Narrator: Listen to part of a lecture in an environmental science class.
Professor: Today we're going to talk about urban heat islands, a phenomenon where cities are significantly warmer than surrounding rural areas. The main cause is the replacement of natural surfaces with materials like asphalt and concrete, which absorb and retain heat. Additionally, waste heat from vehicles and air conditioners adds to the effect. But there are solutions. One effective strategy is increasing vegetation, such as planting trees and creating green roofs. Plants provide shade and release moisture through transpiration, which cools the air. Another approach is using cool roofs, which are painted with reflective coatings to bounce sunlight back into the atmosphere. Studies show that cool roofs can lower a building's temperature by several degrees, reducing energy consumption for air conditioning. However, the choice of solution often depends on local climate and urban design. For example, in dry regions, planting trees might require too much water. So, city planners must weigh the costs and benefits. Any questions?
❓ 题目 What does the professor say about cool roofs?
A. They are more effective than planting trees in all climates.
B. They work by reflecting sunlight away from buildings.
C. They require significant water to maintain.
D. They absorb heat and release it slowly at night.
✅ 正确答案
They work by reflecting sunlight away from buildings.