Given a scientific question and its correct answer, generate supporting facts for the answer. This supporting fact can be an explanation for the answer to the given question.

[Q]: Question: What type of plate is an island arc found on? Answer: oceanic
[A]: An island arc is a line of volcanoes on an oceanic plate. A continental arc is a line of volcanoes on a continental plate.

[Q]: Question: Carbonic acid decomposes easily at room temperature into carbon dioxide and what else? Answer: water
[A]: Some unstable acids decompose to produce nonmetal oxides and water. Carbonic acid decomposes easily at room temperature into carbon dioxide and water.

[Q]: Question: What type of animal in the sea spend most of their lives as medusae? Answer: jellyfish
[A]:
Jellyfish spend most of their lives as medusae. They live virtually everywhere in the ocean. They prey on zooplankton, other invertebrates, and the eggs and larvae of fish.