Narrator: Listen to part of a lecture in an environmental science class. Professor: Today we're going to talk about urban heat islands, a phenomenon where cities are significantly warmer than surrounding rural areas. The main cause is the replacement of natural surfaces with materials like concrete and asphalt, which absorb and retain heat. Additionally, waste heat from vehicles and air conditioners adds to the effect. But there are solutions. One effective strategy is increasing urban greenery, such as planting trees on streets and creating green roofs. Trees provide shade and release moisture through transpiration, which cools the air. Another approach is using cool roofs, which are painted white or coated with reflective materials to bounce sunlight back into the atmosphere. Studies show that cool roofs can reduce a building's cooling costs by up to 15%. However, implementing these measures requires careful planning and public support. Cities like Los Angeles have already adopted cool roof policies, and the results are promising. So, while the problem is serious, it's not insurmountable.
❓ Вопрос What is the main topic of the lecture?
A. A. The causes of global warming.
B. B. The effects of urban heat islands and possible solutions.
C. C. The benefits of green roofs for wildlife.
D. D. The history of urban development in Los Angeles.
✅ Правильный ответ
B. The effects of urban heat islands and possible solutions.
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
