Their approach is flexible enough that in principle other important quality-of-life changes could be incorporated—for example, decreases in total emissions of pollutants and declines in crime rates.
他们的方法足够灵活，原则上可以纳入其他重要的生活质量变化，如减少污染物排放总量、降低犯罪率。
2
The 'obesity epidemic' is largely ascribed to declinesin physical activity and differences in food quality and eating habits.