The answer to this would 4
Very dry conditions caused by high atmospheric pressure, deforestation, desertification, overgrazing which rids land of vegetation causing erosion of fertile topsoil, and warming changes due to global climate change.
Answer:
Idea, A, C
Explanation:
Because the idea hadn't formed to a theory because it had little to no evidence and A and C show the two continents connecting previously and explains that these animals couldn't of swam or flew all the way across the world supporting his idea of pangea.
Answer:
C. the Arctic is free of salt water
You have to be more specific