Georgotte Gavioli, age 14, of Philadelphia, Penna., for her question:

Where is the largest river?

Three great rivers compete for the title of World's Longest River. No one has ever really proved which of the three really merits the title in miles. It is no easy job to measure the exact length of a river stretching thousands of miles. You would have to keep in the exact center of the current around all the bends in order to be accurate.

The people of Africa claim that the Nile is the longest river. From Lake Victoria to the sea it is 3,473 miles long. Add 150 miles across the lake and 430 miles of the Kagera river, headwaters of the Nile, and the Nile is about 4,000 miles. South America claims the Amazon is the longest river. From its source in the snowy Andes to its mouth at the Atlantic is 3900 miles.

North America claims the Missouri‑Mississippi river is the longest. The two great streams meet just above St. Louis and go together to the Gulf of Mexico. From its source to the Mississippi, the Missouri is 2714 miles long. From this point the two streams flow 1158 miles to the Gulf ‑ or 3872 miles in all.

The three great rivers are all about 4000 miles long ‑ there is only a few hundred miles difference between them.