What changes occurred when human civilization evolved from hunters-gatherers to settle societies?

The correct answers are A, B and E. The Eastern European nations that experienced political revolutions immediately following the fall of the Berlin Wall in 1989 were Czechoslovakia, Bulgaria and East Germany.

The 1989 Revolutions were a series of revolutionary movements that swept Central and Eastern Europe in the fall of 1989, causing the overthrow of Soviet-style socialist states within a few months.

Political turmoil began in Poland, and led to a wave of mostly peaceful revolutions in East Germany, Czechoslovakia, Hungary, and Bulgaria. Romania was the only country of the Eastern Bloc that violently overthrew its communist regime and executed its head of state.

The 1989 Revolutions greatly changed the balance of power in the world and marked (along with the subsequent dissolution of the Soviet Union) the end of the Cold War and the beginning of the post-Cold War era.