Answer:
It has crust and trough.
Explanation:
The oceans movements along the shore called waves because it has crust and trough just like waves and vibrates about its mean position. A crest is a higher point of wave whereas trough is the opposite of a crest and lowest point of a wave. Ocean waves is similar to sound and light waves because both waves travel as up and down vibrations and the energy present in these wave travels in forward direction.
