Final answer:
The city where the Rhine River exits Lake Constance is Constance (Konstanz in German). The Rhine is essential for European commerce and industry, with cities like Strasbourg and Rotterdam playing significant roles along its path.
Step-by-step explanation:
The question seems to contain a typo; there is no 'Rhoen' River but it is likely referring to the Rhine River, which is one of the major European rivers that flows from Switzerland through Germany and the Netherlands into the North Sea.
There isn't a specific city where the Rhine River exits a lake with the same name, but the Rhine River does arise from the Swiss Alps and forms Lake Constance (Bodensee) along the Swiss-German border. The city at the point where the Rhine exits Lake Constance is called Konstanz in German (known as Constance in English).
The Rhine River serves as a critical waterway for transporting goods in Central Europe and passes through several important cities, including Strasbourg, which houses the political capital of the EU and eventually reaches Rotterdam, which is Europe's busiest port. Additionally, the region along the Rhine is key for industries, including Lyon, a significant center for modern technology in France.