Narrator: Listen to part of a lecture in an environmental science class. Professor: Today we’re going to talk about urban heat islands. Now, you might think that cities are just warmer because of all the concrete and asphalt, but there’s more to it. The main cause is the replacement of natural surfaces, like soil and vegetation, with materials that absorb and retain heat. During the day, buildings and roads soak up solar radiation, and at night, they release it slowly, keeping the city warmer than the surrounding countryside. But here’s an interesting twist: not all cities have the same intensity of heat island effect. Factors like city size, population density, and even the local climate play a role. For example, a city in a dry, sunny region might experience a stronger effect than one in a humid area, because water vapor in the air can trap heat and also promote cloud cover, which reduces solar radiation. So, when we think about mitigating this, we often consider green roofs and reflective surfaces, but the effectiveness of these measures depends on the specific urban environment. Does anyone have a question?
❓ คำถาม What is the main cause of the urban heat island effect, according to the professor?
A. The large amount of heat generated by vehicles and factories.
B. The replacement of natural surfaces with materials that absorb heat.
C. The lack of wind in densely built areas.
D. The high population density in urban centers.
✅ คำตอบที่ถูกต้อง
The replacement of natural surfaces with materials that absorb heat.
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
