Listen to part of a lecture in an environmental science class. Professor: Today we're discussing the concept of 'urban heat islands,' where cities are significantly warmer than surrounding rural areas. This happens because concrete, asphalt, and buildings absorb and re-radiate solar heat more than natural surfaces like soil and vegetation. Also, human activities—such as driving cars and running air conditioners—generate waste heat. One surprising effect is that this extra warmth can actually extend the growing season in some cities, allowing plants to thrive longer. However, the downside is increased energy consumption for cooling, which leads to higher greenhouse gas emissions. To mitigate this, cities have introduced green roofs—plant-covered rooftops that absorb less heat and provide insulation. Studies show that green roofs can lower rooftop temperatures by up to 40 degrees Fahrenheit compared to traditional black roofs. Additionally, planting more trees and using lighter-colored paving materials can reflect more sunlight and reduce the overall heat retention. These strategies not only cool the city but also improve air quality and manage stormwater runoff.
❓ Pregunta According to the professor, what is a surprising positive effect of urban heat islands?
A. A. They reduce the need for air conditioning.
B. B. They can lengthen the growing season for plants.
C. C. They help cities retain more groundwater.
D. D. They decrease greenhouse gas emissions.
✅ Respuesta correcta
B. They can lengthen the growing season for plants.
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