<h3><u>Answer;</u></h3>
Mid-ocean ridges
<h3><u>Explanation</u>;</h3>
- Sea-floor spreading is the process by which molten material adds new oceanic crust to the ocean floor.
- Mid-ocean ridge is an undersea mountain chain where new ocean floor is produced at a divergent plate boundary.
- Mid ocean ridge occurs when convection currents rise in the mantle beneath the oceanic crust and create magma where two tectonic plates meet at a divergent boundary.
I think it’s the first one
It takes the moon about 27 days to revolve on its axis.