Cities across the U.S. Are cracking down on air pollution by enforcing auto emissions control, limiting the use of wood burning stoves, and by monitoring factory pollution.

• 美国各地的城市都在治理空气污染,做法是控制汽车废气排放、限制使用薪柴炉和监测工厂污染。由动物保护组织提出的权利,目的在于保护动物免受虐待、剥削和灭绝。