Atype of exercise that requires oxygen, develops stamina and has a long duration.

a) aerobic

b) anaerobic

c) both a and b

d) neither a or b

answer; ///i do believe that the correct answer is (a)///once a

the plates spread at mid-ocean ridges (they are divergent plate boundaries) which allows magma to rise through the weakness between the plates. the magma then emerges as lava from the boundary and cools, creating a new crust.