Penny Sue Temple, age 12, of Nashville, Tenn., for her question:

WHAT IS THE LONGEST RIVER IN EUROPE?

The longest river in Europe is the Volga River, which runs 2,194 miles through the Soviet Union. Its source is a small lake among the Valdai Hills. It then flows north to a point above Moscow, southeast to Kazan, generally south to Volgagrad and then southeast to its mouths in the Caspian Sea.

The chief tributaries of the Volga include the Kama, Samara, Oka and the Vetluga.

The Volga and its effluents drain an area that covers about 560,000 square miles.

Most of the Volga's course is navigable from March to mid December, although it is subject to great floods during May and June. Canals connect it with such points as the Baltic Sea, the Sea of Azov, the Black Sea, the Don River and the city of Moscow.

The lower reaches of the Volga are major fishing areas. The entire Volga Valley was claimed for Russia by Ivan IV during the 16th Century.