Listen to part of a lecture in an environmental science class. Professor: Today we're discussing a fascinating phenomenon known as 'urban heat islands.' This occurs when cities are significantly warmer than surrounding rural areas. The primary cause is the replacement of natural land cover with materials like asphalt and concrete, which absorb and retain heat during the day and release it slowly at night. Additionally, waste heat from vehicles, air conditioners, and industrial processes contributes to the effect. Vegetation, which provides shade and releases moisture through transpiration, is often scarce in dense urban areas, exacerbating the temperature difference. Interestingly, the heat island effect can have serious consequences, such as increased energy demand for cooling, higher greenhouse gas emissions, and amplified health risks during heat waves. However, solutions exist, including green roofs, planting street trees, and using reflective building materials. These measures not only lower temperatures but also improve air quality. So, while urban heat islands pose challenges, they also present opportunities for sustainable urban design.
❓ 문제 According to the professor, what is a major cause of the urban heat island effect?
A. A. The absence of wind in city centers
B. B. The replacement of natural surfaces with heat-absorbing materials
C. C. The overuse of air conditioning in buildings
D. D. The lack of rainfall in urban areas
✅ 정답
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