❓ 문제 According to the passage, why are urban areas often warmer than their rural surroundings?
- A. A) Because rural areas have more vegetation that releases heat at night.
- B. B) Because urban materials like concrete and asphalt absorb and re-emit solar radiation effectively.
- C. C) Because cities generate more waste heat only during the daytime.
- D. D) Because rural areas experience higher levels of solar radiation.