Henry Reeves Jr., age 10, of Belmont, N.C., for his question:

ARE THERE MANY IMPORTANT RIVERS IN RUSSIA?

Longest river that flows entirely within Russia is the 2,653 mile Lena River in Siberia. It flows from the south to the north.

Other long rivers in Siberia include the Yenisey, Ob and Amur. They are frozen seven to nine months each year.

The famous Volga River is the longest river in Eu~.,)pe. It flows 2,293 miles from the Valdai Hills, northwest of Moscow, to the Caspian Sea. Most of the Volga is frozen three months each year.

Other important rivers in European Russia include the Dnepr, Don, Neman and the Northern and Western Dvina.