Fact 1: Tectonic plates being pushed together causes earthquakes.

Fact 2: Tectonic plates can contain both continental and oceanic crust F 25.

Given the two facts above, answer the question "What can be pushed together to form an earthquake?" with the following options: 
- fibrils
 - volcanos
 - crust
 - energy
 - trees
 - waves
 - boulders on the earth
 - rocks


 

   crust      