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. This happens because materials like concrete and asphalt absorb and re-emit heat from the sun more than natural landscapes do. Additionally, waste heat from vehicles and air conditioners adds to the effect. But there are strategies to mitigate this. One is increasing albedo, which is a measure of how much solar radiation a surface reflects. For example, painting rooftops white or using reflective materials can lower surface temperatures. Another approach is increasing vegetation, such as planting trees and creating green roofs. Plants provide shade and release moisture through transpiration, which cools the air. A study in Phoenix showed that a combination of reflective roofs and increased tree cover could reduce average summer temperatures by up to 2 degrees Celsius. However, these solutions require careful planning and community support to be effective.
❓ Pregunta What does the professor say about increasing albedo?
A. A. It involves using materials that absorb more heat.
B. B. It is the only effective way to reduce urban temperatures.
C. C. It refers to using surfaces that reflect more solar radiation.
D. D. It has no measurable impact on urban heat islands.
✅ Respuesta correcta
C. It refers to using surfaces that reflect more solar radiation.
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