What physical feature is largely responsible for separating the ethnic groups of the balkans?

iron gate
mountains
the danube
the turkish straits

yes

explanation:

the fighting words doctrine, in united states constitutional law, is a limitation to freedom of speech as protected by the first amendment to the united states constitution. in 1942, the u.s. supreme court established the doctrine by a 9–0 decision in chaplinsky v. new hampshire.

spread of christianity

i do believe the answer is false.