Which choice best describes how the Grand Canyon formed? Tornadoes blow through the same area for many years carving out the bottom of the canyon and wearing down the sides.
Huge landslides bring mud and rocks to the bottom of a canyon then the wind blows it through creating the bottom of the canyon.
Rivers flowing over a long period of time cut out the bottom of the canyon and wind erodes the sides of the canyon.
Repeated earthquakes in the same area push up the sides of the canyon and the river erodes the bottom of the canyon.