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. This happens because concrete, asphalt, and buildings absorb and re-emit heat more than natural landscapes do. Also, waste heat from vehicles and air conditioners adds to the effect. Interestingly, the temperature difference can be as much as 5 to 10 degrees Fahrenheit at night.
Now, one common solution is planting more trees, which provide shade and cool the air through evapotranspiration. But there's another approach: cool roofs. These are roofs painted with reflective materials that bounce sunlight back into the atmosphere, reducing heat absorption. A study in Los Angeles found that cool roofs could lower city-wide temperatures by about 2 degrees Fahrenheit. However, cool roofs are more effective in hot, sunny climates. In cloudy or cold regions, their benefits are limited.
So, while trees are beneficial everywhere, cool roofs are a targeted solution for specific environments. Does anyone have a question?
❓ Pregunta What does the professor say about cool roofs?
A. A) They are more effective than trees in all climates.
B. B) They work best in hot, sunny climates.
C. C) They reduce heat by absorbing sunlight.
D. D) They are less effective at night than during the day.
✅ Respuesta correcta
B) They work best in hot, sunny climates.
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