Narrator: Listen to part of a lecture in an environmental science class. Professor: Today we're going to talk about the urban heat island effect. This phenomenon occurs when cities are significantly warmer than surrounding rural areas. Why? Well, concrete and asphalt absorb and re-radiate heat more than natural surfaces like soil and vegetation. Also, buildings block wind and trap heat, and human activities—like driving cars or running air conditioning—generate additional heat. But here's an interesting point: not all cities experience the same intensity. Factors like city size, population density, and climate play a role. For example, a city in a humid region might have a smaller heat island effect than a dry one, because moisture in the air can absorb heat and reduce temperature extremes. Additionally, green spaces, such as parks with trees and ponds, can mitigate the effect by providing shade and evaporative cooling. So, when urban planners consider how to reduce heat, they often focus on increasing vegetation and using reflective materials for roofs and pavements. Now, let's consider a specific case—the city of Phoenix, Arizona. Its heat island effect is quite pronounced. Can anyone suggest why?
❓ Pregunta According to the professor, why might a city in a humid region have a smaller urban heat island effect than a dry city?
A. A. Because humid air reduces the amount of heat absorbed by concrete.
B. B. Because moisture in the air can absorb heat and reduce temperature extremes.
C. C. Because cities in humid regions tend to have more green spaces.
D. D. Because human activities in humid regions generate less additional heat.
✅ Respuesta correcta
B. Because moisture in the air can absorb heat and reduce temperature extremes.
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