Good morning, everyone. Today we'll continue our discussion on environmental science, focusing on urban heat islands. As we know, cities tend to be warmer than surrounding rural areas due to concrete and asphalt absorbing heat. However, a recent study in Melbourne found that increasing tree canopy by just 20% could reduce surface temperatures by up to 4 degrees Celsius. Interestingly, the study also noted that green roofs, while beneficial, had a smaller effect than street trees, because trees provide shade and evaporative cooling. The researchers emphasized that planting trees along streets, especially in residential areas, is the most cost-effective strategy.
❓ 根据讲座内容，墨尔本的研究对于降低城市热效应有何发现？
A. A. 绿色屋顶比街道树木更为有效。
B. B. 将树木覆盖率提高20%可使气温降低约4度。
C. C. 混凝土和沥青有助于减少热量吸收。
D. D. 住宅区对城市热岛效应没有影响。
✅ 正确答案
B. Increasing tree canopy by 20% could lower temperatures by about 4 degrees.