To compare how different types of soil absorbed water, Christian set up an
experiment. He poked equal numbers and sizes of holes into the bottoms of three
plastic cups. He filled one cup with sand, one with potting soil, and left one empty. He
placed each cup in a stand over a beaker. Christian poured 400 mL (milliliters) of water
into each of the cups. He then measured the amount of water collected in the beakers
beneath each cup at 1 minute intervals for 3 minutes.
What is the control in this experiment?
the amount of water collagted in the boaker
collastad
the cup with the sand
the empty cup
Rt the cup with the soil