Macedonia
That is Turkey. :)
Black sea
No city touches these three but check your paper if it says a sea it is the Black Sea.
Russia
Istanbul, part of Turkey
Europe and Asia are both continents, not countries. And Bulgaria is a country in the continent of Europe.
Turkey But the part touches (borders) with Bulgarian, is the European part of Turkey! Bulgarian side border is called Svilengrad
Bulgaria, Romania, Ukraine, Russia, Georgia and Turkey.
None of Belize, Brazil or Burundi
Germany, Austria, Slovakia, Hungary, Croatia, Serbia, Romania, Bulgaria, Moldova and Ukraine.
It must be the Danube: Germany Austria Hungary Serbia Rumania & Bulgaria