Culture is the answer for your space.
Answer:
Towns grew up along the rivers which had access to the sea. Rivers also provided protection from invaders. Farmers grew crops in the fertile fields that surrounded the towns. The lack of mountains was good for farming, but it made the towns easier to be invaded by enemies.
Explanation:
The Earth's rocky outer crust solidified billions of
years ago, soon after the Earth formed. This crust is not a solid
shell; it is broken up into huge, thick plates that drift atop the soft,
underlying mantle.
The plates are made of rock and drift all over the globe; they move both
horizontally (sideways) and vertically (up and down). Over long
periods of time, the plates also change in size as their margins are
added to, crushed together, or pushed back into the Earth's mantle. These plates are from 50 to 250 miles (80 to 400 km) thick.
Answer:
The Amazon is the world's longest river.