3 Written questions
3 Multiple choice questions
- an undersea mountain chain that is part of a long system of mountains that winds beneath Earth's oceans.
- a device that bounces sound waves off underwater objects and then records the echoes of these sound waves.
- deep underwater canyons
2 True/False questions
What happens at deep-ocean trenches? → deep underwater canyons
sea-floor spreading → a process that continually adds new material to the ocean floor