, and maintenance requires specialized knowledge. Still, the long-term benefits often outweigh these challenges."
❓ 题目 According to the professor, what is one major benefit of green roofs mentioned in the lecture?
A. They reduce the need for air conditioning by generating electricity.
B. They absorb rainwater, helping to manage stormwater runoff.
C. They are cheaper to install than traditional dark roofs.
D. They eliminate all waste heat from human activities.
✅ 正确答案
They absorb rainwater, helping to manage stormwater runoff.