Listen to part of a lecture in an environmental science class.
Professor: Today we're going to talk about urban heat islands. As cities grow, they replace natural surfaces like soil and vegetation with asphalt, concrete, and buildings. These materials absorb and retain heat from the sun much more than natural landscapes do. As a result, urban areas can be significantly warmer than the surrounding rural areas, sometimes by as much as 5 to 10 degrees Fahrenheit. This phenomenon is known as the urban heat island effect.
One major consequence is increased energy consumption, because people use more air conditioning during hot days. This leads to higher greenhouse gas emissions, which contributes to climate change. There are also health risks, especially for vulnerable populations like the elderly.
But there are solutions. Planting trees and creating green roofs can help cool the air through shade and evapotranspiration. Using reflective materials on roads and buildings also reduces heat absorption. Some cities have implemented these strategies with promising results. However, it's important to consider the local climate and urban design when applying these solutions.
❓ คำถาม What is the main topic of the lecture?
A. The causes and effects of urban heat islands
B. The benefits of air conditioning in cities
C. The history of urban planning
D. The health risks of climate change
✅ คำตอบที่ถูกต้อง
The causes and effects of urban heat islands
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