Narrator: Listen to part of a lecture in an environmental science class. Professor: Today we're going to talk about urban heat islands. As you know, cities tend to be warmer than surrounding rural areas. This is due to several factors: dark surfaces like asphalt and rooftops absorb solar radiation, and the lack of vegetation reduces cooling through evapotranspiration. But there's a lesser-known contributor: waste heat from buildings and vehicles. Now, a common mitigation strategy is planting trees, but recent studies show that reflective or 'cool' roofs might be even more effective. Cool roofs are painted white or coated with special materials that reflect sunlight. In a study in Los Angeles, adding cool roofs across the city could lower average temperatures by about two degrees Celsius. However, there's a trade-off: in colder climates, cool roofs might increase heating costs in winter. So urban planners must consider local climate when deciding on mitigation strategies. Any questions?
❓ Вопрос What does the professor say about cool roofs?
A. A) They are less effective than planting trees in all climates.
B. B) They can reduce city temperatures but may increase heating costs in colder regions.
C. C) They absorb more solar radiation than traditional rooftops.
D. D) They are most beneficial in cold climates due to reduced heating needs.
✅ Правильный ответ
B) They can reduce city temperatures but may increase heating costs in colder regions.
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