Tirana is the capital of which country?

What is the name of the famous cave system located in Vietnam? Which river flows through the famous Plitvice Lakes National Park in Croatia? Which river flows through the famous Manaus city in Brazil? Which island is home to the famous Mount Teide volcano? Vienna is the capital of which country? Minsk is the capital of which country? Brussels is the capital of which country? Sarajevo is the capital of which country?