First scenario:
IV: soda, gatorade, orange juice, and water
DV: state of the liquids listed above
Control: freezer and ice tray
Second scenario:
IV: laundry detergent, water
DV: cleanliness of the squares post-wash
Control: chocolate, cloth type, cloth squares
Third scenario:
IV: type of water used, pea plant
DV: growth of the pea plant
Control: pots and daily water amount for the plant