Narrator: Listen to part of a lecture in an environmental science class. Professor: Today we’re talking about urban heat islands, a phenomenon where cities are significantly warmer than surrounding rural areas. This happens because concrete, asphalt, and buildings absorb and re-emit heat more than natural landscapes do. One major factor is the lack of vegetation, which normally provides shade and cools the air through evapotranspiration. Another factor is waste heat from vehicles, air conditioners, and industrial processes. Interestingly, the intensity of an urban heat island can vary by time of day and season. It’s often strongest at night, when urban surfaces slowly release the heat they stored during the day, while rural areas cool off more quickly. Also, it’s more pronounced in winter because heating buildings adds more warmth. To mitigate this, cities have adopted strategies like planting trees, creating green roofs, and using reflective materials on roads and buildings. These approaches not only lower temperatures but also reduce energy consumption for cooling. However, implementing them requires careful planning and funding.
❓ 题目 What does the professor say about the timing of the urban heat island effect?
A. A) It is strongest during the middle of the day when sunlight is most intense.
B. B) It is more noticeable at night because urban surfaces release stored heat slowly.
C. C) It occurs only in winter when heating demand is high.
D. D) It is weaker in winter due to lower air conditioning use.
✅ 正确答案
B) It is more noticeable at night because urban surfaces release stored heat slowly.
