Answer:
Some Russian rivers are used for transportation during winters when they are frozen
Step-by-step explanation:
In harsh winters, many Russian rivers act as a transport arteries as trucks drive over them while rivers are frozen, Most Russian rivers flows from south to north instead of east to west, restricting their use in the winters of Russia. Russia's main coasts are St. Petersburg and Kaliningrad, and Novorossiysk and Sochi are also the largest ports in the Black Sea.