托福听力

🎧 听力原文

Listen to part of a lecture in an environmental science class. The professor is discussing the concept of urban heat islands. "Now, urban heat islands are areas in cities that are significantly warmer than their rural surroundings. This happens because materials like concrete and asphalt absorb and retain heat during the day and release it slowly at night. In contrast, rural areas with vegetation and soil have more moisture, which cools the air through evaporation. One major factor is the lack of trees and green spaces in cities. Trees provide shade and release water vapor, which lowers temperatures. Another factor is waste heat from vehicles, air conditioners, and industrial processes. So, what can be done? One solution is to plant more trees and create green roofs—these are rooftops covered with vegetation. Green roofs not only reduce heat but also manage stormwater. Another approach is using reflective materials for pavements and buildings, which bounce sunlight back instead of absorbing it. However, these solutions require investment and planning. Still, as cities grow, addressing heat islands becomes crucial for public health and energy consumption. Now, let's consider a case study from a city that implemented green roofs..."