Answer:
Pandemics occur for two reasons. The first is a change in the infectious agent and the second is in human patterns. Both involve exposing people to agents they don’t have resistance to. Diseases like SARS, avian flu, and the famous Spanish flu all involved a mutation in the virus that resulted in a new disease that no one had resistance too. Examples of the second are when new groups of humans make contact, like small pox amongst native Americans, and possibly the black death.
Explanation:
Water, wind, glaciers, ice, and waves are the answers I got when I looked it up. But obviously that's five so I believe you could just take ice out since glaciers is there
I think it is liqid but i dont know realy.
B. Scarcity of drinking water