-Coastlines may be different in the summer than in the winter. Summer may have calm wind and waves, autumn winds increase, and winter may have strong waves and wind. This may cause a change in sand dunes. The dunes will shift more in the winter and not as much in the summer.

-Plants and freezing water affect rocks over time. The roots keep digging into the rock, spreading cracks. The freezing water expands, also cracking the rock.

-Rocky Mountains are far inland, therefore hurricanes are unlikely to cause damage because hurricanes form over water and start to die out over land. Since the Rocky Mountains are far from the coast, hurricanes would probably not reach that area.

-Hypothesize means that you think a certain thing will happen. You may think or hypothesize that rain will erode sand dunes more quickly that it will erode sand covered with gravel. You could test your hypothesis by placing sand on one side of a tray and then the same amount of sand on the other side of tray with gravel on top of it. You would then drip water over each side and observe the movement of sand on each side.

-Near coastlines, waves will cause the most erosion.

-Houses built on a plateau are safer from erosion because the land is firmer than a sandy coastline. Earthquakes can cause landslides.

-Earthquakes begin far below the surface of the Earth.

-Weathering and erosion usually take place slowly over a long period of time.

-Draining wetlands may harm our water supply.

-Chemicals can cause erosion under water by wearing away limestone in the rock that is underwater.

-To make room for houses, sometimes forests are cut down, which may add to erosion.

-When water freezes inside a rock, the rock may crack because as the water becomes ice, it expands; just like an ice cube in the freezer.

-Over time, rocks buried deep below Earth's surface can slowly rise into mountains.

-Water cover Earth in lakes, rivers, and oceans.

-The land on the Great Plains is good for growing crops.

-Hurricanes are violent storms with strong winds and heavy rains.

-Landform is a feature of the earth's surface.

-A glacier is a huge heap of moving ice.

-Weathering is the process that crumbles, cracks, and breaks down rocks.

-A flood is a huge flow of water over land that is usually dry.

-Plains are wide, flat land.

-Erosion occurs when weathered materials are carried away.

-Mountains are the highest landforms.

-Sand dunes are mounds of sand.

-An earthquake is a sudden movement in rocks that make up Earth's crust.