Answer:
This is easy, CO2 is (Carbon Dioxide) a main cause of air pollution. We put it in the air every day when we drive cars or vehicles. And from wildfires and volcanoes, but they rarely erupt now.
Explanation:
Cold stun or by predator attack
Reintroduction of wildlife species means an attempt to resettle them within their historical area of distribution (within their range), where they have become extinct
