Listen to part of a lecture in an environmental science class. Professor: Today we're discussing 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 solar energy more than natural landscapes do. Also, waste heat from vehicles and buildings adds to the effect. One key factor is the lack of vegetation, which normally provides cooling through shade and evapotranspiration. So, what can be done? One solution is green roofs—rooftops covered with plants. They reduce heat absorption and improve insulation. Another approach is increasing albedo, or reflectivity, by painting roofs and pavements white or using reflective materials. Studies show that a combination of these strategies can lower city temperatures by several degrees, reducing energy demand for air conditioning. However, implementation costs and maintenance remain challenges, especially in older buildings. Still, as climate change intensifies, urban planners are increasingly considering these measures.
❓ 質問 What does the professor identify as a primary cause of urban heat islands?
A. A. Increased use of air conditioning in buildings
B. B. Absorption of solar energy by construction materials
C. C. High levels of pollution from vehicles
D. D. Lack of rainfall in urban areas
✅ 正解
B. Absorption of solar energy by construction 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