Good morning, everyone. Today we'll discuss the impact of urban green spaces. According to a recent study, parks not only improve air quality but also significantly reduce stress levels. The researchers monitored heart rates of volunteers who walked through city streets versus those who strolled in a park. Surprisingly, the park walkers showed a 20% drop in cortisol, a stress hormone. Additionally, the study found that even five minutes of exposure to greenery can boost mood, though longer periods are needed for long-term benefits. However, the effect was weaker in highly polluted areas, so planting more trees in such zones should be a priority.
❓ What did the study reveal about walking in a park compared to walking on city streets?
A. A. Park walkers had a 20% increase in cortisol levels.
B. B. Park walkers showed a significant reduction in stress hormones.
C. C. City street walkers felt happier than park walkers.
D. D. Both groups had similar stress levels after walking.
✅ 正确答案
B. Park walkers showed a significant reduction in stress hormones.