How might Europe's rivers and mountains encourage the development of different cultures?

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.

Explanation:

idk

du boi was considered a radical because he wanted the immediate end for segregation. the biggest different between him and booker t. washington is that, even though washington believed that segregation should be considered illegal, he did not believe at all that a law was needed to keep blacks away from whites and that this would be something natural (to have the races apart) for a long time until society adjusted, while du boi believe that agitation was the only way to end segregation.