secured their food
Secured their food
Secured their food
Secured their food
built their homes
All the answers are correct. They made many glaciers that are yet to melt and the also lowered the temperature that we have today
The sun
all the answers are correct
themosphere
It is warmed by geothermal energy which is created by RADIOACTIVE DECAY http://en.wikipedia.org/wiki/Geothermal_(geology)
"The earth is warmed by the sun through radiation"
In the northern Arctic seas.
Earth's core is warmed by the slow decay of long lived isotopes.