Boiling Water is a physical change. When water gets to a certain temperature, it's boiling point starts.
Hydrogen (H) was first, followed by helium (He).
Answer:
Many emerging diseases arise when infectious agents in animals are passed to humans (referred to as zoonoses). As the human population expands in number and into new geographical regions, the possibility that humans will come into close contact with animal species that are potential hosts of an infectious agent increases.
Explanation:
B. Deforestation and burning of fossil fuels. <span />