Complex sentence: The boys finally get their fireworks, and when they shoot two off, they destroy the snake trail, ending the terror; the ashes rain to the ground like snow, and people do wintery activities using the black soot.
Split into simpler sentences: The boys finally get their fireworks, and when they shoot them off, they destroy the snake trail and end the terror. The ashes rain to the ground like snow, and people do wintery activities using the black soot.