Final answer:
Oceanic crust sinks into the mantle at deep-sea trenches.
Step-by-step explanation:
At a deep-sea trench, oceanic crust sinks into the mantle.
This statement is true.
Deep-sea trenches are formed at subduction zones where one tectonic plate is forced beneath another. In this process, known as subduction, the denser oceanic crust sinks into the mantle, creating a trench on the ocean floor.
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