I. Lithosphere, Hydrosphere, Atmosphere, or Biosphere
II. Water cycle and rain-shadow effect
III. Climate regions (selection of a climate region means that you must create the neighboring region to the one you selected.
a. Tropical: Rainforest and Savannah
b. Dry: Desert and Steppe
c. Mid-latitude: Mediterranean, Humid Subtropical, Humid Continental, and Marine West Coast
d. High latitude: Polar, Sub-arctic, and Tundra