Question

Ecosystems can be changed by natural events or by human actions. Which is NOT a natural event?

A. A forest fire started by lightning
B. pollution from a factory entering a river
C. a beaver building a dam in a river
D. An earthquake

Answer 1

C. Pollution is man made if it weren’t for our factories there wouldn’t be this much pollution

Answer 2

Hi! The answer would be B. pollution from a factory entering a river because humans built the factory so that it would drain into the river, therefore it is unnatural.