Fill in the blanks to complete the passage.

Question

Through the process of , old, dense crust is pushed toward a deep-ocean . There, it sinks under lighter crust. It returns to molten rock, becoming part of the again.

Answer 1

Through the process of subduction, old, dense crust is pushed toward a deep-ocean trench. There, it sinks under lighter crust. It returns to molten rock, becoming part of the mantle again.