Final answer:
Trenches are commonly found in the Pacific Ocean and are the deepest parts of the ocean. They are associated with subduction zones and form parallel to volcanic arcs.
Step-by-step explanation:
Trenches are commonly found in the Pacific Ocean and are not commonly found in the Atlantic Ocean. They form parallel to volcanic arcs and are the deepest parts of the ocean. Trenches are always associated with subduction zones where one tectonic plate is being forced beneath another.
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