Answer and explanation;
Slow spreading rate
Top middle- rift valley
Top Right- poorly- developed magma chamber
Rapid Speading rate
Top left- Swell
Top Right- Well- Developed magma chamber
Bottom middle- Diverging plates
Step-by-step explanation;
-Seafloor spreading is a process that occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge.
-This is what happens at the mid-oceanic ridge where a divergent boundary is causing two plates to move away from one another resulting in spreading of the sea floor. As the plates move apart, new material wells up and cools onto the edge of the plates.