The physical features of eastern europe were shaped by a time of lower temperatures when much of the land was covered in snow and ice known as a(n)
a. stone age.
b. ice age.
c. emigration.
d. glacier.

the first plants to make the transition

explanation:

a mid-ocean ridge or mid-oceanic ridge is an underwater mountain range, formed by plate tectonics. this uplifting of the ocean floor occurs when convection currents rise in the mantle beneath the oceanic crust and create magma where two tectonic plates meet at a divergent boundary.a geomagnetic reversal is a change in a planet's magnetic field such that the positions of magnetic north and magnetic south are interchanged.