Death rate, infant mortality
Answer:
One way that glaciers change the landscape is by erosion. As they pass over the ground, the ice scrapes up soil and rock. A valley glacier will leave a valley much deeper, as it erodes the underlying surface with plucking and abrasion.
Answer:
Because there weren't enough big brains out there to cover all of the major things and that there we're major time periods of things.
Explanation:
