As per questions,
★ What to do before a volcanic eruption?
Ans • Pack up some belongings especially radio, torch, some extra batteries, if possible then some dry eatables.
• Run out of the house with limited supplies and go to higher altitude areas like in mountains.
• Take some essential pain reducer medicines.
★ What to do during a volcanic eruption?
Ans: • Listen for the emergency evacuation orders as per given by officials.
• Protect yourself from falling ash.
• Use goggles to protect your eyes.
The central nervous system includes the brain and spinal cord.
I think the polymers are the hydrocarbons.
If this helped please mark me as brainliest.