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 materials like concrete and asphalt, which absorb and re-radiate heat. Another factor is the lack of vegetation, which normally provides cooling through evapotranspiration. But there are strategies to mitigate this effect. For example, green roofs—covering building tops with plants—can reduce rooftop temperatures by up to 40 degrees Celsius in summer. Also, increasing tree canopy in urban areas can lower air temperatures by shading streets and buildings. Interestingly, the color of surfaces matters too. White or reflective roofs, often called 'cool roofs,' can reflect sunlight and reduce heat absorption. So, while urban planning often focuses on aesthetics or economic growth, heat mitigation should be a priority for public health, especially as global temperatures rise. Now, consider this: which of these strategies is most effective in a dense city center? Well, combining several approaches often yields the best results.
❓ Question What does the professor imply about mitigating urban heat islands?
A. A single strategy is usually sufficient to reduce heat effectively.
B. Using multiple strategies together is likely to be more effective.
C. Green roofs are the only method that significantly lowers temperatures.
D. Cool roofs are less effective than increasing tree canopy.
✅ Correct Answer
Using multiple strategies together is likely to be more effective.
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