1.
A. An earthquake happens when plates move and send shock waves through the Earth's crust.
B. The Earth's crust moves along cracks called faults at plate margins.
C. Earthquakes often occur close to fault lines.
2. There are lots of faults close to plate margins because plates are constantly moving and rubbing against each other, creating cracks and fractures in the Earth's crust.
3. Movements in the mantle, such as convection currents, create pressure and tension that build up along faults in the Earth's crust, eventually causing earthquakes.