Listen to part of a lecture in an environmental science class. The professor is discussing the concept of 'urban heat islands.'
Professor: Today, we're going to talk about urban heat islands, which are areas in cities that are significantly warmer than their rural surroundings. This happens because buildings, roads, and other infrastructure absorb and re-emit the sun's heat more than natural landscapes do. For example, asphalt and concrete have low albedo, meaning they reflect little sunlight and absorb a lot of heat. In contrast, vegetation, such as trees and grass, provides shade and releases moisture through evapotranspiration, which cools the air. So, cities often have higher temperatures, especially at night when the stored heat is slowly released. To mitigate this effect, some cities are implementing green roofs, planting more trees along streets, and using reflective materials on pavements. These strategies not only lower temperatures but also reduce energy consumption for air conditioning and improve air quality. However, these measures require careful planning and investment. So, the question is: how can we balance urban development with environmental sustainability?
❓ Pregunta What does the professor say about asphalt and concrete in the context of urban heat islands?
A. A) They reflect most of the sun's heat back into the atmosphere.
B. B) They absorb a lot of heat due to their low albedo.
C. C) They release moisture to cool the surrounding air.
D. D) They are less effective at storing heat than natural landscapes.
✅ Respuesta correcta
B) They absorb a lot of heat due to their low albedo.
TOEFL Listening Tips
Skim the questions first to predict the content
Watch for signal words in lectures and conversations (however, actually, in fact)
For main idea questions, focus on the beginning; for detail questions, focus on examples and data
For attitude questions, pay attention to the speaker's tone and word choice
Take notes on keywords; don't try to write down every word