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 it's more complex. One major factor is the lack of vegetation. Trees and plants provide shade and release moisture through transpiration, which cools the air. In cities, we replace green spaces with dark surfaces that absorb solar radiation during the day and release it slowly at night. So, the temperature difference between a city and its surrounding rural areas can be as much as 10 degrees Fahrenheit. Another contributor is waste heat from buildings, cars, and air conditioning units. Interestingly, studies show that adding green roofs—roofs covered with plants—can significantly reduce the heat island effect. For example, a study in Toronto found that if 6% of roofs were green, the city's temperature could drop by up to 2 degrees. So, while the problem is serious, there are practical solutions we can implement.
❓ Câu hỏi What does the professor say about the temperature difference between cities and rural areas?
A. A. It is mainly caused by the dark color of buildings.
B. B. It can be as much as 10 degrees Fahrenheit.
C. C. It is smaller at night than during the day.
D. D. It is reduced by waste heat from air conditioning.
✅ Đáp án đúng
B. It can be as much as 10 degrees Fahrenheit.
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
