positive impact plains
there are humans.
it is a food source for an animal that is a food source for humans
polution
Humans can fly (in jets, in plains) but not with crappy wax and feather "inventions".
yes
,
The negative impacts of the plains on the people is that they are usually displaced when the floods come. The other disadvantage is that the people cannot see other communities people coming to attack them.
No, humans cannot change their past. They can only change their future.
Horses changed the Plains people's lives because they can take you places.
yes
Possibly:loss of the buffalorailroadstelegraph