From my understanding of what i learned from middle school a volcano erupts when it creates enough lava to explode for example if you had a balloon that you were inflating too much eventually it will explode
The European Energy Security Strategy (2014) which acts as guidance for these policies emphasizes the need to become less dependent on other countries.
Because it determines temperatures, wind patterns, and air pressure
C. Fishing
I think fishing would make sense due to living in a river valley.