Narrator: Listen to part of a lecture in an environmental science class. Professor: Today we're going to talk about a surprising solution to urban heat islands—that's where cities are significantly warmer than surrounding rural areas. Traditional methods, like white roofs or planting trees, have limitations. But recently, some cities have experimented with 'cool pavements' made from recycled materials. One promising approach uses porous asphalt mixed with reflective minerals. These pavements not only lower surface temperature but also allow water to drain through, reducing flooding. However, there's a trade-off. They may require more frequent maintenance, and in cold climates, the pores can fill with ice, making them less effective. Still, a study in Los Angeles showed that replacing standard asphalt with cool pavement reduced local temperatures by up to 3 degrees Celsius on hot days. That might not sound like much, but it can significantly reduce energy demand for air conditioning. So, while it's not a silver bullet, it's an innovative piece of the puzzle.
❓ Pregunta What is the main topic of the lecture?
A. A. The disadvantages of white roofs in urban areas
B. B. A new type of pavement designed to reduce urban heat
C. C. The history of asphalt production
D. D. Methods to increase rainfall in desert cities
✅ Respuesta correcta
B. A new type of pavement designed to reduce urban heat
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
