Which three skills were common to hunter-gatherers in the paleolithic age?

I don't know exactly which three but these could be some...
Studying local native traditions and life ways in order to become familiar with the local region
Local ecology
Observation: reading the landscape
Animals: tracking, hunting, trapping, making bow and arrows, animal food preparation
Identifying, harvesting and preparing wild edible plants
Fire making
Tool Making and flint knapping
Creating fishing equipment (hooks, lines, etc.), fishing, gutting and preparing fish for cooking
Shelter: building using local materials found at the site
The waste stream: where to excrete
Invisible structures: tribal culture and local tribal custom
Hope this helped!

Europeans are more concentrated in urban areas.

Humid continental climate is found in the interior of continents between the 30 and 60 degrees latitude, but usually above the 40 degree line.   40 degrees north of the equator means less direct sunlight and therefore less warmth.   this climate is mainly found in the northern hemisphere since there are no major landmasses in the southern hemisphere.  if you live in northern indiana, you know all about humid continental because that is the climate type you have!