<span>So your awnser is mitosis</span>
To solve this you would just divide 720 by 4 so it would take 180 years. Hope this helps!
The answer is; Mantle
Convection currents in the mantle drive tectonic plate movements. The convection currents in this regions are like those of water. The cooler upper mantles sink to the bottom and the hotter lower mantle rises. This circulation causes fiction drag with the overlying crust and therefore causes it to drift.
