What do the periods in the geologic time scale represent?

Ibelieve the answer is c. map projections.hope my answer has you : )

Explosive eruptions are the most hazardous, involving large volumes of tephra and gases emitted from the volcano. lahars, pyroclastic flows, ashfall, and many other volcanic hazards are commonly associated with explosive eruptions. explosive eruptions are very dangerous. basically, any form of hazard can occur.

  the  peripheral nervous system consists of all of the nerves that lie outside the brain and spinal cord.

So were saposed to pick 1 of these