Narrator: Listen to part of a lecture in an environmental science class.
Professor: Today we're going to talk about urban heat islands, a phenomenon where cities are significantly warmer than surrounding rural areas. One major cause is the replacement of natural surfaces with asphalt and concrete, which absorb and retain heat. Another factor is the lack of vegetation, which normally provides shade and cools the air through evapotranspiration. Now, a common solution is planting more trees, but a recent study suggests that reflective rooftops—often called 'cool roofs'—may be more effective in certain climates. Cool roofs reflect sunlight, reducing the amount of heat absorbed by buildings. However, their impact varies. In hot, dry regions, they can lower temperatures by several degrees. But in humid areas, the effect is less pronounced because water vapor in the air traps heat. So, when designing a city's climate strategy, planners must consider local weather patterns and the balance between green spaces and reflective surfaces.
❓ Question What does the professor imply about cool roofs?
A. A) They are always more effective than planting trees in reducing urban heat.
B. B) Their effectiveness depends on the local climate conditions.
C. C) They are less useful in dry regions because they reflect too much sunlight.
D. D) They should be used only in humid areas to avoid trapping heat.
✅ Correct Answer
B) Their effectiveness depends on the local climate conditions.
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
