Listen to part of a lecture in an environmental science class.
Professor: Today we're going to talk about the concept of '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 lack of vegetation and the abundance of dark surfaces that absorb sunlight during the day and release it at night. This creates a significant temperature difference between a city and its surrounding rural areas. But here's an interesting point: not all parts of a city are equally warm. Parks and green spaces can reduce local temperatures by several degrees through a process called evapotranspiration, where plants release water vapor. Also, the layout of buildings affects wind flow, which can either trap heat or cool the area. So, when we talk about solutions, it's not just about planting more trees; it's about strategic urban planning—like creating green corridors that allow cool air to move through the city. Any questions?
❓ 题目 What does the professor say is a primary cause of urban heat islands?
A. A. The lack of vegetation and the presence of heat-absorbing surfaces.
B. B. The amount of heat generated by cars and factories.
C. C. The dense population and high energy use in cities.
D. D. The absence of wind due to tall buildings.
✅ 正确答案
A. The lack of vegetation and the presence of heat-absorbing surfaces.