How could students best model the formation and movement of dunes? Changes to Land Earth and Space 1 A river flowing across the rocky surface of the Earth could create which of the following? A Dunes B Mountains C Canyon D Hill 5.7B 2 How could students best model the formation and movement of dunes? A Pour water over piles of sand. B Slowly drip wet sand into a tub of water. C Use a spoon to dig a hole in a tray of sand. D Use straws and blow piles of sand.

Changes to Land Earth and Space 3 Students propped up one end of a tray of sand. They also set up a jar of water and a rubber hose so that water flowed over the sand. They observed how the moving water carried the sand downhill and made a small pile of sand at the bottom of the tray. When the students created the small pile of sand at the end of the flow of water, they modeled the formation of which of the following? A Dunes B Canyon C Plain D Delta

makes the river slow down and deposits sediment Changes to Land Earth and Space 4 What natural force formed the Grand Canyon by slowly cutting through the rock over many millions of years? A A boulder B A glacier C A river D A landslide 5 A delta is made of sediments deposited at the mouth of a river. A delta forms where the river meets the ocean because the ocean - A makes the river slow down and deposits sediment B contains salt water and rivers have fresh water C is usually much colder than the water in the river D has powerful currents that weather rock on the shore