Answer:
1. Plate tectonics
2. Internal forces
Explanation:
Mainly earths main geological structures and events are caused by plate tectonic, like how we get mountains and earthquakes. These forces come within the earth, the mantle and the core. Hence forth, internal forces.
The answer is Pennsylvanian. I worked on this before. The Pennsylvanian era is a subperiod of the Carboniferous Period. i really hope this helps :)
U use the hemlock method
