What physical feature separated cultural groups from each other in the balkans?

Mountains.  

Explanation:

Balkanization refers to the fragmentation of ethnic societies caused partly by the compartmentalization created by the mountainous geography.

That´s why ethnic diversity is the main social and political characteristic in this area. The Balkan nations emerged from many diverse ethnic roots from previous indigenous civilizations.

according to the report, the government has imposed restrictions on freedom of speech, freedom of the press, freedom of assembly, and freedom of association. the official media remained tightly controlled by government censorship and obstruction. restrictions on the freedom to assemble remain a problem in vietnam.

explanation:

i also think he is correct. i believe they came to washington to protest their rights.