A) Tectonic uplift in the Cenozoic era.
B) Volcanic activity during the Mesozoic era.
C) Erosion by glaciers during the Pleistocene epoch.
D) The collision of continental plates about 150 million years ago.

A) The Pinedale Glaciation.
B) The Wisconsinan Glaciation.
C) The Vashon Glaciation, which lasted from about 19,000 – 16,000 BP.
D) The Illinoian Glaciation.

A) Great Salt Lake.
B) Lake Michigan.
C) The Salish Sea.
D) Lake Erie.

A) Rocky Mountains and Sierra Nevada.
B) Cordillera Blanca and Andes.
C) Pacific Ranges and Vancouver Island Ranges.
D) Appalachian Mountains and Cascade Range.

A) Karst topography with limestone caves.
B) Volcanic mountains and lava plateaus.
C) Sand dunes and desert basins.
D) Glacially striated tablelands and rolling hills underlain by sedimentary rocks.

A) Lateritic soils and peat bogs.
B) Soils formed from glacial till, glacial outwash, and Lacustrine deposits.
C) Alluvial soils and loess.
D) Chernozem and podzol.

A) Fraser Lowland, Nanaimo and Nahwitti lowlands of Vancouver Island.
B) Pocono Plateau and Allegheny Plateau.
C) Great Plains and Mississippi Alluvial Plain.
D) Ozark Plateau and Black Hills.

A) The Puget Sound basin.
B) Colorado Plateau.
C) Columbia Basin.
D) Great Basin.

A) Salish Sea.
B) Hudson Bay.
C) Bering Sea.
D) Gulf of Mexico.

A) Earthquakes and volcanic eruptions.
B) Industrialization, agriculture, forestry, urbanization, and suburban sprawl.
C) Asteroid impacts.
D) Natural wildfires and droughts.

A) Extreme elevation.
B) Variable elevation.
C) Low elevation.
D) High elevation.