Step-by-step explanation:
In mainland Europe, wide rivers like the Rhine also kept groups of people separated. This separation and isolation caused many different cultures to develop.Like the rivers, these made it difficult for one group to control all of Europe and encouraged the growth of independent territories.
Many people became traders and seafarers. Towns grew up along the rivers which had access to the sea. Rivers also provided protection from invaders.The lack of mountains was good for farming, but it made the towns easier to be invaded by enemies.