How does water form a canyon?

How is the Washington Monument affected by weathering and erosion? What connect important cities in India? How can we preserve and protect the oceans? Why was the clifton suspension bridge important? What language is the saying on the Washington Monument? Does Virginia have a desert? How many nautical miles from vancouver bc to panama canal? Why do desert animals not die? Which Indian states bordering the coast along the bay of Bengal? Why does the oceanic crust move below continental crust? What does a zoo smell like? How tall is Niagara falls Canada? What year did John and Abigail Adams move into the White House? There are over 21 Franciscan Missions in? A russian explorer discovered a waterway that was named for him. What is the name of this waterway? Which ocean is not considered a true ocean? What was the hill called on witch the motte and bailey wooden tower was built? Where is the Military Sea Services Museum in Sebring Florida located? What continent is the amur river located on? Why does the Mississippi river flow uphill?