The label 4. is the danube river and river 3. s the Po river.
Explanation:
The Danube is Europe's second-largest river and is located in the central and eastern Europe, and it flows through the tyne counties, flows at a height of 1,078 meters above sea level. And it has a length of about 2,850 km.
It is classified as an international waterway and originates in the black forest of Germany. And once was a strong standing support of the European empire and geological its smaller and much older than the Rhine river.
The river Po is an eastward flowing river across the northern Italy. About 41,000 km of it is the mountainous environment and the 29,000 is the plains. The River has a mouth at the Adriatic sea and flows at a height of 3,700 meters, and is about 652 kilometers in length.
