Todd Wallace, age 11, of Bessemer, Ala., for his question:

JUST WHAT ARE DALLES?

Danes are deep gorges in which rivers flow rapidly over basaltic rocks or slabs. The name comes from the French "dalle," meaning slab or tile. Here's how you pronounce the word: dalz. The "e" is silent.

The singular form of dailes in English is dell. In many parts of the country, these gorges are called dells instead of dalles.

French explorers gave the name "dalies" to scenic gorges of North American rivers, especially those located in the northern part of the United States.

Notable dalles in the United States include the Wisconsin Dells on the Wisconsin River near Wisconsin Dells, Wis., the Saint Louis River Dalles near Duluth, Minn.; and the Saint Croix River Dalles between Wisconsin and Minnesota.