The_second longest river in__---_Europe is_the__River Danube. It starts in_---__Germany and flows though__---_Austria,__---_Hungary,___---_Slovakia,__---_Serbia and Montenegro and __---_Romania before it reaches the Black Sea
The_second longest river in__---_Europe is_the__River Danube. It starts in_---__Germany and flows though__---_Austria,__---_Hungary,___---_Slovakia,__---_Serbia and Montenegro and __---_Romania before it reaches the Black Sea