Explain and describe with details the two ways mountains and mountain ranges have been formed over time.

How Are Mountains Formed? The world's tallest mountain ranges form when pieces of Earth's crust—called plates—smash against each other in a process called plate tectonics, and buckle up like the hood of a car in a head-on collision. ... Well-known volcanoes on land include Mount St.

a and c?

i think it is a and c

offline recommendation systems option b

because recommendation systems produce a list of two ways

1. through collaborative filtering

or

2. through content-based filtering