Narrator: Listen to part of a lecture in an environmental science class. Professor: Today we're going to discuss a concept called 'urban heat islands.' This refers to the phenomenon where cities are significantly warmer than surrounding rural areas. The main cause is the replacement of natural surfaces, like soil and vegetation, with materials that absorb and retain heat, such as asphalt and concrete. Buildings and roads also block wind, reducing cooling. Additionally, human activities—like driving cars, running air conditioners, and industrial processes—release waste heat. Interestingly, the temperature difference can be as much as 10 degrees Fahrenheit on clear, calm nights. This effect has serious implications. For example, higher temperatures increase energy demand for cooling, which leads to more greenhouse gas emissions. Also, heat-related health problems become more common, especially among vulnerable populations. To mitigate this, cities are adopting strategies like planting trees on streets, creating green roofs, and using reflective materials for pavements. So, while the problem is complex, there are practical solutions being implemented.
❓ 質問 According to the professor, what is a major cause of the urban heat island effect?
A. A) The use of reflective materials in building construction
B. B) The replacement of natural surfaces with heat-absorbing materials
C. C) The increase in greenhouse gas emissions from vehicles
D. D) The lack of wind due to tall buildings
✅ 正解
B) The replacement of natural surfaces with heat-absorbing materials
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